Topics

Clutch Plug Removal on AP 900


Robert Chozick
 

I just replaced the clutch plugs on my 2010 AP900 mount and wanted to describe my experience and give some pointers to possibly help someone doing it for themselves.

My mount had gotten to the point where my RA axis would barely turn when balancing. Major variations in movement of my counterweights showed no difference in balance. My DEC axis has never been a problem. It has always balanced easily. I decided to go ahead and replace my RA axis clutch plugs.

I ordered the special screwdriver tool and plugs from AP. I got extra plugs for future changes but only needed 4 to just change the 4 RA plugs.

The first one came out like a charm exactly as described. "Great - this will be easy" I said. I just gave 2-3 fairly hard hits with a smaller size hammer and screwed it out. You have to apply a lot of downward pressure as you screw it out but as it gets to the end start applying less pressure or you will have the problems described below. Even if you do apply less pressure at the end you may have the below issues.

The second and fourth one had the same issues. The plug came out fine up to the point it got the the edge of the channel but at that point started going backwards. I let off the pressure but it would only turn in place. I decided that the plug needed to be larger in diameter to be able to screw out. (These plugs are really only the width of between the threads but are larger in diameter only because of expansion from use and the tool going inside to expand them) The plugs have a hole through the middle. I took a screw and turned it about half way through the plug to expand its diameter. I took out the screw and then put the screwdriver tool back in and could turn it a bit more using very slight pressure. I could get it to the point it was about 3-5 mm above the edge and then took a small pliers and turned it for the remaining rotations to get it out. On the fourth one i squeezed a bit too much and almost had to start over but it came out. Be careful how much you squeeze.

The third one was the worst. I had to do the same procedure as I described above for the second and fourth but the plug kept going back in. I reinserted the screwdriver tool a few times and had to whack it with the hammer again. It did finally go above the edge but as I took it out with the pliers half of it crumbled. The remaining stub proved to be enough to grab to unscrew it with the pliers.

Thankfully this procedure worked and all 4 plugs have been replaced. I am glad i did not have to take the axis apart since George’s description of that process sounded awful.

Once you get the old plug out you just drop a new one in and screw the clutch knobs back in. George recommended not putting any oil in so disregard that part of the instructions.

If you have real problems with your clutch plugs it is worth replacing them. My RA axis balances beautifully now. I put a scope on the mount and the axis moved for very slight changes in the counterweight.

If you do not need to replace the clutch plugs I do not recommend doing it just for maintenance purposes.

I decided that when my mount is not in use I will leave the clutch knobs slightly loose so maybe the plugs don’t deform as much over time. I usually leave my mount outside without a scope on it. I just have a pier and a cover so I don't leave scopes or any electronics out. Your situation may not allow doing this.

I hope I can save someone some grief when replacing clutch plugs.


Robert Chozick
rchozick@aol.com


DFisch
 

Robert, great description, thanks for the inside info on these small but mighty devices. Tom Fischer, Indy

On Apr 4, 2020, at 1:18 PM, Robert Chozick via groups.io <rchozick=aol.com@groups.io> wrote:

I just replaced the clutch plugs on my 2010 AP900 mount and wanted to describe my experience and give some pointers to possibly help someone doing it for themselves.

My mount had gotten to the point where my RA axis would barely turn when balancing. Major variations in movement of my counterweights showed no difference in balance. My DEC axis has never been a problem. It has always balanced easily. I decided to go ahead and replace my RA axis clutch plugs.

I ordered the special screwdriver tool and plugs from AP. I got extra plugs for future changes but only needed 4 to just change the 4 RA plugs.

The first one came out like a charm exactly as described. "Great - this will be easy" I said. I just gave 2-3 fairly hard hits with a smaller size hammer and screwed it out. You have to apply a lot of downward pressure as you screw it out but as it gets to the end start applying less pressure or you will have the problems described below. Even if you do apply less pressure at the end you may have the below issues.

The second and fourth one had the same issues. The plug came out fine up to the point it got the the edge of the channel but at that point started going backwards. I let off the pressure but it would only turn in place. I decided that the plug needed to be larger in diameter to be able to screw out. (These plugs are really only the width of between the threads but are larger in diameter only because of expansion from use and the tool going inside to expand them) The plugs have a hole through the middle. I took a screw and turned it about half way through the plug to expand its diameter. I took out the screw and then put the screwdriver tool back in and could turn it a bit more using very slight pressure. I could get it to the point it was about 3-5 mm above the edge and then took a small pliers and turned it for the remaining rotations to get it out. On the fourth one i squeezed a bit too much and almost had to start over but it came out. Be careful how much you squeeze.

The third one was the worst. I had to do the same procedure as I described above for the second and fourth but the plug kept going back in. I reinserted the screwdriver tool a few times and had to whack it with the hammer again. It did finally go above the edge but as I took it out with the pliers half of it crumbled. The remaining stub proved to be enough to grab to unscrew it with the pliers.

Thankfully this procedure worked and all 4 plugs have been replaced. I am glad i did not have to take the axis apart since George’s description of that process sounded awful.

Once you get the old plug out you just drop a new one in and screw the clutch knobs back in. George recommended not putting any oil in so disregard that part of the instructions.

If you have real problems with your clutch plugs it is worth replacing them. My RA axis balances beautifully now. I put a scope on the mount and the axis moved for very slight changes in the counterweight.

If you do not need to replace the clutch plugs I do not recommend doing it just for maintenance purposes.

I decided that when my mount is not in use I will leave the clutch knobs slightly loose so maybe the plugs don’t deform as much over time. I usually leave my mount outside without a scope on it. I just have a pier and a cover so I don't leave scopes or any electronics out. Your situation may not allow doing this.

I hope I can save someone some grief when replacing clutch plugs.


Robert Chozick
rchozick@aol.com






George
 

Robert,

A good description. You have helped many future plug replacements! Thank you.

Regards,

George

George Whitney
Astro-Physics, Inc.
Phone: 815-282-1513
Email: george@astro-physics.com

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Robert Chozick via groups.io
Sent: Saturday, April 04, 2020 12:19 PM
To: main@ap-gto.groups.io
Subject: [ap-gto] Clutch Plug Removal on AP 900

I just replaced the clutch plugs on my 2010 AP900 mount and wanted to describe my experience and give some pointers to possibly help someone doing it for themselves.

My mount had gotten to the point where my RA axis would barely turn when balancing. Major variations in movement of my counterweights showed no difference in balance. My DEC axis has never been a problem. It has always balanced easily. I decided to go ahead and replace my RA axis clutch plugs.

I ordered the special screwdriver tool and plugs from AP. I got extra plugs for future changes but only needed 4 to just change the 4 RA plugs.

The first one came out like a charm exactly as described. "Great - this will be easy" I said. I just gave 2-3 fairly hard hits with a smaller size hammer and screwed it out. You have to apply a lot of downward pressure as you screw it out but as it gets to the end start applying less pressure or you will have the problems described below. Even if you do apply less pressure at the end you may have the below issues.

The second and fourth one had the same issues. The plug came out fine up to the point it got the the edge of the channel but at that point started going backwards. I let off the pressure but it would only turn in place. I decided that the plug needed to be larger in diameter to be able to screw out. (These plugs are really only the width of between the threads but are larger in diameter only because of expansion from use and the tool going inside to expand them) The plugs have a hole through the middle. I took a screw and turned it about half way through the plug to expand its diameter. I took out the screw and then put the screwdriver tool back in and could turn it a bit more using very slight pressure. I could get it to the point it was about 3-5 mm above the edge and then took a small pliers and turned it for the remaining rotations to get it out. On the fourth one i squeezed a bit too much and almost had to start over but it came out. Be careful how much you squeeze.

The third one was the worst. I had to do the same procedure as I described above for the second and fourth but the plug kept going back in. I reinserted the screwdriver tool a few times and had to whack it with the hammer again. It did finally go above the edge but as I took it out with the pliers half of it crumbled. The remaining stub proved to be enough to grab to unscrew it with the pliers.

Thankfully this procedure worked and all 4 plugs have been replaced. I am glad i did not have to take the axis apart since George’s description of that process sounded awful.

Once you get the old plug out you just drop a new one in and screw the clutch knobs back in. George recommended not putting any oil in so disregard that part of the instructions.

If you have real problems with your clutch plugs it is worth replacing them. My RA axis balances beautifully now. I put a scope on the mount and the axis moved for very slight changes in the counterweight.

If you do not need to replace the clutch plugs I do not recommend doing it just for maintenance purposes.

I decided that when my mount is not in use I will leave the clutch knobs slightly loose so maybe the plugs don’t deform as much over time. I usually leave my mount outside without a scope on it. I just have a pier and a cover so I don't leave scopes or any electronics out. Your situation may not allow doing this.

I hope I can save someone some grief when replacing clutch plugs.


Robert Chozick
rchozick@aol.com


Don Anderson
 

Thanks for sharing your experience Robert.
I have yet to need to change my 2009 AP900 GOTO clutch plugs. Both axis move freely when the clutches are loosened. I am conservative on how much I tighten my clutches. I only tighten them using the short end(tightened as much as I can using my fingers)of the allen wrench. I make sure my scope-camera rig is well balanced in the saddle and the counterweights are properly positioned so that excessive tightening is not required.

Don Anderson


On Saturday, April 4, 2020, 11:18:45 a.m. MDT, Robert Chozick via groups.io <rchozick@...> wrote:


I just replaced the clutch plugs on my 2010 AP900 mount and wanted to describe my experience and give some pointers to possibly help someone doing it for themselves.

My mount had gotten to the point where my RA axis would barely turn when balancing.  Major variations in movement of my counterweights showed no difference in balance.  My DEC axis has never been a problem.  It has always balanced easily.  I decided to go ahead and replace my RA axis clutch plugs.

I ordered the special screwdriver tool and plugs from AP.  I got extra plugs for future changes but only needed 4 to just change the 4 RA plugs.

The first one came out like a charm exactly as described.  "Great - this will be easy" I said.  I just gave 2-3 fairly hard hits with a smaller size hammer and screwed it out.  You have to apply a lot of downward pressure as you screw it out but as it gets to the end start applying less pressure or you will have the problems described below.  Even if you do apply less pressure at the end you may have the below issues.

The second and fourth one had the same issues.  The plug came out fine up to the point it got the the edge of the channel but at that point started going backwards.  I let off the pressure but it would only turn in place.  I decided that the plug needed to be larger in diameter to be able to screw out.  (These plugs are really only the width of between the threads but are larger in diameter only because of expansion from use and the tool going inside to expand them)  The plugs have a hole through the middle.  I took a screw and turned it about half way through the plug to expand its diameter.  I took out the screw and then put the screwdriver tool back in and could turn it a bit more using very slight pressure.  I could get it to the point it was about 3-5 mm above the edge and then took a small pliers and turned it for the remaining rotations to get it out.  On the fourth one i squeezed a bit too much and almost had to start over but it came out.  Be careful how much you squeeze.

The third one was the worst.  I had to do the same procedure as I described above for the second and fourth but the plug kept going back in.  I reinserted the screwdriver tool a few times and had to whack it with the hammer again.  It did finally go above the edge but as I took it out with the pliers half of it crumbled.  The remaining stub proved to be enough to grab to unscrew it with the pliers.

Thankfully this procedure worked and all 4 plugs have been replaced.  I am glad i did not have to take the axis apart since George’s description of that process sounded awful.

Once you get the old plug out you just drop a new one in and screw the clutch knobs back in.  George recommended not putting any oil in so disregard that part of the instructions.

If you have real problems with your clutch plugs it is worth replacing them.  My RA axis balances beautifully now.  I put a scope on the mount and the axis moved for very slight changes in the counterweight.

If you do not need to replace the clutch plugs I do not recommend doing it just for maintenance purposes.

I decided that when my mount is not in use I will leave the clutch knobs slightly loose so maybe the plugs don’t deform as much over time.  I usually leave my mount outside without a scope on it.  I just have a pier and a cover so I don't leave scopes or any electronics out.  Your situation may not allow doing this.

I hope I can save someone some grief when replacing clutch plugs.


Robert Chozick






Michael Hambrick <mike.hambrick@...>
 

Hi Robert

I am glad you were able to remove the old clutch plugs.

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head.

There are several tricks to getting a screw extractor to work:
  1. Use the correct size extractor for the screw thread size
  2. You have to drill the correct size hole in the broken screw.
  3. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.

Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it.

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before.




Best Regards

Michael Hambrick
ARLANXEO
TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...


Robert Chozick
 

I actually have only hand tightened my clutches before now and they still needed replacement.  I think it can happen from temperature and age.

I was going to use something like a screw extractor if this process did not work.  As long as you are really careful and don’t hurt the threads in the channel or go too deep into the axis I dont think you could hurt it.  If all fails you separate everything and get to it from underneath.

Robert


On Apr 4, 2020, at 4:51 PM, Don Anderson via groups.io <jockey_ca@...> wrote:

Thanks for sharing your experience Robert.
I have yet to need to change my 2009 AP900 GOTO clutch plugs. Both axis move freely when the clutches are loosened. I am conservative on how much I tighten my clutches. I only tighten them using the short end(tightened as much as I can using my fingers)of the allen wrench. I make sure my scope-camera rig is well balanced in the saddle and the counterweights are properly positioned so that excessive tightening is not required.

Don Anderson


On Saturday, April 4, 2020, 11:18:45 a.m. MDT, Robert Chozick via groups.io <rchozick@...> wrote:


I just replaced the clutch plugs on my 2010 AP900 mount and wanted to describe my experience and give some pointers to possibly help someone doing it for themselves.

My mount had gotten to the point where my RA axis would barely turn when balancing.  Major variations in movement of my counterweights showed no difference in balance.  My DEC axis has never been a problem.  It has always balanced easily.  I decided to go ahead and replace my RA axis clutch plugs.

I ordered the special screwdriver tool and plugs from AP.  I got extra plugs for future changes but only needed 4 to just change the 4 RA plugs.

The first one came out like a charm exactly as described.  "Great - this will be easy" I said.  I just gave 2-3 fairly hard hits with a smaller size hammer and screwed it out.  You have to apply a lot of downward pressure as you screw it out but as it gets to the end start applying less pressure or you will have the problems described below.  Even if you do apply less pressure at the end you may have the below issues.

The second and fourth one had the same issues.  The plug came out fine up to the point it got the the edge of the channel but at that point started going backwards.  I let off the pressure but it would only turn in place.  I decided that the plug needed to be larger in diameter to be able to screw out.  (These plugs are really only the width of between the threads but are larger in diameter only because of expansion from use and the tool going inside to expand them)  The plugs have a hole through the middle.  I took a screw and turned it about half way through the plug to expand its diameter.  I took out the screw and then put the screwdriver tool back in and could turn it a bit more using very slight pressure.  I could get it to the point it was about 3-5 mm above the edge and then took a small pliers and turned it for the remaining rotations to get it out.  On the fourth one i squeezed a bit too much and almost had to start over but it came out.  Be careful how much you squeeze.

The third one was the worst.  I had to do the same procedure as I described above for the second and fourth but the plug kept going back in.  I reinserted the screwdriver tool a few times and had to whack it with the hammer again.  It did finally go above the edge but as I took it out with the pliers half of it crumbled.  The remaining stub proved to be enough to grab to unscrew it with the pliers.

Thankfully this procedure worked and all 4 plugs have been replaced.  I am glad i did not have to take the axis apart since George’s description of that process sounded awful.

Once you get the old plug out you just drop a new one in and screw the clutch knobs back in.  George recommended not putting any oil in so disregard that part of the instructions.

If you have real problems with your clutch plugs it is worth replacing them.  My RA axis balances beautifully now.  I put a scope on the mount and the axis moved for very slight changes in the counterweight.

If you do not need to replace the clutch plugs I do not recommend doing it just for maintenance purposes.

I decided that when my mount is not in use I will leave the clutch knobs slightly loose so maybe the plugs don’t deform as much over time.  I usually leave my mount outside without a scope on it.  I just have a pier and a cover so I don't leave scopes or any electronics out.  Your situation may not allow doing this.

I hope I can save someone some grief when replacing clutch plugs.


Robert Chozick






Robert Chozick




George
 

Michael,

 

You are correct.   An extractor is an alternative extraction technique.   As you point out, sizing it correctly is important.   There have been sveral customers who have used it successfully.  

 

Unfortunately, I am working from home and I can’t give you a hole size for the plug, but will be able to do so the next time someone needs to extract the plugs.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Michael Hambrick via groups.io
Sent: Saturday, April 04, 2020 7:42 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Hi Robert

I am glad you were able to remove the old clutch plugs.

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head.

There are several tricks to getting a screw extractor to work:

  1. Use the correct size extractor for the screw thread size
  1. You have to drill the correct size hole in the broken screw.
  1. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.


Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it.

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before.




Best Regards

Michael Hambrick
ARLANXEO

TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...


Robert Chozick
 

I just measured the new ones and old ones.  The inside hole diameter is 2.5mm and the outside diameter of the plug is 7mm.  I did note a bit of variance in hole size with the smallest about 2.3 and largest 2.6.  One was 2.8 or so on one side.  The plugs I pulled out are the same as the new ones.

Robert

On Apr 6, 2020, at 8:55 AM, George <george@...> wrote:

Michael,
 
You are correct.   An extractor is an alternative extraction technique.   As you point out, sizing it correctly is important.   There have been sveral customers who have used it successfully.   
 
Unfortunately, I am working from home and I can’t give you a hole size for the plug, but will be able to do so the next time someone needs to extract the plugs.
 
Regards,
 
George
 
George Whitney
Astro-Physics, Inc.
Phone:  815-282-1513
Email:  george@...
 
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Michael Hambrick via groups.io
Sent: Saturday, April 04, 2020 7:42 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900
 
Hi Robert 

I am glad you were able to remove the old clutch plugs. 

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head. 

There are several tricks to getting a screw extractor to work:
  1. Use the correct size extractor for the screw thread size
  1. You have to drill the correct size hole in the broken screw.
  1. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.

Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it. 

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before. 

<image001.gif>


Best Regards

Michael Hambrick
ARLANXEO
 
TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...


Robert Chozick




George
 

Robert,

 

Thank you for the heads-up and info!

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Robert Chozick via groups.io
Sent: Monday, April 06, 2020 9:47 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

I just measured the new ones and old ones.  The inside hole diameter is 2.5mm and the outside diameter of the plug is 7mm.  I did note a bit of variance in hole size with the smallest about 2.3 and largest 2.6.  One was 2.8 or so on one side.  The plugs I pulled out are the same as the new ones.

 

Robert

 

On Apr 6, 2020, at 8:55 AM, George <george@...> wrote:

 

Michael,

 

You are correct.   An extractor is an alternative extraction technique.   As you point out, sizing it correctly is important.   There have been sveral customers who have used it successfully.   

 

Unfortunately, I am working from home and I can’t give you a hole size for the plug, but will be able to do so the next time someone needs to extract the plugs.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Michael Hambrick via groups.io
Sent: Saturday, April 04, 2020 7:42 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Hi Robert 

I am glad you were able to remove the old clutch plugs. 

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head. 

There are several tricks to getting a screw extractor to work:

  1. Use the correct size extractor for the screw thread size
  1. You have to drill the correct size hole in the broken screw.
  1. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.


Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it. 

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before. 

<image001.gif>


Best Regards

Michael Hambrick
ARLANXEO
 
TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...

 

Robert Chozick

 

 

 


DFisch
 

George, are all of these the same plug size for 900/1100/Mach 1   ?   This would be nice info to keep around for eventual use for my 1100 and Mach 1

 

TJF Work Thinkpad

 

From: George
Sent: Monday, April 6, 2020 11:04 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Robert,

 

Thank you for the heads-up and info!

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Robert Chozick via groups.io
Sent: Monday, April 06, 2020 9:47 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

I just measured the new ones and old ones.  The inside hole diameter is 2.5mm and the outside diameter of the plug is 7mm.  I did note a bit of variance in hole size with the smallest about 2.3 and largest 2.6.  One was 2.8 or so on one side.  The plugs I pulled out are the same as the new ones.

 

Robert

 

On Apr 6, 2020, at 8:55 AM, George <george@...> wrote:

 

Michael,

 

You are correct.   An extractor is an alternative extraction technique.   As you point out, sizing it correctly is important.   There have been sveral customers who have used it successfully.   

 

Unfortunately, I am working from home and I can’t give you a hole size for the plug, but will be able to do so the next time someone needs to extract the plugs.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Michael Hambrick via groups.io
Sent: Saturday, April 04, 2020 7:42 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Hi Robert 

I am glad you were able to remove the old clutch plugs. 

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head. 

There are several tricks to getting a screw extractor to work:

  1. Use the correct size extractor for the screw thread size
  1. You have to drill the correct size hole in the broken screw.
  1. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.


Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it. 

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before. 

<image001.gif>


Best Regards

Michael Hambrick
ARLANXEO
 
TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...

 

Robert Chozick

 

 

 

 


Michael Hambrick <mike.hambrick@...>
 

A 2.5 mm hole will allow a #1 screw extractor, and possibly a #2. These are the smallest sizes available which means that they can easily be broken if too much force is used.




Best Regards

Michael Hambrick
ARLANXEO
TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...


George
 

Tom,

 

The 900 may use different sizes based upon the year.    If you go to the Tech Support page for Legacy Products and then to 900 mounts, you’ll find a PDF for clutch plug replacement that will identify vis clutch knob style.

 

The Mach1 and 1100 mounts do not use clutch plugs.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Thomas Fischer
Sent: Monday, April 06, 2020 10:10 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

George, are all of these the same plug size for 900/1100/Mach 1   ?   This would be nice info to keep around for eventual use for my 1100 and Mach 1

 

TJF Work Thinkpad

 

From: George
Sent: Monday, April 6, 2020 11:04 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Robert,

 

Thank you for the heads-up and info!

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Robert Chozick via groups.io
Sent: Monday, April 06, 2020 9:47 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

I just measured the new ones and old ones.  The inside hole diameter is 2.5mm and the outside diameter of the plug is 7mm.  I did note a bit of variance in hole size with the smallest about 2.3 and largest 2.6.  One was 2.8 or so on one side.  The plugs I pulled out are the same as the new ones.

 

Robert

 

On Apr 6, 2020, at 8:55 AM, George <george@...> wrote:

 

Michael,

 

You are correct.   An extractor is an alternative extraction technique.   As you point out, sizing it correctly is important.   There have been sveral customers who have used it successfully.   

 

Unfortunately, I am working from home and I can’t give you a hole size for the plug, but will be able to do so the next time someone needs to extract the plugs.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Michael Hambrick via groups.io
Sent: Saturday, April 04, 2020 7:42 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Hi Robert 

I am glad you were able to remove the old clutch plugs. 

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head. 

There are several tricks to getting a screw extractor to work:

  1. Use the correct size extractor for the screw thread size
  1. You have to drill the correct size hole in the broken screw.
  1. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.


Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it. 

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before. 

<image001.gif>


Best Regards

Michael Hambrick
ARLANXEO
 
TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...

 

Robert Chozick

 

 

 

 


Roland Christen
 

We don't use plugs in the 1100/1600/Mach1. These mounts have completely different clutch design. There is nothing to wear out on these mounts.

Rolando



-----Original Message-----
From: Thomas Fischer <manusfisch@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Mon, Apr 6, 2020 10:10 am
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

George, are all of these the same plug size for 900/1100/Mach 1   ?   This would be nice info to keep around for eventual use for my 1100 and Mach 1
 
TJF Work Thinkpad
 
From: George
Sent: Monday, April 6, 2020 11:04 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900
 
Robert,
 
Thank you for the heads-up and info!
 
Regards,
 
George
 
George Whitney
Astro-Physics, Inc.
Phone:  815-282-1513
Email:  george@...
 
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Robert Chozick via groups.io
Sent: Monday, April 06, 2020 9:47 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900
 
I just measured the new ones and old ones.  The inside hole diameter is 2.5mm and the outside diameter of the plug is 7mm.  I did note a bit of variance in hole size with the smallest about 2.3 and largest 2.6.  One was 2.8 or so on one side.  The plugs I pulled out are the same as the new ones.
 
Robert
 
On Apr 6, 2020, at 8:55 AM, George <george@...> wrote:
 
Michael,
 
You are correct.   An extractor is an alternative extraction technique.   As you point out, sizing it correctly is important.   There have been sveral customers who have used it successfully.   
 
Unfortunately, I am working from home and I can’t give you a hole size for the plug, but will be able to do so the next time someone needs to extract the plugs.
 
Regards,
 
George
 
George Whitney
Astro-Physics, Inc.
Phone:  815-282-1513
Email:  george@...
 
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Michael Hambrick via groups.io
Sent: Saturday, April 04, 2020 7:42 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900
 
Hi Robert 

I am glad you were able to remove the old clutch plugs. 

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head. 

There are several tricks to getting a screw extractor to work:
  1. Use the correct size extractor for the screw thread size
  1. You have to drill the correct size hole in the broken screw.
  1. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.

Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it. 

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before. 

<image001.gif>


Best Regards

Michael Hambrick
ARLANXEO
 
TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...
 
Robert Chozick
 
 
 
 


DFisch
 

Good to know , I have been believing that they were the same construct as the older 900

 

TJF Work Thinkpad

 

From: uncarollo2 <chris1011@...> via groups.io
Sent: Monday, April 6, 2020 11:24 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

We don't use plugs in the 1100/1600/Mach1. These mounts have completely different clutch design. There is nothing to wear out on these mounts.

 

Rolando

 

 

 

-----Original Message-----
From: Thomas Fischer <manusfisch@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Mon, Apr 6, 2020 10:10 am
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

George, are all of these the same plug size for 900/1100/Mach 1   ?   This would be nice info to keep around for eventual use for my 1100 and Mach 1

 

TJF Work Thinkpad

 

From: George
Sent: Monday, April 6, 2020 11:04 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Robert,

 

Thank you for the heads-up and info!

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Robert Chozick via groups.io
Sent: Monday, April 06, 2020 9:47 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

I just measured the new ones and old ones.  The inside hole diameter is 2.5mm and the outside diameter of the plug is 7mm.  I did note a bit of variance in hole size with the smallest about 2.3 and largest 2.6.  One was 2.8 or so on one side.  The plugs I pulled out are the same as the new ones.

 

Robert

 

On Apr 6, 2020, at 8:55 AM, George <george@...> wrote:

 

Michael,

 

You are correct.   An extractor is an alternative extraction technique.   As you point out, sizing it correctly is important.   There have been sveral customers who have used it successfully.   

 

Unfortunately, I am working from home and I can’t give you a hole size for the plug, but will be able to do so the next time someone needs to extract the plugs.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Michael Hambrick via groups.io
Sent: Saturday, April 04, 2020 7:42 PM
To: 
main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Hi Robert 

I am glad you were able to remove the old clutch plugs. 

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head. 

There are several tricks to getting a screw extractor to work:

  1. Use the correct size extractor for the screw thread size
  1. You have to drill the correct size hole in the broken screw.
  1. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.


Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it. 

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before. 

<image001.gif>


Best Regards

Michael Hambrick
ARLANXEO 
TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: 
mike.hambrick@...

 

Robert Chozick

rchozick@...

 

 

 

 

 

 


Joe Zeglinski
 

Hi,
 
    I had to replace all the clutch plugs on my AP-900 and it was a bear of a task, almost unbearable, even with AP’s special plug removal tool. It was only possible thanks to George and his marvellous advice, on the easy and smart way of using a 3 or 4 inch long (socket head) as a  “push screw” and my socket wrench, to pull the axle head  off and disassemble the axes. Then it was easy to remove the badly deformed old plugs.
 
    As usually happens, the DELRIN plugs aged and flattened out at their tips (from a few years of being tightened down too hard), becoming mushroom-shaped, and had spread out between the bottom of the clutch screw  hole, and the clutch axle  itself. There was no way it was ever going to be extracted, up the clutch hole, no matter how good the tool. The mount axes had to be disassembled.
 
    Thanks to George’s instructions on how they do it, the task was almost a breeze after that. Once the “push-screws” easily did their job,  I drilled out a larger centre hole down the old plugs, and tapped some looser ones into the now empty clutch channel. I think later, for some of them, I threaded the drilled plug – only half way in, to produce a “tapered threaded” hole. That way, the tap then had enough grip to then push & screw the old plug, down into the channel without much force.
A little WD-40 may have helped loosen it from the hole threads.
 
   The old clutch plugs not only formed mushroom heads in the channel, they also thickened and embedded themselves into the hole threads.
With the axles disassembled, the mushroomed head did not need to force its way upward, but be screwed inward,  for extraction.
 
*****************
    However, the next time I have to do it – and I really hope there will never be one – I think I might substitute the AP clutch plugs with one’s I found on the web, in CHINA. Or, I will modify the standard AP plug kit.
 
    Those are almost the same, except they are “rounded, bullet-shaped”, at the tips. I figure that their narrowed tips, rather than AP’s straight cylindrical plugs, will not mushroom as much into the empty channel space, beyond the diameter of the clutch screw hole, making extraction much easier the normal way using  the AP tool.
 
    Alternatively, I might put each new AP standard kit plug in a drill or lathe, and “round-off” the tips to likewise become bullet-shaped. That would probably be easier than sourcing from China, where they might become unavailable over time, and possibly not precisely the same size. If rounding-off would work, I would much prefer to trust the ones from AP, and modify them.
 
**********
    Also, if those Chinese substitutes are used, you should still source the regular AP clutch plugs to perhaps replace the “bearings” on both axes. The same AP clutch plugs are used as “rollers” in the race channel – i.e. there are not typical “steel ball-bearings”.  You will need a KIT of each, plus spares, since you will likely drop and lose some during assembly - about 24 on one and maybe 22 in the other (?) axle. The DELRIN axle bearing rollers may flatten out over time, just like the clutches, perhaps shatter with age and stress. Eventually will need replacement as well, although that has never been mentioned here, or even written about in any AP documents.
 
    The mount really was a joy to use again, after its clutch rejuvenation, and I didn’t need to replace the ones in the bearing race yet, since I am the original owner. But I suppose, under  more frequent use and heavier loading than mine, the axes may get “bumpy”, when one or more DELRIN plug rollers chip or shatter, causing a log jam in the race channel. So, keep that in mind.
 
    Here is a link, to the Chinese company – to see what those look like.
 
 
    Actually, it would be nice if AP could be the source of both the regular clutch plugs for the bearings, and bullet-nosed ones for the clutch holes. The “rounded section” should be slightly longer than the channel depth, to prevent even those from mushrooming and getting stuck.
 
Joe Z.
 
image


Greg Salyer
 

Are there any written instructions on how to do such a disassembly ? Just in case we find it’s necessary.

On Apr 6, 2020, at 12:49 PM, Joe Zeglinski <J.Zeglinski@...> wrote:


Hi,
 
    I had to replace all the clutch plugs on my AP-900 and it was a bear of a task, almost unbearable, even with AP’s special plug removal tool. It was only possible thanks to George and his marvellous advice, on the easy and smart way of using a 3 or 4 inch long (socket head) as a  “push screw” and my socket wrench, to pull the axle head  off and disassemble the axes. Then it was easy to remove the badly deformed old plugs.
 
    As usually happens, the DELRIN plugs aged and flattened out at their tips (from a few years of being tightened down too hard), becoming mushroom-shaped, and had spread out between the bottom of the clutch screw  hole, and the clutch axle  itself. There was no way it was ever going to be extracted, up the clutch hole, no matter how good the tool. The mount axes had to be disassembled.
 
    Thanks to George’s instructions on how they do it, the task was almost a breeze after that. Once the “push-screws” easily did their job,  I drilled out a larger centre hole down the old plugs, and tapped some looser ones into the now empty clutch channel. I think later, for some of them, I threaded the drilled plug – only half way in, to produce a “tapered threaded” hole. That way, the tap then had enough grip to then push & screw the old plug, down into the channel without much force.
A little WD-40 may have helped loosen it from the hole threads.
 
   The old clutch plugs not only formed mushroom heads in the channel, they also thickened and embedded themselves into the hole threads.
With the axles disassembled, the mushroomed head did not need to force its way upward, but be screwed inward,  for extraction.
 
*****************
    However, the next time I have to do it – and I really hope there will never be one – I think I might substitute the AP clutch plugs with one’s I found on the web, in CHINA. Or, I will modify the standard AP plug kit.
 
    Those are almost the same, except they are “rounded, bullet-shaped”, at the tips. I figure that their narrowed tips, rather than AP’s straight cylindrical plugs, will not mushroom as much into the empty channel space, beyond the diameter of the clutch screw hole, making extraction much easier the normal way using  the AP tool.
 
    Alternatively, I might put each new AP standard kit plug in a drill or lathe, and “round-off” the tips to likewise become bullet-shaped. That would probably be easier than sourcing from China, where they might become unavailable over time, and possibly not precisely the same size. If rounding-off would work, I would much prefer to trust the ones from AP, and modify them.
 
**********
    Also, if those Chinese substitutes are used, you should still source the regular AP clutch plugs to perhaps replace the “bearings” on both axes. The same AP clutch plugs are used as “rollers” in the race channel – i.e. there are not typical “steel ball-bearings”.  You will need a KIT of each, plus spares, since you will likely drop and lose some during assembly - about 24 on one and maybe 22 in the other (?) axle. The DELRIN axle bearing rollers may flatten out over time, just like the clutches, perhaps shatter with age and stress. Eventually will need replacement as well, although that has never been mentioned here, or even written about in any AP documents.
 
    The mount really was a joy to use again, after its clutch rejuvenation, and I didn’t need to replace the ones in the bearing race yet, since I am the original owner. But I suppose, under  more frequent use and heavier loading than mine, the axes may get “bumpy”, when one or more DELRIN plug rollers chip or shatter, causing a log jam in the race channel. So, keep that in mind.
 
    Here is a link, to the Chinese company – to see what those look like.
 
 
    Actually, it would be nice if AP could be the source of both the regular clutch plugs for the bearings, and bullet-nosed ones for the clutch holes. The “rounded section” should be slightly longer than the channel depth, to prevent even those from mushrooming and getting stuck.
 
Joe Z.
 
<image[2].png>


George
 

Greg,

 

I can assist you if necessary.   Only replace plugs if it is truly necessary.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Greg Salyer
Sent: Monday, April 06, 2020 12:03 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Are there any written instructions on how to do such a disassembly ? Just in case we find it’s necessary.



On Apr 6, 2020, at 12:49 PM, Joe Zeglinski <J.Zeglinski@...> wrote:



Hi,

 

    I had to replace all the clutch plugs on my AP-900 and it was a bear of a task, almost unbearable, even with AP’s special plug removal tool. It was only possible thanks to George and his marvellous advice, on the easy and smart way of using a 3 or 4 inch long (socket head) as a  “push screw” and my socket wrench, to pull the axle head  off and disassemble the axes. Then it was easy to remove the badly deformed old plugs.

 

    As usually happens, the DELRIN plugs aged and flattened out at their tips (from a few years of being tightened down too hard), becoming mushroom-shaped, and had spread out between the bottom of the clutch screw  hole, and the clutch axle  itself. There was no way it was ever going to be extracted, up the clutch hole, no matter how good the tool. The mount axes had to be disassembled.

 

    Thanks to George’s instructions on how they do it, the task was almost a breeze after that. Once the “push-screws” easily did their job,  I drilled out a larger centre hole down the old plugs, and tapped some looser ones into the now empty clutch channel. I think later, for some of them, I threaded the drilled plug – only half way in, to produce a “tapered threaded” hole. That way, the tap then had enough grip to then push & screw the old plug, down into the channel without much force.

A little WD-40 may have helped loosen it from the hole threads.

 

   The old clutch plugs not only formed mushroom heads in the channel, they also thickened and embedded themselves into the hole threads.

With the axles disassembled, the mushroomed head did not need to force its way upward, but be screwed inward,  for extraction.

 

*****************

    However, the next time I have to do it – and I really hope there will never be one – I think I might substitute the AP clutch plugs with one’s I found on the web, in CHINA. Or, I will modify the standard AP plug kit.

 

    Those are almost the same, except they are “rounded, bullet-shaped”, at the tips. I figure that their narrowed tips, rather than AP’s straight cylindrical plugs, will not mushroom as much into the empty channel space, beyond the diameter of the clutch screw hole, making extraction much easier the normal way using  the AP tool.

 

    Alternatively, I might put each new AP standard kit plug in a drill or lathe, and “round-off” the tips to likewise become bullet-shaped. That would probably be easier than sourcing from China, where they might become unavailable over time, and possibly not precisely the same size. If rounding-off would work, I would much prefer to trust the ones from AP, and modify them.

 

**********

    Also, if those Chinese substitutes are used, you should still source the regular AP clutch plugs to perhaps replace the “bearings” on both axes. The same AP clutch plugs are used as “rollers” in the race channel – i.e. there are not typical “steel ball-bearings”.  You will need a KIT of each, plus spares, since you will likely drop and lose some during assembly - about 24 on one and maybe 22 in the other (?) axle. The DELRIN axle bearing rollers may flatten out over time, just like the clutches, perhaps shatter with age and stress. Eventually will need replacement as well, although that has never been mentioned here, or even written about in any AP documents.

 

    The mount really was a joy to use again, after its clutch rejuvenation, and I didn’t need to replace the ones in the bearing race yet, since I am the original owner. But I suppose, under  more frequent use and heavier loading than mine, the axes may get “bumpy”, when one or more DELRIN plug rollers chip or shatter, causing a log jam in the race channel. So, keep that in mind.

 

    Here is a link, to the Chinese company – to see what those look like.

 

 

    Actually, it would be nice if AP could be the source of both the regular clutch plugs for the bearings, and bullet-nosed ones for the clutch holes. The “rounded section” should be slightly longer than the channel depth, to prevent even those from mushrooming and getting stuck.

 

Joe Z.

 

<image[2].png>


Don Anderson
 

Hello George
I have never changed the plugs on my 2009 AP900GOTO. They seem to be working well at this point. Should I change them out because of age? Do they get brittle with time?
Cheers

Don Anderson


On Monday, April 6, 2020, 07:53:04 a.m. MDT, George <george@...> wrote:


Michael,

 

You are correct.   An extractor is an alternative extraction technique.   As you point out, sizing it correctly is important.   There have been sveral customers who have used it successfully.  

 

Unfortunately, I am working from home and I can’t give you a hole size for the plug, but will be able to do so the next time someone needs to extract the plugs.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Michael Hambrick via groups.io
Sent: Saturday, April 04, 2020 7:42 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Hi Robert

I am glad you were able to remove the old clutch plugs.

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head.

There are several tricks to getting a screw extractor to work:

  1. Use the correct size extractor for the screw thread size
  1. You have to drill the correct size hole in the broken screw.
  1. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.


Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it.

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before.




Best Regards

Michael Hambrick
ARLANXEO

TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...


George
 

Don,

 

No.   You will be fine.   Change them in about another 150 years.   <G>

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Don Anderson via groups.io
Sent: Monday, April 06, 2020 3:22 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Hello George

I have never changed the plugs on my 2009 AP900GOTO. They seem to be working well at this point. Should I change them out because of age? Do they get brittle with time?

Cheers

 

Don Anderson

 

 

On Monday, April 6, 2020, 07:53:04 a.m. MDT, George <george@...> wrote:

 

 

Michael,

 

You are correct.   An extractor is an alternative extraction technique.   As you point out, sizing it correctly is important.   There have been sveral customers who have used it successfully.  

 

Unfortunately, I am working from home and I can’t give you a hole size for the plug, but will be able to do so the next time someone needs to extract the plugs.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Michael Hambrick via groups.io
Sent: Saturday, April 04, 2020 7:42 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Hi Robert

I am glad you were able to remove the old clutch plugs.

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head.

There are several tricks to getting a screw extractor to work:

  1. Use the correct size extractor for the screw thread size
  1. You have to drill the correct size hole in the broken screw.
  1. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.


Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it.

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before.




Best Regards

Michael Hambrick
ARLANXEO
TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...


Don Anderson
 

Ok. I should be middle aged by then!

Don Anderson


On Monday, April 6, 2020, 03:18:08 p.m. MDT, George <george@...> wrote:


Don,

 

No.   You will be fine.   Change them in about another 150 years.   <G>

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Don Anderson via groups.io
Sent: Monday, April 06, 2020 3:22 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Hello George

I have never changed the plugs on my 2009 AP900GOTO. They seem to be working well at this point. Should I change them out because of age? Do they get brittle with time?

Cheers

 

Don Anderson

 

 

On Monday, April 6, 2020, 07:53:04 a.m. MDT, George <george@...> wrote:

 

 

Michael,

 

You are correct.   An extractor is an alternative extraction technique.   As you point out, sizing it correctly is important.   There have been sveral customers who have used it successfully.  

 

Unfortunately, I am working from home and I can’t give you a hole size for the plug, but will be able to do so the next time someone needs to extract the plugs.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-282-1513

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Michael Hambrick via groups.io
Sent: Saturday, April 04, 2020 7:42 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Clutch Plug Removal on AP 900

 

Hi Robert

I am glad you were able to remove the old clutch plugs.

This is really a question for George or Roland, but after reading your description of the plug removal process I am wondering if anyone has ever tried using a screw extractor to get of the clutch plugs out. These devices are used in automotove repair shops and machine shops. They are very tricky to use, but if done correctly they will help the shop owner avoid having to do a major repair job on an engine block or cylinder head.

There are several tricks to getting a screw extractor to work:

  1. Use the correct size extractor for the screw thread size
  1. You have to drill the correct size hole in the broken screw.
  1. Don't use too much force to turn the extractor. They are made from hardened tool steel, and they are very brittle. If you break one off in the screw you are totally out of luck.


Since the clutch plugs already have a hole drilled in them, 2/3 of the work is already done. Next, you tap the screw extractor into the hole until the flutes dig into the hole and then turn it counterclockwise while pushing down on it using a T-handle tap wrench to grip the square head of the screw extractor. The counterclockwise turning motion causes the screw extractor to grip the hole very firmly allowing it to turn the broken screw along with it.

I DO NOT recommend trying to do this unless Roland or George sanction doing so. As both of them seem to be very mechanically inclined, I expect that they have probably tried this technique before.




Best Regards

Michael Hambrick
ARLANXEO
TSR Global Manufacturing Support
PO Box 2000
Orange, TX 77631-2000
Phone: +1 (409) 882-2799
email: mike.hambrick@...