Issue with DOVELM162


DiscoDuck
 
Edited

I've always used an allen key to tighten up the knobs on the 16" saddle plate (DOVELM162) when mounting the scope. And then an allen key to untighten them when packing up

However, when packing up this morning, the inner bolt on one of the knobs unscrewed rather than the whole knob. Have I just been lucky so far that this hasn't happened before? Are there any tips/tricks on how to ensure it is in there tight and tight enough to allow me to tighten/untighten the main knob with the allen key without this inner bolt  unscrewing when loosening the main knob? Was there perhaps some sort of adhesive fixing it in that may have come loose and caused this?

Pic attached to show the knob I mean.

Are the knobs/bolts attaching the Mach1 to its base the same, i.e. is the inner bit the allen key goes in separate from the main knob/bolt and likely to unscrew before the knob does, as I also usually nip them up with an allen key too when setting up?

Comments appreciated.

Paul

P.S. I had to use a monkey wrench in the end this morning, as I just could not loosen the knob by hand.


Cheng-Yang Tan
 

I had the same issue when I first got the DOVELM because I’m stronger than I look :) Now, I just go finger tight and then 1/4 turn with my Allen key. Scope is held very tightly and the knobs release without problems.

On Sunday, March 21, 2021, 12:25 AM, DiscoDuck <montagoo@...> wrote:

[Edited Message Follows]

I've always used an allen key to tighten up the knobs on the 16" saddle plate (DOVELM162) when mounting the scope. And then an allen key to untighten them when packing up

However, when packing up this morning, the inner bolt on one of the knobs unscrewed rather than the whole knob. Have I just been lucky so far that this hasn't happened before? Are there any tips/tricks on how to ensure it is in there tight and tight enough to allow me to tighten/untighten the main knob with the allen key without this inner bolt  unscrewing when loosening the main knob? Was there perhaps some sort of adhesive fixing it in that may have come loose and caused this?

Pic attached to show the knob I mean.

Are the knobs/bolts attaching the Mach1 to its base the same, i.e. is the inner bit the allen key goes in separate from the main knob/bolt and likely to unscrew before the knob does, as I also usually nip them up with an allen key too when setting up?

Comments appreciated.

Paul

P.S. I had to use a monkey wrench in the end this morning, as I just could not loosen the knob by hand.


Cheng-Yang Tan
 

Update: I had to remount everything again after my imaging session last night. And after tightening the knobs by hand, I tightened it by another 1/8 turn with the Allen key -- not 1/4 turn. It's plenty solid with the 1/8 turn.

cytan

On Sunday, March 21, 2021, 08:29:19 AM CDT, Cheng-Yang Tan <cytan299@...> wrote:


I had the same issue when I first got the DOVELM because I’m stronger than I look :) Now, I just go finger tight and then 1/4 turn with my Allen key. Scope is held very tightly and the knobs release without problems.

cytan


Sent from Yahoo Mail for iPad

On Sunday, March 21, 2021, 12:25 AM, DiscoDuck <montagoo@...> wrote:

[Edited Message Follows]

I've always used an allen key to tighten up the knobs on the 16" saddle plate (DOVELM162) when mounting the scope. And then an allen key to untighten them when packing up

However, when packing up this morning, the inner bolt on one of the knobs unscrewed rather than the whole knob. Have I just been lucky so far that this hasn't happened before? Are there any tips/tricks on how to ensure it is in there tight and tight enough to allow me to tighten/untighten the main knob with the allen key without this inner bolt  unscrewing when loosening the main knob? Was there perhaps some sort of adhesive fixing it in that may have come loose and caused this?

Pic attached to show the knob I mean.

Are the knobs/bolts attaching the Mach1 to its base the same, i.e. is the inner bit the allen key goes in separate from the main knob/bolt and likely to unscrew before the knob does, as I also usually nip them up with an allen key too when setting up?

Comments appreciated.

Paul

P.S. I had to use a monkey wrench in the end this morning, as I just could not loosen the knob by hand.


DiscoDuck
 

Thanks Cytan. So you release the knobs by hand or using the Allen key?


M Hambrick
 

I started using one of those jar lid grippers to tighten and loosen the knobs on my DOVELM162. It works great ! It is also good for tightening the other thumb screws. My fingertips used to get shredded tightening and loosening all of the various knurled knobs and screws on my scope and mount, especially in the cold, dry weather, but this little green wonder has practically eliminated that problem.

Mike


DiscoDuck
 

Thanks Mike.

All - is there any particular thing I need to do to retighten the inner bolt that was loosened? Does it need Loctite added or something like that?


Cheng-Yang Tan
 

Release with Allen key. It's tight enough that I can't release with my fingers.

cytan

On Sunday, March 21, 2021, 03:48:57 PM CDT, DiscoDuck <montagoo@...> wrote:


Thanks Cytan. So you release the knobs by hand or using the Allen key?


Cheng-Yang Tan
 

Like you, the bolt came off and the knob got stuck. I then had to use pliers to remove the knob. To get the bolt and knob back on DOVELM, I had the knob threaded loose on DOVELM, held it with pliers and then tightened the bolt with the Allen key as tightly as I could. Once I did that and then simply tightened the knob by 1/8" turn after finger tightening it to hold my scope, I've never had a problem of the bolt separating from the knob after that. No need for loctite.

cytan

On Sunday, March 21, 2021, 06:42:32 PM CDT, DiscoDuck <montagoo@...> wrote:


Thanks Mike.

All - is there any particular thing I need to do to retighten the inner bolt that was loosened? Does it need Loctite added or something like that?


DiscoDuck
 

Thanks cytan.


Frank Widmann
 

If an allen bolt unbonds from the knob, I find the safest way to loosen a knob that is beyond hand tight is to use a strap wrench. The strap wrench is the astronomer’s secret weapon.


M Hambrick
 

Hi Paul

From what I can tell, the Allen head in the clamp looks like the head of a standard 1/4-20 socket head cap screw that has been press fitted into the recess hole in the aluminum clamp. The knurling in the head helps to hold it into place. This is very similar to the way that the lug nut studs are attached to the brake drums and rotors on cars.

Unfortunately, once this Allen head strips out and breaks free, it would seem that the only recourse is to order a replacement. However, even with a stripped Allen head however, the clamp itself should remain functional. You just won't be able to use an Allen wrench to tighten or loosen it, but pliers, the green jar lid gripper, or the strap wrench all mentioned above will work.

I never use an Allen wrench to tighten these clamps, even with my heavy 180 EDT imaging and guiding setup. If I need to torque them a little more, the jar lid gripper works really well, and it also works really well for loosening the clamps. Before using the jar gripper, I used to need an Allen wrench from time to time to loosen the clamps.

Mike


Robert
 

"From what I can tell, the Allen head in the clamp looks like the head of a standard 1/4-20 socket head cap screw that has been press fitted into the recess hole in the aluminum clamp. The knurling in the head helps to hold it into place."

This is not the case at all.  The knob is threaded and the screw is held in place with Loctite.  All that needs to be done to fix it is to remove the loose screw, clean the threads up a bit and re-apply some red 271 Loctite.

Robert


M Hambrick
 

Thanks Robert That is good to know.

Are the section of the clamp with the female threads and the Allen head screw all one piece ?

Mike 


Robert
 

I'm not sure I understand your question.  The clamp isn't threaded so I'm going to assume you're talking about the knob, in which case, it is one piece.

Robert


DiscoDuck
 

Thanks Robert. So Loctite would've been used originally by AP in manufacturing? I guess it degrades over time. The mount had been outside too for a few days (under a Telegizmos 365 cover) in some heat (not too bad ... we're into early autumn hear so the peak summer heat is gone).


Worsel
 

I wonder if A-P did use Loctite, then they consciously used blue Loctite, rather than red to ensure that, if needed, the Allen bolt could be removed.  Red takes very high temps to release.

Bryan


George
 

Bryan,

 

Red Loctite is used.   One in a thousand will break loose when overtightened.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Worsel via groups.io
Sent: Tuesday, March 23, 2021 3:25 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Issue with DOVELM162

 

I wonder if A-P did use Loctite, then they consciously used blue Loctite, rather than red to ensure that, if needed, the Allen bolt could be removed.  Red takes very high temps to release.

Bryan


Woody Schlom
 

And red thread-lock needs temperatures above 600° F to start loosening up.  And my experience with the stuff is that it lasts for decades.  I have a trailer hitch that’s been outside for 20 years and the red thread-lock is still holding quite firmly.  I’m sure it’ll take a blow torch and impact wrench to loosen up.

 

Woody

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of George
Sent: Tuesday, March 23, 2021 1:31 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Issue with DOVELM162

 

Bryan,

 

Red Loctite is used.   One in a thousand will break loose when overtightened.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Worsel via groups.io
Sent: Tuesday, March 23, 2021 3:25 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Issue with DOVELM162

 

I wonder if A-P did use Loctite, then they consciously used blue Loctite, rather than red to ensure that, if needed, the Allen bolt could be removed.  Red takes very high temps to release.

Bryan


Cheng-Yang Tan
 

Then I'm really stronger than I look :) I had two bolts that that came off the knobs.

cytan

On Tuesday, March 23, 2021, 03:33:58 PM CDT, Woody Schlom <woody_is@...> wrote:


And red thread-lock needs temperatures above 600° F to start loosening up.  And my experience with the stuff is that it lasts for decades.  I have a trailer hitch that’s been outside for 20 years and the red thread-lock is still holding quite firmly.  I’m sure it’ll take a blow torch and impact wrench to loosen up.

 

Woody

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of George
Sent: Tuesday, March 23, 2021 1:31 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Issue with DOVELM162

 

Bryan,

 

Red Loctite is used.   One in a thousand will break loose when overtightened.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Worsel via groups.io
Sent: Tuesday, March 23, 2021 3:25 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Issue with DOVELM162

 

I wonder if A-P did use Loctite, then they consciously used blue Loctite, rather than red to ensure that, if needed, the Allen bolt could be removed.  Red takes very high temps to release.

Bryan


George
 

Cytan,

 

We won’t pick a fight with you!   <G>    Seriously, it is an easy fix…add a drop of red Loctite and wait at least 24 hours and they will be fixed.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Cheng-Yang Tan via groups.io
Sent: Tuesday, March 23, 2021 3:39 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Issue with DOVELM162

 

Then I'm really stronger than I look :) I had two bolts that that came off the knobs.

 

cytan

 

On Tuesday, March 23, 2021, 03:33:58 PM CDT, Woody Schlom <woody_is@...> wrote:

 

 

And red thread-lock needs temperatures above 600° F to start loosening up.  And my experience with the stuff is that it lasts for decades.  I have a trailer hitch that’s been outside for 20 years and the red thread-lock is still holding quite firmly.  I’m sure it’ll take a blow torch and impact wrench to loosen up.

 

Woody

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of George
Sent: Tuesday, March 23, 2021 1:31 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Issue with DOVELM162

 

Bryan,

 

Red Loctite is used.   One in a thousand will break loose when overtightened.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Worsel via groups.io
Sent: Tuesday, March 23, 2021 3:25 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Issue with DOVELM162

 

I wonder if A-P did use Loctite, then they consciously used blue Loctite, rather than red to ensure that, if needed, the Allen bolt could be removed.  Red takes very high temps to release.

Bryan