Date
21 - 37 of 37
400GTO
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Roland Christen
A loose nut will show as backlash in PHD. Will see it if you physically push and pull on the axis
A worm that's not fully in mesh will show as backlash in PHD. Will see it if you push and pull on the axis.
A spur transfer gear that's not fully in mesh will show as backlash in PHD. Will not see it by pushing and pulling on the axis.
3 places to look. Take covers off and explore.
If you can't figure out where the backlash is coming from, you may need the mount serviced. I'm sure we can find the place that has backlash.
I don't know your particular build, but I believe this
mount has a stepper drive with a gearbox on the stepper. If none of the
above, then it's possible that the gearbox has inherent backlash. In
that case we may or may not be able to fully fix it. It is a very old mount that goes back some 30 years, and may have seen a lot of use (and wear). Backlash inn the stepper gearbox will not be visible as play in the mount axis (when you push and pull on the back of the scope).
Roland
-----Original Message-----
From: Chris White <chris.white@...> To: main@ap-gto.groups.io Sent: Mon, Jul 4, 2022 4:46 pm Subject: Re: [ap-gto] 400GTO Good tip on the nut.
Would A loose nut be seen as backlash in phd? You are correct. While I feel wiggle in both axis, I only have a problem in declination. The backlash is so great that it is not able to be measured by guiding assistant. -- Roland Christen Astro-Physics |
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Chris White
Good tip on the nut.
Would A loose nut be seen as backlash in phd? You are correct. While I feel wiggle in both axis, I only have a problem in declination. The backlash is so great that it is not able to be measured by guiding assistant. |
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Roland Christen
f the worms are fully in mesh, then it's possible that the end-play not is loose. It should say end play nut.
Rolando
-----Original Message-----
From: Roland Christen via groups.io <chris1011@...> To: main@ap-gto.groups.io <main@ap-gto.groups.io> Sent: Mon, Jul 4, 2022 4:36 pm Subject: Re: [ap-gto] 400GTO Thanks Roland. I do have play in the axis, but any tighter and it stalls. If the worms are fully in mesh, then it's possible that the end-play not is loose. This is the adjustable nut on the end of the worm gear that holds it in place. If it's loose, then the worm gear is able to move back and forth sideways as you push on the scope or counterweight shaft.
By the way, having backlash in RA has zero effect on guiding. In Dec you want to have little or no backlash, because during guiding you will be reversing the axis as the guide software tries to keep the star on the centerline. If there is too much backlash delay, it takes a long time for the axis to react during a reversal.
Roland
-----Original Message-----
From: Chris White <chris.white@...> To: main@ap-gto.groups.io Sent: Mon, Jul 4, 2022 3:57 pm Subject: Re: [ap-gto] 400GTO Thanks Roland. I do have play in the axis, but any tighter and it stalls.
I'll remove the housing and take a look. It's a fun project! Ps- will any high end silicone grease with good temperature ratings be ok? I have a high end silicone vacuume grease on hand. Otherwise I can get the 105 grease specified in the service guide you made. Thanks and happy 4th! -- Roland Christen Astro-Physics -- Roland Christen Astro-Physics |
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Roland Christen
Thanks Roland. I do have play in the axis, but any tighter and it stalls. If the worms are fully in mesh, then it's possible that the end-play not is loose. This is the adjustable nut on the end of the worm gear that holds it in place. If it's loose, then the worm gear is able to move back and forth sideways as you push on the scope or counterweight shaft.
By the way, having backlash in RA has zero effect on guiding. In Dec you want to have little or no backlash, because during guiding you will be reversing the axis as the guide software tries to keep the star on the centerline. If there is too much backlash delay, it takes a long time for the axis to react during a reversal.
Roland
-----Original Message-----
From: Chris White <chris.white@...> To: main@ap-gto.groups.io Sent: Mon, Jul 4, 2022 3:57 pm Subject: Re: [ap-gto] 400GTO Thanks Roland. I do have play in the axis, but any tighter and it stalls.
I'll remove the housing and take a look. It's a fun project! Ps- will any high end silicone grease with good temperature ratings be ok? I have a high end silicone vacuume grease on hand. Otherwise I can get the 105 grease specified in the service guide you made. Thanks and happy 4th! -- Roland Christen Astro-Physics |
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Chris White
Thanks Roland. I do have play in the axis, but any tighter and it stalls.
I'll remove the housing and take a look. It's a fun project! Ps- will any high end silicone grease with good temperature ratings be ok? I have a high end silicone vacuume grease on hand. Otherwise I can get the 105 grease specified in the service guide you made. Thanks and happy 4th! |
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Roland Christen
There are two mesh points in the 400. One is the worm gear to worm wheel mesh. It sounds like you have that tight enough. You can judge that by putting slight pressure on the end of the scope in both directions to see how firm the position holds.
The other mesh is the gearbox mesh, which is not obvious , but is easily adjusted by loosening a couple of screws and gently pushing the motor spur gear into full mesh with the spur gear on the end of the worm.
Checking things like the above, it always helps to remove cover plates and to take a look at the mechanics. That way you can see how things are put together and can get a feel for how it's supposed to work. Also, there are many helpful PDF's on our website for legacy products that can give you information on how to adjust these products. If all else fails, there is always George or Howard during business hours.
Rolando
-----Original Message-----
From: Chris White <chris.white@...> To: main@ap-gto.groups.io Sent: Sat, Jul 2, 2022 11:03 pm Subject: Re: [ap-gto] 400GTO Any tips or tricks on fine tuning gear mesh? I have a lot of backlash in both ra and dec. If I mesh any tighter I get motor stall issues. I'm having some stall issues as it is and can feel significant wiggle in both axis.
I've got a 130gtx on it. Balance is pretty darn good. Wondering if these symptoms are me not meshing right (and needing tips) or if it's a sign that I should do a full service. Ps- I have the AP mesh procedure document and followed the directions. Thanks. -- Roland Christen Astro-Physics |
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Chris White
Any tips or tricks on fine tuning gear mesh? I have a lot of backlash in both ra and dec. If I mesh any tighter I get motor stall issues. I'm having some stall issues as it is and can feel significant wiggle in both axis.
I've got a 130gtx on it. Balance is pretty darn good. Wondering if these symptoms are me not meshing right (and needing tips) or if it's a sign that I should do a full service. Ps- I have the AP mesh procedure document and followed the directions. Thanks. |
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Chris White
On Sat, Jun 25, 2022 at 06:58 PM, Roland Christen wrote:
Nailed it! I've just barely gotten the mount setup in the daytime and have not done a PA yet. That exactly accounts for why I was pointing below the horizon in Park5. Thanks for helping me see the "hidden" obvious culprit. Head slap city! |
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Roland Christen
You also know that the altitude axis has to be set to your latitude, yes? In fact, if you have the proper latitude set on your keypad (or other initialization program), you can start from Park3, send it to Park5 and turn the azimuth screw so that the scope is horizontal. This is the first step in setting the mount to polar alignment in the daytime.
Roland
-----Original Message-----
From: chris1011@... To: main@ap-gto.groups.io <main@ap-gto.groups.io> Sent: Sat, Jun 25, 2022 5:51 pm Subject: Re: [ap-gto] 400GTO In that case you have told the CP5 the wrong location information.
To test this, send the mount to Park3, then Park2. If these are correct, and Park1 and 5 are wrong, you have the wrong location in the keypad or whatever program you are using to initialize the mount.
You see, Park3 is a known reference which does not care about location. That's why you should always start there in any troubleshooting scenario. Same with Park2. They will always be correct and you should always start with these axes set to their proper place.
Park 1 , 4 and 5 all use Location data to point to the northern and southern horizon. So if they are off, your location settings are wrong. Logical, yes?
Roland
-----Original Message-----
From: Chris White <chris.white@...> To: main@ap-gto.groups.io Sent: Sat, Jun 25, 2022 5:23 pm Subject: Re: [ap-gto] 400GTO On Sat, Jun 25, 2022 at 06:19 PM, Roland Christen wrote:
Roland, The problem is, that if I do that... then go to park5, DEC is pointing below the horizon, while APCC and the driver reports that it is pointing at the horizon. When you slew the mount, it is moving farther than the software thinks it is... -- Roland Christen Astro-Physics |
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Roland Christen
In that case you have told the CP5 the wrong location information.
To test this, send the mount to Park3, then Park2. If these are correct, and Park1 and 5 are wrong, you have the wrong location in the keypad or whatever program you are using to initialize the mount.
You see, Park3 is a known reference which does not care about location. That's why you should always start there in any troubleshooting scenario. Same with Park2. They will always be correct and you should always start with these axes set to their proper place.
Park 1 , 4 and 5 all use Location data to point to the northern and southern horizon. So if they are off, your location settings are wrong. Logical, yes?
Roland
-----Original Message-----
From: Chris White <chris.white@...> To: main@ap-gto.groups.io Sent: Sat, Jun 25, 2022 5:23 pm Subject: Re: [ap-gto] 400GTO On Sat, Jun 25, 2022 at 06:19 PM, Roland Christen wrote:
Roland, The problem is, that if I do that... then go to park5, DEC is pointing below the horizon, while APCC and the driver reports that it is pointing at the horizon. When you slew the mount, it is moving farther than the software thinks it is... -- Roland Christen Astro-Physics |
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Chris White
On Sat, Jun 25, 2022 at 06:19 PM, Roland Christen wrote:
Roland, The problem is, that if I do that... then go to park5, DEC is pointing below the horizon, while APCC and the driver reports that it is pointing at the horizon. When you slew the mount, it is moving farther than the software thinks it is... |
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Roland Christen
park 3, DEC is not pointing at the pole. Loosen the clutches and move the Dec axis manually until it points to the pole.
Roland
-----Original Message-----
From: Chris White <chris.white@...> To: main@ap-gto.groups.io Sent: Sat, Jun 25, 2022 4:47 pm Subject: Re: [ap-gto] 400GTO i received my 400GTO and this thing sure is a beauty. What a wonderful little mount! I'd MUCH rather have this than any of the new harmonic designs.
My stowaway is out of commission as I need a PP adapter and I've sold my 900GTO in anticipation for the Mach2 delivery so that leaves me with just the 130GTX right now. I added a CP3 to the mount, updated the CP personality and have successfully connected to APCCPro. I put the 130 on it today and did some testing. The mount slings the 130 around like it weighs nothing. I still need to run a PE curve with Pempro and build a model with APCC. It will be interesting to see how this little mount performs! One thing that I find a little strange is that DEC seems to be off a little bit. Example: If I'm in park position 5, with DEC pointing at altitude zero, and then repark the mount into park 3, DEC is not pointing at the pole. It's off by a fair bit. I've checked the time settings, and all looks good. I'm wondering if there is a setting somewhere that could be causing this, or if there is something a little off between the CP and the mount. When I do the test above, APCC shows that DEC is pointing directly at the pole, as does the driver. -- Roland Christen Astro-Physics |
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Chris White
i received my 400GTO and this thing sure is a beauty. What a wonderful little mount! I'd MUCH rather have this than any of the new harmonic designs.
My stowaway is out of commission as I need a PP adapter and I've sold my 900GTO in anticipation for the Mach2 delivery so that leaves me with just the 130GTX right now. I added a CP3 to the mount, updated the CP personality and have successfully connected to APCCPro. I put the 130 on it today and did some testing. The mount slings the 130 around like it weighs nothing. I still need to run a PE curve with Pempro and build a model with APCC. It will be interesting to see how this little mount performs! One thing that I find a little strange is that DEC seems to be off a little bit. Example: If I'm in park position 5, with DEC pointing at altitude zero, and then repark the mount into park 3, DEC is not pointing at the pole. It's off by a fair bit. I've checked the time settings, and all looks good. I'm wondering if there is a setting somewhere that could be causing this, or if there is something a little off between the CP and the mount. When I do the test above, APCC shows that DEC is pointing directly at the pole, as does the driver. |
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Hi Chris,
George asked me to assist you. We'll get your CP3 personality changed. I'll respond privately. HKH |
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Chris White
Thanks for the tip Bill. I've been using a 900GTO, which I think has the same potential danger with the clutch knobs. But it is good to know, so thanks for bringing this up.
Glad to hear you like this little mount! |
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WMarton@...
You have an identical configuration to mine (upgraded CP3 with V2 chip). It is a terrific little mount. My only advice: be careful and do not overtighten the clutches. Unlike the Mach1 and later mounts, the clutch knobs have delrin tips that can deform if you apply too much pressure. The original manual came with an insert reiterating this fact; you may not have access to it secondhand. Also, I would mark the 90 degree RA and DEC axes using painter's tape so putting the mount in the various park positions is easier.
Bill |
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Chris White
Well, since the big announcement wasnt a newly designed 400GTO... I decided to try and find an old one!
It's on its way and will arrive early next week. I also picked up a CP3v2 so I can use APPC with it. I understand I need to change the "personality" and I've reached out to George to get this process started. I'm really excited to receive this mount, it will pair so nicely with my Stowaway. Almost as excited as the Mach2 that comes later this month! Any tips or tricks or reminiscences about this sweet little mount? |
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