Hello James, thanks for your content I have followed you for some time, the depth and breadth of your content is quite amazing and appreciated. I have a very similar setup same focuser on a EHD 8". What I found is that the original fitment following Celestron intructions was hopeless! So I dismantled the standard focuser which included the removal of the philips screw at the end of the focuser shaft allowing removal of the brass sleeve together with the bearing assembly behind set into the body of the ota. In there on my setup, between the 2 bearings there was a copper spacer, completely redundant in my view which extended the overall length of the assembly. Net result was that the inside flange (Telescope side of the focuser adapter) was fouling the rotation on the outermost bearing race on the assembly preventing correct seating on the ota casting! I loosened and removed the retaining nut for the bearing assembly, separated the bearings and removed the spacer, replaced everything, and refitted the retaining nut. Then reinserted the bearing assembly in to the ota by threading it back on and replaced the retaining philips screw into the end of the focuser shaft. I then refitted the adapter plate for the focuser which seated flush against the ota housing without fouling the outer bearing race of the focuser assembly. Tweaked up the retaining screws so they were able to grip the casting reasonbly well. It has been working well ever since no fouling stalling and no weird focuser gyration and screw loosening . Thanks again for the content.
Thank you for the kind words and for hanging around! Your solution approach is very diligent. Well impressed. If I get frustrated enough, you’ve provided great insight into “next steps”. I must say, I’m not in the mood to “fix” Celestron’s issue. But, as they say, “It may not be our fault, but it is our problem.”
For me the solution was to leave the original plate in place and to mount the new focus motor plate on top of it using longer m6x10 screws. I believe that the reason for the problem is a missing rebated area around the hole of the new plate. If you look at the original plate and the 2nd focus motor plate for non-9.25 SCT you will see that a rebated area has been milled into them. It seems that the focus mechanism of the SCT sticks out ~1mm and the non-rebated plate can interfere with it causing movement and eventual screw loosening. Anyway, my solutions works for me. Hope this helps people out there.
Thanks James Lamb for your work and knowledge, gonna try finding some 10mm screws locally. Also, instead of using Loctite 242 I am going to use Vibra-Tite VC-3 or VC-4.
something to think about. If your binding then the focuses spindle inst moving right? this presumably means that as far as the software driver goes, the focuses has not moved and is still at its last know position (assuming its using a coding wheel of some sorts). So maybe the fine adjustment clicks your making while the spindle has bound are getting pushed into a cue. When the binding eventual comes free, the cue is played back while the motor tries to play catch-up with the click cue giving the impression of motor runaway?
I’ve thought about that. But I’m only making a 3-step move inward when it locks up. When it “runs away,” it’s moving 2000 steps outward. I sent Celestron a link to the video. We’ll see if there’s any feedback from them.
That's certainly doable as long as I'm not using an autofocus routine in, say, NINA. I believe the real source of my problem is the focuser working itself loose and that, somehow, "causes" the run-away response. Just guessing. I've never experienced the run-away motion when the focuser attachment was solid. I have used that app before. It seems to make "large" moves. Does it have a mirror flop correction built in? Like, if you command a small inward movement, it moves much farther inward, then outward - like the overshoot backlash compensation method? Not sure. Just seems like it's moving the focuser a lot more than what I ask it to do.
@@Aero19612 Good questions, can't say I have the answers. I'm not sure about mirror flop compensation but it makes sense, according to the manual the motor will always approach focus in a positive direction (Focus knob rotating counter clockwise and primary mirror moving outwards). Its done to improve move to accuracy by eliminating potentially lost index position steps due to backlash. If the desired focus is inward, the focuser moves 500 steps inward past the selected index position before reversing direction to return to the selected position. (Gleaned from the user guide :D ). One other thing, if you remove the focuser and re-install it you MUST re-run the calibration routine.
One day I'll learn to read manuals. That sounds like what it's doing. I know the manual says to re-do calibration if you remove then replace the focuser; however, if the OTA focuser isn't moved and the focus motor isn't moved, then there should be no need to re-calibrate to my way of thinking. I hate their calibration routine. It runs the focuser all the way in and all the back out and then puts the focuser at mid travel. That's a ton of movement for a focuser than barely stay attached to the OTA.
Loctite added and reattached. All seems well but no true darkness for the next few weeks so we’ll have to see. If it doesn’t stay put I’ll try the longer screws. Fingers crossed.
A pre-emptive application of the longer screws is the path to take. Persisting with the shorter screws will lead to the state James is in with flogged out threads.
I found that the plastic adapter sleeve that fits over the telescopes focus shaft was too large, when clamped down tight enough to grip shaft, the focus motor would wobble, bind, and become loose causing the focus motor to not work. Once I built up the shaft with tape all is good, no longer screws or lock-tite needed. No more wobble, binding or focus problems. I have not had a problem since.
Thank you very much for the insight, James! I will take a closer look at that interface next time I remove the focuser. I think a more compliant interface may well help the focuser to “find” its axis. In effect, that’s what the loosening screws are doing...with a lot of bad side effects. The tape layer may also increase the effective backlash, but I’ll take that trade-off any day.
Hi James, Thanks for this video! I was having trouble with my motor focuser for several nights trying to capture Saturn and Jupiter. My focuser wasn't responding and doing the runaway thing too. I picked up some 4-40 1/2 long (12.7 mm long) machine screws at Rona here in Canada. They went in without any issues so you can go longer than 10 mm. Just thought I'd let you and anyone else know. I hooked up the focuser, calibrated it and it seems to be working fine now. We'll see tonight when I go after Saturn and Jupiter again. Thanks, Alex
Thanks Aleksandar! Very interesting that you also experienced the "run-away" effect too. I replaced my 8 mm screws with 10 mm screws as noted in the video, but it's good to know that 12 mm screws work as well. Is a 4-40 screw "equivalent to an M3x0.5? Good luck with Saturn and Jupiter!
@@Aero19612 Hi James, I was actually experiencing the "run away" effect for a while but didn't know why. When I removed my focuser the other day to replace the screws I found one of the 3 screws completely loose. The 4-40 is equivalent to the M3 0.5 pitch. I couldn't find M3 here in Canada but the 4-40 is equivalent. I had no problems screwing them in. The 4-40 1/2 inch (12.7 mm) is the screw length, thread length is 10 mm. I have a picture of the screw box I purchased but don't know if I can add a pic here. Thanks, Alex
@@Aero19612 I can't post a picture but here is a link to the screws I bought which seem to fit just fine. Flathead with countersink, main difference is square vs star for screwdriver needed. Don't let the picture on the website fool you. The picture makes the screws look long, they are only 12.7 mm. www.rona.ca/en/flat-head-zinc-plated-machine-screws-4-x-1-2-14-box-63868206
I'm running the Celestron Focus Motor on a EdgeHD 11". I too have seen runaways and freezing. In each case I've unplugged the USB cable and that's cleared it, but it's certainly annoying. After having this happen last night I plugged in external power, hoping that will help. In any event, I just check my screws and sure enough they weren't tight.
They're 30mm long. The trick with the C11S and C14s is to use both the 'old' (orginal ) mounting plateand the plate that came with the motor stacked on top of each other. The screws are long enough to go through both plates. I have done this and all my problems - binding, etc - went away. The two plate solution takes pressure off of the focus bearing which is what causes the binding.
By runaway do you mean the field shifting about as the focuser moves? My Rasa 8 had rock solid stars and now they shift around when I run the focuser. I've taken the focuser off and on a few times, I still haven't found a resolution for it. If you find one please share it! I don't know if the torque of the focuser is enough to shift the screw, but having the axis of the focus motor match the focuser spindle will reduce the 'wiggle' of the focuser and that ReeReeeReeeeReee noise as it runs. When I found alignment errors between the mounting plate and the focuser itself, the focuser spindle wasn't perfectly square against the plate when mounted per Celestron's instructions. I found that locking the focuser spindle to the shaft using the set screw and THEN tightening the mounting screws on the focuser. Maybe shimming the mounting plate until it's perfectly square will help.
No, the “run away” motion I’m referring to is when I command a 3 step inward motion, the focuser “freezes” and doesn’t move, then when I press the stop button, the focuser moves 2000 steps OUT. What resolution number are you looking for? Although your number may be different from mine. Our focuser are the same, of course, but the OTA focuser may be different. Thanks for watching, Michael!
Thanks for the follow-up! I have another one of these motors coming with my RASA 11 V2. I have seen the same issues you have with the screws getting looser over time in my RASA 8 but never bad enough to bind. I have also never seen it run away like that. Perhaps that is because they never have gotten loose enough to bind up. I'll let you know if there is anything new or improved with the one coming this week. Also, how much backlash does your specific setup have?
Yes, this fix seems to have worked. At least I haven't had any problems since this video. Different people are having different problems with this focus motor. My problem seems to be different from most. Celestron requires that you replace the existing bracket with the new one. In my case, one of the threaded holes in the SCT was damaged and could not hold onto a screw. So I replaced the short screws that came with the SCT with longer ones and put LocTite on the threads. All good so far.
@@janeclark1881 Very frustrating. There are various problems that different people have had (see other comments to this vid). Seems that not over tightening the screws is a plus - let’s the motor tilt a bit to accommodate misalignement. Hope you get it working! Took a while, but I finally did. Not the best design.
I'd be asking for a replacement, a RASA 11 should cover it :) I'd consider bonding the adapter plate to the scope to resist the torque especially since the threads in the OTA are damaged. Hi strength Locktite would be removable in the future but epoxy would be superior for a permanent but irreversible solution.
Maybe 3 RASA 11's. HaHa. YES! Exactly what I've been thinking: I would like to bond the aluminum bracket to the aluminum plate in the OTA. Let the screws just deal with the pull-out force and let the shear strength of the bond deal with the lateral forces. Know any good aluminum-to-aluminum bonding agents? Seems like I've had difficulties bonding to aluminum in the past.
@@Aero19612 Sorry bonding to Aluminium is not something I have had great knowledge of and you are quite correct on the bond strength point. However I may have an alternative and less intrusive cunning idea. As you point out the object is to create a high µ between the parts. If we glued two washers back to back from say abrasive paper (wet&dry) and interposed the washer we should get a high µ contact assuming the OTA has a flat mounting face. In the past you have said tapping oversize is not something you are comfortable with. So as a last ditch hack you could try self tapping screws. Don't cringe just yet, self tappers have the advantage of being coarse in the tread pitch which for Aluminium is a good thing. Down side is there is no going back short of tapping oversize. Did you contact C before on this issue? Did you get a response? It seems to be a fairly common issue so I am tipping they will assume a denial stance lest they are deluged with repair requests. Other than that you will have to rise to Chuckstar fame to get a freebie :)
Make sure the M3x0.5 is the right size as they vary from SCT to SCT. I got mine from Amazon, but they saw they're out of stock now. Try this link: www.walmart.com/ip/M3x10mm-Stainless-Steel-Hex-Socket-Flat-Head-Countersunk-Bolts-Screw-50pcs/171196985
@@Aero19612 Thanks James... i have a horror story to tell about the used C8 Edge HD800 ... i dont even know how to put it into words .. lets just say the guys at Celestron tech support are going to freak when they open the box and look it over .
@@BrokenPik Oh dear. That doesn't sound good at all. I've dropped mine and it got soaked in an out-of-nowhere rain storm. But it keeps ticking...At least you feel yours can be fixed. How long will Celestron have it?
@@Aero19612 --- its not clear but my guess is 6 weeks.. that's if they have a full secondary unit including the mirror,,, then there is the corrector offset , focusing unit (less the motor ) which got jammed.. im stopping here. :-( and most likely 800-1200$ US for parts , Bench work and Shipping 2 ways from Canada East coast to West via Fedex,
I submitted a support ticket yesterday and included a link to this video. I haven't heard back yet, but it's early. We shall see. Not expecting Pegasus Astro-level response. Any response will be appreciated.
Not alone here... is it possible that there are at least three different versions of the V2 orange plate e.g. two in the manual 94155 and one shown here: ruclips.net/video/y8DIrT18WGo/видео.html (0:35). The difference between them seems to be that they are matched to the size of the bearing that's around the focus shaft, to hold it firmly in place. An "after the install revisit" covered some issues (with some good pointers on careful centring on C9.25 and not being too tight) ruclips.net/video/UEZOYyDZ_Dg/видео.html - Perhaps you could measure the depth of the threads behind the bolts because it needs to be long enough but not longer than necessary? Compared to your C9.25, I do wonder how this could ever work with the focus locks of an EdgeHD. Limiting the number of focus operations seems counterproductive because you want to expose (and fix) all potential issues in Test (and not at 2am)? Simon
Hey Simon. That plate in the video does look different. It has 6 holes where mine has three. There are only 3 screws, so 6 holes is overkill. My version of the plate fits fine. The problem is we're having to re-use the little screws and it seems like the new orange plate is thicker so you're loosing thread engagement in the OTA part beyond. The longer screws I bought should solve that at least. You would have to leave the focus locks on the EdgeHD unlocked. The reason I mentioned cutting down on back and forth focuser movement is to lengthen the time (number of imaging nights) the focuser is attached and operating. It's the back and forth focuser movement that works those screws loose. I do agree that you want to fix problems in the daylight. I just don't know if this problem can be fixed (easily). Thanks for watching and commenting!
Hey James, did you hear back from the Celestron team yet? I sent a ticket for my binding issues this Tuesday and as of yet no response other than the obligatory “a member of our team will be in touch as soon as possible.”. Me thinks they know they have a problem but are waiting on a resolution from the dev team before responding. Of course that’s just speculation 😬 but who knows 🤷🏻♂️
I also submitted my ticket on Tuesday and, no, I have not heard from them except for the automated reply. I agree with you. They know they have a problem but no good solution.
James Lamb Hi James, Thanks for the update. I sent a chaser message and will report back if i get anywhere. In the meantime, i’m going to 3d print a shim which will do two things, centre the focus bearing and keep the focuser from pinching the baring. Ill let you know how it pans out. 👍
James Lamb Hi James, My screw length is 10mm with a thread length of 8mm. I original used 3 nuts as spacers which were 3mm thick. This left around 2mm of thread to hold the focuser to the OTA which seemed to hold. The shim will be around 2-2.5mm which should give me around an extra mill to grip the OTA. Worse case scenario ill procure some longer screws but i think ill be ok if theres no significant tork on the screws?
As an alternative, you might consider something like this: www.metricscrews.us/index.php?main_page=product_info&cPath=81_91&products_id=1325&gclid=EAIaIQobChMIgYn-mu2Q6gIVx8DACh2lrg3EEAQYAiABEgJ0dfD_BwE This would provide some stand-off and tension the screws at the same time. I think you'd definitely want longer screws so you can engage as many threads as possible. I have some concern that I will damage the aluminum threads by having too high of a tension force. Just a thought.
Celestron comes up with some good products, but somehow I feel their engineering gets rushed or something and they neglect the devil in the details. After many years of refinement like with the C-11 it becomes a hall of fame piece of equipment. But I think it takes a lot of user complaint based refinement. It’s like any early adopting customer is an involuntary beta tester.
Hello James, thanks for your content I have followed you for some time, the depth and breadth of your content is quite amazing and appreciated.
I have a very similar setup same focuser on a EHD 8". What I found is that the original fitment following Celestron intructions was hopeless!
So I dismantled the standard focuser which included the removal of the philips screw at the end of the focuser shaft allowing removal of the brass sleeve together with the bearing assembly behind set into the body of the ota. In there on my setup, between the 2 bearings there was a copper spacer, completely redundant in my view which extended the overall length of the assembly. Net result was that the inside flange (Telescope side of the focuser adapter) was fouling the rotation on the outermost bearing race on the assembly preventing correct seating on the ota casting! I loosened and removed the retaining nut for the bearing assembly, separated the bearings and removed the spacer, replaced everything, and refitted the retaining nut. Then reinserted the bearing assembly in to the ota by threading it back on and replaced the retaining philips screw into the end of the focuser shaft. I then refitted the adapter plate for the focuser which seated flush against the ota housing without fouling the outer bearing race of the focuser assembly. Tweaked up the retaining screws so they were able to grip the casting reasonbly well. It has been working well ever since no fouling stalling and no weird focuser gyration and screw loosening .
Thanks again for the content.
Thank you for the kind words and for hanging around! Your solution approach is very diligent. Well impressed. If I get frustrated enough, you’ve provided great insight into “next steps”. I must say, I’m not in the mood to “fix” Celestron’s issue. But, as they say, “It may not be our fault, but it is our problem.”
For me the solution was to leave the original plate in place and to mount the new focus motor plate on top of it using longer m6x10 screws. I believe that the reason for the problem is a missing rebated area around the hole of the new plate. If you look at the original plate and the 2nd focus motor plate for non-9.25 SCT you will see that a rebated area has been milled into them. It seems that the focus mechanism of the SCT sticks out ~1mm and the non-rebated plate can interfere with it causing movement and eventual screw loosening. Anyway, my solutions works for me. Hope this helps people out there.
Thanks James Lamb for your work and knowledge, gonna try finding some 10mm screws locally. Also, instead of using Loctite 242 I am going to use Vibra-Tite VC-3 or VC-4.
Mine is holding so far. Fingers crossed. The Vibra-Tite should work just fine. Thanks for watching, Jim!
Thanks for the follow-up. I have had to retighten once so far. I will invest in the longer screws with loctite..
Buy the LocTite by the barrel. It’s cheaper. Good luck. Let me know how things go.
something to think about. If your binding then the focuses spindle inst moving right? this presumably means that as far as the software driver goes, the focuses has not moved and is still at its last know position (assuming its using a coding wheel of some sorts). So maybe the fine adjustment clicks your making while the spindle has bound are getting pushed into a cue. When the binding eventual comes free, the cue is played back while the motor tries to play catch-up with the click cue giving the impression of motor runaway?
I’ve thought about that. But I’m only making a 3-step move inward when it locks up. When it “runs away,” it’s moving 2000 steps outward. I sent Celestron a link to the video. We’ll see if there’s any feedback from them.
James Lamb hmm, maybe you could try using the dedicated celestron focuser app for a little while to eliminate APT/Ascom?
That's certainly doable as long as I'm not using an autofocus routine in, say, NINA. I believe the real source of my problem is the focuser working itself loose and that, somehow, "causes" the run-away response. Just guessing. I've never experienced the run-away motion when the focuser attachment was solid. I have used that app before. It seems to make "large" moves. Does it have a mirror flop correction built in? Like, if you command a small inward movement, it moves much farther inward, then outward - like the overshoot backlash compensation method? Not sure. Just seems like it's moving the focuser a lot more than what I ask it to do.
@@Aero19612 Good questions, can't say I have the answers. I'm not sure about mirror flop compensation but it makes sense, according to the manual the motor will always approach focus in a positive direction (Focus knob rotating counter clockwise and primary mirror moving outwards). Its done to improve move to accuracy by eliminating potentially lost index position steps due to backlash. If the desired focus is inward, the focuser moves 500 steps inward past the selected index position before reversing direction to return to the selected position. (Gleaned from the user guide :D ). One other thing, if you remove the focuser and re-install it you MUST re-run the calibration routine.
One day I'll learn to read manuals. That sounds like what it's doing. I know the manual says to re-do calibration if you remove then replace the focuser; however, if the OTA focuser isn't moved and the focus motor isn't moved, then there should be no need to re-calibrate to my way of thinking. I hate their calibration routine. It runs the focuser all the way in and all the back out and then puts the focuser at mid travel. That's a ton of movement for a focuser than barely stay attached to the OTA.
Loctite added and reattached. All seems well but no true darkness for the next few weeks so we’ll have to see. If it doesn’t stay put I’ll try the longer screws. Fingers crossed.
A pre-emptive application of the longer screws is the path to take. Persisting with the shorter screws will lead to the state James is in with flogged out threads.
Crossed fingers is the astrophotographer’s most reliable tool. Good luck, John!
I found that the plastic adapter sleeve that fits over the telescopes focus shaft was too large, when clamped down tight enough to grip shaft, the focus motor would wobble, bind, and become loose causing the focus motor to not work. Once I built up the shaft with tape all is good, no longer screws or lock-tite needed. No more wobble, binding or focus problems. I have not had a problem since.
Thank you very much for the insight, James! I will take a closer look at that interface next time I remove the focuser. I think a more compliant interface may well help the focuser to “find” its axis. In effect, that’s what the loosening screws are doing...with a lot of bad side effects. The tape layer may also increase the effective backlash, but I’ll take that trade-off any day.
Hi James,
Thanks for this video! I was having trouble with my motor focuser for several nights trying to capture Saturn and Jupiter. My focuser wasn't responding and doing the runaway thing too.
I picked up some 4-40 1/2 long (12.7 mm long) machine screws at Rona here in Canada. They went in without any issues so you can go longer than 10 mm. Just thought I'd let you and anyone else know.
I hooked up the focuser, calibrated it and it seems to be working fine now. We'll see tonight when I go after Saturn and Jupiter again.
Thanks,
Alex
Thanks Aleksandar! Very interesting that you also experienced the "run-away" effect too. I replaced my 8 mm screws with 10 mm screws as noted in the video, but it's good to know that 12 mm screws work as well. Is a 4-40 screw "equivalent to an M3x0.5? Good luck with Saturn and Jupiter!
@@Aero19612 Hi James,
I was actually experiencing the "run away" effect for a while but didn't know why. When I removed my focuser the other day to replace the screws I found one of the 3 screws completely loose.
The 4-40 is equivalent to the M3 0.5 pitch. I couldn't find M3 here in Canada but the 4-40 is equivalent. I had no problems screwing them in. The 4-40 1/2 inch (12.7 mm) is the screw length, thread length is 10 mm. I have a picture of the screw box I purchased but don't know if I can add a pic here.
Thanks,
Alex
Exactly!!!!
@@Aero19612 I can't post a picture but here is a link to the screws I bought which seem to fit just fine. Flathead with countersink, main difference is square vs star for screwdriver needed.
Don't let the picture on the website fool you. The picture makes the screws look long, they are only 12.7 mm.
www.rona.ca/en/flat-head-zinc-plated-machine-screws-4-x-1-2-14-box-63868206
HaHa. Yeah, those screws look 4" long. The ones I used are only 10 mm, so it's nice to see that 12.7 mm still works.
I'm running the Celestron Focus Motor on a EdgeHD 11". I too have seen runaways and freezing. In each case I've unplugged the USB cable and that's cleared it, but it's certainly annoying. After having this happen last night I plugged in external power, hoping that will help. In any event, I just check my screws and sure enough they weren't tight.
Very annoying. Does your EdgeHD 11 have the same 3 M3 screws? Thanks for feedback, Ben. Much appreciated!
@@Aero19612 Nope. I didn't measure, but I think they're 20mm long.
Ok. Good info.
They're 30mm long. The trick with the C11S and C14s is to use both the 'old' (orginal ) mounting plateand the plate that came with the motor stacked on top of each other. The screws are long enough to go through both plates. I have done this and all my problems - binding, etc - went away. The two plate solution takes pressure off of the focus bearing which is what causes the binding.
By runaway do you mean the field shifting about as the focuser moves? My Rasa 8 had rock solid stars and now they shift around when I run the focuser. I've taken the focuser off and on a few times, I still haven't found a resolution for it. If you find one please share it! I don't know if the torque of the focuser is enough to shift the screw, but having the axis of the focus motor match the focuser spindle will reduce the 'wiggle' of the focuser and that ReeReeeReeeeReee noise as it runs. When I found alignment errors between the mounting plate and the focuser itself, the focuser spindle wasn't perfectly square against the plate when mounted per Celestron's instructions. I found that locking the focuser spindle to the shaft using the set screw and THEN tightening the mounting screws on the focuser. Maybe shimming the mounting plate until it's perfectly square will help.
No, the “run away” motion I’m referring to is when I command a 3 step inward motion, the focuser “freezes” and doesn’t move, then when I press the stop button, the focuser moves 2000 steps OUT. What resolution number are you looking for? Although your number may be different from mine. Our focuser are the same, of course, but the OTA focuser may be different. Thanks for watching, Michael!
Thanks for the follow-up! I have another one of these motors coming with my RASA 11 V2. I have seen the same issues you have with the screws getting looser over time in my RASA 8 but never bad enough to bind. I have also never seen it run away like that. Perhaps that is because they never have gotten loose enough to bind up. I'll let you know if there is anything new or improved with the one coming this week.
Also, how much backlash does your specific setup have?
Excellent, Charles, thanks! I measured 20 steps for the backlash. Your mileage may vary.
I know this is 3 year old video. What was the conclusion? Was the problem fixed and if it did how did you fix it, please
Yes, this fix seems to have worked. At least I haven't had any problems since this video. Different people are having different problems with this focus motor. My problem seems to be different from most. Celestron requires that you replace the existing bracket with the new one. In my case, one of the threaded holes in the SCT was damaged and could not hold onto a screw. So I replaced the short screws that came with the SCT with longer ones and put LocTite on the threads. All good so far.
Been there, done that. I almost went so far as to abandon the motor and go back to focusing by hand.
@@janeclark1881 Very frustrating. There are various problems that different people have had (see other comments to this vid). Seems that not over tightening the screws is a plus - let’s the motor tilt a bit to accommodate misalignement. Hope you get it working! Took a while, but I finally did. Not the best design.
I'd be asking for a replacement, a RASA 11 should cover it :) I'd consider bonding the adapter plate to the scope to resist the torque especially since the threads in the OTA are damaged. Hi strength Locktite would be removable in the future but epoxy would be superior for a permanent but irreversible solution.
Maybe 3 RASA 11's. HaHa. YES! Exactly what I've been thinking: I would like to bond the aluminum bracket to the aluminum plate in the OTA. Let the screws just deal with the pull-out force and let the shear strength of the bond deal with the lateral forces. Know any good aluminum-to-aluminum bonding agents? Seems like I've had difficulties bonding to aluminum in the past.
@@Aero19612 Sorry bonding to Aluminium is not something I have had great knowledge of and you are quite correct on the bond strength point. However I may have an alternative and less intrusive cunning idea. As you point out the object is to create a high µ between the parts. If we glued two washers back to back from say abrasive paper (wet&dry) and interposed the washer we should get a high µ contact assuming the OTA has a flat mounting face.
In the past you have said tapping oversize is not something you are comfortable with. So as a last ditch hack you could try self tapping screws. Don't cringe just yet, self tappers have the advantage of being coarse in the tread pitch which for Aluminium is a good thing. Down side is there is no going back short of tapping oversize.
Did you contact C before on this issue? Did you get a response? It seems to be a fairly common issue so I am tipping they will assume a denial stance lest they are deluged with repair requests. Other than that you will have to rise to Chuckstar fame to get a freebie :)
can you link to those M3 screws , no one has them in CAD that i know of and i asked a lot of stores,
Make sure the M3x0.5 is the right size as they vary from SCT to SCT. I got mine from Amazon, but they saw they're out of stock now. Try this link:
www.walmart.com/ip/M3x10mm-Stainless-Steel-Hex-Socket-Flat-Head-Countersunk-Bolts-Screw-50pcs/171196985
@@Aero19612 Thanks James... i have a horror story to tell about the used C8 Edge HD800 ... i dont even know how to put it into words ..
lets just say the guys at Celestron tech support are going to freak when they open the box and look it over .
@@BrokenPik Oh dear. That doesn't sound good at all. I've dropped mine and it got soaked in an out-of-nowhere rain storm. But it keeps ticking...At least you feel yours can be fixed. How long will Celestron have it?
@@Aero19612 --- its not clear but my guess is 6 weeks.. that's if they have a full secondary unit including the mirror,,, then there is the corrector offset , focusing unit (less the motor ) which got jammed.. im stopping here. :-( and most likely 800-1200$ US for parts , Bench work and Shipping 2 ways from Canada East coast to West via Fedex,
@@BrokenPik you're getting dangerously close to just buying another one...
Has Celestron offered any assistance w the focuser issues? thnx
I submitted a support ticket yesterday and included a link to this video. I haven't heard back yet, but it's early. We shall see. Not expecting Pegasus Astro-level response. Any response will be appreciated.
Not alone here... is it possible that there are at least three different versions of the V2 orange plate e.g. two in the manual 94155 and one shown here: ruclips.net/video/y8DIrT18WGo/видео.html (0:35). The difference between them seems to be that they are matched to the size of the bearing that's around the focus shaft, to hold it firmly in place.
An "after the install revisit" covered some issues (with some good pointers on careful centring on C9.25 and not being too tight) ruclips.net/video/UEZOYyDZ_Dg/видео.html - Perhaps you could measure the depth of the threads behind the bolts because it needs to be long enough but not longer than necessary?
Compared to your C9.25, I do wonder how this could ever work with the focus locks of an EdgeHD. Limiting the number of focus operations seems counterproductive because you want to expose (and fix) all potential issues in Test (and not at 2am)? Simon
Hey Simon. That plate in the video does look different. It has 6 holes where mine has three. There are only 3 screws, so 6 holes is overkill. My version of the plate fits fine. The problem is we're having to re-use the little screws and it seems like the new orange plate is thicker so you're loosing thread engagement in the OTA part beyond. The longer screws I bought should solve that at least.
You would have to leave the focus locks on the EdgeHD unlocked.
The reason I mentioned cutting down on back and forth focuser movement is to lengthen the time (number of imaging nights) the focuser is attached and operating. It's the back and forth focuser movement that works those screws loose. I do agree that you want to fix problems in the daylight. I just don't know if this problem can be fixed (easily). Thanks for watching and commenting!
Hey James, did you hear back from the Celestron team yet? I sent a ticket for my binding issues this Tuesday and as of yet no response other than the obligatory “a member of our team will be in touch as soon as possible.”. Me thinks they know they have a problem but are waiting on a resolution from the dev team before responding. Of course that’s just speculation 😬 but who knows 🤷🏻♂️
I also submitted my ticket on Tuesday and, no, I have not heard from them except for the automated reply. I agree with you. They know they have a problem but no good solution.
James Lamb Hi James, Thanks for the update. I sent a chaser message and will report back if i get anywhere. In the meantime, i’m going to 3d print a shim which will do two things, centre the focus bearing and keep the focuser from pinching the baring. Ill let you know how it pans out. 👍
Great thanks. Are your screws long enough to account for the shim thickness?
James Lamb Hi James, My screw length is 10mm with a thread length of 8mm. I original used 3 nuts as spacers which were 3mm thick. This left around 2mm of thread to hold the focuser to the OTA which seemed to hold. The shim will be around 2-2.5mm which should give me around an extra mill to grip the OTA. Worse case scenario ill procure some longer screws but i think ill be ok if theres no significant tork on the screws?
As an alternative, you might consider something like this:
www.metricscrews.us/index.php?main_page=product_info&cPath=81_91&products_id=1325&gclid=EAIaIQobChMIgYn-mu2Q6gIVx8DACh2lrg3EEAQYAiABEgJ0dfD_BwE
This would provide some stand-off and tension the screws at the same time. I think you'd definitely want longer screws so you can engage as many threads as possible. I have some concern that I will damage the aluminum threads by having too high of a tension force. Just a thought.
Celestron comes up with some good products, but somehow I feel their engineering gets rushed or something and they neglect the devil in the details. After many years of refinement like with the C-11 it becomes a hall of fame piece of equipment. But I think it takes a lot of user complaint based refinement. It’s like any early adopting customer is an involuntary beta tester.
I think there is a great deal of truth in that statement, James. Thanks for watching!