Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

NenoVento

Altitude motor not working

Recommended Posts

Hi all,

 

After updating my legacy HC to the 99.22 (I had to, because of the GPS rollover issue) and the MC to the 5.23 firmwares (siply because it was there, and I've got greedy), both acquired via Teamcelestron, my CPC was operating normally until, all of the sudden, its altitude motor stopped working. I've uploaded a video at youtube showing what happens:

 

https://youtu.be/p2cHJkPt9Vc

 

As you can see, I don't get any error message in my HC but, if I try to move the scope in altitude, nothing happens (no movement, no motor noises, nothing). When I release the clutch and move the scope manually in altitude, it does move but has a weird noise by the same place where previously it used to make a snap one, which I already reported to celestron tech support once, and even made a video that I also uploaded to youtube:

 

https://youtu.be/KCc69eUSbeY

 

I've already seeked help from Celestron Tech support (and the folks at Cloudy Nights) but any help from you would be very much appreciated. Best regards,

 

NV

Share this post


Link to post
Share on other sites

This is a CPC800? I own one.

I have no idea what the problem is. Maybe take the covers off and have a look. Or arrange to get it serviced? You are sure it is not a bad button on the handset?

Share this post


Link to post
Share on other sites

Hi Cosmic Geoff. Yes, it is a CPC 800 GPS (the 50th annyversary carbon fiber one). This is pretty much what Derik (the firm engineer at TeamCelestron) told me to look at but, before start dissasembling, I was hopping that someone around here could recognise its symptoms and provide me with directions... One can always wish...

And no, getting it serviced is not an option, considering where I'm living at :-(.

Regards,

NV

Share this post


Link to post
Share on other sites

If you look on the Cloudynights forum you should find some dismantling hints for the CPC800.  At the back of my mind is something about rotary encoders with glass discs ? so check that and take care.

Share this post


Link to post
Share on other sites

Hi all, me again...

 

I've opened the mount and retigtened all the connections with no improvement on the situation. Then I decided to switch the dot connector with the square connector (see the last picture in the set below) and, after switching on the scope, the up/down buttons in the hand control moved the scope in azimuth, instead of altitude, while the left/right buttons did nothing. 

57441221_WhatsAppImage2019-05-04at18_07_27.thumb.jpeg.83c8a6501c9223da1eb59f8c362c1cc6.jpeg

A picture of the scope with the arm without the cover.

1679016839_WhatsAppImage2019-05-04at18_08_11.thumb.jpeg.dfd7193575a4ac731bea18480c272b89.jpeg
A picture of the board that is placed in the arm.

1822824317_WhatsAppImage2019-05-04at18_09_04.thumb.jpeg.c7d1ec847b1853e397124198d144eb15.jpeg
A closeup of the connectors which I switched positions.

 

I'll ask a colleague at work to look at the boards, just in case any component has been damaged but, as far as I can see, everything looks fine, even the altitude motor...

 

NV

 

Share this post


Link to post
Share on other sites

I have just read your post and tried to follow what you have done and it seems to me that swapping the connectors has eliminated the hand set and the board. Switching the drive output over tested the buttons and the driver so my guess is that is that you have a motor problem.

Looking at the wiring going to the motor it looks like a DC motor (the two wires on their own and the multi connector a positional encoder. If you have a multimeter then I would disconnect the two wires either side of the motor and check for continuity across the motor connections and see if its open circuit.

It might just be a stuck brush so a sharp tap on the side of the motor might unstick it.......you never know you might be lucky.

Best I can suggest

Edited by Tomatobro
uodate
  • Like 1

Share this post


Link to post
Share on other sites

Yes, as Tomatobro said, your connector swap indicates the problem is with the Dec motor or the cable connecting it to the board. Check that the individual pins on the Dec motor connector are fully pushed into the socket housing.

Alan

  • Like 1

Share this post


Link to post
Share on other sites

Thanks Tomatobro and symmetal, yes my thoughs also, the motor seems dead (which could also explain why lately, when I was using the scope with the wedge and there was more strain on the motors, the objects slowly drifted away in the FOV). Pity I don't have a multimeter here (this is one of those things I've always meant to buy but I never had), I'll try to get hold of one as soon as possible but, by looking at the motor and its two cables, I don't see how to unplug them without damaging them. Should I simply pull them out?.

Regards,

NV 

Share this post


Link to post
Share on other sites

The two wires going to the motor body look as if they are soldered to tags on the motor and coverered with heatshrink so no they won't pull off. The wires going to the connector at the end of the motor look like low profile plug and socket which should pull apart. Apply a little leverage to one end with a small screwdriver to see if it moves and then apply a little leverage to the other end. Don't pull on the wires themselves with any significant force as you may just end up pulling the wires off. As you say a multimeter is a very useful tool in this situation. Good luck. :smile:

Alan

  • Like 1

Share this post


Link to post
Share on other sites

Or simply put the tester's probes (if they are thin enough) in their corresponding socket in the bus of cables at the other end (where it connects with the board).

By looking at how Celestron sells this componnent, it seems like you have to buy the whole thing. How to install it is yet another story because I don't see an easy access to one of the screws... Ah well, I'll cross that bridge when (if) I get there.

https://www.celestron.com/products/motor-azmra-for-cpc-series-telescopes

Thanks a million Alan (symmetal) 

Share this post


Link to post
Share on other sites

If the probes aren't thin enough just wrap a bit of wire round the probe tips and poke the wire into the connector. If it's still powered make sure you don't short anything out. :wink2:

A motor that has burned out due to over stressing it will usually have a distinctive smell which will linger for days after. If your dec motor doesn't smell 'odd' it may be OK though that doesn't rule out a wire connection failing internally.

Hope the replacement if needed isn't too expensive.

Alan

  • Thanks 1

Share this post


Link to post
Share on other sites

I've got hold of a multimeter and found out that there is no continuity across the motor connections, so it looks like I have an open circuit issue in the motor (which, by the way, doesn't smell burnt). I think it is time to dissasemble it to try to find out what is wrong inside or to order a spare motor from Celestron.

Share this post


Link to post
Share on other sites

Good that you've narrowed it down to the motor. If you're able to disassemble it it's worth having a look inside. :smile:

Alan

  • Thanks 1

Share this post


Link to post
Share on other sites

A small DC motor might have permanent magnets for the field and a commutator to feed the rotor. The likely failure area is then the commutator & brushes.  Given the modest volume of CPC scopes manufactured, I doubt that the motor will be unique to Celestron.  You might try giving the motor a twirl and a squirt of cleaner/ lublricant (sold as "3 in 1" over here.) 

  • Like 1

Share this post


Link to post
Share on other sites

Thanks symmetal and Cosmic Geoff. Derik (at TeamCelestron) told me that my multimeter test confirms that I either have a problem with the alt motor or in the wires leading to the alt motor. Also he informed me that the motors don't usually fail open. They fail in a short. So since I don't have continuity he would guess a bad connector is the issue. However, Celestron sells the motor and the cable attaching it to the PCB as an assembly, so I've already asked for a replacement unit from the local dealer.

NV

  • Like 1

Share this post


Link to post
Share on other sites

Hi all,

Finally I received the motor and, before I did the replacement I conected it to the board in order to test it and, yes, as you can see in de video below, it did work (hurra!):

https://youtu.be/rmx6skIi_1c

However, after installing it, I noticed some oscillation in the entire motor set, as you can see in the video below:

https://youtu.be/m94rUzcQaBU

Since I never saw it working before its failure, I don't know whether such oscillating movement is normal or not. Can you please help me out with this?.

Silly me, I've justo noticed that I had my phone's camera capturing video in slow motion so it is hard to noticed the oscillating movement. Ah well, I've uploaded yet another video at normal speed below:

https://youtu.be/1MV6Dd9u9O0

Hopefully this one is more clear :-).

Best regards,

NV

Edited by NenoVento

Share this post


Link to post
Share on other sites

The oscillations may be due to the grubscrews in the coupler not being aligned and tightened correctly.

Make sure that one of the pair is properly aligned with the flat on the motor unit output shaft and fully tighten this one first, then tighten the second one.

It is possible you have tightened the second one fully which would cause the shaft to tilt in the coupler.

Hope this helps.

 

  • Thanks 1

Share this post


Link to post
Share on other sites

Thanks @Lonestar70 but this is exactly what I did. Anyway, I uninstalled it and looked at the flat part and it did have the mark of the screw, so I did place it properly... Then I reminded that the azimuth motor was exactly the same and decided to take a look at it and, yes, as you can see below, it also oscillates:

Therefore either they are both misinstalled or that is the way they are ment to operate. Hopefully tomorrow (or rather later today) I'll get a chance to try it out properly.

Best regards,

NV

Edited by NenoVento
Typos

Share this post


Link to post
Share on other sites

Hi NV,

Glad to see it's all working again with the new motor. The movement looks like it's normal behaviour given the way the motor unit is attached. You could loosen the three screws holding the motor unit to the scope and see if there is some play in allowing it to move sideways. You may find a position where the oscillation is minimised. Very thin spacers under one or two of the screws would probably help too. As the oscillation is at a low speed it's not causing much harm so whether you want to try is up to you. :smile:

Alan

  • Thanks 1

Share this post


Link to post
Share on other sites

Thanks @symmetal, I think I'm going to see how it behaves by trying gotos and doing tracking before. If it does work properly (fingers cross), I'll let it be as it is now.

By the way, from the three screw sockets only two are actually in use (by its corresponding screw, I mean). The third is not needed because the motor is fixed to a kind of holder which is the one that lets room enough for the oscillations to hapen without afecting much to the shaft. Pretty simple but well thought of engineering, I think.

NV

  • Like 1

Share this post


Link to post
Share on other sites

Hi all,

 

This is the final chapter of this story which, as you can see below, had a good end 🤩 :

Saturno3mDeRotL_2019-08-10-0002_7-2019_08_10_01_01_10-DeRot_g6_ap292_convRegFW.png.0f267a4f25330acb70bc3fb48445fc08.png
I took this picture of Saturn last night from my terrace (by the seaside, with a lot of dew coming from the sea and leving the corrector plate pretty dirty) and it was such a pleasure to have my CPC not only back to life, but operating way better than it did before . The target stayed centered and practically unmoving for minutes and minutes, without having to manually recenter it!... Such a pleasure.

Now the technnical details for the picture (in case you were interested):

The gear:

  • 50th Anniversary Celestron CPC 800 GPS XLT
  • GSO 2.5 Barlow Lens
  • Risingcam GPCMOSS02000KMA
  • ZWO Luminance filter (I also took RGB videos but I haven't had time for processing them yet)

The software:

  1. ToupSky (I took 3 minutes @ 46.69 gain and 15 ms)
  2. Autostakkert
  3. Registax (slight touch with wavelets)
  4. WinJUPOS (for derotating the video, then back to step 2.)
  5. The Gimp (color curve adjustment)

Regards,

 

NV

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By Tugboat
      I'm having a bit of a clearout to make way for a new project.  For sale here are a couple of items that have seen very litle use:
      1) Celestron Omni CG-4 GEM Mount + Tripod - £125 *** SOLD ***
      This is in generally very good condition.  There are a few marks, and scuffs consistent with normal use.  There are also a couple of minor (small) patches of surface rust on a few of the bolts and steel legs.  It has seen very litle use, and has been in storage for the past few years so it is time to find it a good home.  The small rubber tips that go on the very end of the feet have perished, so these won't be included.
      It includes tubular steel tripod, 2 counterweights, built in polar scope, built in bubble level and slow motion controls.
      Due to size and weight, collection would be preferred from the RG27 area.  If you are reasonably local, I would also consider delivering.
      Price: £125, but I am open to offers.  Payment can be made via Bank Transfer (preferred), Paypal or cash on collection
      2) ***SOLD*** Celestron Omni XLT 127mm Telescope ***SOLD ***
      Again this is in very good condition, and has been in storage for the past few years and has had very little overall use.  A few marks on the dovetail as is to be expected.
      It includes a small finderscope, diagonal and a 25mm eyepiece
      Can be collected from the RG27 area, I could deliver if you are reasonably local, or can be posted for an additional £8.
      Price: £110, but am open to offers.  Payment can be made via Bank Transfer (preferred), Paypal or cash on collection *** NOW SOLD ***
      Any questions please do let me know.










    • By Gregely
      Hi SGL
      I popped this topic on CN too but noone seems to know anything.

      I came by an old Celestron Ultima 8 pre-PEC. I really like the scope and the mount it may be that I have read too much of Uncle Rod's and other's praise that I feel this scope has some intangible personality and charm.
      Anyway...
      Circuitry in the base seems to work fine even though the batteries don't hold charge but drive the Ra axis . I have 2 replacement on its way to me.
      Now my issue: It didn't come with a hand controller. I know it is not needed for tracking, and I don't have a Dec motor but I find it would be useful for centering in RA and D.A.R.V. method drift alignment.
      I was on the verge of making a crude controller out of veroboard and 4 momentary switches that I thought to be correct from the info on various sites, but then I came across an Ultima 8 project that clearly showed the hand controller for my scope.
      The pic attached is the one.
       
      I am looking for help on how the dial and buttons are wired in and/or photos of the innards of the hand controller or if anyone knows what else is inside the handbox.
      The sources I was going on so far is a combination of the following 3 links:
      https://www.cloudyni...ding/?p=8015749
      https://onstep.group...in/message/6300
      https://github.com/garlick/ultima8/blob/master/base/README.md
       
      These of course don't include drive rate rotary switch in the middle and if I could I would really like to to restore the full ability of this mount without spending too much  on electronics. Plus I don't want to spend time and effort on wiring something that doesn't work.
       
      Oh and lastly I have no background  or experience in electronics just own a soldering station and a whole lot of determination.
       
      Thanks in advance
      Greg

    • By Dodger3k
      Hi all, looking for some help please! 🙏 I have a wedge for my 8SE and when using EQ North to align it, it says it is slewing to Vega but ends up all the way over at Polaris!?  Any ideas? 🤞🏻 Thanks in advance! 😊
       
      I have updated the firmware, Mount is pointing at north, have inputted my latitude and longitude, I have tried picking the nearest city too and nothing seems to work! 😟
    • By willcastle
      Has anyone used the celestron lithium powertank (the small one, not the pro version) with a skywatcher HEQ5?
      It looks like it should be perfect but that is coming from someone who is relatively clueless
      From the skywatcher specs, it looks like the mount needs 2 amps of current, and the powertank supplies 3, so that should be good?
      It also looks like the power cable is a double-ended tip-positive 2.1 mm plug, so i assume that even though it doesn't have one of those 12V car battery inputs, it shouldn't matter right?
      (just to save people some time, i'm not going to bother with a lead battery / leisure battery / jump-start pack / etc)
    • By stevebb
      Celestron C8 XLT + extras and SkyWatcher Star Travel 80 (ST80)
      I have a Celestron C8 with XLT Starbrite coatings. Will include the full length base plate, both visual and imaging backs, scope rings, front 8" end cap and the finder scope with it. No box I'm afraid. Optics are good and clean, focal length is huge - 2300mm from memory. This lot would cost close to £1300 new and one with less spec went for £750 on fleabay recently. Might be interested in a part exchange or will let it go for £450 collection only.
      Also, I have a SkyWatcher Star Traveler 80 - good optics, used as a guide scope - just the scope itself (does not include the barlow in the photo) - now including dovetail bar and scope rings looking at around £50 for it.
      I have decided to save up for another refractor, WO, Equinox or even toward an Esprit. However, I would also consider p/ex for an Intel NUC and/or Pegasus Astro Pocket Powerbox.
      Please excuse some of the colours - I used my astro modded 6D which was in the observatory so the "nice" purple is actually black !!
      Both these are collection only.




×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.