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.

sgl_imaging_challenge_banner_globular_clusters_winners.thumb.jpg.13b743f39f721323cb5d76f07724c489.jpg

Sign in to follow this  
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
Posted (edited)

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

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.

Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By GavinC
      Hello,
      Does anyone have any experience or knowledge about whether it's possible to mount alternative OTAs with a dovetail or rings to the mount that comes with a Celestron Nexstar 80GT?  In particular I am wondering about attaching a SW Heritage 130P?  I know that Celestron did a 130mm reflecting 'scope on his mount, but it looks to also have that plastic tube clamp, seen on the 80mm image below.
      Thanks,
      Gavin

    • By MarsG76
      Hi All,
      If anyone is looking for a great telescope, I'm selling my NexStar 8SE. It's in great condition, Optics are immaculate and there is only some signs of use on the dovetail bar and the black rim that has faded a bit on one side. The reason that I'm selling is that I'm looking to upgrade.
      I had some amazing views of planets and DSO through this scope.... it really is a performer in quite a compact package.
      This scope was on a CGEM most of it life so the NexStar Alt-Az mount was hardly used.
      I prefer to have this scope local pickup or I'm happy to deliver and even give a tutorial and demonstration of how to use it.. for that reason I'm targeting a buyer around Sydney Australia.
      The price I'm asking is $1650AUD.
       
      Clear Skies.








    • By HenryFitz
      Help me understand how this equatorial mount CGE pro own a price tag of 5000 usd? As a beginner; will it be a smart choice for me? 
    • By Kronos831
      Hey guys,im currently on a school trip and brought my celestron firstscope with, tonight we ll  be trying some dsos and maybe saturn and jupiter,the telescope itself is not collimated and dirty (on the mirrors)So I wanted to ask.in the scope, there is no primary adjustment screws,only the ones to take it off .Does that mean that its set , allowing me to take it off wash it and back on without having to recollimate the primary?
      Thanks
      Kronos
    • By Cosmic Geoff
      I have discovered that the Nexstar+ handset of my CPC800 has a Camera sub-menu, apparently for controlling a camera.  This is not documented in the CPC800 manuals and I could not find any instructions online.  All I found on the Celestron website was a picture of a C8 SE with a camera attached and a cable leading from the camera to the aux port.
      Has anyone used this feature, or have some instructions?  Is it really useful for anything?
×
×
  • Create New...

Important Information

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