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Replacement Stepper Synchron Motors for old C8 scopes

Celestron Classic
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#1 tmozdzen

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Posted 19 September 2021 - 12:13 PM

I've got a couple of scopes like this where the motors don't even humm when power is applied.

Any thoughts on new forks to put the optical tubes on?

Or any motors that might replace these?

Many thanks in advance.

Tom

 

Attached Thumbnails

  • C8_small1.jpg
  • C8_small2.jpg


#2 tim53

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Posted 19 September 2021 - 03:14 PM

Make sure they really aren't running before you do anything.  You can see if they're running by viewing through that little "window" in your second pic.  I've had these not turn because they've sat for a long time, and gotten them to run again by removing the cover and giving them a twist by hand.  A little sewing machine oil on the gear shafts internally might also help.

 

You can probably find replacement motors for about $25, last time I checked a few years ago.  Make sure you get the same RPM and spur gear.

 

I've wondered out loud a couple times where it might be possible to find stepper motors that would fit, so one could goto one of these old mounts without radically modifying them.

 

-Tim.



#3 1939Dodge

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Posted 22 September 2021 - 01:25 PM

Try a shot of silicone spray in the sight window.



#4 DAVIDG

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Posted 22 September 2021 - 02:54 PM

 These motors  are pretty tough so the first thing I would check is there isn't a broken connection to the motors or something wrong with the plug, power cord or if the mount has on/off switch is switch good.  It would be  unusual  for both motors in a C8 to be dead. The covers over the armatures with the window come off pretty easily so you can spin the armature and see if the motor starts. 

  The problem with replacing the  motors in a vintage C8 which is not the rpm which is pretty common  but the direction that they turn. 

 

                        - Dave 


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