I adapted a DC powered (cable hand controller CR2) old Moonlite CR3 focus unit to my small Megrez refractor (yes, they were made for Newtonian telescopes but only the adapter changes of which I designed and made one). The problem was a grinding noise, on separating the motor and gearbox and cleaning old grease from the gears and putting new high quality grease the grind was still there. I checked the motor on it's own and that is the problem.
Where would I obtain a suitable replacement motor?
I know AliExpress have a huge range of 12 volt motors with gearboxes but I can't find anything based on the numbers on the original motor.
The motor doesn't appear to have a bearing as such, just a nylon washer the non driven end spins on.
The motor has numbers on the case but I can't find information based on the numbers:
RA200275-505K1R
DC12 V 20120523
Usually these motors have specs embedded in the numbering but I can't find any information.
I have contacted Moonlite in the U.S.A. and the gentleman suggested if I sent a photo and details he's sure they have a variety of stepper motors which will fit. That's no good, then I have to rig up a different controller. Hopefully he can provide specifications on the original unit and I can maybe match it up somewhere. The unit has the most amazing gearbox which has me baffled as to why the little motor didn't have a bearing of any type.
EDIT: I can't praise Moolite enough, I've had a couple of emails from a gentleman and while he's suggested several stepper motors will fit it means I have to buy or design and build my own driver circuit, I can but I don't want to. The same gentleman mentioned they were long superseded to switch from direct DC motors to stepper motors he also mentioned he'd have a look around the workshop and could have a spare motor or 2 laying around. That would be so simple and I'm beyond impressed, even if they can't find one.
I contacted Ron at Moonlite directly and these motors are long out of use but Ron said he'd have a look around to see if he still had a few new DC motors (and gearbox) laying around. He's gotten back to me with an email this morning confirming having a couple and offering one to me at his initial purchase price plus shipping.
I can't express how much praise and respect I have for the gentleman even going to the bother of looking for an older DC focuser motor which have long been superseded.
Ron certainly is a good guy in my books and I appreciate that he took the time to look for me for such an old discontinued item, more than I can express here.
Of course I'd love a stepper motor unit but they are far from my financial capabilities at this stage but the little DC thing I have is great or will be when I receive the new motor and gearbox.
It's damaged through my stupidity, it as a clutch system but I didn't at first realise I had to loosen a knob to activate the cluthc, I know now and it should last my lifetime with general use on my little 80mm Megrez semi APO (first model).
