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EQ3-2 RA motor arm help

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#1 Montana

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Posted 15 August 2010 - 10:17 AM

Hi,
I have an old Helios (Skywatcher) EQ3-2 mount which I recently bought some motors for to get it tracking. I fitted them following the instructions and last night went out to try it. I spent a long time trying to move the telescope towards Jupiter but it just wasn't moving. I then noticed that the RA arm which is attached to the telescope had snapped. I enclose a photo.

I have 2 questions:
1. Can a replacement be easy to buy or is there anyway I can fix this eg superglue?
2. I really don't understand how you can move the telescope with the motors attached, as I must have broken it by slewing round manually. The motor doesn't turn when not in use and was attached to the arm of the telescope. Therefore when I moved it manually I must have ripped it off. If I moved the scope using the 8x speed from north it would take 4 hours to get to where Jupiter was. What have I done wrong and how do you move the telescope when these motors are attached?

I've probably been really silly and missed the obvious but I really need help, I was so disappointed last night. Hopefully the picture will help you understand what I have done.

Thanks for any help.

Regards
Alexandra

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#2 Andy Taylor

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Posted 15 August 2010 - 11:48 AM

No fix - it's knackered.

There is no clutch between the motor and worm drive so the motor cannot be disengaged without loosening screws - you have to loosen the lock levers to slew the scope. Sorry.

As to a replacement, I've seen these flexible couplings at RS Components but they ain't cheap! Try Maplins - they have solid shaft couplers that may fit.

Maybe a trip to your local model shop? They stock loads of nerdy (useful) stuff...

#3 orlyandico

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Posted 15 August 2010 - 08:33 PM

You can buy 'em on ebay too about $10.

Or go to smallparts.com
http://www.smallpart...f_rd_s=center-3

the flexible coupling is better though (like the original). digi-key and RS only have some.

#4 Montana

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Posted 16 August 2010 - 04:19 AM

Thanks for the bad news folks, I feel such an idiot that I didn't think about it properly. What a bad design though to have to take it apart every time you want to view something different! I guess in the summer it isn't too bad but I can't imaging trying to unpick that little screw without loosing it with numb fingers in winter.

I have had a go at superglueing it but it may just snap again but doesn't hurt to give it a try while I source another. I just need another clear sky at night to test (took 6 weeks to get one the first time!).

Regards
Alexandra

#5 naavis

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Posted 16 August 2010 - 04:48 AM

Thanks for the bad news folks, I feel such an idiot that I didn't think about it properly. What a bad design though to have to take it apart every time you want to view something different!


You don't actually have to take it apart everytime you want to view something different. You can't use the manual RA fine-slewing while the motor is connected, but you can always open the RA axis lock and just turn the telescope by hand.

#6 orlyandico

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Posted 16 August 2010 - 07:53 AM

superglue will not work. order the part from smallparts :-)

i agree, the design is poor. you can loosen the RA lock and push the tube by hand, but you lose fine manual control. What I do is loosen the lock, use a low-power eyepiece, point the tube by moving it, then after locking the RA, using the forward/reverse buttons to center the object.






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