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MI250 and Maxon Motors

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#1 David Pavlich

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Posted 14 September 2009 - 03:30 PM

I just installed a set of Maxon motors on my MI250. I haven't had an opportunity to do any observing with them, but just running them, there is already an unexpected benefit; the mount is now nearly as quiet as an Orion Atlas. They look pretty cool, too with the finned finish.

Further report once I get a night out with them.

David

#2 skybsd

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Posted 14 September 2009 - 03:33 PM

Hi David,
Good to hear..,

Can you say at this time if there are any chances of where the addition of the Maxons introduce any clearance issues at all, please?

How about a couple of photos?

Congrats :) !

Regards,

skybsd

#3 f29pc

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Posted 14 September 2009 - 04:31 PM

I did the same, there are a few photos on this page of my site
http://www.burkesobs....com/mounts.php

I sent my mount to Larry for all the upgrades. When he had it, he installed my motors. One of the upgrades he does is reposition the Dec. motor to the gearbox. The motor is rotated slightly to increase the clearance in Dec. The Maxon motors are about a 1/2 inch longer than the stock motors, so you will loose some clearance. My mount is quieter with the Maxon's, mostly in RA. My Dec sounds about the same. On a 250 the Dec. and RA. will never sound the same, the enclosures are way different.
Dave, you might recheck the Dec. worm adjustment, if both sound the same, the Dec. probably too loose and will have a lot of backlash.
Paul

#4 David Pavlich

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Posted 14 September 2009 - 08:47 PM

Hey Paul...I didn't really pay attention to whether or not the pitch was different. Quite frankly, I was glad that I was done and wanted to get out of the obs. I sweat about 2 gallons just changing the motors. 86° and really high dew points...and the Sun was out to boot. I'll check that next time I'm out there. Thanks for the heads up.

I called Larry about me changing the motors in the field. He said the only thing that I'd lose is the pointing model....said it's a straight forward swap. He did mention the clearance. Hope he's right. :grin:

David

#5 skybsd

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Posted 15 September 2009 - 04:15 AM

Hi Paul,
Good to hear from you..,

I did the same, there are a few photos on this page of my site
http://www.burkesobs....com/mounts.php


Excellent - thanks for the link..,

I sent my mount to Larry for all the upgrades. When he had it, he installed my motors. One of the upgrades he does is reposition the Dec. motor to the gearbox. The motor is rotated slightly to increase the clearance in Dec. The Maxon motors are about a 1/2 inch longer than the stock motors, so you will loose some clearance. My mount is quieter with the Maxon's, mostly in RA. My Dec sounds about the same. On a 250 the Dec. and RA. will never sound the same, the enclosures are way different.
Dave, you might recheck the Dec. worm adjustment, if both sound the same, the Dec. probably too loose and will have a lot of backlash.
Paul


I guess I can't visualize it properly.., but looking at this shot from your link, I can't imagine how DEC rotation can result in anything hitting the DEC Maxon.

Or did you mean that the DEC Maxon is liable to hit something during a physical RA slew towards the EAST?

Thanks!

Regards,

skybsd

#6 f29pc

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Posted 15 September 2009 - 07:21 AM

The Dec. motor itself isn't much of a problem. If the scope is on the east side LOOKING west at the meridian, the Dec motor has about an inch clearance from the RA assembly. The only way this would be a problem is if you wanted to slew the scope to the east of the meridian with the scope looking west and I don't know of any reason why you would want to do this.

The bigger problem is the Dec. assembly hitting the RA. motor. when the scope is on the west side of the mount looking east, and allowed to track past the meridian. If the safety limits are set properly in the gemini, the mount will stop before this happens. The only thing you will loose by installing Maxon motors is amount of tracking time past the meridian(with the scope looking east, and setting custom safety limits). The default MI 250 safety limits SHOULD be ok with the Maxons, BUT I would check them after the instillation with the handset and make sure the mount stops before any contact.
Hope this helps, if you have any more questions, feel free to PM me.
Paul






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