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More Lhires III mods

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Alun_H's picture
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Last seen: 1 week 6 days ago
Joined: 05/03/2014 - 08:04
More Lhires III mods

 Been busy again tinkering with my Lhires III,this time automating the micrometer arm (grating angle actuator) and the focusing of the collimator lens. For the micrometer I used a JMI motofocus unit off my C9.25 attached to the lhires using two right angle brackets. Drive belt was taken from an old printer,cut a length and used araldite and heat shrink tubing to rejoin the ends. Didn't bother with gears as such,the belt grips the motor shaft and micrometer due to small teeth on belt. Motor is operated either manually with handheld control box,or connects to PC via a Shoestring Astronomy FCUSB box.

 For the focusing of the collimator lens I made a replacement cover so as to mount a Skywatcher focus motor. Cover is locked in place using original screw and is held by metal clip at other end. Using same belt,again cut to desired length and rejoined with glue and heat shrink,just looped over barrel of the collimator lens and over the shaft on motor (wrapped in hook side of velcro) and using enough tension to allow rotation but not too much to cause tilt in lens. Again PC control is via a Hitecastro focus control box.  Both systems work well and along with the automated calibration/flat lamp I don't need to touch the spectroscope at all whilst in operation and also allows me to work remotely when it's too cold :)

      Regards

        Alun

       

       

      

     

Anthony Rodda's picture
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Last seen: 1 day 7 hours ago
Joined: 01/09/2014 - 14:15
Ingenious...

Well done Alun, that's a neat mod. 

Is there much weight added or vibration? 

Regards Tony

Alun_H's picture
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Last seen: 1 week 6 days ago
Joined: 05/03/2014 - 08:04
A little..

Thank you Tony, there is a little bit of weight added,depends on size of motors, and the box to cover the motor is made from foam card so no weight there :)  As far as vibration is concerned I haven't witnessed any as such. I do know there is a very slight shift within the collimating lens when using motor but that can be sorted by adjustment of the original lock screws (found this out after my posting the info above).  I always thought I had focus on neon lines sharp when I set it up manually,but it's surprising how much sharper the lines get when I  can just nudge the rotation,certainly makes a difference.

     Regards  Alun