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Old 20-06-2012, 10:35 PM
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Nico13 (Ken)
Galaxy Hunting

Nico13 is offline
 
Join Date: Jul 2009
Location: Geelong region.
Posts: 947
New Stepper control for Focuser

Hi All,
Had an idea the other day when I came upon these steppers with control boards but wasn't 100% sure of the connections so with a bit of advice fron Bojan I hooked it up and away it went.

The aim is to build a Focus control to fit to the crayford for fine adjustment without bumping the scope.
As I'm still using an SLR for imaging this is a problem when trying to achieve good focus even with live view.

So this will when fitted allow very precise control, as with the encoder I used to control it (a volume encoder from a car radio) this is the type that just keeps going around when turned with no stops, it has 40:1 reduction because the gearbox in the stepper is a 60:1 for a start.

The result is plenty of torque. precise control, running at 5V with a holding current of 0.25A running of 0.2A

All I have to do now build a nice neat version of it and fit it up, still need to come up with a clutch or something for the drive as yet.

Here is a short Video to show control movement.
Attached Thumbnails
Click for full-size image (geared stepper.jpg)
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Click for full-size image (step2.JPG)
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Click for full-size image (step3.JPG)
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Click for full-size image (step1.JPG)
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