I'm adapting a little skywatcher motor to use with my Baader steeltrack focuser. The Baader motor looks like a great piece of kit, but I can't justify the $1000 price tag. The second photo is of the skywatcher unit, which I have, the others are the Baader which I'm trying to emulate.
My first step is to source a timing belt to run between the focuser and motor, and a small cog wheel to put on the motor. Does anyone have any ideas on the best place to get these items?
I’ve fitted the SW motor to all my solar scopes....six so far.
Miniature Bearings can supply a 6mm bore pulley to suit theSW motor.
I use a thirty tooth pulley and a 100 tooth XML timing belt.
Works very well for me.
Assuming they are not one of the things on perpetual backorder at the moment, have you considered the ZWO EAF? I have been running one of those for nearly a year with zero issues. If I keep imaging with my SCT I will probably make an adapter and fit one to that in place of the Celestron focus motor it has on it now as that lacks a temperature sensor.
Hi Paul, no I haven't thought of the ZWO. I saw the skywatcher and thought it looked good enough for my needs, at a good price and able to be software controlled if need be. Temperature sensing isn't something I need to worry about at this stage. The ZWO stuff seems to be pretty solid though, so maybe down the track I'll go that way.
It's also good to have a lockdown project...
My lockdown project has been building a motorised drive for my crayford focuser. Cost me about $50 in parts and quite a few hours labour, it's finished now but it would have been easier and not much more expensive buying a SW one. It was fun to build though, it works on pulleys. Most of the stuff I got at Jaycar.
I'm at a bit of a loss when it comes to these types of parts. Can anyone help me identify the pitch of this belt? It's the one used in the Baader drive, and fits my focuser. I think I can count 68 teeth.
Stephen,
Measure the distance from peak to peak of the teeth - this will give you the pitch. This, and the width of the belt should allow you to find a suitable XML type timing belt equivalent.
Thanks Ken. I've got the following measurements from the focus cog:
diameter = 33.5mm
36 teeth
width of teeth (belt width) = 6mm
gap from centre of tooth to centre of adjacent tooth = 2.8mm (approx, as close as I can tell)
Stephen,
I'd send the image of the pulley to the guys at Miniature Bearings, they've been very helpful to me in the past.
They could probably identify to type of belt....
The 36 teeth is halfway down page. Looks like May be in stock too.
Link is for the 6mm wide htd 3mm pitch.
There is a seperate pages for wider 3mm pitch belts.
Steve
A word of caution, going by the photo of the pulley, that is not a standard timing belt profile, which is a truncated "V" shape, as in XML belts.
The rounded teeth of the pulley ( and belt ) shown in the photo is an SP profile. Still a standard engineering drive belt profile though and commonly available. Does the belt that you have in the photo, have any other numbers printed on it other than shown . From your measurements of diameter and teeth number I get a pitch of 2.92mm, most likely 3.00mm, a standard pitch.
I've placed an order, the only potential issue is the narrower bore of the pulley. The only option with 16 teeth, which is my estimate of the Baader version, has a bore of 4.8mm. The skywatcher motor shaft is 6mm, but has a couple of adapters that I might be able to work with. There is a round socket in the end with a diameter of 4mm, plus a grub screw, so hopefully I can cut someting down to fit.
At any rate, this is a big step forward, thanks for the help.