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Rotary angle encoder for a dob

irishbloke

By irishbloke
in DIY Astronomer

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Doc

Doc

Posted
Posted

Hello Brian.

I had one until my son tripped over the wire while I was refitting it and pulled the wires out. Still trying to find out in what order the wires are soldered to the board. Have e-mailed supplier but now waiting.

When it was working it was very accurate I would say down to 1/4 degree. This for the Az motion and a Wixey for the Alt motion made a very good set up.

Fitting it can be a bit of a pain but what I did was replace the Az bolt with a Allen key type bolt. I then drilled a 6mm hole into the end where the allen key goes about 5mm deep. Then I tapped a 4mm hole and thread for a grub screw through the side of the bolt head.

So the encoder shaft fits into the 6mm hole and is held in place by the grub screw.

I then bolted the encoder to the base board.

So now the az bolt is tight and does not move but the base board rotates and turns the shaft.

I know it's cheeky but if you get one just slip the cover off and tell me what order the 5 coloured wires connect to board.

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irishbloke

irishbloke

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Doc that wouldn't be a problem, I'm just not quite sure if I'm going to take the plunge. The pro and cons of going "push to", would it make me lazier in learning the sky? I am not long at this so know I need to learn my way around the sky. Would I become reliant on the az alt codes rather than using the stars. I suppose I could use the az alt info to confirm what I'm looking at.

Brian

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Chris Stacey

Chris Stacey

Posted
Posted
Hello Brian.

I had one until my son tripped over the wire while I was refitting it and pulled the wires out. Still trying to find out in what order the wires are soldered to the board. Have e-mailed supplier but now waiting.

When it was working it was very accurate I would say down to 1/4 degree. This for the Az motion and a Wixey for the Alt motion made a very good set up.

Fitting it can be a bit of a pain but what I did was replace the Az bolt with a Allen key type bolt. I then drilled a 6mm hole into the end where the allen key goes about 5mm deep. Then I tapped a 4mm hole and thread for a grub screw through the side of the bolt head.

So the encoder shaft fits into the 6mm hole and is held in place by the grub screw.

I then bolted the encoder to the base board.

So now the az bolt is tight and does not move but the base board rotates and turns the shaft.

I know it's cheeky but if you get one just slip the cover off and tell me what order the 5 coloured wires connect to board.

I've never seen these rotary angle encoders close up. This is a different unit so won't be much use but are the wires on yours the same colour?

D528.jpg

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maksutov

maksutov

Posted
Posted

Hi Doc

I have just ordered one online, and I will have a look inside if it isn't to difficult to open up. Then I will let you know the wire colours.

This is my first post by the way, I have been lurking/watching for some time, and find it a great forum.

Bob White

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Doc

Doc

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Bob no need to take yours apart I have received a photo from the supplier.

I've got a soldering iron from work and am going to attempt it myself.

lol how hard can it be.....

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Doc

Doc

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I thought of the degree circle as well but then saw the above encoder and thought I would try that.

In theory the degree circle should be as accurate as you are able to print it. But I think 1/4 degree is about the best you will get. which is damn good.

The wixey works great as long as the OTA is levelled before being zero'd.

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  • 2 weeks later...
svdr

svdr

Posted
Posted

Hi Doc,

I'm new here; I like what you did with that encoder on your dob and I likely will order one , too.

However, one thing that I'm not sure about : does the shaft rotate 0 to 360° (start and fixed end point), or can it rotate continuously? Can you zero it at random position? I'd like to setup the scope, find polaris and set it to zero.

From what I saw in the PDF manual, it looks ike it has fixed start and end points.

Thanks!

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Doc

Doc

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Hi Doc,

I'm new here; I like what you did with that encoder on your dob and I likely will order one , too.

However, one thing that I'm not sure about : does the shaft rotate 0 to 360° (start and fixed end point), or can it rotate continuously? Can you zero it at random position? I'd like to setup the scope, find polaris and set it to zero.

From what I saw in the PDF manual, it looks ike it has fixed start and end points.

Thanks!

It will record 0 to 360 degrees then if you push past 360 degrees it starts recording at zero again. There's no mechanical end point.

You can zero at any position and you describe exactly what I do.

Find polaris and set to Zero then move scope to required AZ setting and accuracy is within 1/4 of a degree.

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Doc

Doc

Posted
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Repair went well. Very fiddly those wires are really tiny. Only problem was the wires were also broke by the plug so had to shorten an all ready short flex so will have to reposition it.

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  • 3 years later...

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