Manufacturer of degree circles for my dob.

[Doc]

Good idea I'll look into that. Paper needs to be 800mm minimum as I don't want to do this is sections for accuracy needs.

[irishbloke]

Thanks for this....

The problem with having a design like this is that you have to get your ground board exactly North as you only have a little window to view the scale with and no way of adjustment unless the scale can be moved and locked down.

Mick what about if there was some sort of magnetic thing that allowed you to turn it. Weareborg's link had the disc with a tab that might have stuck out a bit. With the disc snugbetween the washers you mite be able to twist the ring round to the right az making aligning a bit easier.

Brian

[Doc]

What I have in mind is the degree circle secured to the ground board. Then a cut out in the base board with a magnetic sliding needle so I can adjust for any deviation in pointing north.

[Doc]

Just an update...

What I have done is got the degree circle printed out for £2.57 then cut out a 795mm circle out of 3mm plywood which cost me £1.50.

I then glued the circle to the plywood and got some sticky back plastic, 3 metres for £5.00. I cut it to the approx size, pealed the backing off and stuck this on both sides of the degree circle.

I then trimmed off the access leaving approx 5mm that is sealed on the outside of the circle.

This fits perfectly on the dob ground board.

So it's waterproof and it only cost me £9.07.

Just got to build up the courage to cut the upper board now

Will post pics in a new thread once it's all done.

[Reggie]

have you guys tried a sign/banner makers? surely they must be able to print something A0 thats waterproof and print to it too? Probably not as cheap as £9 though unless its an offcut....

[Doc]

have you guys tried a sign/banner makers? surely they must be able to print something A0 thats waterproof and print to it too? Probably not as cheap as £9 though unless its an offcut....

I did try a sign maker and for him to cut it out of i think it was 5mm acrylic and then engrave the circle onto it was £85 + vat.

[albedo0.39]

Mick - I'm going to do the same, but in my case, I'll take the pre-printed version from the Yahoo Lightbridge group page and then print on A0.

I'll then glue it to the base board and then paint over in either gloss or clear laquer. That way the damp cannot get in and of course, it will dry clear.

[Doc]

Mick - I'm going to do the same, but in my case, I'll take the pre-printed version from the Yahoo Lightbridge group page and then print on A0.

I'll then glue it to the base board and then paint over in either gloss or clear laquer. That way the damp cannot get in and of course, it will dry clear.

Sounds very good indeed look forward to seeing it.

My finished one is here:

http://stargazerslounge.com/diy-astronomer/79817-my-dob-degree-circle-modification.html

[mike-h]

I made myt own setting circles for my 250px with card and sellotape. Iplan to put some pictures up this week.

Mike-h

[Doc]

can't wait to see them Mike.

Just to add I've used my new degree circle 3 times now and each time they have worked a treat. I would say they have an accuracy of 1/4 of a degree and 95% of the time the object is in the FOV of a widefield eyepiece.

[mike-h]

After reading this thread I decided to make my own setting circles for my 250 px dob.

I took a different approach and used a cereal box and sellotape (and a calculator and ruler). I did it yesterday and it took about 90 minutes. It works amazingly well - it tranformed how I spent my viewing time last nite. Combined with the wixey I can find objects very quickly. I plan to put some fotos in the DIY section later to see what people think.

Mike H

[morrmorr]

http://www.blocklayer.com/protractor-printeng.aspx dont know if this will help anyone

[Kropster]

I printed mine on glossy A4 photo paper and then used a photo mount spray adhesive to stick them to the base board.

Small cut out in the rotating part of the base with a red paperclip stuck to a magnet on a metal strip as the pointer.

So cheap, I can just replace the scale if it gets damaged.