diy 200p dob base

[scogyrd]

I've spent the last 2 days building a new dob base for my 200p and thought I'd post some pic's in case anybody else was thinking of doing the same.

I've not had the chance to try it at night yet but I would say that it's a vast improvement over the original mount. Mainly because it's got a smaller footprint, it's about half the weight and it glides smoothly and effortlessly in both axis.

It's made out of 18mm plywood and I've used a 300mm lazy susan for the azimuth bearing and teflon for the alt bearings. The total cost was just over £50. £15 for the bearing, £35 for the wood (this included having it into squares and I still have half a sheet left) and about £3 for the teflon off ebay.

It's not quite finished yet though. I'm going to paint it white, replace the retaining arms with teflon, fit the ep holder and handle from the skywatcher mount and cut some holes in the front and sides to reduce the weight a bit more.

And here's a zip file with the google sketchup plans I based it on inside.

[swamp thing]

Looking good. Always good to build ya own stuff.

Let us know how she works on the sky.

ps. Don't cut the dog out next time. Wanna see him/her

Regards Steve

[Moonshane]

Superb job mate. I am about to do this myself and will be looking back at this thread.

When you paint the base, earn some brownie points and paint that door too

[UTMonkey]

Very nice

[Rob]

Thats just the job.. nice one

[scogyrd]

Superb job mate. I am about to do this myself and will be looking back at this thread.

When you paint the base, earn some brownie points and paint that door too

I would paint the door but I fear the extra weight would be too much and it'd fall to pieces.

If you have any questions when you make yours just ask here, or start your own thread, and I'll try to help.

Looking good. Always good to build ya own stuff.

Let us know how she works on the sky.

ps. Don't cut the dog out next time. Wanna see him/her

Regards Steve

I will update this thread when I've tested it at night, and once it's been painted.

I'll try getting a picture of the dog as well, but it's hard because he doesn't sit still for more than 2 seconds.

[scogyrd]

I managed to take it out last night for half an hour and my first impressions are that it's very good. It still needs tweaking a bit, mainly the azimuth needs a bit more friction, but other than that I'm more than impressed with it.

[swamp thing]

That's good to hear.

You have a nice long weekend to get some coats of paint on her.

If it stays warm, it should dry enough each night to give it some more shake down sessions.

Clear skies

Regards Steve

[Dob]

Do you have problems with altitude friction?

I have problems with alt friction on my GSO Dob 200.

It has springs but if i tilt him too much he starts to "fall".

Are you cosidering adding springs to alt bearings to improve friction?

[scogyrd]

Because it's on teflon it does "fall" if it's not counterbalanced properly, hence the magnet on the tube, but I don't really think that's a problem because I used to use a weight to counterbalance it before.

I would like to see how it performs in the wind though. If it's too slippy then I'll either change the teflon for acrylic or add a piece of wood so I can fit the tension control handles, or possibly both, but for now I think I'll leave it as is. I hadn't considered fitting springs because, if I'm honest, I wouldn't know where to fit them.

Basically I just want it to stay put when I let go, and for it to take no more effort to move in alt as it does in az. If I can do that I'll be happy with it.

[scogyrd]

I ordered an ebony star ring for the base and some strips to go round the scopes alt bearings the other day, mainly to see how the es compares to the lazy susan, but I now think it'll be far too slippy with the es fitted on the alt bearing and I think I may have wasted my money... so I'll post the results on here once I've tried them out.

[scogyrd]

The teflon for the retaining arms and the ebony star arrived earlier and my first impressions are -

The teflon for the retaining arms isn't really needed because it hasn't made much difference to the smoothness, so wood is just as good imo. Although, if I'm honest, I'm not sure either of them are really needed because the scope doesn't move much from left to right and the the way the bearings are shaped means the scope can't fall out either.

I've decided not to fit the ebony star to the alt bearings because I don't think it's needed. I think it's smooth enough as is.

I have decided to ditch my lazy susan for the ebony star ring though. I wouldn't say it's a vast improvement on the LS, in fact I would probably say the LS is better because you have more scope for tweaking it and getting the friction exactly how you want it, it's just that now I've bought the ES I think it'll be a waste not to use it... I've only stuck the ES down with duck tape atm, just to see what it was like, so it might be better once it's glued down properly.

[scogyrd]

Just a quick update to show what I've been doing.

I cut rectangles out the side so I can still fit the ep holder to it. I don't think I need the handle any more though, it's easy enough to carry as is.

It's a lot lighter now too.

[Gina]

Nice doggy The woodwork's not bad either

[wiseman]

Hi chaps. Looking for my first scope "dob on a budget"

I have seen this for sale, any ideas how I could make a similar mount for it, It doesnt seem to have the same side "bits" to balance on the mount?

U.K. Astronomy Buy & Sell

TA

wise

[GazK]

Hi chaps. Looking for my first scope "dob on a budget"

I have seen this for sale, any ideas how I could make a similar mount for it, It deosnt seem to have the same side "bits" to balance on the mount?

U.K. Astronomy Buy & Sell

TA

wise

Its been mounted on an equatorial mount, which is why it has the two mounting rings joined by a dovetail plate. No reason you couldn't remove them and fit some sort of dob bearing - plenty of people have done it before and you will find examples all over the internet.

[scogyrd]

Nice doggy

Thank you.

The woodwork's not bad either

You've not seen it close up.

[scogyrd]

Hi chaps. Looking for my first scope "dob on a budget"

I have seen this for sale, any ideas how I could make a similar mount for it, It doesnt seem to have the same side "bits" to balance on the mount?

U.K. Astronomy Buy & Sell

TA

wise

I found these pages useful when designing my mount.

Stellafane: Build a Dobsonian Telescope

Plans for a Dobsonian telescope

The mounts aren't hard to make, if I can do them anyone can.

[scogyrd]

Its been mounted on an equatorial mount, which is why it has the two mounting rings joined by a dovetail plate. No reason you couldn't remove them and fit some sort of dob bearing - plenty of people have done it before and you will find examples all over the internet.

I'd try attaching some plywood bearings to the tube rings before making a box for the scope. I was thinking about using tube rings myself, so my scope could be balanced better, but decided against it because I couldn't find any cheap rings.

[Moonshane]

hi Glen

is the stability of the mount affected by the cut outs at all? I think I will be doing this with my 16" dob.

[davehunt]

IMHO your excellent mount would look nicer varnished rather than painted-love the wood look,old bean.

PS My LS from Axminster is such an improvement.Thanks again for the recommendation.

Dave

[scogyrd]

hi Glen

is the stability of the mount affected by the cut outs at all? I think I will be doing this with my 16" dob.

I put my scope on the mount yesterday to test it and the cut outs didn't seem top have made any difference to the stability. I wouldn't like to say whether it'd be the same with a 16" dob though, the extra weight might make a difference.

Now is probably a good time to point out that because I've made a smaller mount than the original it isn't as stable as it, just in case anybody is thinking about making one. I don't think it's a problem though, it rotates fine with both the ebony star and the lazy susan, it's just that if you try pushing it round without any bearings (plywood against plywood) it might well fall over. The only reason I made the smaller base is so it'd fit in my boot and I'd be able to go out with my scope, so if anybody is worried about the stability of the base it might be a good idea to make the circles a bit bigger. All the other dimensions (in the sketchup file) will still be the same.

Who is Glen btw?

[Moonshane]

ha ha

sorry mate. confused again!!

I have PM'd so many people recently they are all melding into one! (and they are all called Glen!!)

[Moonshane]

ps. my 16" base will have 30mm sides and be a lot lower to the ground (bigger alt bearings) so stability won't be an issue. I'll make a decision when I see how heavy it all is.

[scogyrd]

The cut outs are certainly an improvement because it makes the base lighter so you're not pushing such a heavy load round, and they haven't caused the scope to wobble about, or the plywood to bend when the scope's in it, or anything like like. It seems just as strong as it was before to me.

You'll have to see what you think when you're making the mount.