Good link for dob bearings.

[spaceboy]

Hi Everyone

Found this link for dob bases. CodeIdol - Thinking about Astronomy - Scope Hacks - Upgrade Your Dobsonian Bearings

Unfortunately what is easily available to US astronomers is a different story for us in the UK.

I would definitely do this mod if I could find ebony star at a realistic price.

[Oldfort]

I believe that Ebony Star (interesting what you get with a search engine btw) is closely related to Formica. which is more familiar over here. It looks like ebony star isn't cheap anyway, but Scope Stuff sell it.

ScopeStuff

I have no affiliation to Scope Stuff, but have found them reliable.

Good luck

[sixela]

"Ebony Star" is simply a colour scheme from WilsonArt High Pressure Laminates. By the way, you couldn't care less about the colour, it's the slightly rough -50 finish that's important. Sadly, WilsonArt is no longer producing that finish, so the only stocks are whatever ATM suppliers have hoarded. Once all of that is gone, people in the US are probably going to switch to the -45 finish (called "Facet"), though.

Just expect US people to moan and groan a lot and pay exorbitant prices for the last -50 finish Ebony Star before they finally move on, though, just like they moved on from Corning Pyrex to Schott Supremex after having predicted the End of the World when Corning closed their thick Pyrex kiln.

There are alternatives. From Formica, you want HPL in either "Sparkle" (now "Crystal PremiumFX") or "Quarry" finish. Quarry will give you something that doesn't stick but has more static friction. "Sparkle" is pretty much like the -50 form WilsonArt.

Sparkle has changed name recently (the -42 finish is now the "Crystal Collection"). 909-42 is plain black with the correct finish; that's probably the most ubiquitous.

For the record, my scope uses Formica Graphite Tuff with Quarry finish. Works well, and actually a lot better than the type of laminate that David Lukehurst at the time I bought a scope from him was using.

[CGolder]

I brought mine from a company called bearing king, was good quality gear and service

[spaceboy]

It's the price that I can't get my head around. For what you pay for a dribble of laminate sheet you would get the whole 3mtr work top.

Is there anywhere in the UK you can get it cheap?? My mod to the center bolt has improved the situation but if I havn't nudged for a while it sticks again.

I brought mine from a company called bearing king, was good quality gear and service

Is this not a lazy susan bearing you are on about CG ??

[Hypernova]

I have just bought a ring of Ebony Star laminate from Teleskop Service in Germany. Not cheap at around £24 including delivery but I have thought that it'll be well worth the money for the improvements.

http://www.teleskop-express.de/shop/product_info.php/language/de/info/p3875_Ebony-Star-Ring-D-50cm-zum-Selbstbau-von-Gleitlagern.html

[spaceboy]

Hi Hyper

I would probably go for this if someone else in the UK wanted one and we could split the postage and I'd mail their's once it was on UK soil.

I looked into it before from teleskop but the postage is like £11. I thought OK maybe if I get a couple of things it wouldn't work out so bad, but the postage goes up as you add to the cart. I just couldn't bring myself to pay the high postage.

Did you get the teflon bearings aswell? Let me know how you get on PLEASE as at this price I would want to know it was worth it.

[Hypernova]

I haven't bought the teflon pads, I will see how the laminate works and then decide whether or not to change the pads or not.

I will definitely keep you informed on how it all goes. Seeing as you have a nearly identical scope to mine, I realise this is something that you'd really like to know.

[sixela]

Oh, one other thing: try to get SailKote or something similar (from e.g. Hobie Cat) on the laminate, at least on the Az bearing (not so much on the Alt bearing unless you're desperate to see the scope move when changing eyepieces!)

One layer (only where the pad make contact with the laminate), let it dry, second layer. Do not wipe.

[spaceboy]

I was told turtle wax

[sixela]

Yes, but that's very old advice. SailKote really works a lot better.

[irishbloke]

i've been talking to a fella in my wifes work, a kitchen manu place, about the different laminates. I had an old sample which was good, but it seems they dont do it anymore. :-( the next best isnt as rough or buttery over teflon.

They were going to make a new top board for me out of plywood and laminate. I'm just not sure if the improvement will be worth it, or should i hold out and buy ebony star. They'd do a good job on the routing of the board.

Decisions!

[sixela]

Hi Hyper

I would probably go for this if someone else in the UK wanted one and we could split the postage and I'd mail their's once it was on UK soil.

I looked into it before from teleskop but the postage is like £11. I thought OK maybe if I get a couple of things it wouldn't work out so bad, but the postage goes up as you add to the cart. I just couldn't bring myself to pay the high postage.

Then nag. If you think the postage computed by the web site thinggummie is excessive, send a mail to Wolfi (urhm...sales@teleskop-service.de) and ask him if that is really the postage. You'll usually get a better offer.

[sixela]

i've been talking to a fella in my wifes work, a kitchen manu place, about the different laminates. I had an old sample which was good, but it seems they dont do it anymore. :-( the next best isnt as rough or buttery over teflon.

See above: if you can't find #50 finish WilsonArt (doesn't have to be "Ebony Star" colour) get WilsonArt #45 "facet" finish or Formica -42 ("Sparkle" or "Crystal PremiumFX"). If that doesn't work, get Formica -75 "Quarry" finish (sometimes labeled QRY in addition to -75).

Don't buy -90 finish Ebony Star. That's the same colour as the stuff of legends, but not the right texture.

[spaceboy]

Then nag. If you think the postage computed by the web site thinggummie is excessive, send a mail to Wolfi (urhm...sales@teleskop-service.de) and ask him if that is really the postage. You'll usually get a better offer.

This is an option but Ithe whole language thing would drive me nuts. I can't even make scenes of the web page. Someone told me they can translate the page using google translator in the tool bar but I can't find the tool bar. Everywhere I look just gives instructions but no link to download the app.

Are they fluent in English at teleskop ? or would I have to bablefish my emails. I'm not even sure what I'm supposed to order. I think I found the laminate to fit my size base but I figured I may as well get the better Teflon pads while I was at it. This is easier said than done

[sixela]

This is an option but Ithe whole language thing would drive me nuts.

Then use English. Might be that it's Patrick rather than Wolfi answering, but they're not going to bat an eyelid if you address them in English.

I can't even make scenes of the web page.

The main web page is at http://www.teleskop-express.de/ and has a language button at the top.

I'm not even sure what I'm supposed to order.

Things from this page:

Zubehör für den Selbstbau von Teleskopen - Teleskop-Express: Astro-Shop + Fotografie + Naturbeobachtung

under "Neumann".

You can order them from Neumann as well; supposedly also in English but that's going to be a bit more difficult (prices are better, though).

Gerd Neumann jr. ---Ebony Star Formica---

Pick English and that page will replace itself with a pointer to his mail address.

There are Ebony Star sheets and rings (for the rings you pick the size just smaller than your rocker box side dimension and base diameter and simply put teflon pads to match). He's quickly running out of the sheets, though.

[spaceboy]

Thanks Sixela

I may give it a go and see what prices they come back with. Do you think the laminate is better than a lazy Susan and a piece of carpet tile? A lazy Susan can be picked up cheap and there is no doubt that the will turn freely with no hint of sticktion. I don't see any problem with causing friction to slow the turn as I could use some carpet tile, but the only thing that puts me off with this is the larger gap between the cradle board and base board. (possible area for water, condensation, dust & **** to gather)

Although putting questions like this out there brings back some good feedback you find that you never get a solid answer as you either get the lazy Susan crowd or the laminate crowd and very rarely any one who has tried both crowd. There must be one person who has tried both and one of the two to be the better option but I have yet to come across such a person. It is well known about sticky dob bases and this is a mod that is often carried out but I can't find anyone vouching a clear winner for resolving the issue.

Although I can see how the laminate could work in theory I'm thinking you need to give it a wipe with sailkote every now and again. There is no doubt a lazy Susan will work but I have also had opposition against this being a good solution.

I just have a VERY TIGHT budget and I have no room for error. If I make a mistake when the budget has gone I'm going to be stuck!

[sixela]

Thanks Sixela

I may give it a go and see what prices they come back with. Do you think the laminate is better than a lazy Susan and a piece of carpet tile?

Oh yes. The problem is not that you want something with low friction. The thing is that you want something with well matched static and dynamic friction, and roughly as much resistance on Alt as on Az.

A lazy Susan has very low dynamic friction, so once you move the scope, it's hard to stop it. It's not ideal. -50 Ebony Star with SailKote on teflon (with 15 psi loading) is usually just perfect (if it's a bit too much friction for you, then make a teflon washer around your central bolt that can take a fraction of the load).

you either get the lazy Susan crowd or the laminate crowd and very rarely any one who has tried both crowd.

Well, I've certainly used both kinds of Dobs. I've personally selected an HPL flavour that gives you a little more friction (I don't mind a little more resistance and in Alt ik keeps the scope from moving too easily when switching eyepieces), but if you ever pilot an Obsession with the tip of two fingers you'll understand what the fuss is all about.

The point about SailKote, by the way, is that it stays put for over a year, and Turtle Wax and ArmorAll etc. do not. You don't need it, by the way, unless one of your bearings has a little more friction than the other.

[spaceboy]

I quickly tried www.gerdneumann.net but their English page wasn't working. If I ever get this speed restriction lifted from my broadband account I will get in touch with both the companies mentioned and see what I can get sorted price wise as I still think it's a lot of dosh for what you get but it looks like it's the price I'm gona have to pay

Thanks

SPACEBOY

[spaceboy]

SORRY guys and girls but having gone over all the pros & cons in my head I cannot justify paying £11 postage (£25 total) for a slither of worktop surface. There is an Axminster tool store not far so I'm going to go for a 300mm lazy Susan £13.90. What I like about this is that it's a matter of adding friction not taking it away. If the ebony star and teflon pads are not to my liking I am stuck in the same boat as I will have limited adjustment to adding or removing friction. With the lazy susan I can make adjustments to suit my needs. As it acts like a solid washer between the base and cradle I will not suffer any rocking either. I had an idea for a friction brake some time ago so I may have a go at this.

Thank you for your advice Sixela and it would have been taken if there was a UK supplier and ES was cheap so if it didn't work I wouldn't be at no great loss. I admit I am a tight ar*e when it comes to certain items that appear to me to be manufactures taking advantage of the situation. I'm sure ES works very well but other than slapping a bit of sailkote on there is no real way of adjusting friction. I just think the lazy susan will be more versatile. I'm sure I will be proved wrong but only at a cost of 4 screw holes in my base board and a lazy susan bearing I could always make into a roundabout for the kids.

Good luck with your ebony star hypernova as I'm sure you will be happy with it. After all anythings got to be an improvement over the stock teflon pads. Either way let me know how you get on.

Thanks all

SPACEBOY

[sixela]

SORRY guys and girls but having gone over all the pros & cons in my head I cannot justify paying £11 postage (£25 total) for a slither of worktop surface.

But you do't have to. I've given complete references for both currently produced WilsonArt and formica surface finishes that work. You can find it locally if you know a furniture builder who uses HPL laminates; sometimes they'll even offer you scrap pieces for nothing.

[scogyrd]

As it acts like a solid washer between the base and cradle I will not suffer any rocking either.

I fitted a 300mm lazy Susan I bought from Axminsters in Nuneaton about 2 weeks ago (if you're going there I bought the last one so it might be wise to ring first) and it wobbled so much I decided to take it off and try the ebony star instead.

The main problems are that the bearing isn't solid, there is a good 4mm of sideways movement, and its about 1cm tall so the plastic spacer that keeps everything in line wasn't connected to the top half of the base. I seem to recall you said your bolt is fixed in place so it might not be a problem for you. I've yet to do that mod to mine.

I'm just pleased I used carpet tape to try it out before I drilled anything.

Edit: I forgot to say that the 300mm lazy Susan barely fits on a 200dob because some of the screw coverings (I presume this is what they are as I didn't build my base) catch as it wobbles when it's rotating.

[scogyrd]

Just a thought but if you live anywhere near Nuneaton you could use mine to see how you get on with it, and if you like it you could buy that.

[spaceboy]

I fitted a 300mm lazy Susan I bought from Axminsters in Nuneaton about 2 weeks ago (if you're going there I bought the last one so it might be wise to ring first) and it wobbled so much I decided to take it off and try the ebony star instead.

QUOTE]

The wife popped in today and grabbed one from the Nuneaton branch.

I fitted it in 5 minutes cut a little carpet tile to fit around the pivot bolt and I'm glad to say it works a dream. I can't believe I've been on the fence about this for the last month stressing about what to do.

Just using the carpet tile cut into a circle twice then put back to back and placed on the plastic spacer shaft has enabled me to vary the tension by tightening and loosening the center pivot bolt. I would imagine that as I modded the pivot bolt this has made this mod an easy fix. The cradle board sits nice on the bearing and I haven't experienced any rocking or lateral play but again this is most likely to sorting the pivot bolt.

I am TBH shocked at the negative feedback I have come across regards this mod as for me I am over the moon (forgive the pun) It is not sloppy or too loose I have a fair bit of control over rotation speed by adjusting the center bolt and it all together feels quite sturdy. The reason why I was leaning towards ebony star was I did want to avoid a larger gap between the 2 boards which with the lazy Susan has now gone from 3mm to 8mm. This will have to be a compromise I will have to live with. I don't see any near future problem from the bearings but it is true that they are not sealed bearings but as they are sandwiched between the 2 boards I cannot see them becoming contaminated with dust or mud any time soon.

It is all down to personal taste I guess but I am more than happy to have finally resolved this issue and at a reasonable cost and in quick time. Should I decide to remove in the future there will be 4 small screw holes that a bit of putty would soon fix and I can keep the bearing for the next dob base I have sticktion with.

SPACEBOY

P.S Sixela I have done no end of internet searches hoping to find a local joiners that may have a scrap of laminate I could have but as you have said its getting the right type stuff. I just felt the chances of me finding a joiner when they are doing the job with the same laminate I need and having a big enough scrap would take to long.

[scogyrd]

I did the lazy suzan mod on a dob base I made for my 130eq a while ago and as you said it worked like a dream. There was no wobble with that base because I screwed the LS to both base plates and had a bolt fixed in the middle. I just wasn't too impressed with how it worked on my 200p.

I think I'll try the ebony star, it should be here tomorrow, and if I don't like it I'll have another go with the lazy suzan. Although I might try the smaller one off my old dob next time.

I'm pleased it worked for you though.