Attaching crayford focuser to 6" dob?

[StutzJr]

It may seem like a waste of money to some, but I'm not in a rush to upgrade my 6" dob just yet. I don't really like the existing rack and pinion focuser and I think it would be a good little project to replace the focuser and recollimate the scope. I am planning to get a GSO 10:1 crayford style focuser but sites normally say it is suitable for an 8-10" newtonian tube, however my tube has a 6" diameter.
I have 2 reasons to believe this will not be a problem. Firstly I know some higher end photographic newtonian 6" scopes have crayford focusers as standard. Secondly my scope's focuser is mounted on a thin spacer that has a larger radius curve on the outside - it is slightly thinner in the middle.
I am not sure if there will be an issue with the mounting holes. I think the GSO focuser should be a stardard fit on a Skywather tube?

Do you think this would work?

[glend]

A 6" tube usually means a shorter overall focal length than those 8 and 10 tubes. Have a look at this 6" Bintel dob which has a Crayford style focuser, that one should fit your scope, why not ring Bintel and as them if you can source that focuser for your scope.

Alternatively, just buy a focuser that will fit your tube. Here is a base that will probably fit:

http://www.teleskop-express.de/shop/product_info.php/language/en/info/p3701_Base-for-Newtonian-focusers-for-tubes-with-D--160-205mm.html

Here is a discussion on mounting it:
http://stargazerslounge.com/topic/102047-revelation-crayford-focuser-and-base-plate-for-6-newtonian/

[StutzJr]

I'm going to give Bintel a call tomorrow to see what they can do.. I see they now have thier own branded 6" dob that wasn't there when I bought my skywatcher, but that only takes 1.25" eyepieces. I only have those size eyepieces, but I think the existing hole on my tube might be too big for that focuser.
I'd rather try and source one that fits befor drilling new holes if possible. I notice they sell an orion low profile crayford focuser that would fit, but if I'm going to have to spend that much I'd sooner get a moonlite with universal adapter which would possibly work out cheaper.

[StutzJr]

I spoke to Bintel today and they said that the footprint of thier focuser was different, and they were not able to source one that would fit without drilling new holes. They also said they Skywatcher would not sell a focuser seperately.
I had a look at the TS spacer linked above and the matching focuser TSFOCN2M from the same site, indluding postage that works out to over $300.
I plan to call Andrews when they open again tomorrow from holidays but at this stage I'm not sure what to expect.

[barx1963]

This may be a little expensive but I replaced my standard GSO focuser with a Moonlite ( www.focuser.com ) and would never bother using another focuser (except maybe a Feathertouch)
The good things is that you can buy an installation kit whic includes spacers, curved adapters for for all the standard size tubes including 6" and it is all predrilled to fit most major brands including Skywatcher.
If you decide to upgrade you can simply put your old focuser back and buy another curved adapter to suit your new scope and the focuser moves with you.
The great thing about these focusers is that they are actually an investment in your scope, the one thing you spend more time doing ,apart from observing, with your scope is probably focusing , so you want the best and easiest to use focuser you can get!
I bought direct from Moonlite in the US and their customer service was superb.

Cheers

Malcolm

PS the single speed version is very good ( I have one on my 8") but if the budget allows, the dual speed is wonderful!

[StutzJr]

I am actually considering the moonlite option, for all the reasons you've mentioned. I just need to at least make an attempt to exhaust any cheaper options first so I won't feel so bad about going overboard on this.