Celestron CPC Bolts

[Colinlp]

Anyone know off the top of their heads what the thread is on the three screws that hold the scope to the tripod on a CPC1100 by any chance?

Quite coarse, guessing a UNC

[damnut]

Col,

From Rod Molise

Bolt Sizes Needed for Base of Celestron CPC

Tom wrote:
I have just purchased a CPC 1100 XLT and have a Celestron Heavy Duty
Wedge. I want to bolt the wedge to the CPC tripod and then bolt the
scope to the wedge. I don't have any bolts for this. Could you tell me
what size bolts I will need to attach the wedge to the tripod as well
as the size needed to attach the scope to the wedge? Thanks in advance!

Tom

Hi:

You might want to get on our SCT User Yahoogroup and ask this, but what
I recall from my increasingly fuzzy memory is:

Base: 3/8

Tripod: 5/16

As you know, no metric for Celestron yet; all imperial. ;-)

These bolts should have been included with either your scope or your
wedge, however...I'm surprised they were not.

Peace,
Rod Mollise
Author of:
Choosing and Using a Schmidt Cassegrain Telescope
and
The Urban Astronomer's Guide
http://skywatch.brainiac.com/astroland

[Colinlp]

Cheers matey! Doesn't say what thread it is but thinking about it , it must be UNC as I doubt the Americans would use a BSW thread (even though it was made in China)

[Psychobilly]

You can normally get away with either BSW or UNC thread forms IIRC I used BSW for mine... But if you can get UNC go for it... I just used what I had to hand...

Peter...

[Colinlp]

Yes it turns out there is a minimal difference between the two at 3/8" ~ .05 on the core diameter so BSW could be a tad stiff but would still probably fit. I'll order some UNC nuts to try from ebay or somewhere then once I build my pier I'll get some screws the right length

Cheers all

[ronin]

For information, I had to get some 1/4" UNC bolts for a Meade, the best source I found was Falcon Workshop Supples on ebay.

They seem to be one of the few that actually still supply them relativesly easily and also supply in fairly small quantities.

I got the 1/4" button head varieties.

Checked old emails and seller name may be massiveattack007, for whatever reason

[Colinlp]

It would be useful to have a database of stuff like this, piers especially are a popular DIY build

[ronin]

You're right, I think it took longer for me to identify the required bolts then it took to actually order and receive them.

Part of the problem is that a lot of "noise" gets added to a thread like that.

People start asking what size, then where to get, then which head shape is best and it is all in the thread and it ceases to be a reference.

Warthog put a post up saying the eyepiece he suggested you needed, likely between 3 and 5 eyepieces in number, that is now 24 pages long. For a "simple" post which was recommending a few eyepieces 24 pages now seems a bit over the top to me. I will never read it as 24 pages is just too much.

[Colinlp]

True

Anyway for future reference the threads are 3/8 UNC (protruding 3/8") at a radius of 3 3/16"to centres or 6 3/8" circle diameter, the centre locating pin is 7.6mm Dia (5/16"? and also protruding 3/8")