Diagonal tubes!! Any lathe whizards?

[damnut]

Does anyone know where I can get extra diagonal tubes so that I can unscrew the sct adapdter and screw in a push fit tube. Need two, one for Meade and one for GSO??

Thanks in advance

Damian

[Astrogeordie]

Hi Damian,

maybe the best solution is to contact the dealer you got the diagonal from. Usually 2" diagonals are sold with either SCT thread or 2" push fit, so there may be spare parts available.

The problem is that the outer thread used to screw the nosepiece into the mirror housing is not standartised. So (i) it is not a standard item where a part of manufacturer A will fit on a diagonal made by B, and (ii) it is difficult to make one on the lathe without having the mating counterpart.

If you get stuck, I may have a go on my lathe. But I would need the diagonal to check the threads are mating. It is extremely difficult to just cut a thread which has to fit into an existing part without the mating check - especially on an amateur's lathe (mine is the Chester DB10V). If the thread is imperial (e.g. US manufacturer), things get even worse on a metric machine ...

[damnut]

Hi Astrogeordie,

Manythanks for reply, have sent a few requests out to suppliers but have had no response as yet. Would have been fine except the new 2" visual back for the lx is push fit. Have tried push fit to sct in my st 120 and just pushes the focal plane too far to focus!

Of course they are also both different with one being an outside thread and one being internal or would that be infernal.

Best Regards

Damian

[Astrogeordie]

Hi Damian,

maybe it can be an alternative to just buy two additional diagonals ? Unless you have very expensive dielectric ones ...

[barkis]

Have you coinsidered fitting a SCT Crayford focuser. If it doesn't add too much length and interfere with the OTA passing through the forks you'd have the best of both worlds. Single speed ones are fairly cheaply priced.

Alternatively, there is this from Flo.

Ron.

http://www.firstlightoptics.com/diagonals/william-optics-2-dielectric-diagonal-with-sct-adaptor.html

[damnut]

Hi Astro Geordie,

Thats what I did first, now I have 5 2" diags... ( a long story!!)..None of the other tubes fit on each other.. (have 4 scopes)

Whilst on hol Alan from sky's the limit sent me a push fit diag for very little dosh so I could use my hol scope as the sct adapter pushed the focal path to far.

Used 2" open back with a quartz sct diag attached to sct - push fit adapt on lx and it was fine last night.

So two meade uhtc diags one with sct has external thread on tube the other push fit has internal thread.. Think I'll take hacksaw to the sct flange!. Th other push fit has external thread but does not fit any other.

So the easiest so that I can grab any of these bad boys is to have push fit all through.!!

Many thanks to barkis for taking time to reply, had also seen Celestron sct / push fit but all I need is 2 tubes!!.. :-)

Best Regards

Damian

[Spider]

Would this help just seen it on Astro buy ad 46936

colin

[damnut]

Hi Spider,

Thanx for the heads up already have one, and works fine on the lx. But when I use in the refractors with the other diag it pushes the focal plane so far that I cannot bring to focus.

Cheers

Damian