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Tal/PST mod focuser recommendations

Posted: Tue Apr 13, 2021 1:38 pm
by DJD
Dear All,
My venerable Tal/PST stage 2 mod is failing, or rather the Tal 100 2" Crayford focuser is failing and is struggling
with the plug and play back-end that I use on a couple of scopes. The focuser has been repaired a number of times
and I think it needs retiring.
Can anyone recommend an affordable replacement for the Tal 100 2" focuser?
On a related note I have some annoying reflection issues I think. Can anyone suggest a simple way to tilt the
2" Baader 35nm filter that might be the culprit ?
Thanks,
David

Re: Tal/PST mod focuser recommendations

Posted: Thu Apr 15, 2021 2:31 pm
by marktownley
Hi David.

I use a Moonlite m68 focuser on my Tal, its' great. Mike Garbett has one too.

Regards the 35nm, back off the retaining ring so the filter is loose in it's cell, then use a couple of dibs of blue tack (or similar) diametrically opposite, one beneath the filer and in between the back of the cell. The other piece between the retaining ring and the filter. This will give a couple of degrees of tilt that should sort your reflection.

Mark

Re: Tal/PST mod focuser recommendations

Posted: Sat Apr 17, 2021 7:13 am
by DJD
Thanks very much Mark, knew you would know the answer.

Re: Tal/PST mod focuser recommendations

Posted: Wed Apr 28, 2021 7:09 am
by DJD
Mark,
Is the Moonlite M68 you mention the same as the Moonlite CFL 2.5" Focuser with TAL100RS fitting flange ?
Got a quote for the above which made my eyes water a bit.
Thanks,
David

Re: Tal/PST mod focuser recommendations

Posted: Wed Apr 28, 2021 9:07 am
by marktownley
Yes, will be the same one. How much was it if you don't mind me asking? Mine certainly cost more than the scope, but I do think it is worth it...

Re: Tal/PST mod focuser recommendations

Posted: Wed Apr 28, 2021 10:50 am
by DJD
Mark,
£453 + postage.
Makes the TS R&P 2" focuser with 10:1 look positively cheap.( But would have to get a bespoke adapter made )
One question, the Moonlite Tal100RS mounting adapter is a 4.1" ID that presumably pushes over the telescope tube end.
My native Tal 100RS focuser has a threaded section that the focuser threads on to, any idea what the thread size is ?
Don't know why the moonlite does not just thread on to that.
Best wishes,
David

Re: Tal/PST mod focuser recommendations

Posted: Thu Apr 29, 2021 5:46 am
by marktownley
My moonlte has a flange that pushes on and then bolts onto the bare ota, all signs of the old focuser had to be removed completely for it to fit.