Help with refitting focuser to Tal 100 please

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PlaneSkies
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Help with refitting focuser to Tal 100 please

Post by PlaneSkies »

Hi,

I have finally managed to obtain all the bits and pieces, filters and adapters for a stage 2 PST mod, and have made the scope cuts. It took well over an hour of hack-sawing both the OTA and then the focus draw tube to avoid it hitting the first baffle - built like a tank!! (pic below)
Due to my lack of technical, engineering or DIY skills my next problem is refitting the focuser :unsure:

It seems as though I need to 'file down' the outside of the new cut OTA for the focuser to slip over, and then create some new bolt-threaded holes for the original bolts to go through - or possibly create new type holes in the new cut OTA for self-taping screws? I guess I will need some new DIY items from Santa...

There seems to be some fearsome metal to contend with on the Tal to refit the focuser, and any advice on how to make my life easier would be much appreciated please :)

Ironically I bought a brand new SW Evostar 102 f10 after waiting for ages for a second had Tal to become available and then the Tal came up while the evostar was in the post! Might use that one for the moon instead.




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Re: Help with refitting focuser to Tal 100 please

Post by marktownley »

You could mark the position on the tube of holes that you need to drill using the focuser as a template, then when the holes are drilled glue some nuts on the inside of the OTA (make sure you get no glue on the threads!), then simply bolt back on...


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Re: Help with refitting focuser to Tal 100 please

Post by uplooker »

There was no need to cut the focuser tube, just remove the baffle or push it further up the tube so that the focuser tube does not impact it. Do not file the end of the TAL tube, the focuser unit will just push on. It may be a bit tight but is easily enough done. Do you know anyone with a set of taps?
Have a read of this thread, it explains what I had to do when refitting the focuser.

http://solarchat.natca.net/index.php/en ... -mod#67865

Onwards and upwards with your mod

Ian


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Re: Help with refitting focuser to Tal 100 please

Post by PlaneSkies »

Mark - Gluing the nuts on the inside is something I would never have thought of! ingenious - many thanks :thanx:

Ian - Looks like I could have saved a lot of time hack-sawing :) Unfortunately the focuser will not slip back on to the cut OTA because of the thickness of the paint at least. The focuser on the original scope was directly on metal.
I'll see whether the focuser slides on (with a bit of coaxing) once I manage to fathom out the best way to get of the quite thick and well applied paint. These scopes were certainly built to last...

Thanks again,

Steve


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Re: Help with refitting focuser to Tal 100 please

Post by uplooker »

Hi Steve,
You should not need to remove the paint. It will go on without too much effort, just persevere. Good luck.

I can't remember off hand but check if there is cutout in the focuser to allow the folded seam of the tube to slot into.

Where are you, Heston? Where abouts is that?

Ian


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Re: Help with refitting focuser to Tal 100 please

Post by marktownley »

Mine went back on with perseverance and cajoling too!


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Re: Help with refitting focuser to Tal 100 please

Post by PlaneSkies »

Thanks for the reassurances chaps - I'll persevere and let you know how I get on with the refit.

Ian, Heston is very near Heathrow Airport - hence the user name ;)
I can practically see the white's of the pilots' eyes on some landing pathways!!
Quite good fun when a vortex from the wing hits the garden too - certainly helps dry the clothes...


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Re: Help with refitting focuser to Tal 100 please

Post by marktownley »

Bet those vortexes can play havoc with the seeing if they get between you and the sun...


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Re: Help with refitting focuser to Tal 100 please

Post by solarchat »

vortices


Stephen W. Ramsden
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Founder/Director Charlie Bates Solar Astronomy Project
http://www.solarastronomy.org
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Re: Help with refitting focuser to Tal 100 please

Post by marktownley »

:whistle:

Spelling was never my strong point :P


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Re: Help with refitting focuser to Tal 100 please

Post by uplooker »

Stephen,
You should certainly know the terminology, baring in mind the industry that you work in :P

Steve,
Was not sure of location, a number of instances came up on google maps. If you were closer to me I would have popped round to give some assistance.
Just spend some time reading the frankenscope threads on hear and you will be right :cheer:
The closest I have come to vortices is just hearing the ringing sound they give off, even though I work at an active airfield building military aircraft.

Ian


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