Removing a stripped screw

[Astropic]

Hi Guys,

I have recently bought a 2" dual speed focuser 10:1 to replace the old crayford focuser for my F/9 Refractor. There are 3 screws that locking the old focuser in place, the first 2 screws have been removed successfully without much problem. However, the last screw is playing up with me and the screw head is now stripped.

Is that any solution that I can remove the stripped screw without damaging the telescope?

Any help would be much appreciated.

http://s15.postimg.org/4iaeoh9wn/20150331_185330.jpg

[raymo]

Go to your local hardware store and get a set of "easyouts", drill through the screw with a small drill [around 1.5 or 2mm] and screw the smallest
of the "easyouts" anticlockwise into the hole using a small spanner or shifter on the square end of the "easyout, which will undo the stripped screw. Have the objective end of the scope higher than the focuser end when drilling,so swarf from the drilling stays away from the lens.
Ensure that you drill as near centre of the screw as possible, so you don't damage the female thread in the focuser. Two minute job with the right gear.
raymo

[Joshua Bunn]

Also, to add to what Raymo said, The screw is likely to be a hardened steel, so drill slowly, make sure the bit is sharp, use a drilling compound (being careful not to get it over your gear) and keep the bit relatively cool.

Josh

[Astropic]

Thanks Raymo and Josh, I will get the easyouts set on Friday and thanks for the tips of preventing swarf get on the objective lens. Fingers crossed that I can replace the new focuser before the blood moon eclipse! ;)

Kenny

[raymo]

In turn, to add to what Joshua said, if the scope is of Chinese origin the
screw will probably be fairly easy to drill through, as, in my experience nuts, bolts, screws , etc: from China are usually of poor quality.
raymo

[Astropic]

I have check that 2 screws that I removed, it seems like that is a glue or some liquid form that stuck on the screw thread and I suspect that caused the problem. I have to agreed with you, Raymo, I tried to reapply that 2 screws and the screw head are stripping now, better off replace them with a new set of screws.

Kenny

[glend]

That would be 'thread locker' so they don't work loose over time. I believe you can desolve the thread locker with something but I can't recall what.

[raymo]

That would be Loctite, although why anyone would bother with it on a
scope beats me. Medium strength Loctite can be softened with acetone, but it takes a while to seep into the thread if the surface under the head of the screw is very smooth, as the painted surface of a scope would be.
High strength Loctite can also be softened with acetone, but is more successful if the head of the screw is removed to allow the exposed end of the screw to be really soaked in the acetone. In less critical situations
such as on heavier machinery, it can be dissolved with a blowtorch.
raymo

[Logieberra]

Try heating the screw head with the tip of a soldering iron to release the Loctite. Worth a shot :)