Sight-tube

[asimov (John)]

Made a quick sight-tube today for the 12.5"

Part's: 2" exhaust tubing....1 skim off in the lathe for a snug fit in the 2" focuser.

1 cardboard disk with a 2mm hole in the centre....masking tape to hold it on.

cost: 10 buck's labor for the lathe work/2 buck's for the pipe.

Work's a TREAT!!!! (How far was my secondary out? Not much! )

[ballaratdragons (Ken)]

Great sight-tube, but your car is certainly louder now! LOL

[asimov (John)]

AAAAHAHAHA!

[Starkler (Geoff)]

Tis a shame there doesnt seem to be any off the shelf pipe or tubing that fits snugly into a 1.25 or inch focuser, or is there ?

[ving (David)]

yay john!!!!

do you get a fully sick exhaust note fromyour scope now?
where are you going to stick the sub-woofers?


er... btw, excuse my ignorace but whats a sight tube for?

[acropolite (Phil)]

Exhausting work...

[Starkler (Geoff)]

Originally Posted by ving

er... btw, excuse my ignorace but whats a sight tube for?

Its for aligning the secondary mirror to the focuser . Many cheshires (not the Andrews one) are a combination cheshire and sight tube. You insert the tube far enough to sight the edge of the secondary to the edge of the tube.

[ving (David)]

oh ok... couldnt you just roll up a piec of paper?

[ballaratdragons (Ken)]

No David, the hot exhaust fumes would burn it!

[ving (David)]

hey john, do ya go cruising for chicks in your fully sic telescope now?

[vindictive666 (John)]

starkler

what do you mean not the andrews one i got one of his and has cross hairs and the slanted surface in the side of the aluminum case you know the one i mean

[RAJAH235]

I think the 'normal' Cheshire is referred to as a sight tube/collimator???? The ones that have cross hairs are 'combination' sight tubes/collimators. Both have a 45 deg alum. plate inside. L.