Bolts for skywatcher 12 ich reflector rings

[Stephen Greenfield]

Im doing a project converting a 12 inch skwatcher ota into a dobs mount scope. Plan is to use the mount rings already on the tube and use round butcher blockrrs as bearings attached to the rings and then use worktop edging around the butcher block as the bearing surface and also teflon pads. Problem i have is what bolts fit the skywatcher ota rings , they are 3/8 inch so bought some three inch ones as the butchers blocks are 4 cm thick, however the thread seems to shallow and close together . Any idea where i could get bolts to fit the holes or there is also a smaller threaded hole between the two larger ones anyone know the size and where can get them from ?

[steppenwolf]

Sky-Watcher tube rings have M6 threads on their bases and effectively 1/4" Whitworth bolts on their tops.

[NGC 1502]

I've actually done the same project about 5 yrs ago with a second hand 250px

OTA. I made two plates from 6mm ali plate and bolted them to the tube rings.

I then made some altitude rings that bolted to the ali plates.

Thinking back to then, post #2 is correct with the bolt sizes. I recall that each

tube ring had an M6 threaded hole on each side, that I used to bolt the ali plates

to. To be certain, you could take the the tube rings to B&Q etc to see what fits.

I expect they will know at the checkout that the tube rings are not theirs !

Good luck with the project, Ed.

[Stephen Greenfield]

Excellent, thanks for the help guys!