Mounting a SW ST80 on a SW150PDS

[Coastliner]

Hi,

I have a 150PDS, I would like to mount  my SW ST80 as guidescope.

I have the ST80 short dovetail bar and tube rings and was hoping I could bolt the dovetail bar to the top of the 150's tube rings, but it's way to short, it fits between the rings.

Has anyone done this? And what size bolts fit into the tube ring holes?

I am happy that I don't need to perfectly align the two scopes, so I don't need guidescope rings or anything else equally expensive.

TIA,

Neil.

[Moonshane]

I think they are 1/4 UNC

You could buy a piece of flat ali bar and bolt that to the rings and then bolt the dovetail to the ali bar?

[Stub Mandrel]

3 minutes ago, Moonshane said:

I think they are 1/4 UNC

You could buy a piece of flat ali bar and bolt that to the rings and then bolt the dovetail to the ali bar?

Which is the standard for camera tripod threads so you should be able top get screws with thumbscrews on from the usual suspects (e.g. the 'bay)

[Dr_Ju_ju]

I just bought another dovetail bar, & bolted the short st80 bar to that (all 1/4" whitworth bolts off fleabay http://www.ebay.co.uk/itm/130989136765?_trksid=p2060353.m2749.l2649&var=430193976787&ssPageName=STRK%3AMEBIDX%3AIT) and then bolting the bar to the top screws (adding another screw) of the scope rings.

[Coastliner]

Thanks for the replies, for cheapness I've ordered a strip of 1/4" thick aluminium. I'm looking for those locking thumbwheel bolts - what are they called? I am having difficulty finding any!

[Stub Mandrel]

Here's one for £1.75

http://www.ebay.co.uk/itm/1-4-hinged-D-Ring-Tripod-Monopod-Quick-Release-QR-Plate-Camera-Screw-Slotted-/181430531602?hash=item2a3e1a3612:g:scsAAOSwrklVX61S

try searching for camera screw 1/4, then sort on lowest price and you will see loads of options for not very much.