attaching the additional piggy back mount

[prbaxter]

I'm finding that my skywatcher 150P is quite bulky and removing it from it's mount is quite tricky. you find yourself hugging the OTA whilst you undo the bolts.

There's a piggy back mount in the box. I think iif I attach this to the scope mount rings without a piggyback scope attached to it, it will in fact provide a useful handle to aid handling of the scope.

But I need some screws. I've bought some m6 25mm bolts but they're just a little too big and the thread isn't right. Any ideas anyone?

[prbaxter]

FYI... I believe the screws to be 1/4" screws similar to those that you attach camera to their mounts.

still cannot find any long enough though.

[vulcan]

My local hardware shop has 2" 1/4" Whitworth bolts. I got half a dozen last week but they are very hard to come by in the UK now. I had to cut them down AND reduce the head diameter to be able to use them with my dovetail bar and scope. Some enterprising astro shop should get a load of these from the USA where they are relatively common.

[prbaxter]

Perfect thank you!!!

1/4"x2"Whitworth bolts CSK Screws (10)CAMERA MOUNTING on eBay (end time 09-Mar-11 11:49:44 GMT)

[vulcan]

Ah, very useful. The ones I got were round heads. I'll have some of these too. Unfortunately, these don't come with nuts. If you are cutting down a bolt to a shorter length, you are supposed to put a nut on the bolt first as the hacksawing mangles the end of the screw thread. Removing the nut, repairs it again.

[prbaxter]

there's loads of whitworth nuts and bolts on ebay:

Whitworth 1 4 nut items - Get great deals on Business, Office Industrial, Vehicle Parts Accessories items on eBay UK!

spoilt for choice now! Those dome cap nuts will prevent any pretruding screws from piercing my telescope carry bag so I won't need to trim them down.

[vulcan]

Countersunk heads are more useful for attaching dovetails to scopes. Round or hex heads don't allow the dovetail to slide out so you have to screw the dovetail retaining bolts out further. Still, beggars can't be choosers ;?)

[tbird]

I think iif I attach this to the scope mount rings without a piggyback scope attached to it, it will in fact provide a useful handle to aid handling of the scope.

What a good idea, wish I'd thought of it ! Just attached the spare bar to my 150p. Being a classic motorcycle enthusiast, whitworth fasteners no problem.