replacement O ring SW finder

[Merlin66]

Anyone have a spare O ring for the SW finder?
I think it's 48mm x 1.75mm

[Allan_L]

Hey Ken,
Let us know if you find a place that sells them,
I need one also.

[mikerr]

I have had success getting odd O rings from the hydraulic specialists like Pirtek. There should be some one nearby.

[dannat]

try blackwoods also -

[rrussell1962]

You could try Small Parts and Bearings in Capalapa. Amazing variety of useful bits and bobs. Website and online ordering.

[traveller]

As temporary (or in my case, ongoing after 3 years) solution, cut a small cross section off a mountain bike inner tube and stretch it over the finder OTA, it works!
Bo

[Merlin66]

Correction....
Re-measured the old ring and the groove on the SW finder..
1.78mm section x 52mm diameter (groove is 53mm)
None of the "Usual" suppliers seem to have large diameter O rings in such a small section.....

[The Mekon]

http://www.ebay.com.au/itm/50mm-x-2mm-Industrial-Black-Rubber-O-Ring-Seal-Washer-10-Pcs-/331592432080?hash=item4d3472f9d0:g: DAEAAOSwzhVWq4dC

Try this supplier. I have bought O rings from them in the past and they are quite OK 50mm will stretch quite a bit and 2.0mm should fit.
I bought some 32mm o rings from them to act as focal extenders for eyepieces as all I needed was about another 1 or 2 mm of focuser travel.

[VPAstro]

Mine was missing when I first received my 10" newt. I ended up using an elastic hair tie (black), which was a similar diameter and worked perfectly. It has never moved.
Andrew...

[dimithri86]

I have a bunch of 40mm (diameter) x2mm of quite stretch rubber

Would they suit?

[Merlin66]

Thanks for the input, guys.
I'll keep looking at the moment.

[dimithri86]

I am happy to post a few to you free of charge, if you want to try them out.

[Merlin66]

Dimithri,
Thanks, but I have some similar 40 x 1.5 I used in the spectroscopes....
Let me see what I can find closer to the original.

[Allan_L]

Thanks Bo,
That sounds like a good solution. But Let's
..." hope that somethin' better comes along" (as Rowlf and Kermit put it)

[Merlin66]

My mates at Simply Bearings in the UK have the 50.4 x 1.78 O ring but the postage to Oz is a killer.....

[Saturnine]

Hi Ken & All
Thought I'd chime in with my experience with locating the "O" rings. From my measurements with verniers, they are 54mm od x 50mm id , therefore 2mm thick and I bought a packet of 10 for $4.65 from an Ebay store ( Chinese ) called solaluna88. My GSO and Skywatcher finders measure 53mm od and the groove the ring locates in is .5 deep, so 1mm off the dia. The rings have to stretch a little to fit over the finder body but that just makes them a nice and snug fit in the groove.
I still have some left, so if you would like one PM me your address and I'll put it in the mail.
Sorry folks the offer isn't open to everyone who might like one as the supply is limited and I want to keep a few spare for myself.

Cheers
Jeff.

[Allan_L]

Thanks Jeff :thumbsup:

[Merlin66]

http://www.smallparts.com.au/store/partscombined/orings/#SIZES

Small Parts seem to stock a suitable size....