Bits for a barn door tracker

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Samaritan
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Joined: Sun Jan 29, 2006 6:24 pm
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Bits for a barn door tracker

Post by Samaritan »

Hi all

I'd like to build a barn door tracker for wide field astrophotos. All the plans I've seen look nice and simple, but I can't for the life of me find anywhere that stocks 1/4"x20 tee nuts to form a stable attachment to a tripod.

Its all metric stuff, and the equivalent (M6) has a different pitch thread so it won't attach to my tripod (or anyone's for that matter!!)

Anybody got any ideas where I could get one from??

Thanks a lot!

Sam
Steve P
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Location: Grantham
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Post by Steve P »

Wow, I thought that this would be an easy problem to sort out. I have consulted with all our joinery suppliers at work and sure enough they only have metric tee nuts these days.
I can only suggest that you find somebody who is going on holiday to America in the near future. Apparently you can get 100 tee nuts of the size you require for only a few dollars there.
Steve
Samaritan
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Joined: Sun Jan 29, 2006 6:24 pm
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Post by Samaritan »

Hi Steve

Thanks for the reply. Don't know anyone holidaying to america soon - but checked on the internet. Guess what? All of the sites that sell them online only ship to mainland US!!

I'm stuck without a tee nut in site!!

Sam
applecounty
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Post by applecounty »

I found this link (to ebay) which may be of help.....
http://business.stores.ebay.co.uk/Manuf ... 8641QQtZlw

This lot may be able to help, they supply imperial fittings, nuts and bolts...
http://stores.ebay.co.uk/WVS-FASTENERS

I also found these
http://www.toolfastdirect.co.uk/cgi-bin ... P=%20&PN=2

You may have found the above already of course.
Best of luck. :)
Chris_Barlow
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Location: Cheshire (Lat: 53:09:49N Lon: 2:12:15W)
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Post by Chris_Barlow »

T-nuts may be hard to find but normal nuts are OK

Have a look for shops that sell nuts & bolts especially to the engineering and machinery trade.

You are looking for a 1/4 " Whitworth thread nut. If you drill your hole through the base as normal then a slightly larger hole from the "top" side just a little smaller that the points of the nut. Apply a little "superglue" to the sides of the hole and press the nut in with a small washer underneath using a vice or clamp.

This has worked fine for me since the base is "clamped" between the tripod and the nut. All the superglue and tight hole does is secure the nut whilst you tighten the tripod screw. The washer spreads the load accross the base to stop the nut pulling through.

From experience though you'd be better off mounting the barn door onto something more rigid like the top of a wall or good fence post. They carry a lot of weight with a camera attatched and even large tripods will struggle to hold everything still.

Alternatively look out for a solid tube tripod like those used for building site lighting. I have one of these and although it's quite heavy it far stronger than any of my camera tripods.
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