Evening all,

I'm having a browse round the web, and collecting the bits I need to make some wishbones for my Sprite. However, when it comes to the top bones I am confused about something. I'm planning on making the top bones adjustable with rose joint inner pivots, and have been looking at threaded inserts as the top bone will be fairly narrow, allowing the joints to go straight in.

The ones I have found to fit 1" 12 swg tube so far are M12 x 1.75 and 1" long. Will this be enough? I would feel happier with a longer thread, but without the bits in my hand it's hard to say for sure. If longer is better, I could use a length of threaded tube and weld the wishbone arms to that, rather than screw the joints in directly. What are peoples thoughts on it? Am I worrying over nothing, and should I just buy the 1" long ones and get on with it?

I made my own as I couldn't find the correct size ones for my joints and tube. For what its worth I made them 45mm long

RalDes do rose joints and suitable threaded inserts.
Worth having a look on their website?
Perhaps that will answer the question without calculating it - on the assumption they've already done that.
HTH
Cheers, Pewe

Surely they just need to the the same or a bit longer than the thread on the rose joint?

I'm in the same boat here for the top rear arms of the Jago using M20 rose joints.

Would also like to know what the thinnest tube requirement is. EG: M20, 18.5 hole, threaded 20mm, is a 22mm outside diameter (as an extreme example) big enough? What's the minimum requirement??

Ta,
Steve

[Edited on 8/5/11 by coozer]

quote:

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Originally posted by pewe
RalDes do rose joints and suitable threaded inserts.
Worth having a look on their website?
Perhaps that will answer the question without calculating it - on the assumption they've already done that.
HTH
Cheers, Pewe

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FWIW the maximum thread strength is achieved at 1.5 times the diameter of the thread. Anything more won't increase the pull out strength.

David