Outer Limits 4x4 Board

i need a temporary fix for me car so i am going to make up a
SHS driveshaft

so heres the plan:

flange1 gets 50mm of 40mm SHS welded to it
4 holes are drilled into the 4 sides of the 50mm SHS
50mm slipped over the 40 and welded to the flange and button holes

flange 2 gets the same treatment but using 40mm length inside
50mm SHS

can anybody tell me what wont work?
or if this is the right way of doin it

cheers

1. it'll work, just hard to balance and may clunk due to looseness of fit

2. i think tow bar hitch material is best to use as they are stout and have tight tolerances for the internal fit

or try to track down flash out RHS. The weld is on the outside of the RHS then. Not very common but should be able to get it at a good steel supplier.

you could use the tube they use for tractor pto shafts, it's triangle in shape and not as sloppy as the sqaure ones i've looked at. has a better contact area.

Go to the metal shop and find some 50mm RHS, depending on how thick the walls are will be how thick your inner shaft needs to be.

Mine is 6mm, all i did was slice a groove in the inner shaft too accomodate the seam from the outer. Also used some thin steel plate as shims to take up the majority of slack.

Makes little or no noise and vibes at 80kmh, over that it can get a little bit rough but nothing that is unbearable.

You can use hitch material but the 2 dramas are finding it and paying for it.

I'm not sure whether 50mm is big enough, sounds a bit light on to me. But given that get some 50x50x4 and the heaviest 40x40 you can. This will give you 2mm of "Slop" but given the weld and a decent length of interaction you should be OK.

What length of interaction are you looking at?

I put a Hayman Reece style adaptor on my camper trailer to carry a bike rack and got some 65x65x6 and with the insert at 50x50 about 250mm interaction was quite good.

50mm SHS outer with 40mm SHS inner will be fine. I've given mine as much abuse as anybody over the past 3 years and it's still fine.
I used 4mm wall for the 50 SHS and only 3mm wall for the 40 SHS.

I don't know that it's necessary but I also welded a support ring around the end of the female shaft to resist any likelyhood of pealing the SHS open.