Tubular front axle

[mhacche]

I would like to make a tubular front axle and wonder if someone has dimensions or made one themselves. I have some cold drawn stainless tube with en24t for the stubs. These will have to be machined and welded in. It would save time if I could share a fellow members experiences.

Cheers Martin

[richard wyatt]

It is essential to incorporate a swivel joint,which will make fabrication quite difficult,otherwise you will get severe intractable understeer-I found out the hard way.[I am fairly  sure topic is on "old" forum.]

[Rogerfrench]

It is essential to incorporate a swivel joint,which will make fabrication quite difficult,otherwise you will get severe intractable understeer-I found out the hard way.[I am fairly  sure topic is on "old" forum.]

I'd just like to point out that it's not the tubular axle that requires a swivel joint, it's the mounting of the radius arms on the side-members rather than centrally on the cross-member.

[mhacche]

hi Hello Richard, I thought that’s what we had rose joints for! I’ll have to make new radius arms too. I’ll check the old forum.

[Paul N-M]

If you design it like a live rear axle four link set up you dont need an articulated beam. However if you have a fixed rod/fabrication at the axle end and a single ball/rose joint at each chassis pick up point you do need an articulated axle for the reasons already given. The assembly acts as a large anti roll bar resulting in understeer.

Paul N-M

[Alan]

Well, it’s because if you mount the radius arms spaced away from the centreline, the assembly acts as an anti roll bar, with the axle as the torsional member. A 1.75in dia axle tube has considerable torsional stiffness. Roll bar stiffness = understeer. If you attach the radius arms to the chassis side members you have to lose the roll bar effect somehow. I’m sure there must be other ways but a slip joint in the axle is a simple way of doing it.

[richard wyatt]

Roger,it is the use of laterally located radius arms not meeting in the middle that necessitates a joint in the axle,but mhacche was asking for advice on making a tubular axle.As regards radius arms,mhacche[real name?] I used rose joints but they were insufficiently flexible,I'm afraid. Tubular axles look very sporty "works"like and do get you nearer the ground,but its hard to beat a lowered Girling beam and strengthened central radius arms for good track performance unless you get them right in every detail.

[mhacche]

Well I had to ask the question guys! I only want information, I understand about all the forces/issues and Mumbo jumbo, just a set of plans or measurements even, I can manufacture anything?, cheers Martin.