Homemade axle question

[MrJoePodge]

So the last axle i had snapped clean in two in the middle because the metal wasn't strong enough. Now i have much stronger metal (solid round tubing) and am wandering if i can weld a 16mm thread (5/8)right on the end of the round bar. This is shown on this website and Im not sure if that is going to be strong enough to withstand the weight and torque the go kart produces. I went over to next doors house because he has a welder and is building his own house, and he said that it wouldn't be strong enough and you wouldn't be able to get it perfectly in the center. That's true but I thought the weld would be strong enough and not just snap off. Am I wrong or will welding thread on the end of the round bar be strong enough? Here is a picture of the Kart

 

[Rustydog2010]

No, your neighbour is correct, unless you have access to a lathe, getting the thread dead centre is almost impossible.

 

[MrJoePodge]

No, your neighbour is correct, unless you have access to a lathe, getting the thread dead centre is almost impossible.

But would the weld hold?

 

[Rustydog2010]

If welded correctly, 'yes' it will hold. Depends whats on the weld/thread as in forces. If you were to bevel the edges and get good heat into it, you 'should' be right. The only thing, is the axle high tensile? If you weld it, it will loss its strength.

 

[MrJoePodge]

If welded correctly, 'yes' it will hold. Depends whats on the weld/thread as in forces. If you were to bevel the edges and get good heat into it, you 'should' be right. The only thing, is the axle high tensile? If you weld it, it will loss its strength.

my axle is 20mm threaded rod. Im welding my sprocket hub onto it

 

[r_chez_08]

I wouldnt weld the hub to it.
The butt weld would not be very strong IMO. you are better off taking it to a machine shop and getting them to cut a thread in it.

 

[MrJoePodge]

I wouldnt weld the hub to it.
The butt weld would not be very strong IMO. you are better off taking it to a machine shop and getting them to cut a thread in it.

Yeah thats the preffered option but that would cost a fair bit. About $350 i was told

 

[r_chez_08]

Well thats a plain rip off!!! Could you not buy a pre made axle with threads on for a decent price in Australia?

 

[MrJoePodge]

Not for my 20mm bearings. I was told by my neighbour that it would cost $350 to get it machined but I wouldnt think it would be that dear seeing as though it's a pretty simple part. How much would you say it would cost to get it machined? Just a plain bar with thread on both ends.

 

[bighead]

Not for my 20mm bearings. I was told by my neighbour that it would cost $350 to get it machine but I wouldnt think it would be that dear seeing as though it's a pretty simple part. How much would you say it would cost to get it machine? Just a plain bar with thread on both ends.

Have the machine shop cut a key way as well.

 

[MrJoePodge]

Have the machine shop cut a key way as well.

Well my sprocket hub isn't keyed because it's homemade. So it would be useless to me. Does anyone know how much it would cost to get my simple axle machined though?

 

[r_chez_08]

It varies. Ask the machine shop.

 

[bighead]

Well my sprocket hub isn't keyed because it's homemade. So it would be useless to me. Does anyone know how much it would cost to get my simple axle machined though?

Well in the states each shop would ask a different price. I am sure it is the same for you. I would expect to pay about $50 or so.

You said you are using threaded bar?

 

[MrJoePodge]

Yeah that was the first plan but I don't have access to a welder. I think I just machine it myself at school for free $)

 

[fowler]

it wont cost $350 thats a stupid estimate

i got a big 25mm axil made of chomeolly for about 100 incudling material
i got mine done in my small hown town in WA

where in aus are u

 

[MrJoePodge]

it wont cost $350 thats a stupid estimate

i got a big 25mm axil made of chomeolly for about 100 incudling material
i got mine done in my small hown town in WA

where in aus are u

Brisbane

 

[fowler]

well it should be cheaper over there

 

[MrJoePodge]

Well I finally finished my axle at school!!! It's a one inch round bar and bored out about 50mm on each side to fit the thread for the wheel in, then the thread is welded in place. It looks fantastic and I can t wait to hook it up and get it running for really, the first PROPER test drive!!! Videos and pics will be up in the oncoming day!

 

[landuse]

Glad you got it sorted out