Author Topic: steel axel spec  (Read 93 times)

Tinworm

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steel axel spec
« on: 13 Aug 22, 10:06 am »
for a front axle, can I use ERW instead of seamless mechanical tube? I know it is less strong (though how much so, I do not know)
Is the extend to which it is less strong very important for us in the way we are using the tube?

One additional factor is that the Bedelia has central sliding pillar suspension, so all the action will be at the centre of the length rather than distributed.
I don't want to bore you all with the details, here. But if you are interested, have a look at my blog https://peteskart.blogspot.com/

-Peter

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jim

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Re: steel axel spec
« Reply #1 on: 14 Aug 22, 07:13 am »
Hi Peter, If I was making your axle I would use 40mm o/d cds tube with a 2 to 2.5mm wall. Welded seam tube of a similar size should be strong enough but it will bend easier.
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RhysN

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Re: steel axel spec
« Reply #2 on: 14 Aug 22, 08:23 am »
FWIW the axle on Tim Gunn's Grafton is 25 x 2.5 mm tube ERW. Tested by time. He does however have 2 springs so less of a point load. f you wanted to go as small as that you could make a diamond shaped spreader plate to help distribute the loads.
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Tinworm

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Re: steel axel spec
« Reply #3 on: 14 Aug 22, 10:09 am »
Hi Peter, If I was making your axle I would use 40mm o/d cds tube with a 2 to 2.5mm wall. Welded seam tube of a similar size should be strong enough but it will bend easier.

Thanks very much, Jim.
I don't want to bore you all with the details, here. But if you are interested, have a look at my blog https://peteskart.blogspot.com/

-Peter

Tinworm

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Re: steel axel spec
« Reply #4 on: 14 Aug 22, 10:13 am »
FWIW the axle on Tim Gunn's Grafton is 25 x 2.5 mm tube ERW. Tested by time. He does however have 2 springs so less of a point load. f you wanted to go as small as that you could make a diamond shaped spreader plate to help distribute the loads.

Yes, I think you are right, point load is the issue with mine. The Bédélia has a support structure, but I am not sure mine will add much strength, so need to think about having it strong enough on its own
I don't want to bore you all with the details, here. But if you are interested, have a look at my blog https://peteskart.blogspot.com/

-Peter

Tinworm

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Re: steel axel spec
« Reply #5 on: 14 Aug 22, 10:21 am »
use 40mm o/d cds tube with a 2 to 2.5mm wall.

I was hoping to use 34.9mm x 2mm (converting from the imperial measures normally quoted 1 3/8th x 14swg). Do you think the 40 is significantly better? Aesthetically, the smaller tube might look better, but not if it is bent at the side of the road.
I don't want to bore you all with the details, here. But if you are interested, have a look at my blog https://peteskart.blogspot.com/

-Peter

Tinworm

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Re: steel axel spec
« Reply #6 on: 14 Aug 22, 10:51 am »
Hi Peter, If I was making your axle I would use 40mm o/d cds tube with a 2 to 2.5mm wall. Welded seam tube of a similar size should be strong enough but it will bend easier.

on the strength of your recommendation, I have just ordered a length. Thanks very much
I don't want to bore you all with the details, here. But if you are interested, have a look at my blog https://peteskart.blogspot.com/

-Peter