chrisf
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| posted on 11/10/05 at 12:54 PM |
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Halfshaft joining
Hi guys:
I'm posting this here because I think you guys do more of this than the other locosters...
I have a Sierra diff (CV) that I need to join to my MX-5 uprights. I have both the Sierra halfshafts and CVs and the MX-5 bits. My thought is to cut
the Sierra halfshafts for the diff side and mate them to the MX-5 halfshafts.
My concern is that the Sierra halfshafts are about 1/4" larger in diameter than the MX-5 bits. The plan was to have a steel sleeve machined and
slide it over each side. Since I have a lower amp welder, I planned on taking it to the TIG (or stick, if more appropriate) shop and have it welded
around.
Does this sound reasonable? I'm a little concerned that the differences in diameter will result in stress issues.
Any guidance is appreciated.
--Thanks, Chris
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Alan B
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| posted on 11/10/05 at 01:53 PM |
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I don't see a problem IMO provided that the sleeve is suitably sized, the shafts are weldable, and the welding is good.
Sure the diameter difference will mean the smaller shaft is always more highly stress, but I don't see a problem, unless you are planning for
monster horsepower.
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tadltd
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| posted on 11/10/05 at 02:54 PM |
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Why don't you have new driveshafts made-up? That way you could use the Sierra inners and the MX-5 outer joints. There's a few companies
around that can do this, but give Drivelink a try.
Best Regards,
Steve.
www.turnerautosport.com
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Mr G
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| posted on 11/10/05 at 04:03 PM |
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A good safety aspect of sleeving is that if the weld goes then the shaft just turns in the sleeve and does'nt flail about taking your back out.
Normal is getting dressed in clothes that you buy for work and driving through traffic in a
car that you are still paying for - in order to get to the job you need to pay for the clothes
and the car, and the house you leave vacant all day so you can afford to live in it.
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mark chandler
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| posted on 11/10/05 at 08:46 PM |
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Why not cut them both long and get the smaller diameter one turned down a bit , larger one machined out.
Simply insert the smaller and weld up ?
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MikeR
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| posted on 11/10/05 at 10:05 PM |
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Talk to NS DEV he knows a company that does this for autograss at a very reasonable rate.
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ady8077
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| posted on 11/10/05 at 10:10 PM |
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Hi Chris
Are you planning on using one sierra cv and one mx5 cv? If so are they the same type? There was a post on the Tiger list about this, and some engineer
(useless with names) said they have to be harmonically balanced or they will wear out quicker. Only repeating what was said, but best to check
Adrian
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Rorty
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| posted on 12/10/05 at 06:08 AM |
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Generally speaking I wouldn't see a problem with sleeving the axles and welding them, but I would be concerned about the smaller diameter end.
Try and leave a reasonable length of plain bar and don't make the joint to close to the splines on the smaller axle.
I would also use a separate lump of steel for the sleeve rather than plugging the smaller diameter axle into the larger diameter one.
Quality welding and slow cooling are the key to success here.
The axles will likely warp a bit from the welding, but if it's only just visible it won't actually matter. If it's very noticable
then the axles can be "nudged" in a press to straighten them.
UJs have to be timed, but CV joints are quite happy in any position because, as their name implies, ther velocity is constant.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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chrisf
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| posted on 12/10/05 at 12:58 PM |
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Gentlemen:
Thanks for all the kind suggestions. The planned sleeve will be right in the middle of the halfshaft. It will have to be a custom machined sleeve with
a larger insider diameter end and a smaller inside diameter end. I'm thinking that the fitment of the sleeve will need to be tight enough that
the halfshaft will need to be gently tapped in. Of course it will have the "V"shaped ends to try to distribute the load.
I never thought about the sleeve itself captivating the halfshaft in case of welding failure. But that is good news.
Of course if all this doesn't work, custom halfshafts will be required. Honestly, this is the more elegant solution, but I would prefer to have
a go at the sleeved method first. I'm using a bike engine, so the torque should be significantly less than even a modern 4 cyinder acr--or so I
hope.
Rorty, how should the weld pattern go? Should I ask my welder (I can't TIG) to weld 1/2 of the side, then move over and do 1/2 of the other?
Also, what wall thickness of the sleev should I shoot for? .125" minimum?
--Thanks again, Chris
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Rorty
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| posted on 12/10/05 at 01:21 PM |
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I would use 6mm [.25"] over the larger axle diameter for your sleeves. As you say, the torque from a bike engine isn't going to kill
them.
I would gently preheat the assembly around the sleeve area, weld it all and stick it in an oven, then turn the oven off and let everything cool down
at its own pace.
If the welder bloke doesn't have an oven, try heating a deep baking dish full of sand and bury the welded axle in that until it's all
cooled.
Steels of that caliber don't like thermal shock, so just nurse it a little and you'll be OK.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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chrisf
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| posted on 12/10/05 at 01:23 PM |
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Thanks for the info!! Since they don't like the thermal shock, I take it TIG is the prefered method over stick welding?
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Rorty
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| posted on 12/10/05 at 01:31 PM |
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I would be fine with stick welding as the area will be preheated and you get really good penetration with the stick.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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