Drive Shaft/Half Shaft/Drive Axle Questions

[Conor]

I was wondering if anybody could give me a good start on what to use for a drive axle (or half axle or half shaft.. whatever you prefer to call it). The axle we're using now, sadly, is off an old Dodge Omni because the car was scraped together at the last minute with virtually no funding. We're definetely on a limited budget as well. If anybody has some material specs, or some information pertaining to how your team went about designing your drive axle, it would be greatly appreciated. Thanks.

[Conor]

I was wondering if anybody could give me a good start on what to use for a drive axle (or half axle or half shaft.. whatever you prefer to call it). The axle we're using now, sadly, is off an old Dodge Omni because the car was scraped together at the last minute with virtually no funding. We're definetely on a limited budget as well. If anybody has some material specs, or some information pertaining to how your team went about designing your drive axle, it would be greatly appreciated. Thanks.

[Boston]

Hey Conor, I'm doing driveline for MSU. 4340 is the most common material used for half shafts in FSAE. Its strength depends on how deep you heat treat it. The diameter of the half shaft should be less than the lowest point of your spline. Most halfshafts for formula are around .75" to .80" in diameter.

We'll usualy have our shafts ground, splined, and heat treated. This takes a long time sometimes, and a bit of money if you don't have sponsors.

I'm assuming you're using the method below already, but i'll explain it anyway just in case.
Some teams will weld their halfshafts together to the correct size, but this makes them likely to break near the weld (especialy if they are not heat treated after welding). To do this, you make a sleeve, place a splined shaft on either end and weld them together. The sleeve should be cut at an angle like this to increase the welded area:

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What type of differential and CVs are you running?

[CMURacing - Prometheus]

for a while, we used the standard driveshafts of a vw jetta/golf. $80 each, including cv joints (and hubs if you're clever), then cut and weld to length. last year, we went with the complete set from RCV performance. expensive ($1000), but uber-light.

[Harschi]

we use the GKN parts(shafts and joints) from Hewitt Motorsport, UK.

http://www.hewittmotorsport.com

good material and quite good price

[Harschi]

but including the shipping, i think they will cost the same than other ones

Florian Harsch
joanneum racing Graz,Austria

[Conor]

I seems as if using a drive shaft from a productiion vehicle would be unnecessarily heavy. How common is it for teams to do this? It's what our team is using now, but if possible and not too difficult, I'd like to try something else. Is it worth the time?

[Brandon C]

I would think it would be worth the effort. Less rotating mass = less energy lost and more energy to diff.

[Z]

Conor,

Use "Find" to see how many driveshaft failures there have been over the years, before trying to save a few grams.

Z