4340 Axle Heat Treating

[Conor]

For teams making their own axles out of 4340, what type of heat treatment are you using? I know there's a call out in Engineer to Win, but I didn't know if it would be over kill for our application (Carroll Smith talks about race cars with large engines, not FSAE cars). I also asked a metallurgist at work, but his explanation went waaaaaaay over my head. If anybody has some suggestions or pointers, it would be greatly appreciated. Thanks.

[Conor]

For teams making their own axles out of 4340, what type of heat treatment are you using? I know there's a call out in Engineer to Win, but I didn't know if it would be over kill for our application (Carroll Smith talks about race cars with large engines, not FSAE cars). I also asked a metallurgist at work, but his explanation went waaaaaaay over my head. If anybody has some suggestions or pointers, it would be greatly appreciated. Thanks.

[JHarshbarger]

Take a look at this thread.

http://fsae.com/eve/forums/a/tpc/f/125607348/m/97210977...10308731#25910308731 (http://fsae.com/eve/forums/a/tpc/f/125607348/m/97210977731?r=25910308731#25910308731)

[Chris Allbee]

"making driveshafts is not a mystery. you need the right shaft materials, a good oven, a good welder, a rockwell hardness tester, and some TTT curves. we have all of those, so we can build our own driveshafts for the cost of a few feet of steel tubing. enjoy spending whatever ridiculous amount you do on them."

if you don't happen to have those items or the time to learn to do it properly then spec out a hardness range that is acceptable (usually RC45 - RC50 for axles) and try to find someone with the equipment and experience to do it for you (free or at a reduced price if you can). Honestly how many times have you "followed the directions" on something and have it turn not out not quite right?

[Jersey Tom]

I have data sheets on heat treating 4340, straight from ASM, if you're interested.

[Conor]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jersey Tom:
I have data sheets on heat treating 4340, straight from ASM, if you're interested. </div></BLOCKQUOTE>

I sure am. Are they hard copies or .pdfs?

[mtg]

Just because you have less horsepower in an FSAE car than a champ car doesn't mean your parts should see less stress. It just means the parts should be WAY lighter. So, quench & tempered 4340 is not a bad way to go for halfshafts at all.

[carmaxxx]

I'd like those data sheets too, Tom. sujaykawale@gmail.com

[Drew Price]

Tom,

Moi aussi, s'il vous plait?

andrew-price @ northwestern . edu

And is anyone out there cutting splines on their own shafts? I am almost positive that we have the cutters to do splines in the shop, but am not so sure about fixturing to index the shaft after each cut, so what do you use?

Best,
Drew

[Jersey Tom]

Data sheets are .pdf

EDIT -&gt; Since I'm no longer on the team and still getting emails regarding this, figured it would be a good time to change this!

For future reference, if you'd like the data sheets we have, go to formulabuff.com and use the contact information listed there.

Thanks!

[billywight]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">And is anyone out there cutting splines on their own shafts? I am almost positive that we have the cutters to do splines in the shop, but am not so sure about fixturing to index the shaft after each cut, so what do you use? </div></BLOCKQUOTE>

http://img230.imageshack.us/img230/8757/pict1738cl5.jpg

Involute spline cutters work well...

[ACXY]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by billywight:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">And is anyone out there cutting splines on their own shafts? I am almost positive that we have the cutters to do splines in the shop, but am not so sure about fixturing to index the shaft after each cut, so what do you use? </div></BLOCKQUOTE>

http://img230.imageshack.us/img230/8757/pict1738cl5.jpg

Involute spline cutters work well... </div></BLOCKQUOTE>

wow...don't mind me asking but how long does it take just to spline one of those stub shafts?

[billywight]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">wow...don't mind me asking but how long does it take just to spline one of those stub shafts? </div></BLOCKQUOTE>

Just about a minute once everything is set up. It's pretty quick.

[ACXY]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by billywight:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">wow...don't mind me asking but how long does it take just to spline one of those stub shafts? </div></BLOCKQUOTE>

Just about a minute once everything is set up. It's pretty quick. </div></BLOCKQUOTE>

one minute? our machinist says that it takes very long and hence wouldn't agree to do it for us!

[billywight]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">one minute? our machinist says that it takes very long and hence wouldn't agree to do it for us! </div></BLOCKQUOTE>

He probably doesn't have an involute spline cutter... It would take substantially longer on a mill with a lot of set up and probably special cutters.

[ACXY]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by billywight:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">one minute? our machinist says that it takes very long and hence wouldn't agree to do it for us! </div></BLOCKQUOTE>

He probably doesn't have an involute spline cutter... It would take substantially longer on a mill with a lot of set up and probably special cutters. </div></BLOCKQUOTE>

I assume that with the purchase of an involute spline cutter, it is actually possible to complete the splines in under 5 mins?

[billywight]

Ususally takes about 20min for setup and about a minute for each thereafter. Spline cutters are about $500 for the good ones and $100 for the cheap Chinese knockoffs. This of course assumes you have the actual cutter itself (it's not just a lathe, it's a specialized device just for cutting splines.)

[ACXY]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by billywight:
Ususally takes about 20min for setup and about a minute for each thereafter. Spline cutters are about $500 for the good ones and $100 for the cheap Chinese knockoffs. This of course assumes you have the actual cutter itself (it's not just a lathe, it's a specialized device just for cutting splines.) </div></BLOCKQUOTE>

Hey Billy,

Many thanks for sharing. Greatly appreciated. I'll go check with my machinist again to see what can be done. Cheers.