A couple of questions.

[Smoked]

Well I just joined the forum and am in need of some help. I'm not really the best in choosing material.

I am currently designing a spool or mini spool for my differential.

I am torn on which material would be best,cheap, and light. I was going to machine it out of 4140 and I know it would work being that's what a lot of spools are made out of. I would love to make it out of aluminum, since the rotational mass would be greatly reduced. But I don't think 6065 would hold up to 300-400hp. I was told from a few sources that 6065 T56 would work(but isn't cheap). Also 7076 T6(not positive) would work, but there again, expensive.

My question to you guys is, What would you recommend for a cheap,common material that would suffice for a spool? This is about what it would look like.
http://img708.imageshack.us/img708/94/s132.jpg
http://img691.imageshack.us/img691/5981/s13spool.jpg

Now. I have also been tossing up the idea of taking my old carrier and just machining a mini-spool. How the differential is setup is, the axle shafts slide into splined slots and there is 4 pins connected to where the axles slide into that slide into 4 slots on the carrier that connect the axles to the ring gear. I was thinking of machining a mini-spool and drill 4 holes and press in dowl pins to mate the 2. What do you guys think? I will get some pictures posted up tomorrow to help understand what I am explaining. I will also be modeling it on solid works.

Thanks for any input!

[Jawno]

The local metal expert here says don't even consider the 6065. Way to soft and ductile for something like this. The 7076 has strength similar to steel so it might work. He recommended you sleeve it with steel though. Also he said why bother when the housing is cast iron. Your going to save maybe five pounds max. why not just go with 4140 and open it up a bit more.

[Smoked]

The local metal expert here says don't even consider the 6065. Way to soft and ductile for something like this. The 7076 has strength similar to steel so it might work. He recommended you sleeve it with steel though. Also he said why bother when the housing is cast iron. Your going to save maybe five pounds max. why not just go with 4140 and open it up a bit more.

I figured the 6065 wouldn't be the best. I was just throwing out a few metals. I will be going with the 4140 now I guess,unless I can get our Rockwell machine to work to figure out a couple metals laying around. There is some decent sized pieces laying around but I am not sure on which metal they are yet. If it's strong enough I will use it an machine the full spool. But until then I will be planning the mini spool using 4140. I am almost done with the solid works model, I just need to remember how to get the pins mated to the mini spool. When I get that done I will post the image to give you guys a better idea.

Thanks for the help!

[suncles]

How about plastic? Such as POM or PC, PC is harder than POM.
These two plastic material are suitable to be machined.

[Smoked]

How about plastic? Such as POM or PC, PC is harder than POM.
These two plastic material are suitable to be machined.

Did you read what I will be machining? Plastic can be machined yes, but It won't hold up locking the 2 wheels on my car with my drivetrain. The plastic would crack or the splines would strip. Unless there the worlds strongest plastic that is 10x stronger then any metal. Then it would still be expense. Click on the 2 images I posted, That would give you an idea of there it will be going in.

[suncles]

Sorry Smoked, I cannot see your pictures(cannot open your links of pcitures).

For your requirement is best,cheap and light. It is hard to meet it, if POM or PC cannot fit it, I think plastic UHMW-PE will be only one to meet your need of best,cheap and light. UHMW-PE is cheaper than some good Aluminium alloy. If not, aluminium will be your final chose.

But from your information of spool on your car differential, maybe aluminium alloy will be your best chose.

[Smoked]

Sorry Smoked, I cannot see your pictures(cannot open your links of pcitures).

For your requirement is best,cheap and light. It is hard to meet it, if POM or PC cannot fit it, I think plastic UHMW-PE will be only one to meet your need of best,cheap and light. UHMW-PE is cheaper than some good Aluminium alloy. If not, aluminium will be your final chose.

But from your information of spool on your car differential, maybe aluminium alloy will be your best chose.

Very understandable, I did word it terrible, my fault. I guess I should have said cheap but strong(If you have dealt with rockwell I need to be in the ballpark of 30 rockwell strength). I have looked into some aluminum's but for what I need it will cost way to much. I was recommended 4140 steel since before heat treating it's around 30 rockwell so it would be perfect, but somewhat spendy.

This should give you an idea of what it is since those links won't work



Thanks for the help!

[suncles]

Very understandable, I did word it terrible, my fault. I guess I should have said cheap but strong(If you have dealt with rockwell I need to be in the ballpark of 30 rockwell strength). I have looked into some aluminum's but for what I need it will cost way to much. I was recommended 4140 steel since before heat treating it's around 30 rockwell so it would be perfect, but somewhat spendy.

This should give you an idea of what it is since those links won't work



Thanks for the help!

I understood as a fishing spool. My a little poor English

On 30 rockwell steel,4140 is good, also you could consider P20,S316,738,718 which we always use for plastic mold building.