Andymark Churros

[asid61]

Originally Posted by Chowmaster4695

http://www.chiefdelphi.com/forums/sh...0&postcount=16

You stated they would bend here. Please give us accurate information. Our students use chief delphi to help them make decisions where others have more experience. If they see contradictory posts like yours then they and many others will be confused. Please edit your post.

Chow Out

Excuse me. Please read the rest of my post:
"This might have been due to to other drivetriain problems that stopped us from moving too much though.
6063 is considerably weaker than 6061, so I would be wary of using it. For prototyping, it might be fine, but it would be much safer to just purchase some 1/2" 7075 hex stock from Online Metals instead."
Emphasis on my own post mine. If I could edit my post, I would, but I can't. I posted later in the thread to clarify this.
As a side note, please keep in mind that I am indeed a real person, and I have my own experiences, which might be different from yours. Different does not mean incorrect.

Now, to clarify my statement:
My team used some 6061 axles due to 7075 being unavailable late season. We experienced a multitude of drivetrain problems, leading to us only being able to move during half the matches. However, post-season while we were debugging the drivetrain, we discovered that axle bending was not one of the issues in our drivetrain. More likely it was due to incorrect tensioning of chain.
So, I can say this: 6061 is fine for axles, provided is is not under undue stress. It is cheap, which would be the main reason why you would use it. For a prototype drivetrain, it should work fine. However, once the season rolls around, switching 6061 for 7075 should not be a huge issue.

There have been threads in the past detailing shaft strength as compared to shaft diameter (for rounds). There is one here: http://www.chiefdelphi.com/forums/sh...t=38737&page=2
It would be wise to run some calculations, regardless of material being used. It's just plugging in a few numbers.

Originally Posted by Chris is me

What's the point of building a prototype drive if you're not going to test durability? If you're building a drivetrain before the season starts, you should build as close to how you would in build season as you can. That way, if and when you do have failures, you can directly apply them to your future robot. If you use parts you know will fail to cut corners, you won't know if the part you intended to use in build will work properly.

Good point. I was thinking of just a proof-of-concept drivebase, but for a proven design like WCD you're right, it would be better to design realistically instead. Might be a good idea to have some 7075 on hand anyway then...