971's chassis

[highlander]

Thanks for the quick reply: some follow up questions.

- I'm assuming you guys are using 5052. Confirm/deny?
- Are the tolerances on the laser cutter and the turret punch the same?
- How has your experience been in bending over holes? Do the holes deform and you only use them for access sake? Or is it reliable to allow critical parts to interface with those holes?

Thanks a lot for answering these questions; very very helpful.

[AustinSchuh]

Originally Posted by highlander

Thanks for the quick reply: some follow up questions.

- I'm assuming you guys are using 5052. Confirm/deny?

5052-H32 for the parts that are bent, and we use some 6061-T6 when things aren't bent and need to be strong.

Originally Posted by highlander

- Are the tolerances on the laser cutter and the turret punch the same?

No. I'd trust a laser to +- 0.001 or better, and a punch to +- 0.005. Sponsors tend to be pessimistic about what their machines can do.

Originally Posted by highlander

- How has your experience been in bending over holes? Do the holes deform and you only use them for access sake? Or is it reliable to allow critical parts to interface with those holes?

We don't do it to the extent that we will redesign the part to avoid doing that, or only use them for access. We keep all holes about 3/8" away from any bends, otherwise the holes will blow out and the k-factor will be affected. If there is a hole too close to a bend, we will make it into a slot and break the bend. Some machine shops will leave the holes out and put them back with a mill after bending it, which is a waste of everyone's time.

[switte]

Originally Posted by highlander

Thanks for the quick reply: some follow up questions.

- I'm assuming you guys are using 5052. Confirm/deny?
- Are the tolerances on the laser cutter and the turret punch the same?
- How has your experience been in bending over holes? Do the holes deform and you only use them for access sake? Or is it reliable to allow critical parts to interface with those holes?

Thanks a lot for answering these questions; very very helpful.

We do use 5052 for its ability to bend.

I do not believe that the laser and the turrent punch have the same tolerances. The laser can hit holes within .001 and I believe that the turret pouch will get within ~.005, and Travis and or Austin can correct if I am wrong. We will usually spec out holes on transmissions and whatnot that need to be within laser tolerance and we try to make everything else "punchable".

As for bending near holes, you can deform the hole when it is located near a bend, but in a somewhat predictable way. For holes that don't require major accuracy like our tensioner allen key clearance holes, we are okay placing them near bends, but we try to avoid it when possible. You can also see in the siderail of our drivetrain we put a hole on the inside flange where the transmission goes. While we don't like breaking up the flange, the hole is necessary for our second reduction from out transmission.

slots tend not to deform much when the bend is in the middle of the slot. There have been a few side projects where we do some interesting things with this, but I cannot find any pictures right now...

Hope I have answered your questions

Edit: Darn I was too late