pic: 1511 Drivetrain & Orbit Balls

[Kims Robot]

Sorry didnt get back to this thread until now

Yes it is the C channel from the Kit bot, but nearly all the bracing is custom bracketry. We wanted a smaller channel for the wheels than the little joint pieces allowed, so we came up with our own. We also decided that we wanted the wheels as close together as we could get them without compromising our CG.

We are using the 12:1 banebots transmissions and encoders as we have had a lot of success with them in the past, and the programmers like and know how to use the encoders. We also could not get the long shaft transmissions in time, so we actually went with the Regular shaft, and our mechanical engineers helped with the calculation and design to build a bearing block into the C Channel that supports enough of the weight that we dont need to support on the other side of the wheel (trust me, I didnt believe that you could canteliever it and be successful, but we drove it around all weekend fully weighted and its working beautifully). I think part of it has to do that there isnt a lot of torque on these transmissions, and they explained a whole bunch of other math that I forget now

Even with the 4 motors, we were able to get this thing down to 41lbs including the bumper mounts, and that was a big step for us!! (Last year it was close to 60).

As for bumpers, I dont think I have a drawing, but the back corners we are allowing the pool noodles from the back brace to extend 3.5", and I think the ones from the side brace extend out 2.14". This was the best that we could come up with with the rules, and after 5 of us talked about it for nearly 2 hours, I believe this is a completely legal configuration.
I will post a photo/image if I can soon.

[EricH]

Originally Posted by Mr. Van

I like it.

I've got a question, and it's about bumpers - so you can all groan now if you want.

How can you leagally protect the rear corners of this frame with BUMPERS that satisfy all of the rules?

As far as I understand (and no, I don't have my BUMPER RULE DEGREE from FIRST yet), you can't have the bumper extend past the end of the back rail, but you need to protect the corner on both sides. The side bumper can't extend past the end of the side rail, so that leaves a 1.125 inch length that is not protected. (Having a pool noodle extend past the edge of the plywood doesn't count.)

I think this problem was brought up somewhere before.

Any answers?

-Mr. Van
Robodox

The GDC has said in this Q&A that you can't have the backing (the part that defines the bumper) longer than the robot's maximum horizontal dimension, but to satisfy the requirements, you can have the soft portion extend beyond the backing.

[diesel]

I love the simplicity.

[Josh Goodman]

Originally Posted by diesel

I love the simplicity.

Wait till you see the rest of it

[5n1p3r]

I have a feeling this is gonna be a very light robot. lawl.

[Kims Robot]

Originally Posted by 5n1p3r

I have a feeling this is gonna be a very light robot. lawl.

Yup, last number I heard from our mechanical team was that we were at 90lbs. Now I dont know if that was factoring in the electronics, but that still seems pretty good to me for our initial estimate. Right now our CG is far enough back, but we still might put extra weight on the back corners to make sure that we arent front heavy at all. Nearly all our parts are sent into the shop, so hopefully we are in good shape

[Cynette]

Originally Posted by 5n1p3r

I have a feeling this is gonna be a very light robot. lawl.

Originally Posted by Kims Robot

Yup, last number I heard from our mechanical team was that we were at 90lbs...

And its getting to be an obsession with Kim, she has the drivetrain in a full regiment of push-ups, sit-ups, and jumping jacks to make sure it is all muscle and no fat!