pic: (RP) Team 1708 Idea #1

(RePost) I’d like to hear some Feed back and Constructive Criticism please.

Very neat design, and quite visually pleasing. I take it you’re not trying to make it over the hump? And what was your premise for choosing slick wheels over any other options? Just curious.

I failed to mention a few things in the drawing, The wheels were supposed to be the Traction wheels, when I drew this on my computer at school I didn’t have all the drawings handy when I was making this. I was really antcy to post it. So I’ll make a list of all the revisions to this drawing.

  1. Andy Mark Shift-able Transmissions
  2. Any Mark Traction Wheels
  3. 2 Motors with the tough boxes

Sorry for the inconvenience, I’ll take this one down tomorrow and re-post the one with all the real stuff.

Happy Commenting, -Eddie

Can you tell me more about the suspension springs/shocks?

We actually came up from a diesel truck motor, a dodge to be exact. They are Valve springs, they are about 3’’ long and have about 1 1/2’’ of give to them. They are good to support about 145pds.

They don’t have enough give to let the frame slam into the ground, right? Because if so you might be dealing with damage to yourself/the field. Unless I’m interpreting the image wrong…which is entirely possible.

i realize the potential of springs but the hight of your bot seems like its going under the tunnel then why do you neeed the springs?

With the 8" Andy Mark traction wheels, and the springs being capable of hold about 135 - 145 pds, and we are hoping to have to robot as close to weight this year as possible.

The robot was actually planned to go over the hump, the springs are there to absorb the load of the robot when we hit the bump at speed. To keep us moving in the direction we want to, not being flipped :slight_smile:

From the way the image is presented, it looks like there isn’t going to be enough clearance between the frame and the bump to accomplish a 45 degree climb. The frame would contact the bump before the wheels could.:confused:

The wheel’s in the picture are, not the wheels we are going to be using. The Andy Mark 8’’ Traction Wheels are what we are going with.

I understand that you’re going to be switching the wheels out for traction wheels, but those will only add 2" to your wheel diameter. I can’t really tell because of the black background, but it looks as if the framework extends in front of the wheel well and then up at an angle. I didn’t do any math, but it intuitively seems that your frame is going to prevent you from climbing the bump by contacting the bump at one of those two points (the bumper zone, or right in front of the wheel).

This does appoint a possible problem in our design. Thanks a lot for the heads up, I am actually going to draw the “Bump” in Inventor tomorrow and see what happens when I take the robot to it.

Thanks, -Eddie

if you make a scale side view of the bot and the bump, you can just cut the robot out of paper and play with it like a paper doll. We did this for hanging ideas…it works for bumps too.

just for fun, try an 8wd version of your robot with 6" wheels over the bump, as well as 4 and 6 wd with 8" wheels.

No problem, I hope I wasn’t coming off as too harsh. I find that playing devil’s advocate is unusually helpful in many cases :stuck_out_tongue:

Yeah, I appreciate the much needed help, Thanks again!

We actually pretty much did exactly what you just said, except we did it in Vex :] We made a scale bump out of Card Board, and prototyped different Chassis, and drive train ideas

What if you switched where the front support and the front wheel are? That might help with your ramp approach. Ditto with the back wheel and back support. If that’s even possible with your design, of course.

Oh, and your upper frame on the front side seems to violate <R07-M>.

Thanks for pointing that out, I need to look into it, and see what I can do to fix it. Thanks again for the help.

Where do the springs mount to the frame?

Have you figured out how to rout and tension the chain/belt you’re going to use to power the wheels? Also, it looks like the wheels could easily twist (one spring being compressed more than the other for the same wheel). This could easily cause it to throw a chain, or create a lot of weird stresses on the suspension.