pic: Robot cart design

[Peck]

a suggestion:

make the bottom be set up in some way so the sides can move in and out with enough range that you will always be able to fit the robot frame to that (the width of an industry standard door or just smaller would be a good idea) then have the top "rails" be set with holes and have pins that slide into the holes and stop at a certain height. That way, you can have it resting on the wheels if u need to and on the frame when u need to. If you do it right, new pins could be made in a madder of minutes on a lathe if you need taller or shorter.

[iyermihir]

Originally Posted by Tom Line

You really should stay away from supporting a robot by it's wheels while on a cart or in the pits. Controls will probably want to run the transmissions to test the robot, and if it's resting on the wheels that's a bear. In addition, if someone accidentally hits the controls while the robot is on and enabled, it's going to drive off the cart and hurt someone. See if you can plan on supporting the robot by its frame.

This can be very useful. I designed a cart last fall that my team used for this years FRC season, and the programmers were quite happy about this. It let us troubleshoot problems at a regional and gave us a way to test code involving driving without the danger of a moving robot. Another thing to consider is the wheels. I chose 8in pneumatic wheels for mine which worked very well. I bought them from grainger and you might want to consider this as an alternative to making your own casters. Also, to ensure that the cart could be used for many years, it is made out of extrusion which makes it easy to change the wheel positions for future robots. Ill try to post some pictures soon. Also, make sure that a five foot tall robot can be taken through a standard doorway on the cart, it makes life a lot easier.

[Camren]

Thanks for all the support guys

Planning on making a better autodesk design this weekend. I kind of half way did this one (anyone notice the pan legs weren't matched with the base). Some additions I am planning are:

-More support for limbs
-Width and Height constraints (I'm pretty sure the setup i have now fits height but I have not check and bumpers are always a burden when going through doorways.)
-Pan feet for frame support
- A bumper holder that attaches to the bottom. (right now their is just a cushioned board for working on the underbelly
- Fold out seat
- Fan Bracket (Pits, Que and Arena are very hot)

Also in my new sketch I will add color and more views. Ill try and make a portfolio including some good views, annotation and animation

[gracie.]

what are you thinking of making this out of?

[Camren]

Originally Posted by gracie.

what are you thinking of making this out of?

Preferably aluminum but i'm unsure how it will handle the abuse so possibly steel.

[Peck]

Originally Posted by Camren

Preferably aluminum but i'm unsure how it will handle the abuse so possibly steel.

if aluminum can't take the abuse of being a robot cart, you should take another look at your design. Steel will, in all likelihood, hurt more then it will help.

For example (over engineering it): If your robot weighs 200 lbs and you have 4 support beams holding that weight, then each beam will receive (ideally) 50 lbs. Basic mechanical physics tells use that the beams will be receiving a compression from the weight. Go to your school (or local) lifting room and put a 50 lbs weight (or 50 lbs equivalency) on the top of some aluminum of about the dimensions you want to have for your support beam. If it notices the weight at all then beef it up.

[slijin]

Originally Posted by Peck

if aluminum can't take the abuse of being a robot cart, you should take another look at your design. Steel will, in all likelihood, hurt more then it will help.

For example (over engineering it): If your robot weighs 200 lbs and you have 4 support beams holding that weight, then each beam will receive (ideally) 50 lbs. Basic mechanical physics tells use that the beams will be receiving a compression from the weight. Go to your school (or local) lifting room and put a 50 lbs weight (or 50 lbs equivalency) on the top of some aluminum of about the dimensions you want to have for your support beam. If it notices the weight at all then beef it up.

Most aluminum isn't that weak. Do take careful note of which alloy you use, because depending on the abuse your cart takes, that will make a difference.

[howyadugan1730]

i would suggest adding some wheels before doing anything else

[Camren]

Originally Posted by howyadugan1730

i would suggest adding some wheels before doing anything else

I was thinking of old fashion emperor style transport. 4 rookies on each corner.

[Peck]

Originally Posted by Camren

I was thinking of old fashion emperor style transport. 4 rookies on each corner.

I don't think the field volunteers would be happy about a "cart" involving 16 rookies (though i'm sure software would love it).