Hey, so I am a mentor on team 3771. We are a rookie team this year, and would like to know what you guys think about our chassis design. It will have mecanum wheels and toughbox nanos. let us know! 
Looks pretty good you guys, but add the electronic components and let us see and we will really be able to judge it! Keep up the good work!!
Will do once we get an arm design settled so we know exactly where to put everything
Why not try and direct drive the mecanum wheels from the Toughbox-nano? It would save on weight and repair time
Otherwise it looks great. Might i ask how much that weighs approx.
That looks pretty good. I assume that is 1x1" box tubing for the frame. I think you can save some time and weight by removing some of the tubing. I think the pieces that hold the wheels could be removed and you could mount directly to the frame below. Your robot won’t be lower but it will save some time when building it. We use 1x1" aluminium box tubing and its pretty tough stuff.
Also, are you using the andy-mark toughbox gearboxes? You can mount two motors to one gearbox. You can shed some weight and time by reducing to two gearboxes for the four motors.
If you want to do 4 wheel drive on a frame that is longer than its width, it will be difficult to turn. The wheels have to have enough force to break its traction in order to slide. You must gear your drivetrain to have enough torque to skid your tires. Many teams use 6 wheel drive with a lowered center wheel to avoid this. You can search the forums about threads on the many benefits of going to 6 wheel drive.
I have been hearing rumors that direct driving mecanums directly from nanos is bad because of the forces put in all those directions. and we are not sure how much it weighs. we are still waiting on our aluminum to come in the mail. But I will try and post here the weight of it once we have i assembled.
They stated that they will be using mecanum wheels, all 4 need to be driven independently to strafe.
Also the toughbox-nano only accepts 1 CIM motor, I believe those Toughboxes and wheels are only place holders.
Its going to be mecanum wheels and toughbox nanos, so we will need all the separate motors and gearboxes. and with the bumper zone being so low to the ground this year, we wanted to get the wheels as much into the frame as possible.
what he said XD
Precisely
Oh whoops, that makes a lot more sense.
Are you getting 2x1 box alum. in the mail as well? If you are you should look into using that. You could eliminate the top structure and reduce weight.
unfortunately, no. i had thought about that after we had ordered all of our stock. hope we can live with that extra pound or two, and we wont be drilling holes in it when it comes time to weigh in XD
i believe our 2009 robot had about 1000 holes in it, all of different sizes… took us 3 days to reduce our weight by 5 or 6 pounds… though we were using 80-20 material…
XD hopefully none of us have to go through that this year.
its is a good design but you need to lose some weight and remove some parts of the frame
As you build it, you can see how strong it is. The frame we have now kinda looks like your with all the top parts cut off. Its pretty stiff, i could jump in it with no worries. So we are not adding any more structure to it. When we add our arm, we will brace its structure to the frame to make the entire robot it more rigged. I think we are more concerned with the arm bending than the drivetrain.
Trim weight everywhere you can – that looks like twice the chassis than is needed.
…and if you don’t own a reliable, calibrated scale, buy one pronto. That way, as you modify and tweak from your original designs (which already have estimated weights, right?), you can re-weigh and re-estimate what final parts will be.
We’ve never been stuck having to drill lightening holes, but then, I’m awfully paranoid about it!
I’m not certain, but I suspect the much wider mecanum wheels might have trouble fitting in that housing. Also, your frame has a little bit too much unnecessary aluminum. It’s important to be thinking about weight from kickoff day till robot inspection.
Best of luck!
How are you attaching the frame elements together? Welding? Gussets?