Six motor Mecanum Drive?

Looking at the possibility of a six motor mecanum drive train. We are thinking direct drive front wheels with one motor each. And chain two motors for each rear wheel with most weight over rear wheels. It should be fine when moving Forward/Reverse in tank. And should not be a problem in Driver control strafing either. The question comes with left/right strafing in autonomous–there will be no distance sensor for front wheels and we will be powering paired wheels at a lesser power to balance out. And thought is given short distance of anticipated travel, there should not be a big difference between two. Do not have code written yet but looking for feedback on possible issues. We might be able to use line followers to reset course but otherwise left right distance would be determined by quad encoders on rear wheels.

After using a 6 motor mecanum drive in Toss Up, I am here to tell you that you won’t get even strafing. If you double up the motors in the back, then the robot will spin in a circle. Same thing goes for double motors on the front wheels.

Probably the only ways to make this work is through either shaft encoders on both front and back wheels or a gyro.

I didn’t strafe at all during programming skills in Toss Up, other than to align to the wall (I eventually took this out though, because it took too long and wouldn’t always align at the same spot on the wall).

You could do 4 mecanum + 2 Omni’s in the middle for 3 wheels on a side. You would have the power of 6 motors going forward, and still be able to evenly strafe

This is a great idea, but 6 motors on high speed would be great for combating the overheating 4 motors get when strafing over time.

Note that if you try to do the 4 mecanum 2 Omni idea, the wheels are slightly different sizes so you have to use washers to adjust so they are all on the ground

We used 6 motors on a mecanum drive this past year for toss up and did so very successfully. We had 1 motor on each of the front wheels and 2 motors on each of the back wheels with most of the weight of the robot on the rear of the robot. In order to deal with the rotation of the robot during strafing, the students use the gyro and dual optical encoders. It gave us the additional power we wanted without giving up the ability to strafe. It was a little more difficult to program, but the teams programmer was very good and was able to incorporate the sensors and get the program to take all this into account. By the time we got to worlds, the team had the robot loading all three bucky balls from the hanging zone, rotating and driving to the scoring zone, it would then strafe to the center piers of the bridge to verify is location on the field, then score the bucky balls into the stash tube. It was working very reliable, so it can be done. You will just need to incorporate the various sensors and program corrections. I hope this helps.

It does help and we know that it is a challenge. The surest thing about VEX is that anything that might be perceived as a tactical advantage is not without its challenges.

When we get farther along, we may PM you for any programming tips that you might be able to share. Thanks to all.