This year, we will be using a 6 motor drive in our prototype. Any designs or pictures?
This team had a great, agile, six motor drive:
Im thinking about doing an x drive then putting the two more motors geared higher in the middle of each side. That’s what the video did I think.
We’re thinking along the lines of X holonomic or H drive
A 4-motor x-drive seems to work the best for me, it may be a little hard to custom program but it is do-able, but 6 motor drives are just too much in my opinion.
You can also use a 4 motor tank drive with 2 motors powering a strafing wheel (H drive). I’m going to prototype the rest of my design and throw whatever motors I have left into a drive, so I haven’t gotten that part figured out yet.
@DanielIW26 Is it just me, or a bad view, or is something horribly wrong with that drive?
It looks weird to me also, i dont know exactly what, maybe just an angle.
The quality is pretty bad but what is it? Since I am looking at it from the designers perspective I do not see anything wrong .
I don’t see anything wrong with it… I’m not sure why you would want to gear the wheels together though
This is probably because it makes it easier on the programming side. By mechanically making sure that both wheels on the same side go the exact same speed, you will not have to worry about one motor going slower than another. I had this problem this year, so I plan to gear my wheels together this season.
It looks like none of the wheels would touch the ground; the two halves are angled weirdly. It’s probably just me going insane, though.
For a 6 motor x-drive you have a couple of options
- Put 2 motors per wheel on either the front or back of your robot and 1 motor per wheel on the other side. This can help with any weight imbalances your robot has that cause it to strafe crooked.
2.Make a h-drive instead with 4 motors on a standard tank drive and a 2 motor strafe wheel
- Make a standard x-drive with 2 additional wheels in a tank drive configuration powered by motors geared to the correct speed. For example if you use 3.25 inch wheels on the x drive with turbo motors you could use 2.75 inch wheels on the tank drive portion with torque motors geared 1:4. This allows for all 6 motors to be used when going forwards or diagonally, but only 4 motors to be used when going sideways.
240(Motor RPM)*PI(3.14)*3.25(Diameter of the wheel)2^1/2(to account for the speed difference of a x-drive) = 3465 in/min
100(Motor RPM) PI(3.14)*2.75(Diameter of the wheel)*4(external gearing) = 3455 in/min
the difference of in/min is minimal enough that it can be ignored
Each option has its own set of benefits and drawbacks so you really have to choose the one that’s best for you, however I personally recommend that you just use a standard tank drive instead of an x-drive. I’ve found that while x-drives are fun they are often less efficient than tank drives especially with heavier robots and I also don’t think that the ability to strafe will be necessary this year.
use 4 motors, build a light 3.25inch turbo X Drive, then take those extra 2 motors and get pneumatics. there are hundreds of uses for pnuematics this year
Yes it is to help with going the straightest it possibly can. Also to help a motor broke or was unplugged it wouldn’t affect it much.
Somehow I just can’t see it, if it helps, the motors and gears on it are turned inward. And the drive side that is on the left of the picture is the right side of the drive.
I would recommend either a 6 motor tank drive, or an asterisk drive. H drives are kind of a waste since there are usually motors not doing anything, and mechanum wheels are just a pain in my experience.
Thats almost a 3:1 effective gear ratio. (2.758 :1)
With 4 motors, unless you are crazy light you will burn out your motors.
Our robot weighed just over 20 last seson and we never burned out except when we were playing defense and pushing other teams around, which shouldn’t happen this season.