Hello
We design this base after do some research on 2017 FRC robot of team 971 and 118.
The total gear ratio is 7.3:1, free speed is 13f/s.
Something special in this drivetrain is that we put the omniwheels in the rear, and the battery is also in there. Omniwheels in the rear make the front side of robot not so easy to been hit into rotating.
Battery near the omniwheels can make the weight distribution more in the rear ,and then the turning central of the robot move towards the rear side (but still can not reach the middle of the base), and without battery in the rear the turning central is very close to the front wheels.
This base may be a bit no so easy to turn comparing to the base of battery near colsonwheels which is 971 has done. Four omniwheels is just to avoid wear because of the the weight distribution.
Looking for some review and advise。
Thanks:cool:
The handling tends to get weird if you have all of the weight over the omniwheels like that. Your drive base wants to pivot about the traction wheels as they have sideways scrub that the omni wheels do not, but since the traction wheels have so little weight over them, they’ll still slide around anyway, moving your turning center toward the middle. This ends up resulting in a robot that is easier for opponents to push around.
Sometimes you have to do it that way, where putting the traction wheels on the heavy side would make your center of rotation “wrong”, but if you can avoid it you want the traction wheels to be supporting the majority of the weight.
If i change the rear 4 Omniwheels into each side has one omniwheel and one 0.875inch wide traction wheel, and the traction wheel inside. That means rear of the base has 2 traction wheels and 2 omniwheels. Does it become turning not so smoothly?
Bolts to connect the gearbox and chassis are not shown in the picture, you can find more detail in the cad model. We can buy square tube of 76443 mm in taobao.com.
If i change the rear 4 Omniwheels into each side has one omniwheel and one 0.875inch wide traction wheel, and the traction wheel inside. That means rear of the base has 2 traction wheels and 2 omniwheels. Does it become turning not so smoothly?
