We have the Omni Rover 2.0 kit. It came with the 60 mm wheels, but due to a manufacturing error they did not work and can not be replaced. We swapped them out for 40 mm wheels. The hubs will press fit into the wheel, but I have not been able to press fit the hub onto the motor shaft. The fit is too tight and no matter how hard I press, the hub will not fit onto the motor shaft. Am I missing something? Is there some special methods to get the hub mounted on the shaft?
Thank You
I used a caliper to measure the opening and the shaft (see pictures). The tolerances are extremely close. I heated the hub and put the motor in the refrigerator to help. I was able to get the hub to slip on a little farther, but this seems like an extreme to get the wheels on.
Any suggestions on what to try next?
I should have stated that the measurements you see on the caliper are in mm (millimeters).
I like the 48mm wheel and am considering purchasing 4 of them. The biggest problem with the 40mm and 60mm wheel is they are hard plastic and have no grip. It looks like the 48mm wheel is rubber coated.
How will the 48mm wheels mount to the motor studs? Will an adaptor be necessary or is there something else I should order?
The hub should have two different ends: one is made for a servo, while the other is made for the DFRobot motor. The one for the DFRobot motor should have a double flat on it, which needs to line up perfectly with the flats on the motors. It’s a press fit, though we have not heard of people not being able to fit the two. Try different hubs with different motors. The issue with the 60mm wheels is known and we greatly apologize for any inconvenience. If you still cannot get the hubs to fit, can you measure (as exactly as possible) the opening and the motor’s hub to see if they can in fact fit together?
Please contact us via the support center and indicate that the four motors need to be changed for RB-Dfr-51. You can reference this thread in the post. It seems like the motors with the metal shaft is not identical to the one with the plastic shaft. Once again we apologize for any inconvenience.
Creative solution, though we certainly apologize for any inconvenience. The 60mm wheels are having manufacturing issues, in that the hubs do not press fit into the wheels. The manufacturer is suggesting that customers use glue to keep them in place, though we are not a fan of this solution. Currently the most reliable omniwheel is RB-Nex-24, though we are hesitant to change the kits because of the large jump in price. Your opinion is welcome.
Those 48mm wheels include screws. The hubs have two sides: one side is for a Hitec continuous rotation servo, while the other is for a DFRobot DC gear motor. We have not tested them with the DC gear motor which has a metal output shaft. The rubber grip does help a lot, but as you can see the price is a lot higher. Most small plastic omniwheels are taken from conveyor belt systems and adapted to robotics using a hub. The 48mm ones are custom made for robotics.
After leaving the motors in the refrigerator for several hours and heating the hubs with a heat gun, we were able to get the hub onto the motor shaft. We could not get the hub to slip on as far as I think it should, but it is on good enough that I don’t believe it will slip off. Therefore, we are going to stick with the motors we have. However, with the 40 mm wheels, the rover has very little clearance. Will 60 mm wheels eventually be available for the rover?
