Ok so
my team is using the AndyMark Mecanum’s this year but we are experiencing serious shaking when we try to drive the robot in any way, tank or omni style.
Did we screw up in the building of the wheels?
Anyone have any ideas
BTW we are a basically l\l00l35
Did you program the controller for driving with mecanum wheels? there is some info here
that should get you started.
The issue is not in the programming or at least we don’t think its is.
We saw, referenced, and used that link previously.
We think the issue is mechanical.
BTW those with the AndyMark Mecanum’s did you put the wheels together so that the writing was on the inside or so that the two plates that you were using would be parallel. By parallel i mean the fit together flat.
I take it by “shaking” you mean that you are having a pretty bumpy ride.
Us too. We are modifying some of our electronic mounts to handle an increase in vibration.
If you look at the side view of the wheel you will see that it is not perfectly circular. While a “perfect” omni wheel is perfectly circular (or pretty darn close) that involves careful machining of the rollers.
AndyMark’s solution, which is fine by me, was to get “close enough” by using the narrow rollers and wide rollers… but the “close enough” shows up as vibration.
I am wondering if, as the rollers wear down a bit, they might approach closer to perfect roundness.
Watch the backlash on your BB trannies, if that is what you are using. If it starts to increase then you need to pay close attention to the thread on Banebots 56mm tranny problems.
Jason
do you have any sort or suspension for each wheel on your mechanum drive? It may sound odd, but mechanum drives really do need suspension to work optimally. I haven’t personally built a mechanum drive bot, but i know anyone who has would back me up on this.
I don’t know about the original poster, but our mecanums seem to be working okay without a suspension… however we have intentionally left a great degree of flex in the KOP frame. We can raise one corner almost an inch and still keep all four wheels on the ground. Given the flat surface we will be running on, it should be fine… I’d be able to state that more definitively, but right now our 56mm banebots are all pulled apart as we are already seeing serious damage to the final stage.
Jason
based on what i have seen our ride is much more than just bumpy.
Question for those that have used Mecanum wheels and or those people on team xbot.
How have you gotten your robot to roll so smoothly?
I am starting to believe that we did something like assemble the wheels incorrectly.
The TechnoKats built one without suspension. It works because the frame has just enough flex to keep all the wheels on the ground. There can be issues if the weight doesn’t get distributed relatively evenly, but with a good centering of weight it drives great.
Do your rollers spin freely? Our mecanum wheels we giving us a bumpy ride before we fixed the plates and freed up the rollers.
Just a thought,
Jacob