Mounting mecanum wheels... please help?

[Monochron]

Originally Posted by Governators3361

Do you think it would be possible for us to use the AndyMark gearboxes provided in the kit of parts? Additionally, why do single stage gearboxes cause a problem with strafing?

The ToughBox Minis can be mounted with mecanums but it is my understanding that you have to do a lot more machining than if you are using the ToughBox Nanos or 671 or something similar. If you search the forum you can find some pictures of other teams that have done it, but the one I remember mounted the gearboxes below the frame on a seperate plate. There could be easier ways, I haven't looked into it much.

Single stage gearboxes won't cause any strafing problems, just be aware that you may need additional reduction stages to get a slow enough speed. Most single stage COTS gearboxes aren't geared much more than 6:1 or so which, depending on your wheel size, might be faster that you want.

[Monochron]

For people mourning mecanums to the AM14U2, how are you securing the other end of the shaft driving the wheel? The corresponding hold in the outer plate has a diameter of 0.675", so you can't put a .5" Hex bearing in there. Or are you cantilevering it?

It looks like the Upgrade kit that AndyMark is selling has the outer plate attached and I'm guessing the shaft isn't cantilevered, but I can't tell by the pictures shown.

[Whippet]

Originally Posted by Monochron

For people mourning mecanums to the AM14U2, how are you securing the other end of the shaft driving the wheel? The corresponding hold in the outer plate has a diameter of 0.675", so you can't put a .5" Hex bearing in there. Or are you cantilevering it?

It looks like the Upgrade kit that AndyMark is selling has the outer plate attached and I'm guessing the shaft isn't cantilevered, but I can't tell by the pictures shown.

The shafts on both this year's and last year's mecanum upgrade kits were cantilevered. We didn't experience any issues last year, though, so I wouldn't expect this to be too much of a problem. The shafts are durable.

[Jon Stratis]

We're going with mecanums, but with a twist... one pair is direct drive, while the other is chained. Pic of our frame:



Basically, The back wheels are direct driven, and we cut out holes for 1/2 bearings to fully support the wheel, centered on one of the smaller holes along the bottom. The other wheels will be run on a dead shaft in the front, chained to the motors that are in the middle. They are all run using KoP gear boxes (we had two we never used last year and guess what? Same gear reduction!). We're avoiding cutting out any of the flanges on the frame, and instead are building a mount for the gearbox that will stand it off .625" (i think), which is the width of the flange. This also required turning custom axles, as the normal KoP output shaft isn't long enough once we move the gear boxes off the frame like that.

The 6" white wheels in the pic were just used to ensure proper clearances with the front and back frame members... the mecanum wheels aren't in the shop yet.

[GeeTwo]

Originally Posted by Jon Stratis

We're avoiding cutting out any of the flanges on the frame, and instead are building a mount for the gearbox that will stand it off .625" (i think), which is the width of the flange. This also required turning custom axles, as the normal KoP output shaft isn't long enough once we move the gear boxes off the frame like that.

Another solution would be to provide cantilever support for the wheel by boring out the hole in the inner plate to 1-1/8" and using the KOP hex shaft bearing in that hole. You'd also need a hex shaft collar or two to keep things from walking.