AM14U3 chassis with mecanum wheels?
 

There are some threads from a couple of years ago about using mecanum wheels with a KoP chassis, but was hoping for some updates from someone that has done it more recently with the AM14U3 chassis. 6" or 8" mecanums? What gearboxes? What modifications did you have to make to the chassis/gearbox/wheels to get it to work? Will the Toughbox Nano/Mini/Micro bolt in with/without modifications to the chassis? Does the AM14U3 have the relevant holes to be used with any of these?

Basically, what pieces/parts did you use and how much modification was required?

Thanks!

Re: AM14U3 chassis with mecanum wheels?
 

This is a configuration designed into the AM14U3. The AM14U3 has the relevant holes to bolt the Toughbox Micro in each corner (one of the bigger changes from the AM14U2 to the AM14U3). You should be able to direct drive a 6" or 8" mecanum wheel off the output shaft of the TB Micro with some hex hubs bolted to the wheel. Custom length spacers might be needed.

There's also a pretty easy trick to run 4" mecanum wheels on the AM14U3, I'd have to look at CAD for a bit to remember the specifics.

Re: AM14U3 chassis with mecanum wheels?
 

If you're not completely dedicated to the AM14U3 chassis, the 2014 Drive in a Day chassis is very well suited to doing 4" or 6" mecanum wheels. I'm not sure about 8", so you'd have to look at the CAD for that.

Re: AM14U3 chassis with mecanum wheels?
 

As another option, either to use the gearboxes you already have or to make space for an intake, you could do the wheels at one end as suggested by AndyMark, and run the others from a TB-mini mounted in the usual fashion at the center of the robot, then come forward on belts or chain. I saw several robots in 2015 with this setup.

Re: AM14U3 chassis with mecanum wheels?
 

Here is an early iteration of our 2016 stronghold chassis using the AM14U2. We opened up the holes for the 1.125 bearings. The Toughbox Mini's rest on the flange of the inside chassis rails. The holes on the outside rails break into the other punched holes but we had not troubles.

PS. the holes we cut using a fly cutter because they where not on center of the existing holes.

Re: AM14U3 chassis with mecanum wheels?
 

The mecanum wheels are mounted incorrectly.

Re: AM14U3 chassis with mecanum wheels?
 

I figured this was just conceptual when I realized that the wheels at the open end were phasing through the end plate, that there was no support from left to right except the one end plate, and that the TB-minis had CIMS but no output wheel or other device. I missed the wheels being swapped on the closed end.

Re: AM14U3 chassis with mecanum wheels?
 

Hello there,

The AM14U3 was actually designed with the AndyMark Toughbox Micro in mind. It was designed to work with 4" and 6" mecanum wheels without the need of serious modification. With 8" wheels, a small notch in the End Plates may be required to prevent a significant pinch point.

To use mecanum wheels on this chassis, you would use a Toughbox Micro with the output shaft from the Toughbox Mini that was designed for the AM14U. This is the shaft that ships with the Toughbox Micro when you choose the 'No Plate' option on the Toughbox Micro product page. 6 and 8" wheels are to be installed on the output shaft of the gearbox. To use 4" wheels, you actually run a short 1:1 gear stage with two 50T 20DP gears between the output shaft of the gearbox and the 4" wheel hole in Long Configuration of the AM14U3 chassis. I've attached a couple of pictures that show these examples.

Hope this helps!

-Nick

Re: AM14U3 chassis with mecanum wheels?
 

For the 2105 season, Team 1108's robot Tote-O used a stock andymark kit frame and four stock kit Toughbox Mini gear boxes to run eight-inch mecanum wheels.

The front wheels were run on dead axles with sprockets to transmissions that were mounted in the stock location at the center of the frame rail. The sprockets need to have same tooth-number sprocket as the axle.

The back wheels were mounted directly on toughbox minis' shafts, which had been extended (we welded, but you can buy these too). To mount the backs, we had to create some careful holes in the frame, but it wasn't too bad. Just laid it out 1:1 in paper, glued it to the rails, then cut the holes with a rotozip on a dremel.

We also had to cut all new churros so we'd have enough space between the inner and outer frame rails.

Here's the blue-alliance photo of it, and a photo from our facebook album.

blue alliance: https://www.thebluealliance.com/team/1108/2015

facebook:

https://www.facebook.com/13074222031...type=3&theater

I still have CAD of this if you think you'd need it. It wasn't too hard to do.

Good luck.