My beauty, even though I threw it together in about 2 hours. You gotta love those nights when your bored. O yeh, the middle hole on the top is for a mounting/steering piece to be added.
Is the entire module made from one large piece of tubing?
Nice work.
Yeh. Its 3x3 aluminum square with a 1/8" wall thickness. The two horizontal plates will be welded on there.
Question: if those two horizontal pieces will be welded on, then how do you get the shaft for the wheel into the module.
Nice design, it looks hella cool. lol-I still have the nor-cal in me
Hmm…I think standoffs to hold the plates together would make it easier to work with and maintain instead of welding it to make a box. Although, you may have to increase the wall thickness to say, 3/16" or maybe 1/4" just for safety.
I’m wondering, what do you have it geared at? What is the pitch of the gears, and the first stage of reduction?
“Question: if those two horizontal pieces will be welded on, then how do you get the shaft for the wheel into the module.”
Thats a good question. I didnt think of that. I can always attach the bottom plate with L pieces and screws.
“I’m wondering, what do you have it geared at? What is the pitch of the gears, and the first stage of reduction?”
They are 20 pitch gears. Its a 10-1 total reduction. The first stage is 5-1 and the second is 2-1.
With only one CIM per module, you should be able to get away with 24 or even possibly 32 DP gears, significantly lightening the module.
Well its 3/8" face width and as of right now I have and extra 1/10 of an inch on either side of the second stage reduction between the first gear and cim. Heres what the inside looks like. O yeh, I dont know how I’m doing the shafts so I made it simple for now.
PS, I’m not exactly sure how to check the mass on Inventor 11.
For weight, go File>iProperties then to the “Physical” tab and click on a requested accuracy from the dropdown menu. Make sure the materials are set on all your parts (same menu/tab). It has been pretty much the same since at least Inventor 5. 
Like, Cory said, I think 20 pitch for the first stage is a bit overkill, and you might be able to get away with using 24 pitch.
I’m not sure what type of bearings you are using, but you can’t go wrong with flanged bearings.
Did you add any space between the gears in the C-C distance? A 0.001 or 0.002 wouldn’t hurt.
This is really the first time I’ve ever made anything in Inventor. The weight of the whole module gears included is “2.962E+000 lbmass” according to inventor in “Very High” Accuracy
Well, since the gears cant get any smaller, I dont know of any advantages of using 32 pitch or 24 pitch since the gears cant be any smaller (I’m using 3/8" face width).
I love flanged bearings too, adn yes I’m using them
I dont have extra space right now, but there will be in the final version.
Oh, so the distances for clearances with 20 pitch is good and if you were to design with a smaller gear for pitch such as 24 or 32, some things would interfere?
Yeh, exactly.