pic: Inventor Practice Progress


Making progress with my first ever drivetrain in inventor. Still figuring out gearing. Any feedback/suggestions for future projects is much appreciated!

Specs (so far):
-10 Wheel Drive (4" custom wheels)

  • Middle wheel is dropped 1/16" and the outside wheels are raised 1/16"
    -6 CIM gearboxes (gearing still to be determined)
    -6061 Alu. frame/bellypan
    -5 1/4" threaded steel rods run the whole width of the bot to hold it together

So far it weighs 36.68lbs (final weight should be around 40lbs)

Looks great! A couple of suggestions, the black rails on the outside seem like they might be a little weak between bearings. I’d recommend maybe adding some triangle cross beams to increase the structural rigidity in those squareish holes on those rails.

In addition you might be able to take some more weight out of the belly pan with a more efficient lightening hole pattern such as alternating triangles. Squares are not the most rigid of structures so you’ll be able to remove more material with another pattern.

To take it to the next level maybe add mounting holes for electronics into the pan, in addition, if you have the capability with your manufacturing process, I’d recommend adding some flanges in there, flanges will increase structural rigidity by a remarkable amount.

Looks great and best of luck continuing on your robot design journey! :slight_smile:

Looking good. Might want to think about bumpers now and not later though. I am not seeing and good place for them to attach.

Are the wheels offset from center at all? Just looking at the picture it seems flat.

If you don’t already have one, adding an offset on the wheels will reduces scrub and drastically improve turning. :wink:

That is what those red plates on the corners are for :wink:

Yeah it does seem flat in the photo :stuck_out_tongue:

Yes, there is a 1/16" offset :slight_smile:

It’s great to see people practicing CAD! A couple questions and suggestions though. First, why so many wheels, and why custom wheels? Also, I’ll echo what Anthony said about mounting bumpers. From what I can see, I don’t think your frame would be able to adhere to 2017 bumper rules. I’ll also echo what Zach said about beefing up the outermost plates. They look a little flimsy.

This may just be my eyes playing tricks on me, but is the plate the CIMs attach to just a flange off the bellypan? Or are those two separate plates? If it is one piece, I’m not sure how I feel about that. On one hand, it’s probably light and sturdy, but if that bend is even slightly off of 90°, it’ll wreak havoc on the gear mesh. Spur gears don’t do well under even small amounts of angular misalignment. So if you have some way of precisely controlling the angle of that bend, go for it. But if you just have a manual brake, I’d steer clear.

In general, I’d say to always justify the complexity in your design. Complex and beautiful pocketing patterns may look great in CAD, but you’ve still gotta cut all that material in real life. Consider manufacturing when creating designs, and your fabricators will think much more highly of you.

Happy CADding!