problem with chassis design

well I spent this afternoon and built a new chassis, but it seems that the two large wheels are hung in the air. Is there any way to make those wheels work smoothly?

[email protected]
thanks for your help and suggestions.

I can give an example of a holonomic drive that was built for Elevation:

https://vexforum.com/gallery/files/4/1/4/1/picture_005.jpg

C-Chan + 45 Gussets = great octagon

At least a handful of teams have built chassis around this construction method.
-Cody

I would like to point out that when you drive diagonally you will not go at a 45 because you have both small and large omni wheels with the same gear ratio on both (direct drive in your case). you could remedy both this issue and you “floating” wheel problem by using all large wheels or all small wheels.

~DK

well thanks for those suggestions, but there’s no 45 Gussets available in the studio at the moment. I’ve tried to use the same omni wheel but there’s a difference in height between C-chan & slotted angle.

Any way to avoid that based on the current chassis?

You could raise the wheels that are now the small omnis with pillow block bearings and make them large omnis or you could redesign the chassis to use one of the chassis kits that vex sells.

~DK

I’ve already raised those small omni wheels to the highest blocks.Maybe design another one is a better choice?

I was saying that you could use a pillow block bearing on standoffs to raise it above the holes in the chassis.

~DK

The reason I use the gussets is because they hold the C-Chan spacing exactly the same without even the slightest gap or dip. An “L” gusset and square construction method can be used as well but squares don’t look as cool as octagons.

guys I redesigned the chassis, fixed pillow block bearings to hold those wheels. it seems worked but the omni wheels on C-channel are still a little slippy. Will it work if I use washers to adjust the height?

Here it is.

Yes, we had a similar design with our robot, and we used washers to make it touch the ground just the right amount.

very nice to have a similar design, I’ll try that soon.

Any contact available as our team is going to join Worlds in Dallas?

Your best bet in this case would be to use washers. If you use washers to adjust the pillow block height make sure you also adjust the height of the piece of metal that the motor is mounted to. If you go to Dallas stop by my pit there, i’m the only member of team 1768 so if you stop by that pit and somebody is there, it’s me.

Glad to see you go this sorted out.

~DK

Well DK, interested in a talk about engineering, operating, etc? I mean may I get your MSN for communion?

I do not have one. Perhaps i could give you my email by PM if you want.

well that’s good. you can PM me with the email address and here is mine.
kongjw_1993#hotmail.com, remember to replace “#”