Chassis Lift alternative, getting over barrier

A couple of ideas are rolling around in my head (yes, just a couple) about getting over the barrier.

The easiest seems to be a lift kit… but they’re out of stock. Would a short section of KOP c-channel (~4") bolted below the chassis be strong enough to hold the wheels? It would raise the chassis from 3 3/8" clearance to 4 5/8" using 2011 8" wheels, plenty to go over the barrier. A skid plate of some sort might still be need to pop the wheel up a bit on approach.

We can’t test it, and see if it works, but I’d like to hear some veteran opinions on the matter.

Bend your own?

Our experience bending metal last year was miserable. I figured that since the c-channel already has consistent hole placement, and profile, it would make for a good quick replacement.

Since the lift kit is out of stock as you say, reach out to other teams in your area. I’m sure some older teams have some left over from previous years & would be happy to donate/trade them.

Like this

…==O==… ==O==

= is the frame
X is the normal axle position
O is the new axle position?
. is just something I had to put in to make my ascii art work.

I think that this would be just fine.

Good idea.

Joe J.

6061-T6 is not meant to be bent, and it will want to crack. Try 5052-H32 instead, it bends beautifully (but machines poorly)

I’m confused as to where you are getting the numbers for this. Is this with 8 inch wheels (instead of the KoP 6")?

We were hoping to give the robot a “lift kit” to get over the bump as well.

Sorry for not putting that originally. Yes the 8" wheels

Has anyone considered using Tri star wheels for this purpose?

Our team is repurposing some older Kit bot C-channel frames to do exactly as you propose.:slight_smile:

No offense to your idea, but those wheels look insanely heavy.

If built right(meaning not overly big) they could easily weigh less than half of a 10" mecanum. They worked in 2004(340 & 1218).

296 also used them one year.

(And yes, they have indeed been considered.)

1511 is currently doing this with 8" AndyMark pneumatics, at least for our mock/proto chassis. I believe we figured that you would need additional spacers in-between the two c-channel segments, in order to fit hardware for the frame like screw heads over the barrier. We’re currently shooting for 3/4 to 1" of clearance.

How much do the standard wheels wear down? That could possibly affect your spacing.

We did in 2004. Check out the link below!


tri-wheels are elegant when to come to high powered robots that only climb stairs but
but is terms of the our games they are wicked overkill even in 2004 they were

the killer part in my mind is the affect on acceleration and the ability to turn

We mounted the 8"ers on the c-channel bits, but have had some issues actually getting the robot running. Here is a pic of the bot under construction.

A tri-wheel drivetrain would be a bit heavier and thus diminish acceleration for a given powertrain, but I don’t think it would be detrimental or even all that noticeable. And I don’t see how a tri-wheel setup would turn any differently as compared to an 8WD with equivalent geometry.

Can you explain your thoughts?

Do keep in mind that the barrier is steel. You may find it difficult to climb up for this reason alone - test on an actual bump.

We’re also going to experiment with skid plates to help raise the incident wheels a bit.

I think this is going to pretty much kill the idea of using only 2 CIMs.
If it takes more than 2-3 seconds to cross a barrier we’ll probably be facing an opponent blocker, and we’ll need all the torque we can muster.