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.

Re: Chassis Lift alternative, getting over barrier
 

Bend your own?

Re: Chassis Lift alternative, getting over barrier
 

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.

Re: Chassis Lift alternative, getting over barrier
 

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.

Re: Chassis Lift alternative, getting over barrier
 

Like this

======X===========================X=====
........==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.

Re: Chassis Lift alternative, getting over barrier
 

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

Re: Chassis Lift alternative, getting over barrier
 

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.

Re: Chassis Lift alternative, getting over barrier
 

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

Re: Chassis Lift alternative, getting over barrier
 

Re: Chassis Lift alternative, getting over barrier
 

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

Re: Chassis Lift alternative, getting over barrier
 

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

Re: Chassis Lift alternative, getting over barrier
 

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

Re: Chassis Lift alternative, getting over barrier
 

296 also used them one year.

(And yes, they have indeed been considered.)

Re: Chassis Lift alternative, getting over barrier
 

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.

Re: Chassis Lift alternative, getting over barrier
 

We did in 2004. Check out the link below!

http://www.chiefdelphi.com/media/photos/17077

Matt

Re: Chassis Lift alternative, getting over barrier
 

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

Re: Chassis Lift alternative, getting over barrier
 

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.

Re: Chassis Lift alternative, getting over barrier
 

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?

Re: Chassis Lift alternative, getting over barrier
 

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.

Re: Chassis Lift alternative, getting over barrier
 

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.

Re: Chassis Lift alternative, getting over barrier
 

Hmm... For the skid plate, could you possibly use some simple 80/20 corner brackets? Considering that there is overhang before the front wheel, your frame will approach the barrier first. Now, if you bolt the bracket just in front of the wheel on both sides would that 45 degree angle of approach be enough to raise the bot over the bump?
:confused:

Re: Chassis Lift alternative, getting over barrier
 

Skid plates are out. Since we are doing a wide frame, we need the wheels as close to the front and back as possible. This leaves little room for a skid plate.

On a wooden mock-up of the barrier the robot did poorly, but our weight distribution was also poor. Battery was all the way in the back, so the bot got stuck straddling the barrier. Going to try centering the battery, and then pneumatic wheels (shipping).