AM14U3 Kit Chassis Mods to traverse DEFENSES

[MrForbes]

We spend some time trying to figure out how to go over the DEFENSES, and finally came up with this. It seems to work so far, although we just got it running, and the chassis is not anywhere near it's final configuration, and there's not ball handling stuff on it. We intend to make a short robot, the electronics will be on the side near the front, the ball will go down the center of the robot (in one end, out the other).

The lower four wheels are mounted on aluminum brackets, we were very careful to keep the center to center distance for the belts just right, so it took a few days to perform the modifications.

What ideas have you come up with to deal with this?

https://www.youtube.com/watch?v=yWUq1fw4mCE

[MrBasse]

That is a very cool solution, we played around with a staggered 10 wheel drive in a configuration like that but able to go both directions easily. When belts turned out hard to track down we went back to what seems to be the favorite of pnematic wheels.

What's your plan for bumbers on the front? What will make up your rigid mouth out front?

[MrForbes]

Right now we're working on just a few pieces of wood screwed into the ends of the frame, then the original C channel across the wood to tie it together. One neat thing about this design is that it puts the chassis up into the bumper zone.

[GeeTwo]

We're planning a 10 wheel robot this year. 8 8" and 2 4" wheels in a 2015 KoP chassis. Yes, I know that the diameters on one side add up to 36" and the robot is only 32" long (before the wedge that we were going to add even before AM made it an easy COTS thing). Our wheels lie in 4 planes rather than two, and we currently have different treads for the inboard pair of 8" wheels than for the corner wheels. We haven't tested it yet in the real world (vice CAD), but we're on track to do so this Saturday. After this post, I'm rather sanguine that we'll be able to cross the rock wall, moat, rough terrain, and ramparts as easily as the low bar.

Our ball pickup is going to double as lifter and lowerer to get through the portcullus and cheval de frise. Our basic designs just needed some minor tweaks to make this (virtually) work.

Finally, we're leaving the drawbridge and sally port as too easy to defeat via cooperation between two or three robots with working drive trains to waste a mechanism upon.

[MrForbes]

Interesting...one of the ideas we had was to have two kit chassis modules next to eachother with wheels overlapping! But it turns out to be kind of difficult to implement, and it doesn't seem to be necessary.

We're also planning on having a mostly passive ball intake, we really don't want to have to make any extra mechanisms. Too much KISS on our team, I suppose, and I'm probably to blame.

[RichQuinn]

That's a terrific solution for the KOP chassis. Great job with lateral thinking.

Those crossings look downright graceful compared to many, and if your drivers can be trained to keep an easy pace, it should pay off in long term machine durability.

Regarding the lack of bumpers up front and excessive rear overhang: It's funny to look at the pre-drilled chassis and wish you could just shift the entire pattern one way or the other. Would make life a little easier.

Great progress. Good luck with the rest of the build.

[Mr V]

Great solution!

[DaveL]

Very nice!
I noticed you minimized the open spaces between the wheels. That seems to be the key to going over the moat.
We tried a skid plate with our 6" wheels and had some minor success.
Just got 8" pneumatic wheels in today, so will be some time before we can try them out on the real bot.

Can you post video going over the ramparts?

Dave

[MrForbes]

We haven't made the ramparts yet, that's something we need to get done this week.

[evanperryg]

Originally Posted by MrForbes

We spend some time trying to figure out how to go over the DEFENSES, and finally came up with this. It seems to work so far, although we just got it running, and the chassis is not anywhere near it's final configuration, and there's not ball handling stuff on it. We intend to make a short robot, the electronics will be on the side near the front, the ball will go down the center of the robot (in one end, out the other).

The lower four wheels are mounted on aluminum brackets, we were very careful to keep the center to center distance for the belts just right, so it took a few days to perform the modifications.

What ideas have you come up with to deal with this?

This is great! We actually came up with a similar solution with our 8" Pneumatic 8WD. Front wheel is raised about 2 inches, making the pass over the rock wall and rough terrain easy. We also crammed the 8 wheel profile into as short of a length as possible, to ensure continuous wheel contact with the defenses.

[Bruceb]

have you put any weight on that chassis and retested?

[MrForbes]

We have the 20 lb weights on the front of it, and the electronics enclosure on the rear...and I don't expect our robot to be much heavier. (oh yeah...another 15 lbs of bumpers!) But this video was taken yesterday about an hour before I left, so no, we haven't had a chance to play with weight on it yet.

[GeeTwo]

Originally Posted by MrForbes

Interesting...one of the ideas we had was to have two kit chassis modules next to each other with wheels overlapping! But it turns out to be kind of difficult to implement, and it doesn't seem to be necessary.

We don't actually have two modules, but we have increased the width of each side module by 1 1/2" and switched from belts to #25 chain to make room for two ranks of wheels. We gear down 2:1 from the drive axle to the dead axles, which makes the 4" wheel on the drive axle go the same speed as the 8's. We're designing a tortoise to face off against the hares. We just have to do some testing to make sure we're not a tortuga.

[rich2202]

Have you tested over metal, which may not give you as much traction as wood?

[MrForbes]

That's on the agenda for the next day or two. We're making the chassis be the final size right now, then we can do more testing.