pic: 6 wheel suspension

[joeweber]

loading photo ...

[Eugene Fang]

Very cool.

Just a few questions:

1- Do you have springs that try to keep the chassis straight? or is it just gravity that keeps the thing flat.

2- Since it is foldable (meaning two points on the chassis will not stay the same distance from each other), how would you attach an arm/manipulator to the chassis?

[Akash Rastogi]

Lol,

weird thing is that I was playing around with 401's robot design tool on their website a few hours ago and thought of this idea and drew it up. Hehe

Guess my idea came out pretty good didn't it? Looks good, please do elaborate about the actual suspension system/springs. What type of load does it need to be under to actually take effect?

[R.C.]

Man that is cool, is it springeddd on both sides or just the front???

[sgreco]

That's very cool. I'm glad to see that you got it to work.

That would have been really cool in '06 and '07 with the ramps.

How much does it weigh?

[joeweber]

Lots of questions. Vidio http://www.youtube.com/watch?v=urFsD0gA1D4
Its not a good vidio but it works.

More pictures and drawings of the ball diferental http://www.team1322.org/ideas.htm

I will be taking pictures of the ball differental soon for our web sit.

The picture with the aluminum plate is for demostration only. A frame would be attached to the two rods and one of the drive halves will be slotted to allow the suspension to work. I have not made the slots yet but will. The whole idea is to allow for ramp use with mecanum wheels and also give alitle more pushing in forward. The final design will have the gear boxes go right into the mecanum wheels. This means if I order everything from bain bots and anndy mark and make the side plates I can throw the whole thing together in no time. The ball differental was easy to make. The wheel took awhile to make but we had all the stuff show in our inventory.

[Raul]

That is pretty cool.

Team 356 also did something similar in 2003 but without the Mechanums. http://www.chiefdelphi.com/media/photos/14812

Also back in 1999 team 157 had an 8-wheel articulating drive base that could climb the platform by manipulating the height of the front and rear drive wheels. Wish I could find a picture of that one.

[ggoldman]

I am glad you got some use out of the design tool

(P.S. I made it)

The drivetrain looks great!

[R.C.]

Originally Posted by ggoldman

I am glad you got some use out of the design tool

(P.S. I made it)

The drivetrain looks great!

Is there anyway to download that???

[AdamHeard]

Thinking about it, I think it will be impossible to accurately "tune" the ball differential.

If you put it on blocks, the load on the wheel will be substantially different than when on the floor, and if it looks like it's working, it most likely won't when you put it on the floor.

If you try to tune it on the floor, the floor will make it appear to match the speed of the outer two wheels, regardless of whether or not it actually contributes.

[ggoldman]

Originally Posted by rc_cola1323

Is there anyway to download that???

Currently, the only version available is through the website. I do have the flash program still if you have a circumstance that does not let you see the website.

-Gabe

[joeweber]

To test how tight they have to be we will prop up the mecanums up with casters and than run with just the omni wheels. This should give us a good idea on the amount of slippage under pressure.

In studying drive system that teams have used through the years I have found that the mecanum system is the best except for the following items.
1. When going up ramps you must hit it square, but with this suspension you can hit it At an angle.
2. They are not great for pushing. With the added omni wheels it will give a little help (not a lot but some is better than none). We were in a match with our standard drive system and was up against a mecanum system and every time we tried to push and block them the just went around us like we were not their.

The good of the system out weighs the bad by a large amount. We have use omni drive in the past and are familiar with it but are just learning about the mecanum system and we need to know what to look out for with problems. Please let as know.