pic: "Omni Grenade" Wheel

[D.Fahringer]

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[GMKlenklen]

what could i use to make those?!?!?!?!

[geeknerd99]

My God!

I'm making sure my team doesn't see this.

Very cool though. What are those really?

[Simon Strauss]

its an omni wheel with grenade shaped rollers. http://www.chiefdelphi.com/forums/sh...olding+rollers check this out its another thread on the same thing but a different picture.

PS can we get these two threads connected to prevent more confusion.

[D.Fahringer]

Originally Posted by GMKlenklen

what could i use to make those?!?!?!?!

Maybe the threads should be connected thanks!

GMKlenklen,

I would be glad to give you the files needed to make your own, but you might want to use them for making a machined roller out of rubber as opposed to our cast version. You can read about what I and my student Sam Elzarian did at NASA Langley's Technology Development and Integration Branch. Using Rapid Prototyping techniques we, with the help of Gary Wainwright also in TDIB made molds and a fixturing device to produce these wheels very quickly. I am not satisfied with the cure times for urethane plasics that are soft enough for traction. So, if I were going to do this again I would invest the time to machine rubber such as you would find in a trailer store that sells trailer rollers to roll boat hulls on. They already have a hole through and are reasonably priced.

I love the concept of an Omni Wheel but I have to say to be careful what you wish for, the extra mobility you recieve in your robot is unfortunately the extra mobility in your robot that an opposing robot takes advantage of when he pushes you! In 2002 our robot had omnis in front and we had 8 X 8 traction wheels in back but a very wide track distance, we were somewhat hard to push sideways only because of that wide stance mechanical advantage. That robot was five feet wide and 3 feet long!

We in 122 have been solid wheeled for two years, still very manuverable and great at pushing I might add.


Here is the link:

http://www.chiefdelphi.com/forums/sh...t=omni+grenade

[NoSkaOnTheRadio]

this is by far the coolest looking omni i've ever seen. my team is considering a 6 wheel drive system this year, with two omnis as our front wheels. does anyone have any experience with that kind of system?

[Schneidie]

[quote=NoSkaOnTheRadio]this is by far the coolest looking omni i've ever seen. my team is considering a 6 wheel drive system this year, with two omnis as our front wheels. does anyone have any experience with that kind of system?[/QUOTE

Using two omni wheels on a 6 wheel drive could be complicated. If your robot has center wheels that are slightly lower than the other two (creating a teetering effect) the omni wheels would not have much of an effect on the handling of the robot, as they will only be on the ground about half the time. I definitely advise the omnis in the center or a four omni wheel with traction in the middle setup.

[Madison]

[quote=Schneidie]

Originally Posted by NoSkaOnTheRadio

this is by far the coolest looking omni i've ever seen. my team is considering a 6 wheel drive system this year, with two omnis as our front wheels. does anyone have any experience with that kind of system?[/QUOTE

Using two omni wheels on a 6 wheel drive could be complicated. If your robot has center wheels that are slightly lower than the other two (creating a teetering effect) the omni wheels would not have much of an effect on the handling of the robot, as they will only be on the ground about half the time. I definitely advise the omnis in the center or a four omni wheel with traction in the middle setup.

We ran a six-wheeled drivetrain last season with no drop on the center wheel. The outer four wheels were all omniwheels and we had no trouble with this arrangement at all. Our machine was a dumper, so we were less at rish for being pushed sideways than a machine that needed to stay stationary to score.

Using just two omniwheels at one end of a six-wheel drive is another viable strategy that offers a bit more resistance to pushing than our arrangement, but correspondingly is more difficult to turn. However, you're effectively shortening your wheel base to ~18", so turning ought to be pretty easy in any case.

[Josh Goodman]

lol those r awesome, we gotta get some on our bot next year!!