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Re: All New Rotacaster's Omni-wheels to Test Drive!

Posted: 09 Dec 2010, 20:14
by mattallen37
Rotacaster is the company that makes the wheels. Follow some of the links to find out more.

Re: All New Rotacaster's Omni-wheels to Test Drive!

Posted: 09 Dec 2010, 20:35
by nxtboy
Ooh, I really need to get hold of some of those so that I can replace the wheels from http://holonomicwheel.com on my Robocup Junior robots¹. We had a lot of problems with traction last time, and the wheels tended to jitter.

How hard do you reckon it would be to modify the inset so that the wheels would work with the 4mm shafts (or the mounting hubs) on Pololu's Metal Gearmotors?

¹The 3D spin will load. Be patient!

Re: All New Rotacaster's Omni-wheels to Test Drive!

Posted: 09 Dec 2010, 23:24
by aswin0
mightor wrote:Aswin,

Do you think you could take some more detailed pics of your robot? I love how compact it is! I'd love to make one like it :)

- Xander
I placed a building instruction with pictures on my blog.

Re: All New Rotacaster's Omni-wheels to Test Drive!

Posted: 10 Dec 2010, 01:25
by nxtreme
nxtboy wrote:Ooh, I really need to get hold of some of those so that I can replace the wheels from http://holonomicwheel.com on my Robocup Junior robots¹. We had a lot of problems with traction last time, and the wheels tended to jitter.

How hard do you reckon it would be to modify the inset so that the wheels would work with the 4mm shafts (or the mounting hubs) on Pololu's Metal Gearmotors?
I'm starting to drool as well. And, it's hard to know how much stuff is too much stuff...

I imagine that with some Polymorph you could make a pretty solid mount that would also be removable and quite customizable. At ~$17 US dollars it's not too bad (or ~£6 UK)

Re: All New Rotacaster's Omni-wheels to Test Drive!

Posted: 11 Dec 2010, 03:35
by sparramc
aswin0 wrote:Hi,

I got the rotacaster wheels for my birthday. The ones with orange wheels. I'm really pleased with them. Below a picture of my platform. It is good fun to see what kind of movements it is capable of.
attachment=0]IMG_6719.JPG[/attachment]
I agree with Xander in that this design needs some more photographs. I've used PowerFunction Motors to scale my designs down.

I love the look on people's faces when they first see a Killough Platform in action. I've even sucked in the occasion mechanical engineer, including my father, who express that "puzzled vacant look" as the mental cogs engage!

Re: All New Rotacaster's Omni-wheels to Test Drive!

Posted: 11 Dec 2010, 03:44
by sparramc
nxtboy wrote:Ooh, I really need to get hold of some of those so that I can replace the wheels from http://holonomicwheel.com on my Robocup Junior robots¹. We had a lot of problems with traction last time, and the wheels tended to jitter.

How hard do you reckon it would be to modify the inset so that the wheels would work with the 4mm shafts (or the mounting hubs) on Pololu's Metal Gearmotors?

¹The 3D spin will load. Be patient!
You'll find the difference between the two manufacturer's wheels is vast in all respects. The Rotacasters are just Beautiful Piece of Functional Engineering.

:o If you flick the Lego Compatible Axel Hub out, you have a standard 1/2 inch, keyed bore. Anyone with a lathe could turn the bushes in a few minutes. Alternatively a good engineering supplier should have the suitable bush on the shelf.

Each Rotacasters can support a Dynamic Load of 35Kg.

Full design details here: http://www.rotacaster.com.au/omni-wheels---mounts.html

Re: All New Rotacaster's Omni-wheels to Test Drive!

Posted: 11 Dec 2010, 03:46
by sparramc
hassenplug wrote:Not sure if you noticed, but your killough line-following robot doesn't work very well. :)

Steve
Hi Steve,
This bot isn't actually a line follower, and the Ultrasonic Sensors are for looks (my 5 year old is in charge of Robot Appearance). I used that particular board because its original incarnation was a 'Whiteboard', which has a surface almost like glass. I wanted a slippery surface to test the new S45A type rollers for grip. My house isn't wheel-bot friendly as there seems to be acres of carpet. I'm working on a more definitive demonstration on grip which I'll post here soon.

There's quite a difference in the 'Grip Characteristics" between the S45A and the S65A type rollers. The S45A's are made of a lot softer and more sticky type of compound. Not designed for the concrete expanses!

Image
Top S85A, Bottom Left S65A & Bottom Right S45A