Re: Custom Wheels
 

Blue Nitrile. That first picture in this thread shows some, though it's just about indistinguishable from the wheel. Lots of teams use that.

Re: Custom Wheels
 

Interesting, Most wheels tend to wear out from my view. Our team uses custom wheels with Ployurethane and they've got perfect grip and don't tend to wear easily.

Polyurethane is a great material; we did a Cinco de mayo parade with the robot last year on a hot day and walked on the streets and our wheels didn't wear at all. We'll Be doing the parade this year again ( Tomorrow ):D

Re: Custom Wheels
 

I am not going to go into too much detail because I will make a more detailed thread when they are complete.

To make the two part mold I started off by building the clay half way up the master wheel. http://i.imgur.com/Y1UbrUj.jpg After a good coat of mold release I poured half of the silicone in. Those dimples are called keys, they keep the two halves aligned.

After it cured I took the clay and master wheel out, cleaned up the mold, and put the wheel back in. http://i.imgur.com/TyhgwAN.jpg The rest of the silicone was poured in and 20 hours later it was done. This was the finished mold http://i.imgur.com/FmC5ng8.jpg It didn't turn out very well because I rushed through the clay part.

Re: Custom Wheels
 

There is also this stuff http://www.andymark.com/product-p/am-2611.htm

I felt it on 1218's intake roller and it seemed really grippy and soft. I am not sure how well it would hold up on wheels.


I saw these at champs and they were awesome. Here they are with the tread attached. http://i.imgur.com/3W0z2Ik.jpg

Re: Custom Wheels
 

Live-axle version of 971's wheel. Tread is blue nitrile attached with a zip-tie. If your team has the resources to do this, I highly recommend it; not having to use rivets is excellent.

Re: Custom Wheels
 

Actually it's a live axle design, the drive sprockets are mounted on the hex shaft as well, this way we don't have to design a way to attach sprockets to the wheel.

The tread is put on in halfs, so that we can split the wheel off the axle. The tops and bottom of the wheels induce some vibration, but it's not too bad.


If you want a comparison, watch

this video from PNW champs (Before 6wd)

https://www.youtube.com/watch?v=AlG1JUmWnlk

Then this video from CMP where the robot was full 6wd (Note that the mount for the Gopro changed, so there was some more vibration from that as well)

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

Re: Custom Wheels
 

I was wondering how you put the tread back on. Once the tread is on, the wheel is one piece, right? Do you attach tread while on the axle?

Re: Custom Wheels
 

It looks to me like the second video has you driving a lot more erratically. Is this just the extra vibration I am seeing or is that a result of the change in drivetrain? In the first video you seem to do a much better job of tearing across the field and making blocks and stops.

Re: Custom Wheels
 

The point I was trying to make with the videos was the side to side vibration, which wasn't as obvious before 6wd. As far as how our driver drove the robot, we had just been talked to about High Speed Ramming, so we were likely holding back a bit. The overall strategy was also different between those two matches, at PNW we were playing nearly straight defense except when finishing (which didn't happen due to defense) so the driver had a much clearer picture of what to do. Personally, I thought the PNW match had a lot of missed blocks, whereas at Champs it wasn't as bad.

Tearing across the field was actually better with 6wd, we had more acceleration and better control when turning the robot. The Omni's we had on the back two wheels at PNW were horrible because they would break loose and cause us to skid out of control.

Re: Custom Wheels
 

How much did the entire process cost you?

Re: Custom Wheels
 

From the calculations I made it would be about ~$10.75 Per complete Wheel

about $5.5 Per Rim and ~$5.25 Per thread.


These wheels we've made have been great because they are Durable, long lasting, great on the field, and cost efficient.

Re: Custom Wheels
 

What kind of wheels are they? Machined with molded tread? Do you have a picture?

Re: Custom Wheels
 

Here's a Picture from Last Year's ( 2013 )

This year's wheels we decided to get rid of the Bolt Hole and Just Hold or rims together with Snap rings on the Hex shaft and also drilled a hole on the center of the hex shafts to screw in a bolt with spacers.

I will upload pictures of our 2014 wheels soon.

Re: Custom Wheels
 

How does the material you use work on carpet in relation to the other types of traction material?

Re: Custom Wheels
 

Compared to other material I believe the material we use has great traction on the carpet
One of our mentors who gave us some history of the traction materials said that out of all materials wedgetop and roughtop were great for the carpet but wore out super easy; and while designing the wheel we wanted it to have great traction/grip on the carpet, easy thread replacement, cost efficent and YELLOW.
So far we haven't had to swap out threads our threads from last year are still good they just don't seem to wear out; im assuming these are good as wedge/roughtops/Nitrile but very long lasting