OK, lets make a  wheel!

Here is a crayon drawing I made of hte general idea, with some extras



Differences being that were gonna skip the robot its attached to, and the pulley thats atached to it, and instead of a nail were gonna use a bolt.
Here is what your gonna need to make this wheel and where to get it all

Rubber O rings
 Automotive part shop
6"x12" of galvanized flashing
 Building supplies store
2" x 1/4" bolt
 Building supplies store
2 x    1/4" nuts
 Building supplies store
2 x    1/4" washers
Building supplies store
box of misc lamp fittings
Building supplies store

So, here we have our stuff. The rubber O rings will be used for the outside of our wheels.




Step 1 : Layout

1.1 Measure the diamiter of your O ring (oops I have two, tee hee) mine is 1-3/4" we want to take half of that (7/8") and add a little less than the thickness of the ring (my ring is 1/8 thick, so I'll add about 3/32") your safer to be a little big here than small.

were gonna do a layout something like this on our sheetmetal:




The green circle will be the same diamiter as your rubber O ring, the outter circle will be about half hte thickness of your O ring.

First we need to make a middle
1.2  Use a punch to put a dent in your sheet metal , put it far away enough from the edges that there's gonna be room to draw out the rest of the wheel.



1.3 Set a compas to the size of your ring, and draw the inner green circle on your sheet metal. Use the dent in the metal for hte point on the compas.



Put the ring over the circle to make sure the size is right, mine was too small, prolly cause I drew is 3/4" instead of 7/8", fixed.

1.4 Draw the outter ring for your wheel, this will be about half the thickness of your ring larger than that first circle
Once again, use the dent for hte point of your compas.



I suggest using a finer pen than I did :)

Step 2 : Drill hole for hub

Next we need to drill hte hole in the middle for hte hub, this hole will be 25/64". use the dent as the guide for where the hole goes, try to make sure it dosn't move on you or your wheel will be wobbly. You can use a hand drill or a drillpress, I suggest a drillpress if you have one.




Step 3 : Cut out the wheel

Cut it out, around the outter circle. Dont try to cut it out perfect hte first time, cut it out roughly first.




Step 4 : Cut the tabs into the outter edge of the wheel

The next step is to make the tabs that will hold the ring on our wheel. I suggest these tabs be about ever 3/8" all the way around.
Cut these from the outside to whats the green circle on the top diagram ( the inner circle we drew)





Step 5 : Bend the tabs

Now we need to bend the tabs, they need to be bent in alternating directions. If the last two tabs go int he same direction, you can cut one of them in half and bend the other half the same way.



Step 6 : Put on the O ring.

Get hte O ring on, you might want to adjust some of the tabs to fix some bigger bumps in the wheel.





Step 7 : Put pipe fitting through middle.

Next slip the pipe fitting through the hole in teh middle of the wheel and tighten up the nuts.



Step 8 : Put on robot axle

This will slip onto the bolt we got.  You can use hte double nuts and the washers to hold hte axle to the robot




Step 9 : Make another one!

There aren't many applications for 1 wheel, so make 2, or 3, or 4, or 6, make them different sizes, do anything!
If you stop when your done step 5, you can use with with a bigger O ring or a rubber band as a pulley, with the teeth they grip the belt really well, and really dont want to slip