Today i pressed the bearings into the KOP wheels and then went to grab the axel to see them spin. I found out that neither the thin axel or thick axel is the correct size. the thick being to large and the skinny not wide enough. Am i missing something or is there a mistake in the KOP?
No Mistake. You need to “adapt and overcome”
The easy way out is to head over to the Home Depot or Lowes or the home improvement location of your choice and get some aluminum tubing with a
3/8" ID and a 5/8" OD. Slip that over your 3/8" axle and the KOP bearing should fit nicely.
Im pretty sure 1/2" axels work if you use the KOP AM wheels and bearings. Ill have to check tommorow though when I have the parts infront of me.
Yes, the KOP wheels with bearings have a 1/2" ID. And no–a 1/2" axle was not included in the KOP.
Those nice pieces of Igus aluminum shaft are NOT axles - they are used with the igus motion sontrol stuff included with the KOP. Try this: Get the bigger shaft, and go into the kit and find the beige tube thingies that fit onto the shaft. Then slide it back and forth… Hey, a way to move things in a straight line with low friction!!
Don
Of course. You have to go get one yourself. If they put it in the kit it would make it to easy 
Hopefully people caught on to the fact that all those parts were in one bag, and that the shafts werent in the drive train bag
its no big deal, i have .5 in axel on order and the problem has been solved, i just was making sure i wasn’
:yikes: t crazy
Our wheel bearings have an inside diameter of around 0.499" and our axle material is 0.500", so it’s time for the old emery paper.
wow…I’m glad we have a lathe in the fab shop, and a backup lathe in my garage…I did a little experimental turning on some 3/8" id x 1/2" od steel tube I had and discovered you need to reduce the diameter by about .0015" to get the KOP bearings to slide onto the tube.
Tubular axle = way cool
You can get DOM (Drawn On Mandrel) tubing in different wall thicknesses. OnLineMetals has it. .5: OD by .095 wall thickness is about $3./foot. Local suppliers would be cheaper.
(This size, incidentally, could easily be internally tapped for a 3/8" bolt.)