keyway in axle or new axle??

I wanna install a disc rotor on my axle but could i get a keyway cut into axle or should i just buy axle with keyway already cut

you could make them part of the rims

How?

make a flang that comes off of ur rim and have the brake rotor bolt on to that

Ok thanks

What type of axle are you using that isnt keyed?

The only thing about making the rotor part of your rim is that you want to make sure it is dead centered. Otherwise the rotor will "hop" and destroy your caliper.

The keyway isn't long enough

If you're careful about it, you can cut your own keyway. Having done this myself with great results, I offer the following-

This is best done with a Dremel or other mini die grinder. Use a speed square to mark the shaft, ensuring straightness. Mark the shaft with a scribe. Use a cutting disc to trace the scribed lines, cutting down no more than half the depth of the key. Switch to a grinding wheel, narrower than the key, and slowly hog out the material between the slots. Work slowly, using minimal pressure. Stop frequently to check your progress with a length of keystock, and to let the shaft cool.

As doc said. I've cut my own, just take your time. Used an air grinder with cut off wheel.