Something has been bothering me. I spent a lot of effort to get the hole in the drivers concentric with the tyre, but then who knows what happens when the axle passes through that hole? Indeed, I’m fairly certain the axles are neither concentric nor perpendicular to the tyre. So, as I have to make two more drivers anyway, I thought I would see if I could do better.
My idea was to mount the driver blank on the axle before turning the tyre. The axle would then be as close to the centre of the tyre as I can make it, and the tyre would be perpendicular to the axle, guaranteed.
Now, I’ve been struggling to get a solid joint between the axle and the driver, but I got some new flux from Acklands Granger, that seems to do the job with stainless. So, I cut a slug of driver material, drilled a hole in it, soldered it to some axle material, and gave the whole thing a spin on the lathe.
I expected the solder joint to give way, but that’s not what happened. If that didn’t happen, I expected the form tool to chatter like an excited squirrel when forming the tyre. Instead, the torque proved too much for the friction holding the 1/8″ axle in the lathe collet. Even with a freshly sharpened cutting tool, the whole part spins in the collet at the slightest kiss.
I guess I’ll go back to plan A, although I feel there is something here.