Using RC Brushless motors as spindle

[Jonathan]

4 jaw chuck on the lathe ?
Are you measuring the outside or the inside of the chuck for runout ?

You should be measuring the inside and i would measure at the extremes of the taper to see if you have different amounts of runout at the two points.

It wouldn't fit easily on the lathe - it's only a C3 mini lathe with 4" 4 jaw chuck. I probably could have got it to fit, but it wasn't worth it since I needed the rotary table to do the semicircle on the outside anyway. Wish I had a lathe like yours...made so many things on the same one at school.

I used the lathe with 3 jaw chuck for a few of the bearing mounts for the screws - carefully designed the shape to fit the chuck easily.

I measured the runout inside. I'll try again like you said.

Just tried cutting with it. 7mm two flute cutter and some scrap aluminium. Using 0.5mm depth/width of cut it was happy. Sometimes 1mm, machine is a bit too wobbly to do more at the moment. I'll post pictures in a minute to save a thousand words...







The motor drew 30w extra whilst cutting, 100w idle.