I'm using the Graet Planes 3/16" axles with collets and grub screws on my Cessna (big 5" wheels)...anyone got any suggestions on how to ensure the wheels don't come off?
I've filed flats on the axles, but was wondering if it's possble to drill through them and use a split pin to retain the wheels instead.

I have used these with collets and grub screw, not lost one yet, a split pin would ensure they wont come of.

Flair used to suggest putting a brass pipe as a sleeve on the axle, thru the wheel and out past the end of the axle. You then drilled this to put a split pin in. I have seen collets come off. I usually use a tight fitting washer and solder it in place.

Use locktight or even cyno on the collet grub screw...