Problems with a Koil Kutter

I finally received my Koil Kutter from Dave, but the rings are coming out with little nics in them.

I've mailed Dave but I thought I just check to see if anyone else has had this issue and what can I do to resolve the problem.

I'm using a Proxxon to cut them and have changed the blade but it's still doing the same thing.

I attached a photo showing what the problem is.

Thanks
Ani

A couple of things come to mind. Is your blade running absolutely straight? And is the arbour mounted absolutely straight on your drill (the two little adjustment screws are for this).

Lastly, what are you using as lubricant? I'm not sure that's the problem though - I've only ever seen that type of cut from a dull or damaged blade.

You are using mechanically wound coils aren't you?

Thanks George,

I'm winding the coils using an eletric drill and have rechecked the arbor and made sure everything's straight.

Dave has asked if the coils are tight, if we're using a constant speed and is the kutter perpendicular to the coil

do you always cut koils that are the same legnth? i.e. 4 inches in? could that be an issue?

4 inches sounds too long to me - and this might well be the problem - you need to have clear space between the blade and the start of the coil when you switch the power on. I generally reckon on 3 1/4 inches - though you may have a longer holder than I do. As a simple rule, leave enough of a gap for there to be a good 1/4 inch between the edge of the blade when you put it in the slot (you can just mark this with a sharpie on the reverse to check) and the beginning of the coil. Switch on, and bring up to maximum speed and power before gliding the blade across the lubricated coil.

I hope you're only experimenting on copper!