[handlewanker]

handlewanker, not disparaging all Chinese mills, this is why I specifically mentioned Grizzly and their variants by other names I. I know Tormach and Skyfire are Chinese, but those are not grizzly "variants" by other names. I know what those are and what they are not and why low cost mills are the way they are. For the price you are sacrificing something of course.

Anyhow any chance you'll stick a spacer under the column of the Skyfire?

Hi, no way would I even contemplate putting a spacer under the column.......but that does not mean I wouldn't like more Z travel specifically for the same reasons you stated..........getting drills and chucks out etc.

The SMV-0 is a different kettle of fish than the other mills, being already totally CNC, so what I thought about was to extend the Z travel by fitting longer rails and a bracket at the top of the column to enable a longer ball screw to be fitted.

This retrofit for more Z is not rocket science or surgery, as it entails just replacing the existing rails for slightly longer ones.......the existing ones already extend beyond the top of the column and making a bracket to mount the stepper motor and add support to the back of the rails where they go beyond the top of the casting.

This will give 100mm more Z travel and as it's within the design envelope of the whole mill it will not affect the overall scale of the mill.

At the very top you wouldn't want to be doing any machining as such so extending the rails would not put any strain on them, but the extra travel for tool maintenance etc would come in handy and the bracket is a simple welded affair easy to do...........just have to wait and see if it's really necessary.

I don't like the idea of a spacer as it's down where the column is bolted to the base and that is where you need to have the most integrity for rigidity.....that is my opinion for what it's worth, but there's no other way you could have more Z travel without a spacer on the other column mills like the X2 etc, due to them having dovetail ways which cannot be extended above the column top.

The previous post with the video about the Continental guy and the BF30 bolted to the wall was a good way to eliminate most of the column problems, and if a spacer was on the cards for the X2 I'd think that the bracket would also help a lot too.

Going to another option X2 wise, and I would have to think about the possibility of adding a dummy extension to the top of the column complete with dovetails and stepper motor mount.......the stepper motor has to be mounted at the top with a bracket anyway so it may as well be a block of aluminium with dovetails just to allow the head to move off the column and still be in line with the column dovetails.....there being no machining done at the very top as it's only to get the height etc.

The top of the column being a rough un-machined casting would need to be machined flat to accept the extension.
Ian.