Hi with my Chester version i made a washer 2inches diameter and used a standard nut with a long spanner or socket on it to get plenty of leverage.

Can confirm the stiffness is everything… … or so my back & knees keep telling me..

George.

Hi as i said this morning with the chester version i used a nut and a long ring spanner and built the Anthony Mount trapezium engine with it.

http://www.pollymodelengineering.co.uk/sections/stationary-engines/anthony-mount-models/trapezium-Connecting-Rod-Engine.asp

The ring would often vibrate down but the head would stay in place but when you are using the lathe it is useful to push the milling head 90 degrees out of the way.

Hi Bodgit

I have the Warco version of that machine. On my version the mill head casting clamps onto a smooth part of the Upright Column, just above the threaded bit, and not on the threaded bit by the look of things.

Quite a few times in the last 6 years or so, the mill head has jumped up and then violently swung out of the way when a milling cutter has got bogged down. Scary to say the least. But this has only occurred when I have lost concentration and taken too heavy a cut. Most of the time, light cuts, a sharp cutter, and a moderately firm tightening of the locking lever keeps the milling head in place without issue.

Further to Michaels question about the fit, have you taken the head completely off the machine and inspected the fit between the head casting and Upright Column. If the mill head keeps moving and you have done the clamp up tight then maybe the casting has been bored out too much and is a loose fit on the Upright Column. If you find a sufficient gap, is there any chance you can insert a temporary thin shim sheet or wire in there, and clamp up, and see if things improve. I am thinking just a little piece may make a lot of difference. Also, are the threads on the locking bolt in good condition and applying enough force. If the threads are worn or soft then maybe that is why you cannot clamp adequately? A more drastic step would be to lengthen the split in the casting a little (I've seen that done with the casting in the quill area). Also, maybe try a disassembly and dry off any oil or grease and see if that improves matters. Another drastic step, rough up the column to increase the friction between it and the casting. Careful you don't drop the plastic bevel gear during all this (the Warco guys did that to my machine and had to renew the gear).

Maybe you could secure a substantial bar/plate affair to the oil cover plate (blind flange) at the back of the headstock using studs and wing nuts. Drill and tap for a couple of studs in the mill head casting. You could then secure the bar/plate to the mill head casting with wing nuts. All can quickly be removed if you need to swing the mill head.

Or, drill through the mill head casting and a little way into the Upright Column. Then insert a bolt to secure the two together.

I only have to apply a 'quite firm' pressure to my locking lever to secure the mill head casting. Forgive me for saying, but you don't want to extend the lever to gain more clamping force as it could break the casting. It's a different place I know, but I was tightening up the Quill Lock (not applying much force) and one of the casting lugs broke off.

Keep us posted.

Steve