Long, Versatile, Milling Table for Mini Lathe (a Concept)

The concept

I can already hear some machinist saying to stop wasting your time and rather go and buy a dedicated milling machine. That's not my kind of fun. I like to work out ideas and try to make them work. That's my idea of what a a hobby is.

I have been mulling over different ways to turn my 7x14 Chinese Mini Lathe into a useful Milling Machine without taking up a lot of extra space - something I don't have. I have hunted all over and not been able to find a similar modification or attachment for the mini lathe. All the milling setups I see are very limited in the length of cut they can do. Then I wondered, "Why can't I use the length of the ways rather than the cross slide to carry the main axis for milling?" I then pictured a "milling wall" behind the ways, bolted down to the base of the lathe for rigidity. If you were to clamp a blank for a new milling table to the back "wall" it could even be used to mill out the initial T-slot table of at least 300mm long. Onto the lathe cross slide would be secured a CNC milling head in a vertical milling vise and angle plate (much like one sees on many of the lathe milling add-ons). I like the one that Steve Jordan has made for his Chinese mini lathe which you can see on his YouTube channel.

Whether my idea will work, I don't know, but it seems good to me and I hope to get the time and the funds to try it out one of these days, the Lord willing. If I can't get it made I hope to see someone else give it a go - and please, if you do, let me know that you've done it and how it works.

If you would like to download and play with the SketchUp model I made, here's a link to it in Dropbox.

https://www.dropbox.com/s/1907t3o3942zowg/Mini%20L...

If you can't access this Dropbox link please let me know.

I hope this article will generate ideas which I'd love to hear.

The basics that I believe are needed

The new milling wall will need to be very stable and rigid. The distance of the wall away from the back way needs to be set / adjusted so that the cross slide doesn't bump into the milling table. The milling spindle and cutting tool used must extend beyond the length of the cross slide. See the gap I have made in the drawing.

1. The wall needs to be secured well to the base of the lathe

2. A base plate of about 10mm (I think) will be needed to support the lathe bed and the new milling wall.

3. The milling wall should also bolt back into the lathe bed under the ways.

4. The basic wall could probably be welded up from 25mm angle iron with additional cross or vertical bars to support the final T-slot milling table. A solid 10mm steel plate would be better but maybe overkill.

5. When the blank for the T-slot table is fastened to this wall it can be trued up for milling by clamping a dial gauge to the cross slide and sliding along one of the sides.

6. The T-slots can then be milled out as shown in the images using light cuts and lathe's carriage power feed.

7. The new T-slot table can be permanently mounted from the back through the milling wall.

More possible modifications

Even while I've been drawing this extension I'm seeing modifications that would make it very versatile.

1. The milling wall could be hinged at an appropriate place with further stable supports down to the base plate allowing milling angles to be set - possibly up to 30 degrees. I have only drawn the milling wall as solid and flat all the way to the base (see image). Somewhere along the line of the top of the ways the wall could be cut and hinged to swing backwards to accommodate special cuts. There may be a best line to do this hinge on and it will need to be thought out and drawn first.

2. I don't think commercial hinges will be stable enough. One would need to make some solid steel ones with close fitting shafts. You don't want any movement on the table during milling.

3. The milling spindle could also be mounted in a vise that can be angled.

4. I think the T-slot milling table could be mounted on it own X - Y axis using simple CNC linear rail slides and lead screws.