Is it ok to drive this Quill with a ballscrew?

I am converting an old XLO knee mill and I have a question on driving the quill.

Is it ok to drive the Quill from this point (Picture)



The machine I have had an air over hydraulics system that had cylinder and chain drive to drive this point. (picture)



I thought about using a 20 to 1 or higher gear reducer and driving the quill handle but the kits to convert use a ballscrew, I just don't have any information on how they connect the quill feed.

Anyone have links to pictures using a ball screw method?

How does the builder of that machine prevent the quill from rotating in the casting?
If it's not guided by a KEY in a keyway, the quill will try to rotate in the casting.

Converting that design to any high production method is likely to ruin it just that much faster.

It's a manual mill....really it's just a glorified drill press.... keep it for what it was designed to do.

Probably good advice but I already have a manual Bridgeport mill.

I will replace the broken quill spring first and then reconsider.

Thanks for the reply, I had not thought it was designed for keeping the
spindle from rotating. Never had a spindle apart so i don't really know the fine points of it's design.

If I do use a ball screw I will make a ball slide with a linear bearing to drive it.
From using a manual quill feed I don't think there is really that much vertical force on the quill especially with smaller tools. I guess if you did 3D milling with thousands of quill moves it would wear it out pretty quick but I really just want to do some milling a few times faster than manual even if it just does typical manual type moves it can run a job while I do something else. The X and Y already have ball screws and the backlash is less than .0005.

That looks like what Lagun does to there mills.

That's exactly how I drive my quill on my J-head BP, works great. Just make a replacement for the feed trip doo hickey that would hold a ball nut and you are off to the races.

Craig

bmklawt said:

That looks like what Lagun does to there mills.

Click to expand...

It is also I think the way a Bridgeport conversion kit works. I guess since the quill is really made for high stress lateral forces driving it from one edge isn't going to break it. My spring is broken and the quill is quite heavy at the moment. I did have a ball slide I put on the table with the ball nut resting under the quill rotation stop and turned it with two finger force a few ounces and that lifted the 100 lb quill with ease. Once I get the quill spring replaced the only downward force will be the force on the cutting edge of the bit and from what I am familiar with in cutting aluminum and steel if it takes much force to cut the bit is not sharp.

craigS said:

That's exactly how I drive my quill on my J-head BP, works great. Just make a replacement for the feed trip doo hickey that would hold a ball nut and you are off to the races.

Craig

Click to expand...

Any chance you have a picture?