[llilrex]

I am wondering if anyone here has attempted to make a ballscrew? Also I am used to working with hardened ballscrews, but I know that some ballscrews are made from relatively soft material, and bearings can even be made from plastic for special applications. I have found it difficult to track down specific detail on cutting forces for routers as it has a lot to do with how the router is used. I am very tempted to cut my own to give it a try and see how it will perform over time. I am thinking about doing a regular circular profile instead of a Gothic arch and using a double nut to adjust the backlash. I can look up wear characteristics for 1018 steel to get an estimate as to the expected life of the screw if I knew what the load is. I am just wondering if anyone here has experience that might save some headache. my current plan is to machine a .2 inch lead on a 1018 bar that is 1.250 inch in diameter. I plan on using a .1875 ball in a .250 track. It depends on how well I machine the screw to decide if preload will be with springs or thread offset on the nut. I figure I can measure lead error and using computer compensation for it. I am hoping that my equipment can do a good job on that though. The nut will likely be a few single turn circuits with 3d printed recirc inserts.

[ger21]

What's the point? It's a lot of work to do, top end up with an inferior product?

I have found it difficult to track down specific detail on cutting forces for routers as it has a lot to do with how the router is used.

Depends on spindle HP, and what you are cutting. With a 3HP or smaller spindle, it's probably not more than 20lbs. With a 10-15HP spindle, it can probably approach 100lbs or more.

[Eldon_Joh]

what machine would you be trying to make this on?

[llilrex]

ger21, thanks for the force estimate. I was originally thinking about a gantry router with about 2 hp spindle. I might try it on a metalworking lathe project I am working on. I have an old textbook on machine design that estimates tool pressure, might be a good starting point. as far as the point... its fun. besides I learn new techniques this way. I might even end up with a thread whirl-er, who knows.

Eldon_Joh, I don't seem to have a shortage of projects to use ballscrews on, I have a slant bed CNC lathe project I am working on that has a 10 inch swing 12 inch between centers.

[llilrex]

Well I decided to do it 30mm x 10mm lead, here are some pics. I constructed a steady rest for the project and made a form tool. There is a small amount of chatter. I am looking forward to test its properties.

[Coetzee]

Well I decided to do it 30mm x 10mm lead, here are some pics. I constructed a steady rest for the project and made a form tool. There is a small amount of chatter. I am looking forward to test its properties.

This is cool. I'd like to hear more about your experiment's results.

[A_Camera]

What's the point? It's a lot of work to do, top end up with an inferior product?

I guess the point is curiosity. Most of what we (hobbyists) do is "pointless" because if you calculate the hours spent it is almost always cheaper to buy a ready made product then to make one, and that goes also for a CNC, not just a ball screw. Of course, I know making a ball screw is pretty complicated and requires more than what most of us have, but I definitely understand why he is making one and I would definitely make one if I had the proper machines and the knowledge/patience.

[A_Camera]

Well I decided to do it 30mm x 10mm lead, here are some pics. I constructed a steady rest for the project and made a form tool. There is a small amount of chatter. I am looking forward to test its properties.

Cool project, so how was the result, or maybe still not ready? How did you manage to make the nut? I think that is more complicated than the actual screw, but maybe I am wrong.