Cheap balscrew sought desperately - drem desktop CNC machine on the way

Hi!

A am working on building a small desktop mill with ball linear bearings
custom made to fit the design.

I have already made MK 1 machine which is working excellent on a 2A
steppers. I can easily get 50ipm rapids using acme leadscrew and acetal nut.

Work envelope is 230mm (X), 160mm(Y) and 130mm(Z), very high repeatability
and precision due to preload ball bearings and it would be low cost to build
compared to other known desktop systems. I intend to produce and sell kits
for cnc enthusiasts. It would be ideal machine for precision craftsman, pcb
mill/drill, RC modelmaker....

It will be also possible to use it as CNC lathe if equipped with proper
spindle.

As to be the best quality possible and low cost desktop design I am now
searching for a 1/2 inch or if possible even smaller (12 or 10 mm) ball
leadscrew of the lowest possible cost.

My goal is to build ball supported machine for a price of slide guides and
acme screw drive..... This would make better performance and precision for
the same price.

THK, STAR, HIWIN, RELIANCE were too expensive to fit the concept. I could
get 16mm / 5mm pitch leadscrew from ISEL automation at a very good price -
but it is way too big for my design. So it is low cost ball bearing or
backlash adjustable acetal nut. If I can find low cost balscrew it would be
great.

What I am looking at is 50$US per axis assembly including balscrew of 350mm
(14 inch) in length.

For comparison - I can now produce single axis assembly for 15$US

Any help is greatly appreciated!

You can also contact me off list if you want at: kos(at)email.si

Matjaz