Power up down mechanism best option?

[Bcwill250]

Good day folks.  

I'm hoping some of you who have done this in various ways will chime in with what works best and what hasn't.

I have a range road 36 mill and have replaced my cable crank with a 12v winch which has made life much easier. However I'm finding there is still a lot of variability in the travel speeds and I spend a lot of time trying to make tiny movements to get the mill head where I want it.

I'm planning on upgrading the up down motion and am struggling with the best way to do it.

I'm considering large ballscrews on both sides and think this would eliminate the issue when on cables of having to go down past the cut and come back up to ensure the cables are tight.

Alternatively to that I was considering putting a shaft through the top of the millhead with a sprocket on each side that would raise and lower the head on chains instead of cable. This would smooth things out and eliminate cable wear. (Also making it easier to integrate computer artworks) 

Accurate repeatability is important to me and a minimal amount of messing around to get to the right cut level.

Any input appreciated.

Cheers

[jpassardi]

Using a DC PWM controller will allow variable speed control. They're about $20 on ebay.

[maineshops]

Im using a 12v window Motor on my Oscar 18 . It has a worm gearbox on it. Been using it for years. Works fine. Dan