Basic information please.

[Mjolinor]

I am in need of something to let me make prototypes and PCBs. Unsure whether to buy something or make something or convert my Chester MF-42B to CNC. Being somewhat of a nut I prefer the idea of converting my existing machine.

So I have come across the term "ball screw" but other than what it does I cannot find any exploded diagrams to show me how it works. Does anyone have any links?

Regarding stepper / servo power, how do I work this out? Only way I can think is to stick a spring weighing scale on the handles and measure the moment, is this the normal way to find the specification you need?

Why do these machines not use absolute measurement on the moving parts? Surely backlash will become irrelevant if the absolute distance from headstock to saddle or bed to cutter etc is measured using ultrasonic sensors.

First of many questions I am sure. Lots more reading to do before I even contemplate making any decisions.

[Cavalry]

Ball screws are pretty simple. They recirculate ball bearings around a thread to provide a very accurate nut. Accurate, very little backlash, very little friction. Everything a traditional threaded nut is not.

This cut-away shows how they work.

[Mavyryk]

Whether buy new or retrofitting check out our UltraDrive Servo system, uses a dual rotary nut preload design with custom AC Brushless motors....and/or our IronMan XE with comes optional with the UltraDrive system. For position detection we use magnetic linear scales/encoders with resolution @ 5 Microns (.0002"). I've added pics to show the real deal.

To give you an idea of the performance of the UD system, IronMan XE w/UD = 1,500 IPM rapid / 900 IPM cut @ .5G acceleration. The UD motors spin to a comfortably rated 6,000 RPM.

If you want to retrofit we offer UltraDrive packages to system builders. They aren't cheap, but do provide top performance and precision.

Check us out here for more details Blurry Customs