Denford Software & Machines

Customer Writes .................

We have a MICROMILL IST which runs off DOS software. This is my first time using this machine and have been teaching myself how to use it through the manual. I have a project in which I would like to make a notch in a sample and have written a CNC file to do so. When attempting to simulate the file, I am getting an "Invalid Billet Size" error. I have the machine settings set to Metric and I also call G21 for metric in my program. I am wondering if there is actually an issue with how small my sample is... my test stock is 2.5 x 2.5 x mm and 38 mm in length. My actual samples for when I run the real programs will be smaller (1.78 x 1.78 x 19 mm). What is the resolution of this system? Is it unrealistic for me to think that I will be able to write a program asking the machine to cut a notch half the width of my sample?

There is a minimum billet size that can be defined with the [BILLET command (can't remember what it is off hand though).
But this command is only used for the graphical simulation and does not affect the machining process.

So I suggest you change the BILLET command to something larger (increase your 2.5mm dimensions to 25mm) The graphics may look odd but the machining will be correct.

What is the resolution of this system?

The software will probably work down to 0.001mm (1 micron)
The current Micromills (which haven't changed much over the years) have 319.96 steps per mm movement so the best machine resolution would be 0.003 (3 microns)

Cheers Mr Magoo

Ah Ha! Turns out the minimum billet size you can define for simulation is 10mm.

Mr. Magoo,
I recently found an Old Micromill in a closet at my school. I know it needs to run DOS but have not been able to find the manual for it, I found the software but haven't been able to understand how to use it. How did you teach yourself to use the machine? Where could I find the manual?

Thanks
Mathteach47

A search for DOS Milling Manual turns up with this.

viewtopic.php?t=1636

This download will also be useful (as it was originally sent with micromill machines to the USA)
viewtopic.php?f=15&t=2284&hilit=micromill+manual