DIY mill...

[Robin Hewitt]

I'm surprised you get that much flex.. do you know how much, and is it the tool flexing or the mill? what feed rate etc?

Everything bends, the trick is to minimalise it :D

I don't usually post pics of where it goes not so good, but what the heck...

1: Backlash on a change of direction, looks like a ditch, actually 4 or 5 thou deep

2: Chatter, an echo from the roughing out, should have changed speed.

3: Tool flexing, you can see where the tool tip bent inwards and wasn't completely removed by the finishing pass. You know it's the tool becae it gets deeper towards the tip.

[irving2008]

Everything bends, the trick is to minimalise it :D

I don't usually post pics of where it goes not so good, but what the heck...

1: Backlash on a change of direction, looks like a ditch, actually 4 or 5 thou deep

2: Chatter, an echo from the roughing out, should have changed speed.

3: Tool flexing, you can see where the tool tip bent inwards and wasn't completely removed by the finishing pass. You know it's the tool becae it gets deeper towards the tip.

Thanks for sharing Robin, helps know what I'm looking for... :) btw, #3 are you sure the tool flexed rather than had excessive runout or the work was offline? I'm not sure I understand how the tool tip can bend into the work, unless it was catching because of excessive feed rate

[Robin Hewitt]

Hard to tell, the way the tool tip digs in much further than the rest makes me suspect tool bending. Could be wrong. I shall find out when my new CNC controller is up and running with absolute positioning from the digital scales.

I was working on the Mk2 version over the weekend, finally burst in to life around 7pm Sunday evening :D

I have a fancy algorythm for CNC milling I want to try. Problem is it needs lots of memory and processor speed, so it has to be a USB device running under XP. I'm taking a crash course in Visual Studio 2008 from a geek :D