Thread: 3D field milling

Originally Posted by elanjacobs

(any ideas Kuffy?)

Hehe Elan, I came to this thread to see what you did and to also ask "how you did it???"


I agree with you 100% that the physical machine can do it, because although it looks complex. it is nothing more than a series of lines and arcs moving across three axis instead of the usual two XY axis's, (5 axis's if you wanna get super fancy and make a wicked looking youtube film using $1,000,000 worth of equipment!)


I controlled my machines through the NC500 interface directly after sending a bunch of lines and arcs to it from AutoCAD. The only 3D shapes I made was a straight length of handrail which was really just a series of passes using a ballnose/cove bit at different depths. It took me a couple of hours to work out the Y axis offsets and Z axis (depth of cut). It was like 150 straight lines offset 0.2mm or so. Then we scraped the final piece smooth.


The other "3D" work I did was plain jane mortising. I wanted the bit to give me a 30mm deep mortise but I can't do that in a single pass. asking the machine to do it in multiple passes really sucks because it cuts a 10mm pass, then lifts the entire spindle up and out of the wood and plunges back in again to make the 2nd 20mm deep pass and again for the 30mm deep pass, and all of this takes ages. So i programmed it with a bunch of lines back and forwards 50mm wide. So at that point the router bit will traverse 50mm -X and then 50mm +X over n over again. So then on each line of code, I changed the Zs and Ze values (Z axis start and Z axis end), making it lower the bit 6mm at a time so it operated much the same way as a bog standard round end slot mortiser. Much quicker and it allowed me to take lighter cuts and effectively ramping plunge movements which puts very little stress on the bit compared to plunging straight down.


I think it "may" be possible by sending a file NC500. But the file code will show up in the...hmmm...??? "ISO" screen. I think it was ISO...it's a screen where you can plug in oldskewl GCODE. It will probably still give alsorts of issues that you will have to remember to work around for each new job, if it works at all.


The Zs and Ze only gives a straight line. I tried all sorts of things by trying to get a 3 point arc to travel only along the X axis whilst the 2nd of the 3 points would be set lower on the Z axis..NC500 kept tellin me "nuh uh! you cant do that!!"

It's actually even simpler than 3-axis arcs; the way I've seen it done in videos is just straight passes in the X axis with all the motion in the Z axis and stepping over 0.5mm in the Y axis for each pass.

We did the same as you did for the handrail for some bar stools; 180ish lines at 0.5mm offset. Took about 3 hours to run each one, but it worked.

NC500 is actually quite powerful; the manual for it shows it'll do helical interpolation as well as 4th axis milling/routing in the edge of the workpiece with an aggregate head. I'll have a look to see if there's any mention of z axis arcs.

As long as I can get some files that are known to work I can try and get it to read them.

helical interpolation? are you talking about the helical plunge it can do? I think it was the 3D_LA and 3D_RA settings. The problem with it was it would plunge at the normal feed speed rather than the entry speed. So instead of plunging at 1000mm/min, it would plunge at 15,000mm/min!!!!! I used the aggregate for cutting sausage (SOSS) hinges into butterfly extensions for dining tables, was an easy way to do it but the way to set up that aggregate head in the computer was a bit of a head spin

Helical interpolation for milling holes with a router in a z-axis spiral, not the 3D lead-in/out
Aggregates aren't something I need to worry about, ours doesn't have the 4th axis. Pity, 'cos I'd love a cutoff saw.

I've been promised that the next machine we get will be 5 axis, so looking forward to that when the time comes

Turns out NC500 only allows linear Z axis motion, not arcs. Bugger

I wonder if I could get a different CAD/CAM program to talk to the machine instead

Yeah the linear Z motion is what I was talking about earlier. changing the Zs and Ze values. I tried and tried but it refused to let me do anything but a straight line! Assuming the machines controller can handle information involving lines and arcs on different axis and planes, you would need the software to know how to talk to your very specific controller. Which means needing a supergeek to figure it out, or Biesse to hand over the information willingly. I tend to think it might not be possible, because if it was possible they would/should have made Biesseworks do it. I was rather surprised to hear that Biesseworks still needs to go through NC500

I think it's the age of the machine that makes NC500 necessary to translate the new format to old. NC1000 might support more Z axis shenanigans, but for what we do it's in the 'want' pile, not the 'need' pile.

AFAIK, the new machines are a direct interface to Biesseworks (which itself is now outdated) and the new bSuite software