Here is a machine I built for pattern making. It is controlled by Mach 3 and DSPMC. It has AC servo motors, a water cooled spindle and 8 place auto tool changer.

It is used industrially. It is quite fast, 48m/min rapid feed rate. Typical 3D contouring feedrate in wood is about 10m/min with long tools. Generally the tool length is the limiting factor. It uses a lot of long tools to get deep down the sides of patterns. Many of the patterns are built up in layers, some up to 500mm high.

Here is a link to a couple of YouTube videos showing it in action.

http://www.youtube.com/watch?v=ZJzpPVXfoUg

http://www.youtube.com/watch?v=d8wf1fvHtxE&NR=1

And some shameless self promotion at my website

http://bdgengineering.weebly.com/3-axis-router-0672.html

Excellent machine build - more pictures please.

Tweakie.

Hello piv,
very nice machine. I have just one question. What is causing that sizzling noise from the servos? You can hear it in the first video. I'm asking because that noise is also coming out of my servos and I'm also using dspmc. Is that normal?

Peter

I like it!   

Brett

The servo noise is pretty common on a lot of servo systems. It depends how "hard" they are tuned. If you go for a soft tune, ie lower gains, lots less D, then the noise goes away but the response is nowhere near as good. Its all a compromise.  If you can use encoders with more counts per rev, then its less of a problem. These ones are 12 000 counts per rev (3000 lines) or about 1 micron resolution. The new Fanuc machines and some other systems Ive used use million count encoders or sine/cos systems like Hyperface or endat or BISS and they are a fair bit quieter and more responsive. But 10 times the price. Really they should be quiet but its hard to achieve in all cases. I did have an even "harder" tune but it was tripping the drives sometimes, so I pulled it back a bit and its ok now, but like you say a bit noisy. I will look into it a bit more.  Ive done lots of tuning with the DSPMC and havent seen much if any effect from the feed forward terms. Ive used feed forward (position control lagless they call it) on a big system with Beckhoff Twincat and its awesome. Hopefully Rufi can help us with the feed forward stuff.

Hi,

There is a new feature called "low pass filter" on the latest plugin.  I have found it to be very helpful in getting rid all the noise from the servo motors.  It will still leave you with a very "hard" tune.  Please let me know if you have already tried this, for larger motors we we set it to 10-15 and for medium motors set it to 5-10.

Andrew
MachMotion

No I haven't tried the low pass filter, but I did see it. I will try it to see how it works. Thanks.

Here are some more pictures

Rufi says that feed forward works but it might need a really big number to have an effect. I will give that a try except that the machine is at the customers and I wont go there for a while yet.