I poke around here a bit. I love the wealth of knowledge and inspiration I see here. Amazing stuff!

Last year I finished my second (or first 'real') CNC build. A purpose built aluminium router. Built to machine aluminium parts and make use of high spindle speed and fast feeds. Basic spec's as follows:

- 3 axis, Gantry style machine. x2 servos and ballscrews in X, singles in Y and Z.
- 900mmX x 450mmY x 180mmZ envelope. All steel fabricated construction, stress relieved and machined surfaces. Its about 800kg for a tiny size, so its certainly stiff enough for my needs.
- 3.5kw 18k spindle. Fine for initial testing, but hungry for a tool changer now.
- Currently running JMC 400watt 60-30-40-48 integrated servos running 2:1 into 10mm pitch ballscrews. Ex-telecomunications power supplies feeding lots of amps into these thirsty motors.
- Centroids Acorn control. I love this thing.

Honestly, I have been pretty happy with the performance with it so far. The JMC servos throw the gantry around at terrifying acceleration and the whole thing is heavy and stiff enough to take nice cuts in 6061. Rips at 23,000mm/min feeds.

HOWEVER! I am having issues with getting faceted/jaggered machined surfaces on curved cuts (bores, circles etc.). (I struggled to upload an image, but let me know if you don't know what I mean). My research so far has lead me to believe it could be one of the following or a combination:

- Servos aren't tuned (well yes, they aren't tuned, if anybody has a detailed account of how to tune these JMC's (preferably in English. there seems to be lots of German videos on youtube, but auto translate struggles with technical terms, its actually pretty funny)) I played with it a bit even after days of reading about servos and only really made them worse through the tuning software...

- Centroid smoothing control. Played with this with little success. It did smooth out the jerky accelerations on corners which is cool.

- Steps per revolution is too low on the motors/controller. I played with this, absolutely no change going up or down.

If anyone has any ideas on this issue. Or someone knows the dark arts of very affordable servo tuning (JMC integrated) I'd be keen to chat.

Many thanks!! And cheers for the cool forum.