Vibrations in circular interpolation

More
04 Dec 2019 14:34 #151999 by tommylight
@Jools,
Not the same thing, you have resonance from motors, he has chatter from something loose only on one side of the XY plane.

Please Log in or Create an account to join the conversation.

More
08 Dec 2019 22:26 #152342 by Samu_97
Goodnight.
I could only check to machine different arches, and surprise, the vibration disappears when the radius is greater than about 40mm.
The vibration disappears completely if I use an tool less than 8mm, although it use the same depth and lateral pass.
That makes me think that perhaps the step between teeth of the larger tool induces vibration (or also that they force the machine too much)
Soon I will try to machine at different points of the table and cut an internal diameter, I not have time yet.

Responding to the user Jools, I tell you that was my first suspicion.
I had the same problem, the vibration was also produced machining in the air. The solution was to introduce greater freedom of tolerance to movements, with a G64 in my code G. (if anyone knows how to do this by default in linuxcnc I appreciate it)
Now only the vibration appears during machining and in the quadrant of which we are speaking.
My question regarding the resonance you comment is, this harmonic vibration should disappear or move from that band of rpm if I do a higher microstepping and consequently the motors induce a lower vibration. I'm right? It was the first thing I tried and the result was identical. I do not know.
Thanks.

Please Log in or Create an account to join the conversation.

More
08 Dec 2019 22:39 - 08 Dec 2019 22:41 #152344 by Leon82
You can put the g64p value in your preamble or set it to post out on every program.

Size of the cutter can effect radial chip thinning. Also bigger cutters require more horsepower and rigidity
Last edit: 08 Dec 2019 22:41 by Leon82.

Please Log in or Create an account to join the conversation.

More
12 Dec 2019 21:28 #152554 by jools

My question regarding the resonance you comment is, this harmonic vibration should disappear or move from that band of rpm if I do a higher microstepping and consequently the motors induce a lower vibration. I'm right? It was the first thing I tried and the result was identical. I do not know.


Mine only produce it at low rpm's. For me it's in the 400-700mm a minute region. The problem with arcs and circles is that at some point one axis is at low speed when the other is at high round the points of the arc so you can't power through it as such.

I had backlash on my x axis so I'm double ball nutting that one to remove it, it was quite bad so hopefully this will sort it.

Once the mechanicals are done I'm going to tune the PID loop in the hybrid stepper motor driver system. Mine are from leadshine so have this ability. If your's do then maybe this is an area to look at.

For me vibration only occurs on the Y axis. As mine is a gantry this axis moves the X and Z axis too so pushes the most weight. The Y axis has the same motor and that is perfect.

Jools

Please Log in or Create an account to join the conversation.

Time to create page: 0.080 seconds
Powered by Kunena Forum