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Topics - jofriedl

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1
CS-Lab / Jerky movements in complex toolpaths.
« on: July 22, 2016, 12:31:09 AM »
Hi,

  I have retrofit a 1979 matsuura mc500v with a cs labs csmio/ip-a ethernet analog motion controller. The machine was originally capable of accelerating at 40in/secsec and 400ipm rapids.

I currently have the acceleration and rapids set at 80% of their normal values.

I have look ahead set to 200 lines, but I have tried all combinations including 1 line and 1000 lines.

I have CV turned to on. All other settings related to CV are off but I have played with the settings ad nauseum.

I have CV feedrate turned off, although I have tried to run programs with it on.

The problem:

When running a toolpath of any complexity, The machine tends to jerk unpredictably at moments peppered throughout the program. It does not cut in a jerky movement through the whole program, just every few seconds and sometimes throughout entire sections of the the toolpaths. These jerks will always happen in the same places in the toolpaths. These jerks will trigger following errors if I do not have my max following error set somewhere around .05" These jerks do not happen when I'm running simple toolpaths, but only when I'm running complex toolpaths with lots of small arcs and linear movements.

My attempts to fix the problem involve:

What works is to run the program at much lower feeds and rapids. This results in a 40 to 50% longer cycle time. Since this is a production machine in high volume production shop, this is not an acceptable solution. I have also set the acceleration rate at half the value that the machine was designed to run at, but this just makes the jerks less prominent. This also results in a rougher finish when moving in arcs and contours. This is also unacceptable. I have also tuned the servos over and over, trying many different combinations in an effort to achieve the perfect tune. The tighter the servos are tuned, the more pronounced the jerks are. I have also uninstalled and reinstalled a different version of mach3. I am currently running V R3.043.062. I have also installed the lastest version of the firmware for the cs labs controller.


My theories:

I suspect that something is driving the servo drives far beyond their configured limit in brief pulses in order to move the machine along to the correct position. It is almost as if mach or the motion controller are ignoring the acceleration limits when moving in small increments along a contour.

Another possibility is that the look ahead function in mach is missing lines of code. Although this sees less likely since the program will be running along smoothly but then jerk in the same spot every time.   


Response from CS labs:

I have recently made a video outlining the problem and posting it on my youtube channel. It can be found here.

https://www.youtube.com/watch?v=VEE7v3ewd3U

CS labs can't seem to figure out the problem.

2
CS-Lab / Jerky movement between strait movements and curves.
« on: June 09, 2016, 07:13:53 PM »
Hey there guys,

    I've got a matsuura mc500v thats running under mach3 control with a csmio/ip-a controller and I can't seem to get the machine to smoothly transition between straight lines and curves. It's really always had this problem but I am needing to run it faster than I have been and the jerk is so bad that I'm tripping a following error (have my max following error set to 10000).

I'm using mastercam to generate the G-code. Here is a sample below. I can run the code, but only at a rate of 75 ipm. Mach will run smoothly until it gets to the G02 and g03 and suddenly there's a jerk than I can hear clear across the shop. It I try at 150ipm the machine will oscillate like crazy, throw a following error and trip my reset. Its almost as if Mach isn't looking ahead at the circular portions of the path. Or that when the machine arrives at a G02 or G03 command the machine ignores the axis max acceleration settings. ANy thoughts? Thanks for any and all help!

X-3.2416 Y-4.4236 Z.2779
X-3.2487 Y-4.4109 Z.2753
X-3.2552 Y-4.3979 Z.2727
X-3.2608 Y-4.3845 Z.2702
X-3.3469 Y-4.1632
X-3.3617 Y-4.1251
G3 X-3.3646 Y-4.1183 R.1125
X-3.387 Y-4.0863 R.1125
G1 X-3.4046 Y-4.0547
X-3.4184 Y-4.0237
X-3.4276 Y-3.9972
X-3.4336 Y-3.9743
X-3.4376 Y-3.9542
X-3.4423 Y-3.9199
X-3.4446 Y-3.8896

3
*****VIDEOS***** / Coolant pump, enclosure and lights upgrade!
« on: April 26, 2016, 11:25:42 AM »
<iframe width="560" height="315" src="https://www.youtube.com/embed/owJ2zx9cuTg" frameborder="0" allowfullscreen></iframe>

4
*****VIDEOS***** / Encoder swap video
« on: March 12, 2016, 07:33:44 PM »
Hey guys. I just swapped out the encoders on my Matsuura MC 500 be retrofit. The controller needs a 5v signal and the stock encoders were 12v. Machine works like a champ now.
http://youtu.be/G07ck2G7PgE

5
CS-Lab / Choosing a 4th axis for the ip-a
« on: January 08, 2016, 08:15:19 PM »
Hey guys,

     I'm looking into adding a 4th axis to my matsuura mc500v retrofit. Since the ip-a is an analog controller, I'm not sure there are a whole lot of options out there for guys wanting A and B axis. Most if not all the 4th axis I've seen on ebay appear to be digital in nature. Anyone know of a good older model 4th axis that will take + or - 10v? Thanks!

jonathon

6
CS-Lab / missing encoder pulses with the ip-a
« on: December 23, 2015, 01:20:38 AM »
Hey everyone,

   This is truly a shot in the dark, but I'll post it here anyway. I'm having trouble with my machine missing steps. Ill run a program about an hour long, and when the machine is done, it has lost its zero point by 10 to 20 thou. I have the pulses per rev set correctly so I know its not that. I am using optocouplers to convert a 12v signal to 5v signal. I'm wondering if anyone else has experience doing this and have they had trouble with missed pulses?

Jonathon

7
CS-Lab / ENC threading module setup for ridgid tapping
« on: December 14, 2015, 01:34:50 PM »
Hello everyone,
 


    I'm back with another question. I'm installing an encoder on my matsuura mc500v so I can do rigid tapping, but Its looking like I need to install the encoder directly on the spindle rather than the spindle motor. The spindle motor has a belt drive and I think the reduction is 2 to 1 from the motor to the spindle. There is a perfect spot on the spindle motor where the 20 mm shaft pokes out of the top where an encoder could be mounted. Attaching an encoder to the spindle rather than the motor would be a retrofit nightmare. The drawbar at the top of the spindle prevents an encoder from being mounted there and to mount it anywhere else would require me to pull the thing apart and remove the bearings. This is not an option. In the ENC manual it states that the encoder must be mounted such that it reads 1 to 1 to the spindle.  Why is there no way to configure the enc module for a reduction drive? This seems pretty intuitive. Thanks for any and all help.

8
CS-Lab / Position creep in all three axis / csmio/ip-a
« on: October 13, 2015, 10:17:59 PM »
Hello again Guys,

       I can't seem to catch a break with this retrofit. Today I actually got around to cutting the first real part on the Matsuura MC500V retrofit with CSMIO/IP-A. It was a fixture plate for some parts I plan on making. About halfway through the program I noticed two things that must be addressed.

This first was a jerkiness in arc movements when I tried running faster than 30 ipm. I think this either has to do with rough servo tuning or I need to uncheck constant velocity mode in configurations. I would have tried this today, but I didn't have internet at the shop so I couldn't  research and trouble shoot the problem. If its a servo tuning issue, I might need a bit of help. These are the first servos I've tuned and although I'm using the auto tune application in the CS plugin, I'm still showing slight errors. (I think I get 20 for a max error when oscilating at full speed and acceleration over an inch) When I try to adjust the PID parameters to 'tighten' up the tune, The servodrive makes a high pitched oscillation sound. When I think about all the fiddling I've done with the tuning of these servos, I realize that I should probably start a CS labs servo-tuning thread.

The second problem is a bit more scary. It involves position creep. As the machine worked its way through the program, I noticed that my z depth seemed to be steadily increasing. At the end of the program I confirmed my suspicions. Sure enough, not only was the Z axis creeping, but the X and Y were creeping as well. Its like the machine was missing steps but only in the positive directions for all three axis. After the program was finished (the fixture is useless) I re-homed the machine and suddenly my zero point was back were it started. This leads me to believe its a missing steps problem, but why would it only miss steps in one direction? In the case of the X axis, it was missing steps and thus over-traveling while under load and moving at 20ipm rather than at rapid speed.

Thanks for any and all help!

Jonathon

9
Brains Development / DL06 tool change safety brain
« on: September 04, 2015, 02:23:15 AM »
Hi guys,

    I need help designing a brain that is based off the state of a single input (tool change limit switch) that will prevent Mach3 from moving or attempting to start the spindle in the event that the limit is not active. The 16 carrousel tool changer is under the direction of a DL06 plc. The PLC and mach3 communicate via modbus upon activation of the M6 macro.  I have the tool changer working at this time, but I want to implement a few safety measures in the system. I'm imagining a scenario where an inattentive operator triggers manual tool change movements when the spindle is active or the axis are moving. I'm also paranoid that of mach sending the Z axis crashing down through the changer while the carrousel is  in the extended position and linked up with a tool.  Basically, I don't want Mach3 to so much as twitch if the carrousel or the spindle dog move from their resting state limit switches. But I also don't want to send a stop command to Mach3 whenever the switches go low. This would stop the program. Where could I send the command in brains without disrupting the M6 macro or the program in general?

I'll also be designing a brain that will cut power to the relays controlling the pneumatic solenoids whenever the machine axis are moving or mach3 is actively sending a run command to the spindle. I think I have a handle on this brain though. I'll simply create a brain that will set the output controlling the relay power to low if the axis velocity DROs have a non 0 value or if the spindle is active in mach.

Thanks for any and all help!

Jonathon

10
*****VIDEOS***** / PLC tool change running!
« on: September 03, 2015, 12:09:10 AM »
This is just a brief demo. I'm going to try and upload a longer video tomorrow.
The machine has a csmio/ip-a controller and an automation direct DL06 PLC which runs the tool changer.

<iframe width="560" height="315" src="https://www.youtube.com/embed/jSiewzLw_mU" frameborder="0" allowfullscreen></iframe>

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