My PP3 is having issues. The x and y are shutting down after a few minutes into cutting. I have to shutdown the power to the driver board and restart. everything is fine if you do a dry cut, but once you load in a piece of foam and start cutting eventually it stops. The program shows its still cutting but the machine physically stops. the stepper motors are staying cool but I noticed the red lights on the driver board glow dim and there is a voltage drop to the steppers. Also whichever axis quits working, that stepper is no longer locked.
Any Idea's?

 

The symptoms sound to me like your power source may be breaking down.

Do you have a voltmeter? I would start by checking the 24V out of the power supply to see if it is dropping off for some reason.

Have you gone thru your controller setup and set the pots for the drive current on all your steppers? Have you measured them with a voltmeter?

 

I am getting 24.6V from the power source. I set the stepper motors to 2.5V. There is no rhyme or reason to which X or Y axis will shut down, sometimes both sometimes only one of them. Sucks to get half way through a cut and have a failure.

 

I assume you have checked to make sure all your connections are tight? Double check every stepper motor wire going from the stepper motor into the controller.

You mention you can dry run the cuts and the steppers don't shut down? I can see maybe the X axis might act a bit differently under load, but the Y axis is not much different when air cutting vs cutting material aside from a slight load induced by the foam on the stepper as it cuts.

The X carries a heavier load and the pivot arm pressure and other factors may cause problems there.

Could be multiple issues going on.

Can you put your hand on the gantry when moving it with the controller to add a load to it say in the Y axis and not have any binding? What about the X?

 

I second checking the connections to the Easy-CNC board. I almost put one in wrong. I actually had it on top of the clamping. Fortunately I caught it before it caused a problem

Tim

 

Setting up a new machine takes a bit of patience and a lot of checking and rechecking everything, and I do mean everything!

Start with simple and work up. You usually can't just jump in and start cutting foam first thing.

It has taken me days to get my machine in tip top working order but now it is fine tuned and working flawlessly. Yours will be too before you are done and you will learn a great deal about your machine in the process.

Start with one axis and write some gcode to exercise it back and forth over and over. You can do this pretty easily in notepad.

For instance copy and paste the following Gcode a few hundred times into a file and load it to exercise the Y gantry... (moves the Y axis 20 inches at a feed rate of 80ipm and then returns it to home)
Y 20 F80
Y 0

Same can be done for the X axis... (moves the X axis 10 inches one direction then back)
X 10 F80
X 0

You can play with the values to run slower, faster, shorter or longer distances, with and without foam in the machine etc.


Repetitive movement along each axis will break in the machine and get the parts seated well and ferret out problems such as things working loose or not adjusted right to start with.

Make sure you can easily move the gantry along the Y axis with power off and stepper disconnected from the controller. Same for X and Z.

There a ton of variables in getting a CNC machine up and running. Any one can cause havoc. If you got in a hurry with your build and didn't follow a step closely, you will end up paying for it later down the line.

 

I stretched the pressure roller springs because I couldn't get the rollers lowered enough to where they would still engage the foam and not be under too much load. I have checked the connections to the board a few times and they apprear to be fine.
I have been fiddling with it for the past few hours, now I don't have to have any foam in the machine for the Y axis to randomly quit (unlock) but the X axis it working fine regardless if it is driving foam or not.The Y axis run smoothly and easily when moving it by hand. I will work on it tommarrow and if I can't get it solved, I will have to assume the driver board is bad.

 

Swap the x and Y wires and see if the problem follows the change. That is the easiest way to check the board

 

I didnt hear a beep but I have heard a few times what sounded like more of a R2-D2 noise when the machine was setting idle but I probably couldn't hear it when it was running. I don't know where it came from. My settings are feed 100, rapid traverse 800, jog 300.

 

Same here. Mine is running like a fine Swiss watch as well. You really don't want your rapids going that fast even if they could, especially when you get into harder materials.

I run 130 IPM rapids and 80 IPM cuts for most foam products. I also turned down the initial speed and acceleration so that the steppers ramp up to full speed and do not try to yank the material like a someone pulling a tablecloth out from under the dishes if you get my drift.

The high traverse speeds from part to part can cause slippage of the material or cause the machine to loose steps. I prefer to have accurate cuts over speed any day, especially when cutting Depron at $10 a sheet.

 

Understatement of the year 2010!!!

(coming from a measly MKII owner, so what do I know, but funny nevertheless )

 

didn't matter, all the way down to 150 ipm traverse and it still shuts down on the Y axis. I don't know what is causing the stepper to unlock on the Y axis. I measured the voltage at TP1 on the Y axis stepper when this happens and it still reads 2.5V. I need to contact Mark and see what he suggests.
Other than this problem the machine runs smooth.

PS... no foam air cut, no problems, foam being driven with air cut...problem. But I appear to have minimal foam pressure, I think any less and the foam will slip.

 

Still no luck. I worked with it for three hours last night. The X and Y stalls with the steppers unlocking after about 30 lines of code. The Y fails more often then the X. The driver board power light on the failed axis ('s) glow dim compared to the ones that work.
I was able to do one dry cut while driving foam with no failures but repetative attempts failed. Everything runs cool as a cucumber. Either two bad steppers glitching the driver board or the driver board itself is bad.

 

Are you using Planet-CNC or Mach 3? When you say the steppers unlock, I assume you mean they are no longer able to hold and the shaft turns freely, is that true? Mach3 will only process a limited number of steps without a license, that is why I ask.

Were the stepper motors ever hot at one time? If so, you could have damaged the windings. A resistance check will confirm if that is the case. Measure your Z axis pairs with a digital ohmeter and then compare to X and Y. They should be very close in value to one another. If not, you most likely have a fried stepper.

Since the Z axis is not causing any problems, you can switch the outputs from the controller between the Z and one of the other axis to determine if the problem is in the stepper or in the controller, but I would do a resistance check before doing that.

The Mecktronic boards were famous for loose chips and chips going bad back in the MK1 days. I have been told that the new boards have improved, but maybe not... If you can ascertain the problem is in the controller and not the stepper, you might be able to get Mark to send you another one to try.

 

Yep, sounds like a noisy connection to me, or a loose controller chip. Is the controller board mounted securely, and the wire bundles? Or is something flopping around and tugging on a wire?

 

There is a voltage sag, you can hear it with the spindle on. but the problem exists regardless if the spindle is on. I originally though the same problem as you mentioned and when things get up and going, I will have to run a separate extension to the rotary tool.
Mark and me have come to the conclustion the problem lies most likely in the driver board or possibly the CNC USB card. He is going to test both to see which is the culpret.
All the stepper connections were golden so I am sure I eliminated that possibility, not to mention the failures happen pretty much so after about the same time or G code run.

 

Hi everyone,
This is my first time ever posting in any forum, so please be gentle.

I just got mine up and running last night. The first thing I checked was the voltage, and at the 4 o'clock position that Mark suggested, it was at 3.6 to 3.9 volts.
So I turned them down to 2.7, everything seemed to run smooth ( jogging it ), so I decided to calibrate it. After I calibrated it, I ran the test file with the spindle off and no foam in it, I then got the same symptoms as dhc8guru has.

Both the X and Y voltage dropped to 1.7, the two power lights were dim, the Y was unlocked, can't remember if the X was, but my X and Y heatsinks were hot, as well as those pieces ( next to what I think are capacitors ) that stick out by the lower left of the heatsinks. The Z voltage was normal and only lukewarm to the touch.

If you shut it down until it cools off, then it's back to normal, but a little after firing it back up and running the file, the symptoms come back.

I just wanted to chime in and say your not alone on this one dhc8guru. Hopefully we can find a solution to this fairly soon, because I do love the smell of freshly cut foam in the morning.

Also, does anyone know what TP2 is supposed to be set at?

Thanks, Matt

 

Well after I did the X drive fix, I decided to give it another try.
I'm here to report that everything is running smooth. I cut out the Phlat table without a problem, I just have to fine tune the calibration, then I'll be golden.
That little bit of cutting and now I can't get enough.