- June 7, 2017 at 5:36 pm #35421
So I have been playing with my MPCNC for a couple of months now and am getting some pretty decent results. Still a lot to learn. However, I have ruined a couple of nice pieces from a sudden plunge in my Z axis while running ESTLCAM and a wireless XBOX controller. I paused the program and the code looks good. After a couple of times I realized that it could be from my kids playing on an XBOX console in the family room that share a wall with the garage. It seems to coincide.
My question to the broad audience is “could it just be a coincidence, or a likely cause?” Has anyone else experienced this as well? I would think that the controllers are coded to prevent this, but I am not sure if the USB receiver is picking up one of my sons’ other controllers and allowing it to randomly provide input from a weak signal.
I really enjoy the freedom of a wireless controller, but think I should try switching to a wired controller. Thoughts?June 8, 2017 at 4:34 am #35434
I don’t trust wireless for anything I’m not willing to loose signal/control from.
No matter how well built, it’s just too sketchy.
Even my RC quads and helicopters have failsafes in place in the event they loose signal from my transmitter.June 8, 2017 at 11:19 am #35447
Are you looking for an excuse to keep your son off of the xbox? If so, then yes, That’s exactly what it is!
I wouldn’t think that behavior would work very well for gaming though, so I’m going to guess it’s something else. But I also agree with David. Wireless isn’t a good idea when it’s critical. Can you disable the controller (maybe just unplug the receiver) when running gcode? You don’t need it then, do you? That would help eliminate it as a suspect, and it would make it more comfortable (from a reliability standpoint).June 8, 2017 at 6:18 pm #35466
I do love using the controller as I can get my lineup precise without trying to reach the laptop. so, I ordered a wired XBOX controller from Amazon today ($16) that should give me some piece of mind…and the boys can have their fun too. However, I now think that controller interference may not be the problem. If I apply a little resistance to the threaded rod as I try to move the Z axis it sounds like it is turning (albeit louder) but the rod, the connector AND the motor shaft remain stationary. Mainly when going down, hence the plunge issue. Do I need a stronger Nema 17?
I went ahead and ordered a High Torque Nema 17 Bipolar Stepper Motor 92oz.in/65Ncm 2.1A from Amazon. This is to replace the current 64oz Z motor. Although, I am now concerned that if I install it, I could damage the gantry with so much torque. I may opt to convert the gantry to a T8 leadscrew instead. I’ll post my results either way. Thanks to all.June 8, 2017 at 6:21 pm #35467
Z speed has the most to do with it.
If you can smoothly move the zaxis it entire range of motion easily with your fingers the only way it will skip is trying to move it too fast. If you are using a controller I assume ESTLCAM firmware? If so what is your zaxis max speed, travel speed? What is your z axis driver set to, what kind of driver?June 8, 2017 at 7:37 pm #35469
Dui, ni shuo de duiParticipant
It sounds like your pineapple coupler is loose.
Check that.June 8, 2017 at 8:01 pm #35471
He said the motor shaft remains stationary. I think he’s just describing skipping steps.
So either you’re driving it too fast, or you’ve got the driver setting wrong, or the z axis has too much friction.June 8, 2017 at 10:10 pm #35482
Dui, ni shuo de duiParticipantHe said the motor shaft remains stationary. I think he’s just describing skipping steps.
So either you’re driving it too fast, or you’ve got the driver setting wrong, or the z axis has too much friction.
Indeed, I didn’t see that he was mentionning that the motor shaft wasn’t turning. Red too fast. Hope I won’t be banned for this unforgivable mistake XD
So, yes, it is likely to be missed steps, either the rod is not turning freely, or the motor current is too low, or too close to its maximum speed. It can also be that the two Z axis motor and bearing support, or the tool holder were printed slightly too big, which makes them push too hard against the bearings, creating motion resistance (it happened to me in the beginning).June 9, 2017 at 8:50 am #35501
Thanks Ryan, my Z max speed was 10mm/s. I slowed it to 8.5mm/s per your note on the home page. I am running a Ramps 1.4 and polou DRV8825 drivers at 1600 steps for the Z and 3200 for the X&Y. My max for XY is 75mm/s. I am also using ESTLCAM. My bits are set to travel at 35mm/s or less. The Z axis seems to move smoothly.
Should I go to the higher torque Nema 17 motor just to be sure?June 9, 2017 at 8:55 am #35503
You should be fine with what you have now. But I think you should ga a little slower. 8.4mm/s might be the max, but the max strength is about half that.June 9, 2017 at 8:55 am #35504
Thanks for the advice. I’ll look closely at all of those possibilities. I’ll disconnect the coupler see if the axis binds anywhere. Much appreciated.
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