3 Axis CNC router

[JoeHarris]

Thanks Neale, interesting thought and yes I have z tuned the same as y, I think at 5000mm/min velocity and 500mm/s².

To do the pro tuning it looks like you need a serial port and a special cable which is a pain!

I have pretty well copied over my current Mach3 settings to version 022 on an old laptop. Bit laborious but I didn’t want to just use the xml as this was advised against in the Mach support forum. It seems CS Labs recommend version 022 as the most stable, so let’s see!

Also, I’ve just bored out a 20mm cable gland so I can get an rj45 through it - I want to get rid of the two-Ethernet-cables-with-a-connector setup I have at the moment as that can’t be helping (!) and run the Ethernet cable further away from the VFD. It goes out the top of the cabinet and over the top at the moment...

[AndyUK]

I'm with Neale, sounds like Z is trying to move too fast.

I've had to detune my Z quite substantially compared to the X and Y speeds, the rapid upwards Z motions at the start of my cuts caused it to stall. Wonder if its something about moving a heavy spindle directly against gravity - although you'd hope that was only a small factor. It runs approximately 40% of the rapids speeds of X and Y (after correcting for screw pitch differences) and about half the acceleration. Its a 1605 running on a 3.1nm Nema 23, velocity 2m/min, 200mm/s^2 accel. Probably conservative, but works for me. Not a problem in every day life though as the travel is so much smaller :)

Regards the special cable, it requires a slightly custom job. I used a RJ11 crimper and some CAT5 to knock up one - you only use three wires. If you want I'll lend you one.

[JoeHarris]

I'm with Neale, sounds like Z is trying to move too fast.

I've had to detune my Z quite substantially compared to the X and Y speeds, the rapid upwards Z motions at the start of my cuts caused it to stall. Wonder if its something about moving a heavy spindle directly against gravity - although you'd hope that was only a small factor. It runs approximately 40% of the rapids speeds of X and Y (after correcting for screw pitch differences) and about half the acceleration. Its a 1605 running on a 3.1nm Nema 23, velocity 2m/min, 200mm/s^2 accel. Probably conservative, but works for me. Not a problem in every day life though as the travel is so much smaller :)

Regards the special cable, it requires a slightly custom job. I used a RJ11 crimper and some CAT5 to knock up one - you only use three wires. If you want I'll lend you one.

Thanks Andy, yes I will try slowing the Z down a bit and see if that helps. Kind of you to offer a lend and an excuse to head down south sounds nice! but what about one of these: https://www.aliexpress.com/item/32931330627.html probably costs less than the postage back and forth!

[Clive S]

Thanks Andy, yes I will try slowing the Z down a bit and see if that helps. Kind of you to offer a lend and an excuse to head down south sounds nice! but what about one of these: https://www.aliexpress.com/item/32931330627.html probably costs less than the postage back and forth!

Yes that should do it.

Not sure if it will work with win10

I made a cable a few years ago that I keep in the control box. I think mine connects to a serial com port.

[AndyUK]

Looks like the sort, but some concerning reviews.

Half-way house in the meantime from the manual:

Auto configuration by SW4
Change SW4 two times in one second to identify the motor parameter after
power-up if it is the first time installation. Please note that the rotation
switch position must be 0 when using this function.

[JAZZCNC]

Thanks Andy, yes I will try slowing the Z down a bit and see if that helps. Kind of you to offer a lend and an excuse to head down south sounds nice! but what about one of these: https://www.aliexpress.com/item/32931330627.html probably costs less than the postage back and forth!

Don't bother buying the cable Jo you won't need to play with PID settings etc. Just flick the Switch 2 times in quick succession, when you do it the motors will make a buzzing sound for a second then stop. If the motors are whistling at the moment they will probably stop or change the tone.

[JoeHarris]

Don't bother buying the cable Jo you won't need to play with PID settings etc. Just flick the Switch 2 times in quick succession, when you do it the motors will make a buzzing sound for a second then stop. If the motors are whistling at the moment they will probably stop or change the tone.

Thanks guys, pretty sure I did this when I first set them up.

I got the laptop set up - connected it to the ipm but it wouldn’t connect for some reason, then it crashed! Maybe I should persist with plan A!!

[JoeHarris]

I'm with Neale, sounds like Z is trying to move too fast.

I've had to detune my Z quite substantially compared to the X and Y speeds, the rapid upwards Z motions at the start of my cuts caused it to stall. Wonder if its something about moving a heavy spindle directly against gravity - although you'd hope that was only a small factor. It runs approximately 40% of the rapids speeds of X and Y (after correcting for screw pitch differences) and about half the acceleration. Its a 1605 running on a 3.1nm Nema 23, velocity 2m/min, 200mm/s^2 accel. Probably conservative, but works for me. Not a problem in every day life though as the travel is so much smaller :)

Regards the special cable, it requires a slightly custom job. I used a RJ11 crimper and some CAT5 to knock up one - you only use three wires. If you want I'll lend you one.

I have completed a few successful projects now, pocketing, profiling and v-carving, all without much of a hitch. But trying some 3D (2.5D) carving has resulted in my z axis behaving badly again! Part way though a roughing toolpath the z axis started moving a little erratically and then stalled a few times (I think). It moved up and started milling above the work piece. I pressed feedhold then stopped the machine, the spindle stopped but the z axis kept making jolting movements in an upward direction?! It only stopped it's mad movements when I hit the emergency stop. I am going to throttle back the motor tuning some more on Z to see if it relates to that, but it seems very odd to me that it would carry on moving after being told to stop. Has anyone else had a similar issue?

[JAZZCNC]

Don't know why it's doing this never seen it before but the reason it kept going after feed hold was because it was emptying the buffer.

Have you done a check to see if your missing steps from the pulse being on the wrong side of the edge.? If not then Zero the Z-axis and mark it's position then write some G-code so it moves back n forth several 100 times, only needs to be short moves. Make the last move go back to Zero.
If it doesn't return to the mark then you need to change the active Hi/Low in motor tuning for that Axis.

[JoeHarris]

Don't know why it's doing this never seen it before but the reason it kept going after feed hold was because it was emptying the buffer.

Have you done a check to see if your missing steps from the pulse being on the wrong side of the edge.? If not then Zero the Z-axis and mark it's position then write some G-code so it moves back n forth several 100 times, only needs to be short moves. Make the last move go back to Zero.
If it doesn't return to the mark then you need to change the active Hi/Low in motor tuning for that Axis.

Thanks Dean, no I don’t think I ever did that test on the Z axis but I did on the other two. I’ll give it a go and see, but really wanted to finish this job!

I reduced the Velocity on z from 2.5m/min to 2m/min and the acceleration from 250 to 200 and ran the roughing pass again a little slower than before and it cut to the end without any trouble (although it is hard to tell if it lost any steps as it is only a roughing toolpath). But once it was done and had gone back to zero for the tool change it kept making little erratic movements again. Could this still be to do with buffering if it is stopped for a tool change? I videoed it for a few seconds this time, if you have the sound on you can here it making little jerky moves. This was at the tool change so no g-code to tell it to move and nothing changing on the DRO. I don’t get it?

https://youtu.be/m1vlkqPeVMM


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