[Winterdragon]

Hello,

I bought a Chinese model 3040 cnc from Ebay. It came with a 4th axis attachment and for the life of me I can not make this work right. The Manual says to simply replace the 'X' in the gcode with "A" and save and run. this does not work. I Use Mach3 for the gcode and with the Virtual Control on the screen I can click the 'A+' Button and it will rotate Counterclockwise and when I click the 'A-' button it also rotates counterclockwise.

The purpose of using the 4th Axis is for engraving Pen Barrels for Custom Pens. I would like to be able to engrave names and logos into the upper and lower barrels of the pens.


I do not know if Mach 3 settings are incorrect or if 4th axis is wired wrong, or If im a bone head and doing something wrong. Ive been fighting with this for about a year now. Please help...

Thank you in advance,
Winterdragon

[Winterdragon]

Seriously? No one has any input on this issue?

I REALLY need to get this working ASAP. ANY advice would be appreciated.

[awerby]

What do the folks who sold you this thing say? If you REALLY need help, they should be the ones who provide it. It doesn't sound like your A axis is working correctly, since it should be able to rotate in both directions. If it doesn't, that points to faulty wiring. Is there anything you can do to get it to move clockwise, like a MDI command? You say it's been a year since you got this machine - was it working right when you got it, or has it always been bad?

While I don't know anything about this particular machine, using the 4th axis is not as simple as substituting A for X. For one thing, A (the rotary axis) is calibrated in degrees, while the X axis is calibrated in linear units (mm or Inch). They aren't interchangeable; if you're working in inches, for example, a X move of 12 units will advance the tool nearly all the way down the axis, while it would only rotate the A axis 12 degrees.

There are "wrapping" schemes in some CAM programs which translate Y axis positions on a basically flat drawing into moves of the A axis, but these have to be worked out in advance so that the whole thing fits into the 360-degree travel of the A axis. I'd go into more detail on how to make this work, but it looks like you need to get your machine fixed before that's going to be relevant.

Andrew Werby
301 Moved Permanently

[BOATDUDEGUY]

did u tune the a axis motor?

[BOATDUDEGUY]

What do the folks who sold you this thing say? If you REALLY need help, they should be the ones who provide it.]

ya its just some random seller name on ebay
ive got a 3 axis one and it says 1 yr warranty but when i emailed them back about something faulty i never got a response

[Winterdragon]

I contacted them on Ebay. Got the Typical "BS" replies. Got everything from "Weve been on Holiday" to "Our servers got hacked". Gave up on them.

I did reach out to them again yesterday, Hoping that we can get this resolved.

I didn't think the replace X with A was going to work in the first place, but the manual said so, I tried and it didn't work.


Its possible that either my Mach settings are wrong, or the motor is wonky. I do not know which at this point.

[BOATDUDEGUY]

i bet you the stepper motor isnt tuned in and unless you tuned it yourself its probably not
that is one way to program gcode for 4th axis not the only either
but i doubt thats your problem, i program cnc on a daily basis
go to the mach support forum and ask them how to tune the a axis stepper motor

[BOATDUDEGUY]

or seek out helicopter jon here on cnc zone, he helped me alot when i first got my 3040

[awerby]

It's rare for stepper motors to actually go bad, unless someone starts taking them apart. It can happen, but at least 90% of the problems people experience with machines that don't work have to do with other things. While tuning the motors is certainly a good thing to do, no amount of tuning is going to make the motor start turning clockwise if it won't do this initially.

Problems like this are usually due to the direction signal not changing state from high to low (or vice-versa). If you look on your pin-out, there should be a pin designated as "step" and another one as "direction". If you find where that pin is on the breakout board and put your multimeter's probe on it, you should be able to see it change state, ideally from about half a volt to 5 volts, when the direction change is commanded with the jog button. But my guess is that this change isn't happening on your board, which is why your motor keeps spinning in the same direction. You can eliminate the possibility of a bad motor by switching the A axis leads to another axis and seeing if it behaves the same way (make sure everything has powered down and the caps have discharged before disconnecting anything). If the problem follows the leads and the other axis malfunctions, it's the breakout board or driver; if the problem follows the motor, then the motor is at fault.

Andrew Werby
computersculpture "dot" com

[BOATDUDEGUY]

I only suggested motor tuning because I bought the same machine he has and all 3 motors had to be tuned before attempting to run the thing

[Littlemango]

It kind of sounds like perhaps the pins are not set correctly in ports and pins. I have a 3040. Mine Are step pin 8 ,Dir pin 9

[Winterdragon]

Greetings again all. Finally got this issue resolved with the help of another member here. Turns out the main controller board (Where the Parallel cable connects) was bad. Replaced with a different brand, reconfigures the Ports and pins to match this manufacturer and Presto, all 4 of my axis's are now working.

Thank you all for your input.
Winterdragon