Hello every one, sorry if this thread is in the wrong place but i think it’s the right category, so I made my own machine and got in to the hobby and with the hope to actually produce some commercial parts later on.
So the basic details of my machine are as follows:
axis motors: 3.1Nm Nema 24 Stepper Motor 3.5A 4-wire (2 motors on x, 1 motor for y and z)
stepper controllers: m335 driver, unknown/no brand, pictures attached
generic 24v 400watt switch mode power supply
control board: generic parallel board with optical isolation for inputs ( I think…) and amplified signals, schmitt triggers I think, can’t remember what the item listing said… pictures attached
5mm pitch ball screw and linear bearings for all axis
Spindle is controlled via 0-10 analogue output from control board
80 steps per mm on half step is how I drive it
Running mach3 using pcs inbuilt parallel port
the issue is it seems to lose steps, I did not notice it when running simple motion paths, I saw a little bit of lost steps but thought it was just losing steps from too aggressive a cut or moving to fast, but I recently tried a more 3D motion path (pictures attached) and its lost a lot of steps on all axis and pretty equally as well, when I return to home its offset by like 2-10mm in the same direction each time, so…
I tried all manner of setting changes in mach3 and on the motor drivers, I separated all the components to help avoid EM interference, I ended up disabling the spindle and all but one axis, unmounted the stepper so it drives nothing and free spins, I put tape on the shaft and body and mark out the home location and run the program and note each time I return to home the marks never match up. Even when just doing a few jogs from the keyboard it doesn’t match up. I tried driving the motor controller without the breakout board as well, just jumped wired directly from the parallel port and same deal. On a side note, mach3 has my motor speed limits at about 1700mm/min the motion paths should have cuts limited to 1000mm/min in fusion 360, but when I run the program in mach3 I sometimes see the feed peak to over 3000mm/min for a short period and I can hear it rev that high as well, the heck? Isn’t mach3 meant to always limit the top speed to what you set the motor to under tuning? I set the motors to 100mm/min and still lose steps when running my motion path as well, and I tried overriding feed speed to 40% in mach3 and still no luck. I ran mach3s driver test thing and its shows the timing all fine for my pc.
The crux: So I believe the issue is either the parallel port motion control method, mach3 or the motor drivers, unless any one knows something I may have missed, I think I am in for a new motion controller and 4 new motor drivers.
So my questions are:
1. any ideas on the best control combination for my setup that won’t lose steps and is the cheapest?
2. is it possible to not lose steps if your cutting rate and axis doesn’t bog anything down? Or is lost steps a fact of life for open loop stepper motors? In which case I will need to update to a closed loop system
3. Also I notice if the motors spin to fast It gets an oscillation issue and it stops spinning and just whines until the speed changes, I hear gecko drivers have resonance damping, does that help stop this issue and gives faster top motor rpm?
UPDATE: jog spamming in one direction results in no step loss on my unloaded test motor, but if i jog spam in both directions i think it loses a step on each direction change, returning to home never match up with my marks if i do this.