I bought a 3-axis CNC kit from Zapp about 18 months ago but have only just got around to putting it all together. I noticed that Zapp still sell this kit, however the components have now changed. Although the wiring looks fairly straight forward, I have a number of questions. And if I'm honest, I'm shitting myself because I don't want to switch the power on and see my hard-earned disappear in a puff of smoke!
My electronics are as follows:
PSU 1: 24V DC (used to power the BOB and safety circuits)
PSU 2: 50V DC. Datasheet HERE
Stepper Drives: PM542 (unbranded...NOT Leadshine). Datasheet HERE
Stepper Motors: SY60STH86-3008BF. Datasheet HERE
BOB: Diycnc PCPPS V3. Datasheet HERE
Please bear in mind that I'm a complete newbie to stepper drive systems, however I do have experience with industrial electrics such as AC motors and drives, safety circuits, PLCs, etc. I'm rigging up the X-axis on the bench to prove the system before going for the finished build. My questions are as follows:
1. The 50V PSU is only outputting 42.7V. To quote from the datasheet (P4.1): "Note: If the PSU is out of regulation then Uout=42.8+/-0.5V". So there's nothing "wrong" as such, however the DC output is supposed to be 50.5VDC – 56.5VDC. Noting that the PM542 drives have a maximum voltage of 50V, should I actually attempt to use 50V? If so, how do I get this darn PSU into regulation/50V mode?
2. How do I wire the steppers to the drivers? I believe I should be aiming for Bipolar Parallel. The datasheet is a little confusing as the "Bipolar Parallel" diagram seems to confuse the * and - of the coils, for instance showing one end of "C" as both * AND - with the other end simply marked "C". After some head scratching, this is my interpretation:
Join A* to C* and connect to A+ on the drive
Join A- to C- and connect to A- on the drive
Join B* to D* and connect to B+ on the drive
Join B- to D- and connect to B- on the drive
In wire colours, this equates to:
Blue/White & Red = A+
Blue & Red/White = A-
Green/White & Black = B+
Green & Black/White = B-
The datasheet diagram appears to have the phases opposing (i.e. A* to C-, A- to C*, etc) but that seems incorrect to me??
3. Assuming the PM542 now has the following connections: motor wired as above, 42V supply, PUL+, PUL-, DIR+, DIR-, ENA+ and ENA- from the BOB, what switch configuration should I use? My interpretation is as follows:
To set 4.2A peak current: SW1 = off, SW2 = off, SW3 = off.
To set half current: SW4 = off. (or should I use full current??)
To set 1600 pulses per rev: SW5 = off, SW6 = off, SW7 = on, SW8 = on.
How many pulses/rev should I use? Or is it a case of trial and error to get the best/smoothest performance?
Do I even need the ENA connections?
4. Assuming I now have everything wired up OK...how do I test my X axis? Do I have to use the computer, or will the "force" jumper on the PCPPS BOB enable me to run the motor temporarily?
5. As someone who has not used Windows for 5+ years, EMC2 is going to be my control software of choice. I've not used it (or any other CNC software!) before, so could be a steepish learning curve. Does anyone here have experience with the EMC software? In particular, I'm wondering what the hell I'm supposed to to with the configuration wizard as I don't have much idea of what numbers I need to enter. Can I use a default config or will I need to create a custom one to suit my hardware setup?
Apologies for all the questions, though I'm sure you all asked these once upon a time.
Check PM and use the number.!
Set to half current. This is the current dropped to when in stand by mode.
800 is a good starting point. Don't go above 2000 no point it's just wasted resolution the motors can't resolve too and load on parallel port.
Leave the Enable off for now. It's just a way to disable the motor signals but still leave them powered and holding torque. To use it requires setting up in the controller your using.
Last edited by JAZZCNC; 28-12-2012 at 09:45 PM. Reason: WTF strange things happening.!!
Thanks for the replies. I did some RTFM'ing last night, followed by some cellar/workshop time. Wires were put in holes and power was applied. And there was no smoke or fizzzzzing noises. Lost my EMC virginity as well...AND managed to get the X axis stepper running on the bench. The ENA signal is working as expected. The Charge Pump was a simple case of setting it as pin 1 in the software config. It was 3:30AM before I finally decided it was time to sleep. Getting your first stepper running is way better than the joys of Christmas.
I need to learn more about the EMC configuration as there are a few numbers that I left as default because I didn't know what they should be. I'll start a new thread for that and/or start one on the LinuxCNC forums.
I too am using the Zapp 3 axis kit 2. Mine arrived last week, last night was the first time I had to look at my goodies.
Like you, I then had to wonder how the H3ll does it go together.
The description\settings and pic are all very useful. Thank you.
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