[JimmyC]

This is my first CNC project, my current setup is an X2 with a cnc fusion kit, hobbycnc driver board with 24 volt power supply (will be switching to 36 volt) and 305 oz/inch steppers. Computer to run it is using ubuntu with EMC2. So far I have not been able to get any movement, just hissing and the steppers lock up. As far as I know this is a fairly common setup, has anyone had this problem before or know what could be causing it?

[ataxy]

what bob are you using?
are you using a laptop or a desktop?
what are the voltage indicating on your output pin of the bob when you change direction of the axis are they going 0v-->+5v?
is your bob 5v from an external psu or comming from a usb port?

[The Blight]

Had this same problem once. Wired the Step/dir signal backwards (step signal to the dir pin).

[JimmyC]

what bob are you using?
are you using a laptop or a desktop?
what are the voltage indicating on your output pin of the bob when you change direction of the axis are they going 0v-->+5v?
is your bob 5v from an external psu or comming from a usb port?

I'm not using a breakout board, parallel cable comes directly from computer to board. It's an IBM desktop so I don't think there should be a problem with the signal being less than 5 volts. I'm going to try checking the step/direction pin out again however I am 99% sure it's correct. Thanks.


Edit: The parallel cable I'm using is 15' long, could there be an issue with signal loss over it?

[ataxy]

ouch no bob you should really use a bob to prevent electrical spike that could fry you componnent

[Seb]

15 feet is a long way for a parallel port cable... Buy a short, high-quality cable and see if that makes a difference.

What are your emc2 timing parameters like? Did you use stepconf to make your config?

Might put your config files on pastebin and ask on the emc-users mailing list, or in the EMC/Linux forum on this very site... Our trained monkeys are standing by to take your call.

[TOTALLYRC]

I'm not using a breakout board, parallel cable comes directly from computer to board. It's an IBM desktop so I don't think there should be a problem with the signal being less than 5 volts. I'm going to try checking the step/direction pin out again however I am 99% sure it's correct. Thanks.


Edit: The parallel cable I'm using is 15' long, could there be an issue with signal loss over it?

As the others have 15' is a lot. Maybee not for a printer but for a cnc it is. Many of the newer desktops have gone to low voltage parallel ports. Not sure about yours.

Remember, always use protection ie: a breakout board. Many of them will also eliminate low pport voltage problems.

Locking up and hissing is a good sign. You probably just need to get it configured in emc.

[JimmyC]

As the others have 15' is a lot. Maybee not for a printer but for a cnc it is. Many of the newer desktops have gone to low voltage parallel ports. Not sure about yours.

Remember, always use protection ie: a breakout board. Many of them will also eliminate low pport voltage problems.

Locking up and hissing is a good sign. You probably just need to get it configured in emc.

Alright, I'm going to start off by getting a breakout board and a shorter cable, then I'll try to work on the config. Thanks everyone

[JimmyC]

Sorry to drag up this thread again, but does anyone recommend any particular breakout board? It looks like there may be an issue as there is a parallel port input to my hobbycnc driverboard, but the outputs of most BoBs are screw terminals. Do most people just cut the end off a cable and wire to the screw terminals?

[ataxy]

cnc4pc as a good array of bob going from the simplest of them to the mostcomplex and full of option one

[Riceburner98]

LOL Not that it helps the cause much, but I was using a 15' printer cable with one end cut off and the wires right into my drivers (no BOB), now I still have no BOB but I'm using 2 6' cables plugged into each other, so 12' with a connector in between, then wires stuck into the female pins of the cable... If the motors are on but not moving, it sounds like you're just not getting the step signals to the drivers. (even with no DIR signal they will still move with STEP. Just in 1 direction.) If it was degraded signal on any of the lines, I'd think you'd at least get some movement. So far I've been using a laptop for the past 3 years, as I haven't been able to get any desktop to work reliably. I guess I'm the anti-normal.