cnc controller

[natchez]

can it be hook to a pc for control

[natchez]

does any one use the l298 h bridge and l297 controller

[kfong]

That's something EMC worked out. There is only so many pins available on the parallel port. This is a hardware limitation. EMC uses a second parallel port, but I haven't looked at the functions, they have a manual online that goes into more detail. As far as the home switches, the software knows which axis it is moving, so I assume it backs out and checks the rest. We don't use the home switches on our mill since I normally zero with my edge detector, so I can't say much about it. Once I build a gantry mill, I will set it up for it.

Kin

Originally posted by bertvk I see you use only one pin for the X, Y and Z home switch. How does that work? When the tabel moves to (0, 0, 0), how can it know which axis is already at zero when the line goes high due to one switch closing?

[kfong]

Yes, that is what these drivers were built for. To make a CNC system. You need a PC with a parallel port and hardware that translates the signals from the parallel port and turns those signals into motor step and direction. The motors you chose can be Servo or Stepper motors, but the simplest setup is Stepper motors. The drivers we created are for stepper motors, bipolar in particular. You would need one driver per axis and a break out board that plugs into the parallel port. An inexpensive software to use is TurboCNC. You will have to reassign pins to match the breakout board. There is no standard for the parallel port, so most software randomly just assign the I/O pins to what suits them. We went with EMC, since that is the software we like to use so our breakout board is wired to EMC's specs.

Kin

Originally posted by natchez can it be hook to a pc for control

[kfong]

We built some boards early on with this setup, but found micro stepping to work out much better. So that is what we currently sell. I still have boards of the old design if you are interested.

Kin

Originally posted by natchez does any one use the l298 h bridge and l297 controller

[george12]

I was wondering if anyone has built the microstepPLD i am having some difficulty in getting it to work and i was wondering if anyone could submit a picture of a finished board so i could see if i am missing anything.

Thanks

[kfong]

Here are pictures from one of our customers. I wish I could remember who sent it to me. I thought it was very well done. I'm not sure it will help. What kind of problems are you having? Did you try emailing to me? I don't usually have much time to spend on these forums these days, but I usually try to answer all my emails. This is actually an old thead as well, but was on my subscribe list.

Regards,

Kin

http://www.embeddedtronics.com/

[george12]

Thanks

I hooked up my bipolar motors and they just whine and draw large amounts of current they don't move at all. I don't know why

[kfong]

Do you have photos of the board? Did you verify all the components placed and orientation? Double check how you wired the stepper motor, how many wires are on the stepper motor, do you have photos of it. Did you set the current limit. What is the motor rated at. What are you using as a power source. Did you verify that the board has no solder shorts.

Regards,

Kin

http://www.embeddedtronics.com/