does any one build their own controllers

Do you mean the driver board? The controller would be the PC running the control software, I.E. TurboCNC or what ever.
I'm building up micro stepping drivers from boards by Embeddedtronics.com. Nice boards based on National's 18256 driver chips and a PIC 16F84. Opensource firmware and a higher current rating then most of the other designs in this same price range.
Bill

Thanks Bill,

Nice to know someone here is using our boards. If there is any questions with it feel free to ask. I will be on vacation from the 2nd to the 10th, heading down to Hatteras to do some Kite sailing, so I don't know if I will have any internet access.

Kin Fong


Originally posted by radio-op
Do you mean the driver board? The controller would be the PC running the control software, I.E. TurboCNC or what ever.
I'm building up micro stepping drivers from boards by Embeddedtronics.com. Nice boards based on National's 18256 driver chips and a PIC 16F84. Opensource firmware and a higher current rating then most of the other designs in this same price range.
Bill

Hi Kin,
Very pleased with the boards. Haven't spun my motors yet, but the boards are an easy build. Had to order twice from Digi-key (Errr!), didn't realize you had used 3.3mm screw terms; I was going to use terminals from my junk box. So with the cost of the boards, parts I ordered, samples from National and the parts I had on hand, three drivers cost about $80. Good savings, plus I like building it myself.
Bill

Hi Bill,

I listed the Digikey numbers to make them easy for people to order the parts, if there is an error please let me know. Be sure to use a heat sink, since running at 3 amps can create a lot of excess heat plus these can supply peak currents up to 6amps. We took an old car amp apart and use the heat sink from it. Mounted all three boards to it, even put a fan from an old computer. Not even warm to the touch after hours of use. Any block of metal should do, just need to disperse the heat around.

Kin Fong

No error, I just overlooked the size when I placed the first order. I thought I would use some terminals from my junk box. Didn't realize till I was stuffing the boards. No biggie, just had to get some from Digi-key. For my heat sink I'm using the old processor sink from an Iopener mod. I saw in one of your postings that you have an Iopener in your shop, I was planning on using one to run TurboCNC. Its modded with a 350mhz AMD and 256megs so should work fine.
Well have fun on vacation, sounds like good times.
Bill

Yep, we use the I-Opener as a virtual monitor. It allows us to display the EMC gui thru X-windows. We didn't have a display to use at the time and have been using the I-opener ever since. The machine actually running the mill is an old PII-400 running BDI Linux. There is photos on my site under Metalworking, if you haven't had a chance to see it. The whole setup works great and I'm using it to make a bigger gantry mill as well as RC and Robot parts. Will have a fourth axis rotary table finished soon and this will allow me to make more exotic part such as nosecones and gears.

Kin Fong

Originally posted by radio-op
No error, I just overlooked the size when I placed the first order. I thought I would use some terminals from my junk box. Didn't realize till I was stuffing the boards. No biggie, just had to get some from Digi-key. For my heat sink I'm using the old processor sink from an Iopener mod. I saw in one of your postings that you have an Iopener in your shop, I was planning on using one to run TurboCNC. Its modded with a 350mhz AMD and 256megs so should work fine.
Well have fun on vacation, sounds like good times.
Bill

Nice setup. How is EMC? I looked over the FAQ for the BDI and I'd like to learn more about Linux. I have been working on a robot following the OAP project, Linux based; thats kind of the reason I got interested in a CNC table, to make parts for my bot.
Bill

does any one build their own drivers

Emc is great, it has the stuff found in high end systems. Used buy industry and is very reliable. There is a Brain Dead install CD now, so it makes it easier for people it setup. Links found in my web page. Requires you to dedicate a pc for your cnc, but that's pretty much a given. It's good if you are familiar with Linux. Never ran the BDI CD so I don't know how easy it is to really setup. We are running one of the newer GUI for it and I like it quite a bit. My brother is the Linux expert in the family, so he had it all installed for me. You will still need to find a CAD package that will generate the GCODE that EMC reads.

Kin

Originally posted by radio-op
Nice setup. How is EMC? I looked over the FAQ for the BDI and I'd like to learn more about Linux. I have been working on a robot following the OAP project, Linux based; thats kind of the reason I got interested in a CNC table, to make parts for my bot.
Bill

We built ours, go to my site
http://www.embeddedtronics.com/microstep.html
Kin

Originally posted by natchez
does any one build their own drivers

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?

can it be hook to a pc for control

does any one use the l298 h bridge and l297 controller

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?

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

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

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

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/

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

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/