cnc controller

[natchez]

does any one build their own controllers

[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

[kfong]

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

[radio-op]

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

[kfong]

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

[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

[kfong]

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

[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

[natchez]

does any one build their own drivers

[kfong]

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

[kfong]

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

[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?