Bridging EMC and Router

Will do!

At the moment the 74194 + L293D bridge seems to be the way to go (or at least that's what makes the most sense at the moment... Subject to change, lol). I know it's probably not the most efficient method but my first goal is going to just be to eliminate the Arduino. Hopefully some fine-tuning opportunities will present themselves along the way.

Thanks again for the help!

I'll be around.

Greetings, all

I know it's been a while but I wanted to mention that I seem to have everything running (at least for the x-axis... Ran out of diodes.) and it's looking good to begin building the table!

I realize my approach isn't optimal but MUCH was learned about a few new kinds of ICs (binary counters and decoders) and 1" of axis travel was achieved in the "real world"! (I didn't have a lead screw, per se, so a bolt had to do...)

I loosely followed the design provided by Tom McGuire found here:

cratel.wichita.edu/blogs/tommcguire/the-stepper-motor-driver/

The main difference was that I didn't feel comfortable using the resistor/zener combo for the voltage regulator so I put the ICs on their own 5V circuit with the motor power on a separate circuit. I'm not at all suggesting that his approach to the voltage regulation was poor. I was simply limited by my knowledge of the analog side of electronics and didn't want to blow up my "took-a-week-to-arrive" parts.

Anyway, no microstepping or other bells and whistles yet but it's definitely enough to get a desktop "prototype" together.

Thanks again for the help/suggestions!

The Arduino in the image is just being used as a 5V power supply for the counter/decoder. It doesn't handle any other part of the circuit. Also, the 9V supply is disconnected in this image but simply connects to the +/- rails of the smaller breadboard.

The next step (yes... pun most definitely intended) is to implement microstepping. I hope this can somehow be done logically with what I have but I guess we'll have to see.

Other than that this setup runs quite well at just under 1"/s. Quiet motor, no jitters, and I keep waiting for the transistors to heat up but they haven't yet. (Probably will once I get larger/higher voltage motors).

The only issue is, again, when operating at small increments I lose a good bit of resolution. This is also with a 33 pitch "lead screw" (bolt) and I doubt that any larger-scale screw will have so many threads/in so it looks like it's microstepping or nothing.

Pretty Cool! I like messing with my Arduino Uno. I'm working on a multiplexed input to a MAX6675 thermocouple device.

I'd be interested to hear how the 6675 project turns out. Always intrigued by I/O expansion.

Also - I checked out your plasma build... VERY impressive!

Are you feeding it step and direction with EMC?

I am, indeed. In fact, I marked a 1" length on the bolt attached to the stepper, made a simple file with a 1" cut along the x axis and sent it to the driver thinking, "Well, at least I'll be able to see how close this is to accurate" (thinking I would need to make some adjustments) and I just about fell out of the chair when the nut traveled right up to the 1" mark and stopped cold. +10 for EMC!!!

I used to operate a Gerber Sabre for a small shop and always thought, "Man, I'd really like one of these at the house but there's NO way I could afford one". Haha - total cost so far: $21.85.

Quick question: the motors I'm currently using are from an old typewriter and operate at 7.5 degrees/step which I'm coming to find out is WAY too high for a CNC application.

For this first build I think I'm going to stick to a 12"x12" setup much like LumenLab's micRo. Do you think a 60oz, 24V motor would handle carrying/pushing a small dremel or would I need a more powerful motor?

Thanks

That makes sense. I attempted slowing things down and the motor's ability to resist opposing forces increased exponentially. Might try running the motor at full voltage, too.

Thanks again!