A4988 pot range

When adjusting the current, how many turns will the pot physically make? Is zero to max 360 deg? If turned past 360deg, does it go back to zero?

It doesn't really matter how you do it - the pot has a max and min setting. The only thing you need to do is put your meter on it and set the voltage.

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Waitaki 3D Printer

I asked the question because I read advice on setting the driver by turning the pot until the motor does not twitch plus an eighth turn. Then other places I read turn to zero and increase 25%. This indicates there should be a zero stop point. I also see info to set the voltage, but can't find a clear direction on what to set it to or where to measure it.

If you start researching it from a total noob perspective, there is a ton of what to do, but very little how to do it. I think the measure point is ref at .3v for .75 amps.

I am working with sainsmart ramps kit and eBay steppers. Any clear advice is appreciated.

My history is two diy cnc mills driven by steppers through mach3. I cut the I3 frame and parts on my g704. Mechanics are done, just need to learn the electronic setup.

Thanks.

Yeah, I hate those little pots too. It's really something I'd like to eliminate from the design, but while we use the Pololu style modules, we seem to be stuck with them.

These pots have a resistive track which is covered in one turn, but actually its about 300 deg. The wiper should have endstops, but on these micro ones it is just a bump, and it's easy to override. Go past the stop and there is a dead zone, the wiper is not connected, but the pot will continue to turn until it picks up the other end of the track.

The zero point is roughly where the wiper points at pin 1, and the max is around where the wiper points at pin 3.

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Excellent! That answers my original question perfectly. Now to find the answers to all the other questions!

Keep in mind that not everybody uses the same little pot.....

I don't know what you are referring to, all the Pololu type modules I've seen use a similar trimmer, but the principles are the same.

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What is Open Source?
What is Open Source Hardware?
Open Source in a nutshell: the Four Freedoms
CC BY-NC is not an Open Source license

Just my 2 cents, I would check if the motors would move and the current current. Then adjust clockwise or anti-clockwise according.

I've killed one driver by over turning and they're a pain in the ass wait for those ordered from ebay, unless you have a shop nearby that you can pop by and get a replacement. Patience is not one of my virtue. Lol.

Quote
bobc
I don't know what you are referring to, all the Pololu type modules I've seen use a similar trimmer, but the principles are the same.

Similar in style, but some have absolutely no bump at all as they rotate. They will spin 360 degrees just as smooth as can be...

I can find no bump in the ones I have. I did manage to decipher the adjustment and have the motors running well. Ended up adjusting them to a point where they would lock up quietly. Seem to run smoothest at this point.