Micro stepper motors from bluray sleds

[LSRFAQ]

Those are bipolar , and the wierd "unwinding" with the spikes is to provide the needed 90' phase shift in the magnetic field to ensure rotation.

Steve

 

[Morgan]

Thanks Steve. I've just finished my first year as an engineering student, (all distinctions plus 6 extra units! Polishes nails on chest!), and I've now got a little time to play around with these so I'll be back with updates. Just got to figure out how to drive them usefully.

M

 

[HIMNL9]

Uhm, you don't need high current for them, so the couple L297 / L298 is a bit exagerated, for them (i use them for 2A motors ) ..... maybe just the L297 for generate all the signals, and few standard transistors for make the H-bridges may be enough ..... or also just a couple of 3717 for the bridges, and a pic for generate the cycles ..... or an L293D and a pair of transistors ..... or a 754410 .....

Or already made boards ..... there's a lot of them around ..... it really only depend for what you want to use them .....

 

[Morgan]

Now there's a few serial numbers to research! Thank you.

The plan is, as the OP mentioned, to try and build a tiny, simple scanner. I'm not looking for high resolution patterns as I'm sure these won't suit that anyway but small is beautiful in my book and wouldn't it be cool to have a pocket sized display that did more than spiro patterns! I haven't built any scanning setups yet, only spiros so there's quite a knowledge gap to be filled here and any help will be appreciated.

I had thought to tear down a cheap stepper motor scanner for the experience and learning but I'm not adverse to building one, (In fact I'd actually prefer this). I don't think a harvested board would suit either due to the non-compatibility of the motors. Scan angles and step size concern me here. I'm not able to produce SMD boards but can almost certainly get crude PTH boards etched.

I apologise if my line of thinking is way out on this but that's the learning process. I don't know what I don't know at this stage. I know some of what I don't know but that situation improves all the time! :crackup:

M

 

[Morgan]

So I've been looking into stepper motor drivers and the bipolar one on this site simple and comes in a kit.

The question I have here is the input voltage. It says that it requires 0 - 5V. Fine but I would like to drop this if at all possible. As CMOS will run as low as ~3V, is it the voltage regulator that is fixing abov 5? I know I would have to gaurantee the circuit get its 3V but possible to drop it this far?

The next thing up the chain would be a microcontroller. First thoughI would like to see one of these motors spinning step by step in both directions and work up from there.

Valuable post HIMNL9, thanks.

M
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[Uranium]

 

[Morgan]

Not those sort of stepper motors I'm afraid Uranium. These are two phase, bipolar supply motors. Check back a few posts. I tore one down with photos and you'll see these are not the same configuration.

M

 

[Uranium]

Not those sort of stepper motors I'm afraid Uranium. These are two phase, bipolar supply motors. Check back a few posts. I tore one down with photos and you'll see these are not the same configuration.

M

Well then, i use these.
SparkFun Electronics - EasyDriver Stepper Motor Driver

 

[Morgan]

What microcontroller do you use with those drivers? I had a look at these the other day and although the price looks good, an Arduino to control it is not! I'm really looking for a low power/low spec/small size microcontroller just to get some simple patterns. 5V max is the goal as these motors don't require a lot of power.M

 

[Uranium]

What microcontroller do you use with those drivers? I had a look at these the other day and although the price looks good, an Arduino to control it is not! I'm really looking for a low power/low spec/small size microcontroller just to get some simple patterns. 5V max is the goal as these motors don't require a lot of power.M

Nah, you can control it with a 555 timer in astable mode.

 

[Morgan]

Yes, but that only gives you directional/on/off control. I'm looking for a selected number of steps this way; a selected number that. And, just to add to it all, a second motor controlled in the same way.

This project is aiming to produce galvo type displays like the ones achieved in cheap X-Y scanners. For that I need to ultimately designate how many steps a motor takes.

Of course, first I need to get it moving but that's the easy part as I see it from here.

There is a post only a few back that shows a driver kit using the 555 as a pulse generator but these are just the baby steps, (or half steps ).

There is more to this than just rotation.

M

 

[Uranium]

Yes, but that only gives you directional/on/off control. I'm looking for a selected number of steps this way; a selected number that. And, just to add to it all, a second motor controlled in the same way.

This project is aiming to produce galvo type displays like the ones achieved in cheap X-Y scanners. For that I need to ultimately designate how many steps a motor takes.

Of course, first I need to get it moving but that's the easy part as I see it from here.

There is a post only a few back that shows a driver kit using the 555 as a pulse generator but these are just the baby steps, (or half steps ).

There is more to this than just rotation.

M

I know, but for that kind of control, you'd probably want an arduino. You could possibly control 1 555 with another, but you'd get +/- a couple steps causing drift.

 

[Morgan]

Drift would be a bad thing here definitely. So the driver you posted before is already Arduino compatible right? I've been looking at getting one for at least the last 6 months but the cost of laser parts alone is keeping my bank balance low. What is the minimum I can get away with to power an Arduino and this driver? I thought it was more than 5V. Ever tried under driving it? Any chance you could and let me know?

M

 

[Uranium]

Drift would be a bad thing here definitely. So the driver you posted before is already Arduino compatible right? I've been looking at getting one for at least the last 6 months but the cost of laser parts alone is keeping my bank balance low. What is the minimum I can get away with to power an Arduino and this driver? I thought it was more than 5V. Ever tried under driving it? Any chance you could and let me know?

M

more or less random info;
Drier has a min of 7v. It's not too hard if you power the arduino with 12v, and just hook it up to that rail. The motor probably uses 5v, but there is a pot on the board to adjust the output voltage. As for response time, I've managed to get it down to 2us (smalls arduino can handle), however that is mainly dependent on your motor. It's a micro stepping driver, so 4 pulses = 1 full step.

 

[Morgan]

Not random at all! Thanks.

12V?! Nadgers! Still, Arduino do do some small microcontrollers so...

Fine, that is all good info Uranium. Now it's time to make some decisions and purchases I think.

Thanks again, I'll update as and when...

M

 

[Uranium]

Not random at all! Thanks.

12V?! Nadgers! Still, Arduino do do some small microcontrollers so...

Fine, that is all good info Uranium. Now it's time to make some decisions and purchases I think.

Thanks again, I'll update as and when...

M

you could always get a unipolar motor. All you need to drive them is an arduino and transistors. They're easy to drive. Just 4 sequential pulses. Reverse the order of the pulses to reverse the motor.

You could also drive it with some 4XXX series Ic's;
Here is a schematic i made this past hour. It'll drive a 6wire unipolar motor. You can raise the voltage on the TIP120 transistors. I hope it helps.