cnc winder controller board

[David King]

Elepro's German links for the 6 chips (2 x L297 and 4 x L6203) are cheaper than anything I can dig up around here so I'd be interested in ordering some of those if anyone else is interested in joining me.

Motor power supplies? If we want 30V DC out do need more or less AC volts or about the same, I forget.
Let's say a 36V transformer @ 2A, a good sized quad bridge rectifier and some 2200 Mfd 75V electrolytic filter caps. I'm just guessing here.

[RedHouse]

Elepro's German links for the 6 chips (2 x L297 and 4 x L6203) are cheaper than anything I can dig up around here so I'd be interested in ordering some of those if anyone else is interested in joining me....

Could be premature David, you might want to wait a bit until after I get the PIC's from Elepro and build the test unit, things may change, he just sent them yesterday, they will take some time to arive and some more time for me to construct the test unit.

That is a good price, it comes in at like $33-USD for the 5 L6203 drivers, it appears the seller is actually in France and listed the chips on the Italian eBay.

Here is the guy's Francais eBay sales: pixou L6203

[RedHouse]

... perhaps will change the main for have more torque so i'll can mount a 2/1 pulley transmission and have 2X speed..... now i have 600rpm...

I think the 2x pulley idea is a good one as I find myself winding in the 700-1100 RPM range. If the design goal is an automated winder then perhaps the speed is less relevant since the operator doesn't have to attend the entire process.

Can we work in a signal/flag for when the process has ended?. Perhaps a high or low state that we can use to trigger an audible annuciator?
(like when the microwave is finished ...it beeps)

[David King]

Brad,
regardless of whether elepro's pic does exactly what it's supposed to (and I'm confident that it will), these stepper drivers have many other uses in automation. I've been meaning to get a bunch of them for my lathes and mill so once I build one I might as well make a few.

I still want to do a direct drive winder with a 3 phase motor but use the programmable traverse elements we've been talking about here. I might have to do some creative rejiggering to get it all to work together.

[Amplexus]

Elepro
What you are doing may be overkill for a simple coilwinder, scatterwound with a simple speed control works well. If you really want to go the stepper route go to cnc.com and read Mariss' cpld tutorial. it is a geckodrive without midband and morphing on a $1.00 coolrunner cpld. by far the best open source stepper controller available. Mariss will let you use it, market it, modify it, with just a design credit. When it comes to motor controller design Mariss is simply the best there is. if you are going for high accuracy you will need ground ballscrews and linear rails and bearings.
Amplexus
Having just read most of the posts here you should be advised that some of the recommended chipsets have some serious design flaws that impact performance. I strongly recommend that you go to cnc zone and read Mariss's comments on chopper type chips. in a nutshell they suck.

[Amplexus]

Elepro
What are you using for software Mach3 or Linux emc? Mach is a bit more user friendly. Keling has great deals on steppers, voltage should be 32 times the sqrt of inductance not what is listed on the motor faceplate.
If you want constant drag on your tensioner vary the stepper velocity to account for the oblong coil, no oscillation in the tensioner.

[-Elepro-]

What are you using for software Mach3 or Linux emc?

this question say me that you did not read other than the last posts in this thread.... my controller doesn't need any pc for working....

l297-l6203 (and l297-l298) are the most used diy stepper motor driver in the world.... sure not to be compared to gecko but it is cheap and perfectly working = perfect for this application....
i have some experience in the cnc world and i moved for few years a 1000X600X200 mm cnc router with l279-l6203 driver...

bye

[-Elepro-]

Motor power supplies? If we want 30V DC out do need more or less AC volts or about the same, I forget.

DC = (AC * 1.414) - 1.4v...... (1.4v is the diode bridge drop and 1.414 is the rms value)

max tension for l6203 is 48volt then i thnk that a 24-30 volt AC transformer is good and keep DC in fail-safe value (with main tension peak too)

[RedHouse]

Brad,
regardless of whether elepro's pic does exactly what it's supposed to (and I'm confident that it will), these stepper drivers have many other uses in automation. I've been meaning to get a bunch of them for my lathes and mill so once I build one I might as well make a few.

I still want to do a direct drive winder with a 3 phase motor but use the programmable traverse elements we've been talking about here. I might have to do some creative rejiggering to get it all to work together.

Ah I see, well I'll go in on some with you then, I'll send you a PM.

[David King]

DC = (AC * 1.414) - 1.4v...... (1.4v is the diode bridge drop and 1.414 is the rms value)

max tension for l6203 is 48volt then i thnk that a 24-30 volt AC transformer is good and keep DC in fail-safe value (with main tension peak too)

Elepro, is 2A enough rating for a motor power supply transformer? I know the rating of the driver circuit is 4A and I tend to like to over-build so maybe a 5A xformer is OK provided we keep the max voltage under the limit by 30-50%.

I'll poke around for surplus 24V DC supplies as new transformers can be $$ from US suppliers.

Thanks!

[Amplexus]

part of the problem with choppers is summed up by Mariss
My 2 cents? Chopper type current regulators are elegantly simple but esthetically obnoxious. They perform the required function with the least possible parts but that simplicity comes with the often mentioned insult to the ears. A bad chopper PCB layout can even affect motor performance (the motor vibrates instead of sitting still when stopped).

I'm cranking out the rest of the tutorial right now so I just reviewed the comparison between a chopper circuit and the synchronous PWM design we use commercially and in the tutorial.

The difference is the PWM design requires adding three resistors and three capacitors, about $0.02 in parts to a board. The relief is immediate and obvious; the motor is utterly silent while stopped or turning slowly. My 2 cents? It's worth adding 2 cents to the design.:-)

Mariss


see attached file for a better solution.

[RedHouse]

part of the problem with choppers is summed up by Mariss
My 2 cents? Chopper type current regulators are elegantly simple but esthetically obnoxious. They perform the required function with the least possible parts but that simplicity comes with the often mentioned insult to the ears. A bad chopper PCB layout can even affect motor performance (the motor vibrates instead of sitting still when stopped).

I'm cranking out the rest of the tutorial right now so I just reviewed the comparison between a chopper circuit and the synchronous PWM design we use commercially and in the tutorial.

The difference is the PWM design requires adding three resistors and three capacitors, about $0.02 in parts to a board. The relief is immediate and obvious; the motor is utterly silent while stopped or turning slowly. My 2 cents? It's worth adding 2 cents to the design.:-)

Mariss


see attached file for a better solution.

Are you a little late to the show Amplexus? Elepro has already worked out his design, and it seems to work. Why all the last minute critique?

[David King]

Amplexus,
SHow us a working driver schematic that's better and we are all ears. What we are wanting is simplicity and a proven design. The driver is just a small link in a much larger chain so we can't be too fussy or we're likely to lose sight of the bigger picture which is that a decent, programmable, home made coil winder for under $300 beats the pants off an off-the-shelf "pro" model for $5000.
I agree that adding $.20 of components to make it better might be worthwhile but keep in mind that our two motors are never at rest so we don't really care about the shaking and noise when the motors are stopped.

[Amplexus]

If you look at the zip file you will find a complete working schematic code for the cpld h bridge drive etc. As to the design it is a geckodrive minus midband compensation and microstep to full step morphing both of which you are free to impliment without fear of being sued by gecko. This is a cheap elegant high performance stepper drive, the allegro, ST and other chopper chipsets don't even come close. It gets its step and dir data from theparallel port of a pc. If you run linux emc the software is free. It was also extremely generous of Mariss to put it in the public domain even if his upcomming closed loop servostepper will render it obsolete,

[-Elepro-]

Amplexus,

i know and apreciate pwm solution for microstepping control ... and the tutorial seems many interesting and i'll read it for my future work in cnc world....

but.... for this application

we don't need any microstepping

or better,

in this application we don't need 1/2 step resolution too.... (used only just for electrical advantages that you know....)

then:

are you sure that pwm solution could be really useful in half step driver? (where current in motor winding is full or zero) could you link me a half step driver with pwm solution? (without microstepping)



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this thread is not on motor drivers.... anyone can use my controller with driver he wants....
when kits will be ready, your will be without drivers....




bye