[phantomcow2]

I am looking for some mid cost stepper motor drivers to drive some 34 frame motors. I am guessing they are 3-4 amps.
Can somebody recommend a driver? I am not looking for something like Gecko drives, not interested in spending that much money for this. Something middle of the road I guess

[phantomcow2]

One more thing, these motors have encoders mounted on them. What would it take to get these encoders to do some good? Making my system closed loop

[H500]

Assumming they're bipolar, the current performance champ is a lmd18245 based design, like the pic-stepper. If unipolar, hobbycnc has some decent drivers.

You can get some very decent nema34's for $70-$80 new. But to get full performance, your drive need to handle about 6 amps at 60v. (there are currently no cheap drives that can do this)

[phantomcow2]

Well i've already got the 34's with the encoders, got them free. I've got a friend who builds robots, extremely savvy with electronics. I might see if he can build me a driver.
The HobbyCNC is only good for 3 amps, and I am pretty sure these motors are more than that. They are pretty heavy, but I don't know how much of this is encoder.
I've heard the PIC stepper mentioned, I will do some research on that

[H500]

The picstep is also limited to 3 amps. Make sure you find out if your mots are uni or bi before going further.

It's not a trivial undertaking to build a bipolar microstepping mosfet based drive. That's why you don't see any open-source projects yet...

[phantomcow2]

Well i looked inside, they are actually 8 wire motors. But were wired in parallel, so the commons were connectd

[ger21]

Basically, if you need more than 3 amps, your'e looking at Geckos.

As for going closed loop, You're going to have to spend a LOT more than the Gecko's cost. You can use the encoders with this add-on board that works with Mach3, which will pause the machine if it loses position. Not truely closed loop, but close. www.rogersmachine.net.

[pminmo]

phantomcow2,
Are you looking for a premade, tested drive, or willing to do some of the work yourself?

[mcpltd]

The MSD442 or the MSD556 will be good for what you are looking at.
4.2A and 5.6A peak, both at 50V DC. (or the MSD980 (90V 7.8A)
These can be ordered on our website.
www.motioncontrolproducts.co.uk.
We are in the UK, but will ship to the USA,

[phantomcow2]

phantomcow2,
Are you looking for a premade, tested drive, or willing to do some of the work yourself?

I am willing to do work myself, in fact I would prefer it. I would not assemble it though, not confident enough in my soldering abilities! I've got a friend who seems to have an endless well of electrical knowledge who will do it.

[gotis]

The MSD442 or the MSD556 will be good for what you are looking at.
4.2A and 5.6A peak, both at 50V DC. (or the MSD980 (90V 7.8A)
These can be ordered on our website.
www.motioncontrolproducts.co.uk.
We are in the UK, but will ship to the USA,

I´ve got three hybrids 2,5A, 0,76Ohms, 1,9V, 3,8mH will these be Ok for the MSD556?
Any idea what the total for a set of three MSD556 will be to Sweden?

[Mariss Freimanis]

About kits:

In the old days before thru-hole printed circuit boards all wiring was point-to-point and labor consituted 66 to 75% of the price of the finished item. Kits made sense then and it was Heathkit that best exploited reality. This was in the '50s.

Years later thru-hole printed circuit boards replaced point-to-point wiring and labor costs fell into the 33 to 50% range depending on were the the parts manually placed or machines did it. Heathkit was at its zenith and under pressure. The boards were pre-assembled (by machine) but there were plenty of them in a TV and they interconnected by hand-soldered wiring. This is the '70s.

Thru-hole boards were replaced by SMT, board quantity fell from many to 1 or a few in a product and interconnects became sockets or flexible PC wiring.

Today nearly everything is SMT and on a single board. Hand assembly labor now consitutes 5 to 10% of product cost. As an example, a G201 has 151 SMT components and 11 hand-assembled thru-hole parts. Some of these parts (8 MOSFETs) require special assembly techniques that are taught to the assemblers. Once learned, tens of thousands can be turned out easily but it takes 3 to 5 days of training.

These things make a "kit" version uneconomic. A very low labor total cost percentage and specialized skills necessary to perform that portion makes it uneconomic. Would anyone pay $95 for a "G201 kit" when the odds of assembling it would be so low and the savings be so little?

Anyone heard of, let alone bought a Heathkit lately?

Mariss

[phantomcow2]

The reason I prefer is kit is so that I have a better understanding of the driver. If I just get whatever it is that I get, and something goes wrong, its just a mysterious box. My experience with drivers that are a nice neat package is that you do not repair them. WHere with a kit, i've found that you can.

[Mariss Freimanis]

Sadly, that is the way I learned things as a kid; assembling Heathkits in the early '60s. The world has moved along since then and one of the things left behind is the "knowing by building" experience.

I don't know if it can be reconciled; people want electronics to do a lot for very little. Manufacturers like us meet that requirement by using expensive and automated plant equipment and process. It meets the needs of 99% of people buying our stuff.

It's that very important 1% I worry about. That 1% is the source from which future EEs and designers come from. Where are they going to get the inspiration to follow their dreams if not from a seminally satisfing experience of building something with their own hands and thereby gaining the confidence to to go further?

I know this because when I was a kid in the '60s I wanted an RC radio control so badly I still remember the taste even today. My parents were too poor for me to even ask and I certainly hadn't the means to buy a transmitter, receiver and servoes. All cared about were model airplanes and the Cox engines that drove them.

In desperation I got an ARRL handbook (Ham Radio Handbook), from the library and studied the basic electronics 100-page section of that 800-page volume.

The irony and sweet serendipity of life is you search for one thing and in the process you instead find what something else you were born to do. I never built the RC electroniccs I so badly wanted. When I was done with the ARRL book and moved on to other material RC no longer mattererd to me.

A few years later I bought what I wanted from the proceeds of my new talent and love of my life to today.

Mariss

[mcpltd]

Yes it would, but the MSD325 is rated to 2.5A at 30V and may be ok for you application?
Are you going to connect in series or parallel? if parallel the MSD556 would be better.
Email me your address and i will get some shipping quotes.
[email protected]

I´ve got three hybrids 2,5A, 0,76Ohms, 1,9V, 3,8mH will these be Ok for the MSD556?
Any idea what the total for a set of three MSD556 will be to Sweden?

[davesaudio]

Mariss -An eloquent pair of posts,

Nicely capturing the state of the electronics industry,
-Could digress a little about devolving to manufacturers reference designs and
outsourcing/globalization (blah blah blah) but overall seems to hit the mark.

I’m hopeful that 1% or 0.01% will be stubborn and insist on trying things
for themselves, if they are passionate I think they will.
Hard to be spontaneous if you HAVE to send a board out for etching AND stuffing, hopefully they’ll remain innovative and creative.

Visu labu
Dave

[Mariss Freimanis]

Dave,

Well, I've always have considered manufacturer's reference designs as entertaining in their naiveté. A strong exception would be National Semiconductor analog stuff. I've always felt a design should incorporate some artistic talent on the part of the designer; a slavish copy of a reference design does not meet that criteria.

Paldies un visu labu jums ari!

Mariss