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chuckknigh
05-05-2003, 12:09 AM
Well, I looked for HPLJ printers yesterday, at my flea market. Lots of LASER printers but only 1 HP...that I wanted to pay for.

So, I got a batch of 4 printers for $5...one was an HP3, the others were just random...NEC, Lexmark, and something else.

So, since my steppers will undoubtedly not match, and will likely be of differing strengths, which axis needs the biggest one, and which needs the smallest?

So far I've gotten out 2 steppers -- a 31n-cm and a 22n-cm. In US units that's about 100oz-in and 66 oz-in, if I did my calculations correctly. And, like I said, they don't match.

I would imagine Z would need the smallest motor, since its motion can be stepped down more by choosing a different thread pitch on the screw. No penalty, since its length of travel is so short.

And, I assume the longest axis would need the strongest...same reason.

Am I assuming correctly?

-- Chuck Knight

P.S. One other thing. If I turn out to have both unipolar and bipolar motors...there's essentially a distinct driver circuit running each one, so it won't matter, right?

WOODKNACK
05-05-2003, 09:40 AM
do you have any 2 that are the same? I believe you should have 2 of the same stepper for your X and Y axis. other wise it may not do certian moves right, like cut circles. as for the z axis a different one would work fine. Do you have apicture of the motors? Im just curios to see them. How many amp and volts are they?

If those steppers came out of regular bubble jet prints I dont think they are going to be powerful enough to run your machine.

WOODKNACK
05-05-2003, 09:58 AM
To save you a little head ache I saw these on ebay that would be perfect for what you are doing. Id say they are worth the money. Figure all your time looking for steppers!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2528067011&category=26209

and they are double shaft so you can mount a crank to it if you want.

HomeCNC
05-05-2003, 11:08 AM
How about this place. I like the .9 deg per step motors.

http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Product_Code=TM02MTR4550&Category_Code=STEPPING

and

http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Product_Code=TM02MTR4572&Category_Code=STEPPING

WOODKNACK
05-05-2003, 12:00 PM
Hey,
that looks good!I think I might buy a couple of the,4.5 VDC, 187 oz/in Torque, 400 Steps per Revolution, 0.9 Step Bi-Polar Stepping Motors. Good link..
I believe the stepper I have that I got out of lazer printers are .9 degrees and 400 steps prer revolution. but they are only 85 or 100 oz in.They are the same motors Balsaman has. The only info I could find on the net about them was this.

7)Japan Servo 85 oz-in 400 Steps/Rev (http://www.lasermotion.com/TEXT/JSstepMotjpg) . $29/ea, (- and if you want to see what a quality motor looks like inside, here is the dis-assembled motor, showing the clean design and double stack with ball-bearing construction.) (http://www.lasermotion.com/TEXT/JSsint.jpg)
Japan Servo TYPE KP56QM2-001, with Ball Bearings on each end of shaft. (note, unless you burn out the windings, and this takes at least a little effort, the only failure mode in step motors is bearing failure - which is easy to remedy as well as rare with Japan ball bearings)
NEMA23 mounting flange: Motor Length = 75mm from flange to rear of case, Motor Diameter = 57mm. Shaft Length = 14mm, Shaft Diameter = 5.9mm
6 Wire CT windings 3.5 ohm - 0 - 3.5 ohm,
Maximum Current: Center tapped - 1.5A , Bipolar, full winding - 1.0A
note: These motors have been carefully removed from surplus assemblies - leads are 75 mm long, and may require extending for some applications. We guarantee your satisfaction with these motors !! Limited quantity available. $29/ea

chuckknigh
05-06-2003, 01:26 AM
do you have any 2 that are the same?

No, I don't. So far I've retrieved 3 of the steppers from 3 of the printers...I have a large, medium, and small.

The largest is a 100 oz-in stepper, a Minibea Astrosyn 23LM-C701-01. 5.2V/phase, 1.4A/phase.

The medium is unknown so far (still google searching), a Minibea Astrosyn 23LM-S047-G1. 4.2V/phase, 1.2A/phase. Considering the almost insignificant difference between it and the first one, I expect that they're pretty close in capacity. It's 20% less voltage...maybe 80 oz-in? It's a guess, but not an entirely unreasonable one, assuming that it's a linear function.

Both of these are 1.8 deg per step, so 200 steps per revolution.

The smallest is by the same company, but has an IBM part number...thankfully it also has another number, 23LQ-C202-G2V. It has no voltage or amperage specs on it, as well as having no deg/step data. IBM didn't like their motors to be well documented, apparently. By using that number, I was able to find out it has 2/3 the torque of the 100 oz-in one, so it's around 66 oz-in, and get all the voltage and amperage specs. It's around here, somewhere.


I believe you should have 2 of the same stepper for your X and Y axis.

Well, I've still got 1 or 2 more printers, so there's still a chance! :-)


Do you have a picture of the motors? Im just curious to see them.

I'll see what I can do...I've got a digital camera, but incandescent light isn't the best stuff for photos. It's an older model...doesn't have white balance.

...

Well, they seemed to come out acceptably. Now, to figure out how to post them. Hopefully it'll show, below.


If those steppers came out of regular bubble jet prints I dont think they are going to be powerful enough to run your machine.

Big ancient LASER printers...the biggest one came from a gigantic HP laserjet III commercial grade printer. Sadly, the other printers, while heavy duty, are apparently designed for home use and have lighter duty components. Not much lighter...but lighter nonetheless.

-- Chuck Knight

WOODKNACK
05-06-2003, 09:42 AM
Chuck,
One of my motors is the same as your! (The largest is a 100 oz-in stepper, a Minibea Astrosyn 23LM-C701-01. 5.2V/phase, 1.4A/phase.) I too have one of these.
Do you know what your are going to use for a board yet?

chuckknigh
05-06-2003, 11:02 AM
I thought these were big enough...they're nice steppers! Now, I have 1 more printer to disassemble, before I'm done. Hopefully I'll find 2 that match...otherwise I'll make do with what I have, and keep my eyes open for an HP laserjet 1, 2, or 3...they all used the same big stepper.

As to the board, I had intended to homebuild one. The circuits look simple enough, and the chips are commonly available -- can't hurt to try. As I understand it, you build 1 board for each motor (or 3 basically distinct circuits on one board), so I can build pretty much whatever I'd like.

While buying a board might be more efficient, it's definitely not as much fun!

BTW: You posted a link to eBay...these printers that I'm disassembling have cost me $25, and one is being resold to a local garage for $20. My out of pocket expense will be $5 for 4 steppers...not too bad! Definitely better than the $60 opening bid on that auction...and especially considering my budget.

-- Chuck Knight

WOODKNACK
05-06-2003, 12:05 PM
Hey Chuck,
I never said what you had were not big enough! I did not know what you had. From the way you put it, it sounded like you were taken them out of bubble jet printers!
And yes sounds like you got a good deal. I just through that ebay bid at you becouse I know how frustrating it is to collect parts some times. I also found that it is just better to pay for something you find then try to wait for ever for the best deal! I guess it depends on how bad you want to build something and how good you want it to come out.
I am currently working on my 3rd machine now. I have learned alot by building the last 2 machines. I am also learning that it is better to buy the parts you really need then try to make them out of hardware store parts. Don't get me wrong in what I am saying. Im not trying to start a fight, Im just making a statement.
If you would like some plans for a unipolar board ,just give me a email and ill send you some I found off the net a year ago. It has everything you need to build it. even a list of materials.

chuckknigh
05-06-2003, 07:05 PM
Im not trying to start a fight, Im just making a statement.

Wow...no hostility from my side. I'm not trying to fight. Sorry if my tone made it sound that way...it was not my intention.

And, as to small motors, remember...I only found this forum a little over 2 weeks ago, and my first question was: "Is it possible to hook up a Dremel to my old HP pen plotter?" Boy have I come a long way!

It's a testament to this site and the knowledge contained in its members and their posts. Seriously...I started knowing zero about any of this, and now I'm designing my own CNC mill.


And yes sounds like you got a good deal.

As to getting a good deal...I just delivered that guy's LASER printer, along with an extra toner cartridge, extra RAM chip, and extra paper tray scavenged from a related model printer that I took apart.

He gave me double our agreed on price, since I brought extra parts...a pleasant surprise. I've actually managed to gather parts, AND make a profit at the same time! :-) When projects go like that, it's REALLY fun!

He got a good deal, too...it was a very nice printer...one complete one out of 2 parts machines.

I live for the art of the deal -- I think it's in my genes!


If you would like some plans for a unipolar board ,just give me a email and ill send you some I found off the net a year ago. It has everything you need to build it. even a list of materials.

Now...plans for a board. This sounds useful -- I'll send you a PM with my email.


I have learned alot by building the last 2 machines. I am also learning that it is better to buy the parts you really need then try to make them out of hardware store parts.

Well, I've been "inspired" by Cranky and his harware store CNC site. Of course, person that I am, I can't just buy plans and build someone else's design -- I have to do it myself. The good part about it is that I learn a lot more that way!

-- Chuck Knight

balsaman
05-07-2003, 10:52 PM
Chuck,

Those steppers will be fine. You don't need two the same, if you aren't too fussy, because you can make up for any differences in the software setup. Circles etc. will be fine.

Z should not always nessisarily have the smallest stepper. If the router will be heavy, a larger one may be a good idea. The z is the only one that has to work against gravity. If you will be using a Dremel, then go with the smallest on z.

If any of the steppers are 4 wire, they won't work on a unipolar driver. 4 wire is a bipolar motor. Unipolar motors (5, 6 or 8 wires) can be driven by a unipolar or bipolar driver.

I have 3 of the largest of your motors. Those work very well. I am sure the other two will be fine as well.

chuckknigh
05-08-2003, 12:58 AM
I'm delighted to hear that they don't have to match. I was going to size them, based on the mass they move. (moving gantry design) Since I intend to nullify the weight of the milling head through the use of either springs or a counterweight, I had not considered gravity to be an issue.

The biggest would be on my longest (X) axis, and move the entire gantry.

The medium would be on my shorter (Y) axis, and move just the router head assembly.

The smallest would be on the Z axis, and be geared down with a fine pitch thread, if I can find that material locally...less movement, but more resolution that way. Or, am I just obsessing?

The medium and large motors are 6 wire unipolar units...the small one is a bipolar 4 wire. Thanks for the heads up. I'm actually keeping my eyes open for a junker HPLJ 1, 2, or 3, so I can get another big stepper...but in the meantime I'm going to go ahead with what I have.

As I understand the driver boards, they're basically a complete and discrete circuit for each axis -- I saw one design that was literally a separate board for each axis. Because of this, I should be able to implement a board for either type of stepper, depending on what I need for each one. If I implement a backplane for power, it becomes even simpler...almost literally plug 'n play.

Of course, I haven't drawn up the schematics, yet..I'll see if I can get some samples, and then I'll design around what I get. If memory serves, Allegro Micro gives samples in Qty 4...

-- Chuck Knight

ehiebert
09-23-2003, 05:02 PM
Hey Chuck and Balsaman,

I'm pretty happy with this thread. I just pulled 2 of the 23LM 100 oz. in. astrosyn and 2 of the Japan Servo 85 oz. in motors from 4 laser printers. The 23LM Astrosyn come from HP Laserjet II series, and the Japan Servo motors from DEC 2100 printers.

A note for others... Laserjet IIp and Laserjet IIIp aren't worth the effort. The motors in them are a Canon PM60-H418Z21B motor which I can't find any information on. Its a uni-polar stepper (6 wires) but the body is a non-standard size. Judging from the lead size I'd say these are very weak motors too. The winding leads are 22-24 ga. wire.... so they won't take over 1/2 A of current. I did find that these were only 48 steps/revolution too.... ie 7.5 step angle.

Thanks for the help finding cheap motors!!! Oh yes.... my cost was $20 for 7 printers. I got the four good motors and three crummy ones.

I'm planning on building an aluminum frame 4 axis mill similar to what Balsaman has done. I will build my own driver boards and use ACME rod for a drive.

I have the benefit in that I own a 9x20 lathe... so I can turn some stuff as needed. I also intend to use 1/2" drill rod and acetal or bronze bushings for linear rails. I know it won't come out as inexpensive as Chuck's, but I need it rigid enough to mill aluminum.

Later!!!
Eldon.

ger21
09-23-2003, 07:38 PM
Judging from the lead size I'd say these are very weak motors too. The winding leads are 22-24 ga. wire.... so they won't take over 1/2 A of current

I don't think this should be you're determining factor. My 250oz PacSci motors are rated 4.6a parallel and the connectors take 22awg wire. They recommend the 22awg be no more than 12", though.

Gerry

chuckknigh
09-23-2003, 08:21 PM
Inexpensive? Geez, I paid good money for my printers!

In fact, I just picked up another one, an HP LaserJet II, for 40 cents! I consider that EXPENSIVE for tech *that* antiquated. But, I needed another motor for my X-Y vise project.

:-)

-- Chuck Knight

Snipes44
10-30-2003, 04:12 PM
Been ready about you guys getting all these old printers, I was wondering where are you getting them from.

I just lucked out on ebay and got 2 identical nema23 2.4v 2.5A 1.8deg fro $5.50 each :-). They were taken our of an old printer.

They deals you guys are find are are way better. I have not been able to find a place for cheap surplus printers.

-Wes

ehiebert
10-30-2003, 04:24 PM
I just called around to some computer stores that advertised repair services. Copier repair outlets are also a good source for the printer motors as they usually fix printers too.

Eldon.

Mr.Chips
10-30-2003, 05:44 PM
How about the IBM laser printers, what kind of steppers do they use? Sorry don't have a model no. There about 8" high and weigh a ton.
Does anyone know?

ehiebert
10-30-2003, 05:55 PM
Big old heavy printers are a pretty good sign that you'll get some good stuff from them. IBM actually has much of their stuff contract manufactured. So my bet is that those would be HP printers.

If you get a model number I can find out what type of motors are in them.

Eldon.

chuckknigh
10-30-2003, 08:37 PM
They deals you guys are find are are way better. I have not been able to find a place for cheap surplus printers.

I usually hit the local thrift stores. I have 2 particular ones that almost always turn up a LOT of tech surplus, and then there's the Goodwill As-Is store, where all the north Texas "as-is stuff" ends up. If it doesn't work, or if they don't know how to test it, it goes to this big warehouse in Sherman...they have a store, affectionately nicknamed "GoodWill As-Is."

Makes it easy to find this kind of stuff. Unfortunately, their tech has gone up in price, lately, since the arrival of their tech geek. :-( Of course, I still paid a whopping $3 for my last fax machine!

One tip for you. Since I frequent these stores, I know what equipment has been lying around for a while. Then I offer then pennies on the dollar for it -- they ordinarily trash it after 2-3 months, so, from their point of view, getting 50 cents is still better than getting nothing for it. You just have to make the deal with the manager...the clerks don't have the authority to change the prices.

-- Chuck Knight

Carver
11-06-2003, 06:40 PM
Hi Chuck,

Since you are located so close to Dallas, I didn't know if you were aware of the Texas Instruments surplus auction that takes place every Friday Morning. It is on Northhaven in Dallas. They dispose of all types of manufacturing equipment for salvage only. It is a sealed bid auction and opens at 6:30 am They read the bids at 9:00 am. Lots af motion control, it just might be still attached to a 3000lb camera. They regularly dispose of functional robots by their scrap weight. Shout at me offline if you want more details.

Take care,
Phill Pittman
digicarve@verizon.net
www.masterwerkes.com

xairflyer
11-08-2003, 11:45 AM
Came across this site which has circuits for both bipolar and unipolar drives

http://zeus.eed.usv.ro/misc/mirrors/cc/index2.htm