Hey all, Adrian and I have been talking about the RRRF doing a bulk purchase of the 'standard' stepper motors to sell to non-european researchers. I'm posting to find out what type of interest there is from you guys in ordering them. I'm not going to lie, they are pricey. A set of 3 is going to cost $180, minimum. Probably close to $200 once we factor in shipping, paypal, etc. Here is a link to the specs: http://www.nanotec.com/page_product__st5709__en.html Please reply here either way... i'd like to get a feeling for what you're thinking.. yes *or* no. Also, if anyone could find a comparable motor that is more readily available in the USA, we could also go that route. Thanks for your help! ~Zach Smith https://reprap.org/forum/read.php?14,4431,4431#msg-4431 Thu, 17 Sep 2026 00:34:09 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?14,4431,46265#msg-46265 https://reprap.org/forum/read.php?14,4431,46265#msg-46265 -------------------------------------------------------
> Any further problems/comments about the
> KL23H251-24-8B? (11A from Keling) I'm about to
> drop $80, so I just wanted to double check...
> Thanks!

I bought 3 of these exact same motors a couple of years ago and they are amazingly good value - I abused them with a crappy driver and they're still going strong!]]> James Waples Mechanics Sun, 23 May 2010 06:04:29 -0400 https://reprap.org/forum/read.php?14,4431,10354#msg-10354 https://reprap.org/forum/read.php?14,4431,10354#msg-10354
That's what I suspected was going to happen. You just have to pry too many steps/second out of one of those beefy, 0.9-1.8 degree steppers for it to be practical with a threaded rod drive system to get the speeds you need for an extruder. :(]]> Forrest Higgs Mechanics Sat, 15 Mar 2008 10:14:41 -0400 https://reprap.org/forum/read.php?14,4431,10345#msg-10345 https://reprap.org/forum/read.php?14,4431,10345#msg-10345 Using the Darwin Pic steppers I have not been able to get enough speed to build anything with my McWire Repstrap. Too much plastic not enough speed. The Keling motors should be faster , but not enough faster IMHO. I designed and build a belt drive mod for my McWire that has the same speed ratios for X and Y as Darwin. Now all I need is a little free time to tidy up and debug the finished product. Sadly free time is a little short for me right now. The design is pretty obvious, a pulley on the stepper an Idler pulley and washers on a bolt, mounting plates for both and a belt clamp that captures both ends of the belt and is attached to the X or Y stage.

Dan]]> Anonymous User Mechanics Sat, 15 Mar 2008 00:01:36 -0400 https://reprap.org/forum/read.php?14,4431,10053#msg-10053 https://reprap.org/forum/read.php?14,4431,10053#msg-10053 Anonymous User Mechanics Sun, 02 Mar 2008 23:06:27 -0500 https://reprap.org/forum/read.php?14,4431,9351#msg-9351 https://reprap.org/forum/read.php?14,4431,9351#msg-9351 ZachHoeken Mechanics Tue, 12 Feb 2008 12:42:01 -0500 https://reprap.org/forum/read.php?14,4431,9271#msg-9271 https://reprap.org/forum/read.php?14,4431,9271#msg-9271
Also, when you are running at 1000 steps/second and more your available torque drops like a stone, so that big holding torque value and all that power isn't getting you very much at speeds high enough to get some printing done in reasonable time frames.

What I did was opt for a smaller stepper with as big a step as I could buy with a low inductance. It runs fast and the transition per step for the one I bought is like 0.04 mm/step. That's twice as good as I need. Your needs may differ, though.]]> Forrest Higgs Mechanics Sat, 09 Feb 2008 14:32:05 -0500 https://reprap.org/forum/read.php?14,4431,9268#msg-9268 https://reprap.org/forum/read.php?14,4431,9268#msg-9268 I was going to use them for the McWire Cartesian Bot (threaded rods). Bad idea? Would you recommend something else? Less amps?
Thanks!]]> Anonymous User Mechanics Sat, 09 Feb 2008 13:36:11 -0500 https://reprap.org/forum/read.php?14,4431,9261#msg-9261 https://reprap.org/forum/read.php?14,4431,9261#msg-9261 www.kelinginc.net]

I gather you're going to wire it in series to keep the phase amperage down below 2 amps?

Are you using this thing to drive a Darwin or your own design that, iirc, uses threaded rods?]]> Forrest Higgs Mechanics Fri, 08 Feb 2008 23:27:19 -0500 https://reprap.org/forum/read.php?14,4431,9256#msg-9256 https://reprap.org/forum/read.php?14,4431,9256#msg-9256 Thanks!]]> Anonymous User Mechanics Fri, 08 Feb 2008 17:40:46 -0500 https://reprap.org/forum/read.php?14,4431,8725#msg-8725 https://reprap.org/forum/read.php?14,4431,8725#msg-8725 Ian Adkins Mechanics Mon, 21 Jan 2008 03:55:20 -0500 https://reprap.org/forum/read.php?14,4431,8690#msg-8690 https://reprap.org/forum/read.php?14,4431,8690#msg-8690
As an engineer for a large disk/data storage company, I can tell you that it is always best to source from multiple vendors. We could then share our experience with the others as 'mods' that are within spec.]]> Anonymous User Mechanics Sat, 19 Jan 2008 22:56:08 -0500 https://reprap.org/forum/read.php?14,4431,8664#msg-8664 https://reprap.org/forum/read.php?14,4431,8664#msg-8664
Webtronic - $24.95 qty 1 Spec sheet:
[lib.store.yahoo.net]

Circuit Specialist - $24.95 qty 1 Spec Sheet:
[www.circuitspecialists.com]

I just chased google for : nema 23 stepper motor]]> bobt Mechanics Sat, 19 Jan 2008 15:54:44 -0500 https://reprap.org/forum/read.php?14,4431,8656#msg-8656 https://reprap.org/forum/read.php?14,4431,8656#msg-8656 -------------------------------------------------------
> Sorry. I had a blog post typed up about the new
> motors, but it got eaten by my browser. The new
> steppers are in (48). I figured a blog post would
> be overkill

No need to apologize. I just assumed you were too busy, my mistake for underestimating you.

> since my supplier has to re-order
> more steppers in china (~2 months til next set.)

Well, ok. But 16 sets doesn't seem much to me for 2 months, as the feedback on the motors seemed great (I got to see one in action in Houston on Sunday myself). At least I hope we run out. So did we come up with any useful alternates when we found this source ;) Is Keller the direct mfg on these, I can't find that part # anywhere else.


> If you have to know, 48 motors cost $1138
> including shipping.

It seems odd to me that this information isn't open shared. It isn't personal finances we are talking here. You are charging great prices. Maybe I'm out of line on expectations for open source. It isn't like you don't have to deal with returns and other overhead... so gross cost isn't expected to equal net cost.

> You wont be able to order
> any, because the supplier is temporarily out of
> stock. He's reordering more and my plan is to
> keep ordering to perpetually keep the RRRF in
> stock.

We in the USA seem to get favorable pricing from China. That may only be a short-term opportunity (next 6 months) as the Chinese are turning up the heat on the currency imbalance. Part of the reason I expect high demand for motors is I expect even with shipping that overseas demand will be there at USD$25.

Plus one thing that I'm not sure we can really solve (or should try): There clearly is a lot of open source activity out there related to stepper motors - and RepRap project is going to draw attention for people wanting to share technology. This can lead to 16 sets being sold out in 1 day once another project finds out about it ;) Always a reasonable chance of this.

I entirely admit my need for help in finding the correct compatible motors. Please post any leads.]]> RoundSparrow Mechanics Sat, 19 Jan 2008 12:17:15 -0500 https://reprap.org/forum/read.php?14,4431,8650#msg-8650 https://reprap.org/forum/read.php?14,4431,8650#msg-8650
If you have to know, 48 motors cost $1138 including shipping. You wont be able to order any, because the supplier is temporarily out of stock. He's reordering more and my plan is to keep ordering to perpetually keep the RRRF in stock. He's 100% interested in working with us and we even chatted on the phone.]]> ZachHoeken Mechanics Sat, 19 Jan 2008 11:53:11 -0500 https://reprap.org/forum/read.php?14,4431,8646#msg-8646 https://reprap.org/forum/read.php?14,4431,8646#msg-8646 -------------------------------------------------------
> I checked the site Tuesday and the new stepper
> motor order was in and online. I ordered 6 and
> Zach shipped them yesterday.

Thank you for sharing that.

I was not aware of this. As this thread was was the place all this started (fully documented in the messages). And I had asked Zach to let me know when they were in so I can order 3 for myself.

Good to hear.]]> RoundSparrow Mechanics Sat, 19 Jan 2008 11:39:19 -0500 https://reprap.org/forum/read.php?14,4431,8645#msg-8645 https://reprap.org/forum/read.php?14,4431,8645#msg-8645 bobt Mechanics Sat, 19 Jan 2008 11:29:52 -0500 https://reprap.org/forum/read.php?14,4431,8644#msg-8644 https://reprap.org/forum/read.php?14,4431,8644#msg-8644 -------------------------------------------------------
> I don't really have anything to say about the
> motors, but stop the bickering in the forums. If
> you want to bicker, than send a PM, but it is a
> waste of space in th forums and nobody wants to
> read this junk.


If you don't have anything to say about motors, then why the heck did you post in this thread? How about YOU send a PM.

I'm trying to ask what price was paid for a bulk motor purchase that impacts the RepRap community. And I am the one who financed that purchase. And this is the thread where that very purchase was organized.

Where is the second set of motors that Zach purchased? Are they in yet? It was December 19 when I witnessed the first batch come in. As was pointed out in this thread, they sold out in 4 days. It has been another 30 days. And I am waiting to order more myself... is the vendor giving Zach trouble?

My agenda is to get problems on the table and SOLVE THEM. Money seemed to be the issue, so I provided money. First batch was done in less than 3 weeks. Things are slowing down, so maybe the time is to step forward and help out more on the labor side. I know Zach is very busy. I'm asking questions so I can decide if it makes sense to help out by starting a second source here in the USA for some of these parts.

And in case not clear: these questions are directly related to motors for building a RepRap.]]> RoundSparrow Mechanics Sat, 19 Jan 2008 11:19:50 -0500 https://reprap.org/forum/read.php?14,4431,8629#msg-8629 https://reprap.org/forum/read.php?14,4431,8629#msg-8629 redskinsjbs Mechanics Fri, 18 Jan 2008 21:59:31 -0500 https://reprap.org/forum/read.php?14,4431,8628#msg-8628 https://reprap.org/forum/read.php?14,4431,8628#msg-8628 > don't think we need to know.

Ok, so again Robert Teeter has taken upon himself to follow me around on this forum and tell me what I need to know or otherwise discuss.

It is clear to me that price and availability of motors in the USA is a significant factor in keeping people from building RepRap's. But Hey, Robert Tweeter will probably tell me ideas are inappropriate for this forum and haven't researched that enough.

In November 2007 it took me 4 weeks to get my motors from England. And others put the problem on the table... that price was a factor (I did not start this thread).

It is my understanding that the first batch of RRRF motors sold out very quickly and there was demand for a second batch. And I can speculate that it might be more demand beyond another 16 sets.

Is it beyond imagination that some people out here might actually believe in the goals of the project and *gasp* be willing to donate time, travel, and do other things at a loss?

I just asked a straight-forward question on what price to aim for on a bulk purchase - to be sure I'm getting the right motors at a good price. You know, sharing information that might help the project either move quicker or help others build a RepRap.]]> RoundSparrow Mechanics Fri, 18 Jan 2008 21:48:43 -0500 https://reprap.org/forum/read.php?14,4431,8608#msg-8608 https://reprap.org/forum/read.php?14,4431,8608#msg-8608
i hope you dont think the RRRF is trying to rip anyone off. yes, its true the RRRF marks up the prices slightly, but you have to keep in mind that it needs to a) cover expenses such as rent and b) needs to earn money in order to expand and be able to provide more services. its a balancing act, and i think that all the prices on the website are very fair.

finally: ordering the motors singly:

keling: $29.00 ea.
RRRF: $25 ea.

Cheers,
Zach]]> ZachHoeken Mechanics Fri, 18 Jan 2008 12:19:31 -0500 https://reprap.org/forum/read.php?14,4431,8605#msg-8605 https://reprap.org/forum/read.php?14,4431,8605#msg-8605
This is a "KL23H251-24-8B" 8-wire NEMA 23 stepper motor with dual output shafts from Keling Technology, Inc. It can be wired in unipolar, bipolar-serial, or bipolar-parallel modes. It is compatible with both generation 1 and generation 2 stepper driver boards.

You can view the datasheet here, and the torque/speed curve here.

You will need 3 (three) of these to drive a full RepRap machine, one for each axis.

I hope that this helps.

Zach sells these for $25.00 more than that I don't think we need to know. This should give you enough information if you wish not to purchase from RRRF to find your own source of supply.

Disclaimer: I am a very happy customer of RRRF.....]]> bobt Mechanics Fri, 18 Jan 2008 12:00:40 -0500 https://reprap.org/forum/read.php?14,4431,8603#msg-8603 https://reprap.org/forum/read.php?14,4431,8603#msg-8603
Does anyone have identifying information that is printed on the motor itself? Part numbers, etc.

Thank you.]]> RoundSparrow Mechanics Fri, 18 Jan 2008 11:22:33 -0500 https://reprap.org/forum/read.php?14,4431,7981#msg-7981 https://reprap.org/forum/read.php?14,4431,7981#msg-7981 bobt Mechanics Wed, 02 Jan 2008 18:05:51 -0500 https://reprap.org/forum/read.php?14,4431,7832#msg-7832 https://reprap.org/forum/read.php?14,4431,7832#msg-7832
Of course there is always the 'chopper method' which the arduino stepper boards use that monitors the current and cuts power when it hits the predefined limit. That ensures no matter what stepper you use, it always gets the right amount of power.]]> ZachHoeken Mechanics Fri, 28 Dec 2007 16:13:25 -0500 https://reprap.org/forum/read.php?14,4431,7731#msg-7731 https://reprap.org/forum/read.php?14,4431,7731#msg-7731
I haven't done much research into it (yet), but it seems the universal controller boards have all of the necessary circuitry for PWM. I realize it might require some patch wires and firmware changes, but couldn't you use the power transistor usually reserved for the extruder heater to effectively mimic any voltage as the supply for the 298? Then you could drive many different steppers without series resistors.

Scott McClure]]> Scott Mechanics Tue, 25 Dec 2007 10:34:59 -0500 https://reprap.org/forum/read.php?14,4431,7639#msg-7639 https://reprap.org/forum/read.php?14,4431,7639#msg-7639 ZachHoeken Mechanics Thu, 20 Dec 2007 16:43:57 -0500 https://reprap.org/forum/read.php?14,4431,7599#msg-7599 https://reprap.org/forum/read.php?14,4431,7599#msg-7599 mellery Mechanics Wed, 19 Dec 2007 16:15:57 -0500 https://reprap.org/forum/read.php?14,4431,7595#msg-7595 https://reprap.org/forum/read.php?14,4431,7595#msg-7595 Squintz Mechanics Wed, 19 Dec 2007 15:39:21 -0500 https://reprap.org/forum/read.php?14,4431,7593#msg-7593 https://reprap.org/forum/read.php?14,4431,7593#msg-7593 bobt Mechanics Wed, 19 Dec 2007 15:17:57 -0500 https://reprap.org/forum/read.php?14,4431,7588#msg-7588 https://reprap.org/forum/read.php?14,4431,7588#msg-7588 store.rrrf.org]

only $25 each!]]> ZachHoeken Mechanics Wed, 19 Dec 2007 14:39:12 -0500