Nema 17 replacement?

Hello, i'm looking for some help and guidance!
I'm building a diy Makerbot rather than buying one of their kits, but i can't find the Nema 17 motors they use anywhere. It seems they might of been a batch of surplus stock? anyway i was look for a replacement but i know very little about steppers, i have found this and was wondering if people thing they would be suitable?

[www.motioncontrolproducts.co.uk]

or does anyone know of a better motor, or indeed anywhere to get the lin ones, i am planing on using the generation 3 electrics with 2.3 drivers

thanks for any help or ideas!

Hi Chris,

... for europe you can look here: [en.nanotec.com]

Viktor

If you look down a few post in this section you will see where I linked to a ebay auction where there are 40+ available. I ordered several of them.

here's the link to that post
[forums.reprap.org]

Definitely look at auction sites, pfererably local ones, not eBay (that is, if they exist where you live). I was able to get refurbished (read: as good as new, there's nothing to wear out inside, save for two cheap and easily replaced bearings) NEMA23 motors at 5-10PLN a piece, and NEMA17 at ~3PLN at a local auction site here in Poland. That's less than 2GBP per motor at current exchange rates.

whats wrong with ebay? I buy probably $10k worth of stuff a year on ebay. Local auction sites are full of scammers with no buyer protection.

Try

[www.motioncontrolproducts.co.uk]

Fast service, and they are cheap. Very nice motors. They only had the dual shaft one when I ordered but it arrived next day.

Hey guys thanks for all the sources to look at, I'm in the UK so your suggestions were well placed!

I have been looking through the sites but fear i am now getting more confused!!!

I was thinking i would just try to find ones which is closest to the original Lin motors, but there are so many options and i don't know what is best? is there a particular voltage and ampage i need when using the 2.3 stepper driver?

people seem to use such a wide variety.....could anyone suggest one most suited?

Thanks for your time and help it is truly appreciated

Ok so i have now just noticed the there is only room for a 34mm length stepper in the Makerbot, I think i'm gonna go for these FL42STH33-1334A as a single shaft, the basic spec is below and hopefully not too muddled!!!

Model No. Rated Voltage Current /Phase Resistance /Phase Inertia
Single Shaft Double Shaft V A Ω mH Kg-cm
FL42STH33-1334A FL42STH33-1334B 2.8 1.33 2.1 2.5 2.2
[www.motioncontrolproducts.co.uk]

ok so it was very muddled!! i had copy and pasted from a table

FL42STH33-1334A 2.8V 1.33A 2.1Ω 2.5mH 2.2Kg-cm

What's important is really the holding torque - in a Darwin-like design, probably the most important motor characteristic is good deceleration (that is, active braking), as a belt-driven toolhead will have a natural tendency to overshoot at sharp turns and this has to be prevented. Voltage and resistance are somewhat less important. Both 1.x and 2.x stepper drivers can handle a very wide range of motor voltages because they're actually constant-current drivers (well, sort of - chopping alone is not really a cc drive, but it's close enough).

... i'm in Germany and have some unipolar motors Nema-17(5Volts/0.7Amps) and Nema-23-motors (24Volts/0.4Amps) from scrap - look here:



... the Nema17 in the red border and Nema-23 are the greyish in the middle/right.

If you can handle the voltage/amps you can have them for shipping-/transfer-fee ...

Viktor

Edited 1 time(s). Last edit at 06/17/2009 05:01AM by Viktor.

Hi Viktor,
Thanks you for your super kind offer! i ordered the motors the other day before seeing your post..... don't think i can really cancel it either.... that will teach me for being too hasty! thanks all the same!

Where did you get that hoard of motors from? photocopiers? do you just fit them and see what works well or can you calculate the torque etc first?

Enleth, i see what you mean about the torque being most important, i didn't realise that the stepper drivers could used with many voltages, thanks for the insight.

I'm gonna sign up and get a proper login now.
thanks chris

Hi Chris,

... the Nema23-motors are from more than 20 years old old IBM-printers, the Nema17 mostly from AEG-typewriters, some from 5.25" floppy- and hd-drives.

From copiers i got some bigger AC- and DC-motors and magnetic clutches, in many printers between 15 and 10 years old i found 48-steps/turn tin-can steppers, in some (especially NEC) better/stronger 200-steps/turn Nema23-steppers but in modern printers there are mostly small DC-motors with gears and optical sensors as servos ...

Viktor

Wonderfull picture thank you Victor your pile of assorted steppers looks a lot more than my pile so im in the clear with midge now...

---

Bodge It [reprap.org]
=======================================

---

BIQ Sanguinololu SD LCD board	BIQ Stepcon	BIQ Opto Endstop
BIQ Heater Block PCB	BIQ Extruder Peek clamp replacement	BIQ Huxley Seedling
BIQ Sanguinololu mounting	BIQ standalone Sanguinololu or Ramps mounting	Print It Stick It Cut it

My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]

Hi Bodge It,

... this was only a fraction i was willing to give away - some 3-count sets are elsewhere now

I have some bigger/stronger steppers i'll reserve for 'serious' milling/turning applications and some special types (ultraflat, linear, geared, ...)

Beside there are some PZT-motors and micro-/nano-drives for extreme high resolutions and some mechanical 'scrap' as linear stages, spindles or other maybe usefull stuff too.

... it's a real big basement ... but some disputes according tidying up with my wife too

I guess Im getting stick as we are still at Midges house with all the stuff for Solar self sufficenty & CNC machines arriving here waiting to make the move to my house which is a 10 min walk away.

I have a collection of inverters with lids off at the moment im investigating the possibility of a low cost convertion from modified sine wave to pure sine wave.

Midge is also an enginner more a software Architect than Dev Eng , shes built bds now she prefers to burn wood with soldering iorns calling it Pyrography along side designing vertical garden systems.

We keep slipping on house project deadlines we have one bathroom nearly finished to 5 star hotel room standard with just the onsuite with jucuzi left to do.

Once finished we move to my house to slum it & build as near self suficent life style as we can get . By then our design dicussions should be less time consuming.

---

Bodge It [reprap.org]
=======================================

---

BIQ Sanguinololu SD LCD board	BIQ Stepcon	BIQ Opto Endstop
BIQ Heater Block PCB	BIQ Extruder Peek clamp replacement	BIQ Huxley Seedling
BIQ Sanguinololu mounting	BIQ standalone Sanguinololu or Ramps mounting	Print It Stick It Cut it

My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]