Stepper Motor Giveaway

[rmteo]

I have 46 (new and unused) of these stepper motors that I no longer need. Any suggestions for a contest (or other method) to give these away - perhaps in lots 3-4 units per winner? You can view the full spec here http://catalog.nidec-servo.com/digit.../pdf/KH42H.pdf

[Heckler]

Wow! What a generous offer.

I would love to get a set of 4... I have been dreaming of building a CNC mill to route PCB's. I have been looking at building the Mantis 9 CNC, but have not started putting together the parts kit. Here is a link to the project. The bill of materials requires 3 - Nema 17's (they look the same)
http://makeyourbot.org/mantis9-1
Do you know if these are NEMA 17?

I could provide you with my UPS shipper number.
As far as a contest... I am comming up blank for ideas. Unless the contest is first come first served!

Thanks Dwight
here is my email
[email protected]

[rmteo]

Yes, they are NEMA17 (42mm. square). The ones I have are probably a custom OEM version - they are bipolar (4 leads) with a winding resistance of 9.8 measured Ohms per phase.

I guess you just won 4 of these motors just for describing your project. If you would PM your UPS account number (and shipping address), I will get them out to you. Total weight is 3lb.

[Demon]

Those look interesting. I'm also in the process of accumulating parts for a DIY CNC machine. I have 4 Minebea 23LM-C Series steppers for the main machine (Nema 23 I think), but I'm also looking for smaller steppers for auxilliary components.

The machine itself will not be breakthrough design, but it's the add-ons that I'm going to put extra emphasis. I have ideas from tool changer to parts magazines to video supervision, that's where smaller steppers like yours and solenoids will come in handy.

Played a bit with Google sketch-up a while back and did some preliminary designs. It's going to be an upside-down design compared to most designs out there; this way I can have my electronics up top and safe from coolant below. I might have more than 3 axis, that's to be finalized later.

The 2 sides will be where parts will be fed, tool changer on a front door, rear will be for ventilation and cooling. I'll work more on that once I get the basic system running.

(this picture is upside-down really, I drew it this way cause it was easier to draw)





Overall it will look something like this:

[mackrackit]

Those motors look about the correct size for a robotic arm I have been thinking about. A small one for demonstrations.

[Bruce]

I could use 4 of these if you still have them on hand.

Can give you our UPS acct # if you do.

[rmteo]

I could use 4 of these if you still have them on hand.

Can give you our UPS acct # if you do.

PM your UPS account # and address and I will send them out.

[cncmachineguy]

Hello rmteo, just thought of a use for 4 of your steppers. I want to make me a small 4 axis pick and place for prototype SMD boards. I will need X,Y,Z, and a rotary about the Z axis. Not sure if this will be CNC or just jog only, but in any event small light weight steppers are in order.

Now this will be placed around the middle of my project list, but rest assured I will get it done.

I don't really have a ups account, but I could send a pre-paid ups label PDF style if you know the weight. Or if better for you, will they fit in one of those USPS any weight boxes for around $9?

Assuming this is a good enough project to win some.

Edit: just saw 3 pounds, so I could send a label.

[rmteo]

4 motors will fit into one of those USPS boxes. Easiest will be to just PayPal the shipping cost.

[Nicmus]

Some time ago I started working on a giant, three sided, garden clock but never had the chance to seriously finish the design.
This might be a good incentive to finish it and also make some use of a small CNC machine I purchased from an ad in this forum.
So if they are still available I could use 6.
PM me your PayPal information for the charges involved.

Thank you,


Nick

[rmteo]

Nick, PM sent.

[Nicmus]

Your PM box is full.
I could not reply to you but I will go ahead and PayPal you the amount later today.

Thanks again.

Nick

[cncmachineguy]

RMTEO, money sent. Please send the motors to the same address as the board. Please confirm you have received the money as I have never sent money through paypal before.

Thank You!!

[rmteo]

RMTEO, money sent. Please send the motors to the same address as the board. Please confirm you have received the money as I have never sent money through paypal before.

Thank You!!

Received it, thanks - will send motors to MD.

[cncmachineguy]

Received my steppers today They are the cutiest things. I question. There are 6 connections, are these uni-polar or bi-polar?

Thank you for these, I will make good use of them.

[rmteo]

They are bi-polar. Only the 4 inner connections are used - the outermost 2 are NC. See post #1 for a link to the data sheet.

[cncmachineguy]

thanks RMTEO, I had read the datasheet, then I confused myself when they had the 6 pin connector. BTW, do you have a favorite drive or chip (btw, I am not scared of the SMT's anymore)?

[rmteo]

This is what I would use http://www.allegromicro.com/en/Produ...3987/index.asp

[Heckler]

Sparkfun has this same chip on a nice little driver board... http://www.sparkfun.com/products/10267

[cncmachineguy]

Just a little confused. Here is the datasheet for the driver linked by RMTEO. I read it as having 1.5A output. Now I assume this is per coil. Am I wrong - again? The sparkfun board says .75A, so if I am correct, why half?

I am also baffeled by the motor supply current. 4mA max? this is on page 4, Ibb rating. Thats a pretty high gain by my book!

Edit: I see the SF unit is not the exact chip - that makes sense now. Still confused about the motor supply current

[Heckler]

Sorry Bert,

I should have looked closer at the part numbers...

I had just seen that little board on Sparkfun and remembered that it had an Allegro chip on it.

I can't give you any more insight on driving stepper motors. But I can give you another link . Here is a board that has been recomended to me for doing various CNC stuff... It is a 3 channel kit... http://www.hobbycnc.com/products/hob...ver-board-kit/ they also offer a slightly more expensive one that apparently has idle current reduction.

Again, I am a bit out of my league here, but have been doing a lot of reading and studying trying to decide how I am going to drive the motors that (hopefully) rmteo will be sending me soon. There are also tons of boards on ebay... search "stepper driver" but as usual, beware.

There is also a great, huge, group forum called cnczone.com, but goodluck navigating down through all the forums.

Sorry to have mislead you.

[cncmachineguy]

No problem Dwight. I will prolly build my own boards based on the driver reccommend by RMTEO. The easyCNC board you linked is for uni-polar only!! Will not work with these motors. But I do appreciate you sharing what you have found. I need to order some boards for another project, I think I can piggy back some for this on the same panels

[rmteo]

The A3987 is good for up to 1.5A per phase/coil. But make sure that you do not exceed a Tj of 150C - proper heatsinking etc. I measured 9.8 Ohms per phase and you should limit current to about 0.6A (per the data sheet) with an appropriate sense resistor. For best performance I would drive the motor with at least 12V, preferably in the 18-24V range.

[cncmachineguy]

Well I may have to re-think this. If the current draw is .6A, then the SF board will work fine.

[rmteo]

12 motors left.

[mackrackit]

I will take four if you PM your paypal info.

[Demon]

I would take 4 as well please.

PM me cost and paypal addy.

[rmteo]

The previously mentioned 12 motors will go out to scalerobotics, mackrackit and Demon.

I found another 12 motors. These are absolutely the last of them.

[Demon]

...they are bipolar (4 leads)...

Thanks! Got mine yesterday.

I don't see any reference to pin 1 on the datasheet. Is it the pink blob on the connector?

[rmteo]

The nomenclature in the data sheet is somewhat confusing - you can ignore it. The outer 2 pins are "NO connects". The inner 4 are the 2 pair of connections for each phase. You can measure the resistance of each phase - should be about 9.8 ohms.