5 Axis Stepper board on ebay

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01 Apr 2011 03:19 #8364 by bvandiepenbos
I am wondering if anybody has any experience or onions about this 5 axis board on ebay?
cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280629124505

This is just for a "proof of concept" robot type machine so I am thinking it may work.

I need 5axis and am trying to figure out cheapest hardware.

other suggestions?


Thanks!
~*Brian VanDiepenbos

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01 Apr 2011 07:54 #8366 by cncbasher
this is such a subjective question , so realy all depends on it's use and only you know that answer , perhaps you can give more details on the project etc .
however here goes .

the board will work fine if stepper motor current drain is lower than 3A , so this rules out larger steppers of the Nema 23 or 34 series of probably larger than 1.5Nm
( this is a generalisation , until stepper types are known ) and only limit switches are required . if you are looking for more positional control with encoder feedback and other then you would be stuck .
but as you say it is for proof of concept then you may be ok , but your real use here is pure control of 5 stepper motors of small size i.e Nema 17 to midrange Nema 23 .

So give us some more details of the project , size of robot and are you intending lifting or need dual motors etc and we can drill down to whats needed .

to answer your question , yes it will probably work , but to limitations of steppers used and not needing any more than a few switched inputs
outputs for relays are limited too

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01 Apr 2011 15:14 #8374 by andypugh
It looks like a much better quality version of what I started with. I reckon it will be fine. 36V / 3.5A will actually drive some fairly hefty NEMA23 steppers.
The ones here should give you 2Nm at 300rpm or so at the max voltage for that board.
www.slidesandballscrews.com/sy60sth88300...118.html?cPath=45_81

Apropros of nothing, I just found these:
www.slidesandballscrews.com/nema-motor-cover-ip40-p-628.html

That would have saved a lot of messing about!

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02 Apr 2011 22:38 #8397 by bvandiepenbos
The concept prototype will be what I would call "flying optics" so the moving load will be very lightweight... just a mirror and focus lens for a laser beam.
I am thinking of a 24"x24" working area, with 4 stepper motors, one in each corner of engraving area.
Lens will be supported by 4 cables or belts from each motor.
The Kinematics may be a little tricky, hopefully EMC can handle it.

~*Brian

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02 Apr 2011 22:42 #8398 by bvandiepenbos
thanks for the info.

I found another ebay source that has similar board in 4 axis.
Think I will get two of those and use 2 parallel ports, that way I have 8 axis to play with.

~*Brian

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03 Apr 2011 00:57 #8403 by paul11
Hi i'm new here, but I got one of those boards, a three axis board of the same make and hooked it up with three amp steppers and a 36v power supply. It lasted about 5hours and blew all the toshiba chips. I don't think you can us the rated output on those chips. I think the max would be be somewhere below the amount I used. I hope this helps

Paul11

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03 Apr 2011 16:54 #8418 by andypugh
Clever kinematics is one thing that EMC2 is good at.

Rather than a second parport, look at the Mesa 7i43 instead. That plugs into the parport and expands it to 48 IO lines. It also moves the step generation, pwm generation and encoder counting into hardware.

My similar board didn't like me wiring the motors wrongly, so be careful there. I see that one has a fan on the heatsink, and that might help a lot. the one I had was passively cooled.

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06 Apr 2011 01:35 #8624 by bvandiepenbos
I got the (2) boards today, sure looks confusing...the poorly translated Chinese docs don't help. I am feeling maybe I made a bad choice?
Oh well, just need to dig into it and see what happens.

question: would it be safer to start with setting the amp output dip switches to lowest setting so I don't burn things up?
(Max is 3amps, can select 100%, 75%, 50%, 25% of amp output)
My power supply is 24v 6.5amp
motors are
SHINANO KENSHI STEPPER MOTOR
stp-58d2017
1.8 degree step 6.2ohms
Nema 23
torque rated 68 oz in unipolar, 88 oz in bipolar
The coils are equally wound.

how can I figure what amps these need? since it only gives 6.2ohms specs?

thanks
~*Brian

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06 Apr 2011 10:11 #8634 by andypugh
bvandiepenbos wrote:

I got the (2) boards today, sure looks confusing...the poorly translated Chinese docs don't help. I am feeling maybe I made a bad choice?
Oh well, just need to dig into it and see what happens.

It ought to just be a case of figuring out which pin in the connector is step/dir for each motor, then telling Stepconf.

question: would it be safer to start with setting the amp output dip switches to lowest setting so I don't burn things up?

Maybe, though it won't prevent you blowing the drivers if you mix up the A and B phases, or disconnect a motor with the drives powered up. Just be very careful and very sure about the motor connections, the logic/control connections will just not work if you confuse them.
Typical "gotchas" with these boards are a parallel cable which doesn't connect all the pins (it is not unknown for a Laplink cable to be supplied with the boards) and for the documentation to actual refer to a different model. It's all part of the fun.

how can I figure what amps these need? since it only gives 6.2ohms specs?

Try Google of the part number for a fuller spec. Otherwise start at the lowest current and the increase it until the motors get too hot. (perhaps get some thermal stickers?) Too hot is very hot, by the way. Google says 90C is fine.
Google also says:
www.xmarkcomputers.com/stepper.pdf
That they are 0.8A/phase (Those are slightly feeble steppers, compared to others I have seen)
You probably want to ignore the black and the white wires (those are for unipolar operation).

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06 Apr 2011 11:56 #8641 by BigJohnT
There is a wealth of information on the EMC Wiki site about steppers.

wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Stepper_Formulas

John

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