Hi, I recently acquired a MTD 2003 Stepper driver IC. I want to use it with a picaxe to drive a stepper motor (duh), but I can't fully understand the datasheet. I understand most of the inputs, except: where do I connect the power for the stepper motor (12V or 24V). PIN27 seems to be connected to 5V (via a resistor), pins 7 and 21 need to be grounded through a capacitor (probably electrolytic), PINS8,20 need to be grounded throught another capacitor (electrolytic?). PIN 2 is connected to... what? Is THAT the power supply for the motor? Or is it just another 5V? Any help would be appreciated. Datasheet http://datasheet.eeworld.com.cn/pdf/SHINDENGEN/110454_MTD2003.pdf
Using a MTD 2003 Stepper driver with Picaxe
- Thread starter samis_p
- Start date
Vmm A and B are motor power, due to the chopping circuit you should plan this to be up to double what the motor coils aer rated for to get max torque
i have not seen many circuits of this nature with a fixed v-ref (pin 27 from what i can tell, maybe they refrence it as current refrence) on the chopping circuit, most have a variable resistor to allow the circuit to be tuned to the motor.
I0 and I1 are for setting duty cycle of the system, these can either be controlled by the picaxe or by jumper on the board, testing maybe needed to figure out which suit your motor best.
i must say that the IC set up seems a little odd, what happens if input 1 is high and 4 is low, or do you connect them so they both do the same thing
have you found any other material relating to this part on the net any where?
i have not seen many circuits of this nature with a fixed v-ref (pin 27 from what i can tell, maybe they refrence it as current refrence) on the chopping circuit, most have a variable resistor to allow the circuit to be tuned to the motor.
I0 and I1 are for setting duty cycle of the system, these can either be controlled by the picaxe or by jumper on the board, testing maybe needed to figure out which suit your motor best.
i must say that the IC set up seems a little odd, what happens if input 1 is high and 4 is low, or do you connect them so they both do the same thing
have you found any other material relating to this part on the net any where?
Oh, right. Didn't really expect to see a battery in such a circuit...
Well, to tell you the truth both this IC and the stepper are from an old printer. Couldn't find much more about this IC, and I've only found data concerning a higher DC-resistance variation of the motor that I have - those have ratings both at 12V and at 24V, so I suppose any voltage will be good enough. Mine is rated at 1.8ohm DC resistance, hence the need for a driver with constant current. Since this is more or less an exercise for me, I can't afford to shell out cash for a high current driver or another motor. Also, it seems to be a bit ridiculous, as even at 12V it would probable make a lot of heat.
Oracacle, PIN 27 is used to set the chopping freq according to this equation f=1 / 0.72 *Ct * Rt. As I understand, inputs 1 and 2 control one H bridge, and 3 4 control the second bridge, so essentially nothing would happen, if In1 was high and In4 was low, as it would only affect half of one H bridge and another half of another H bridge. I don't know if you googled another datasheet, but mine has the truth table (I've seen another one without some of the data). If I misunderstood your comment, please correct me.
JimPerry - so I just connect 2, 7, 21 to my 5V source (linear regulator) and be done with it?
I would probably run all of this from a PC PSU, would 5V from it be good enough as a reference voltage/supply source for all of these 5V inputs? Or should I run everything from 12V rail and use a 5V linear regulator?
Well, to tell you the truth both this IC and the stepper are from an old printer. Couldn't find much more about this IC, and I've only found data concerning a higher DC-resistance variation of the motor that I have - those have ratings both at 12V and at 24V, so I suppose any voltage will be good enough. Mine is rated at 1.8ohm DC resistance, hence the need for a driver with constant current. Since this is more or less an exercise for me, I can't afford to shell out cash for a high current driver or another motor. Also, it seems to be a bit ridiculous, as even at 12V it would probable make a lot of heat.
Oracacle, PIN 27 is used to set the chopping freq according to this equation f=1 / 0.72 *Ct * Rt. As I understand, inputs 1 and 2 control one H bridge, and 3 4 control the second bridge, so essentially nothing would happen, if In1 was high and In4 was low, as it would only affect half of one H bridge and another half of another H bridge. I don't know if you googled another datasheet, but mine has the truth table (I've seen another one without some of the data). If I misunderstood your comment, please correct me.
JimPerry - so I just connect 2, 7, 21 to my 5V source (linear regulator) and be done with it?
I would probably run all of this from a PC PSU, would 5V from it be good enough as a reference voltage/supply source for all of these 5V inputs? Or should I run everything from 12V rail and use a 5V linear regulator?
run the motor side from the 12v (presuming its rating allows, FYI i ran a 2.6v bipolar at 12v, and now run it at 7.2 volts without issue on faily expensive THB6064AH controller).
I often run picaxe and other logic strait out of the 5v of a computer PSU without issue, it would be owrth while checking the voltage before diving in. also keep some form of load on the PSU, a couple of computer fans is fine (these will hepl to stablise the output).
if it was me i would chuck a circuit as per the data sheet together and see what hapens.
the truth table for the inputs still has at me a little bit of a loss, have they tryed to combine 2 tables into one or something. if so this seem to be a high current dual h-bridge with constant current chopper and could be used to drive 2 normal motors, latching ralys and other things that may need forward and reverse current.
I often run picaxe and other logic strait out of the 5v of a computer PSU without issue, it would be owrth while checking the voltage before diving in. also keep some form of load on the PSU, a couple of computer fans is fine (these will hepl to stablise the output).
if it was me i would chuck a circuit as per the data sheet together and see what hapens.
the truth table for the inputs still has at me a little bit of a loss, have they tryed to combine 2 tables into one or something. if so this seem to be a high current dual h-bridge with constant current chopper and could be used to drive 2 normal motors, latching ralys and other things that may need forward and reverse current.
Yes, I think they combined the truth tables for both H bridges into one. I will be trying out this IC soon, hopefully before this weekend. Also, could you recommend some other driver IC, something similar to this? As I understand from the datasheet, this IC is the perfect thing for my steppers, as it has current limiting, chopping, wide voltage range and very simple controls. I need some sort of an affordable alternative that would have current limiting, as most of the steppers that I own have low DC resistances (2.6ohm and similar).
personally no, the reason i choice the IC i did was it was able to put out up to 4amp continuosly and had a high 64 micro step resolution.
you should be able to do normal current limiting in circuit any how, specitally if you are using a picaxe that has an ADC.
there was a website called stpper world, or something along those lines, i cant seem to find it at the minuite. there are some really good explaination on there that should give a better understanding of what would be needed to do what you want
you should be able to do normal current limiting in circuit any how, specitally if you are using a picaxe that has an ADC.
there was a website called stpper world, or something along those lines, i cant seem to find it at the minuite. there are some really good explaination on there that should give a better understanding of what would be needed to do what you want
Well, i might just buy a biaxial THB6064AH based stepper driver board, as I need control for 3 axis and two ICs would cost almost as much as a preassembled mach3 compatible driver board. Although I might look into some other, cheaper ICs. If I could find something analogous to the mtd2003 that I have it would be great - it has all the features I need and nothing extra.
what is it that you want to build, by the sounds of the 3 axis i would hazard a cause at some form of CNC.
maybe look into an easy driver
some stuff here
http://www.picaxeforum.co.uk/showthread.php?25108-picaxe-28x-project-board-and-easy-driver-4-4-hook-up&p=253589#post253589
heres the cheapest place i found for getting THB6064 kits
http://www.piclist.com/techref/io/stepper/THB6064/index.htm
maybe look into an easy driver
some stuff here
http://www.picaxeforum.co.uk/showthread.php?25108-picaxe-28x-project-board-and-easy-driver-4-4-hook-up&p=253589#post253589
heres the cheapest place i found for getting THB6064 kits
http://www.piclist.com/techref/io/stepper/THB6064/index.htm
Well yes, the final goal is to have some sort of functioning cnc router. This whole project was about how far I could go with scavenged parts from scanners and printers (I had gotten about 10 of them). But the more I look into this, the more issues I run into. I dont mind spending a little bit of money to buy parts I'm missing, but I don't want to spend too much, since for ~250gbp I can get a whole kit. Ofc, there's more learning and fun in building (or trying to build) my own, but I'd like to keep it as simple and cheap as possible.
Well, i checked ebay and theres a THB6064 based driver board for two steppers that costs 47usd, which is probably the best price/performance ratio for me, as I could use it to run x/y axis and leave the mtd2003 for z.
What do you think about tb6560 ic? Driver boards based on this IC cost around 30% of what thb6064 based boards cost, and are rated at 3A. Also, if I read the datasheet correctly, it has microstepping.
Well, i checked ebay and theres a THB6064 based driver board for two steppers that costs 47usd, which is probably the best price/performance ratio for me, as I could use it to run x/y axis and leave the mtd2003 for z.
What do you think about tb6560 ic? Driver boards based on this IC cost around 30% of what thb6064 based boards cost, and are rated at 3A. Also, if I read the datasheet correctly, it has microstepping.
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one of the reason i did't use the TB6560 is because it very fussy about power up sequence, if you are willing to maybe cook a few one a trial and error for start up, they will be fine.
unfortantly it only something you can make a final desicion on once you know A) all of the motor specs, B) the machanical drive set up C) what resistance the cutting material is going to provide D) the mass of the cutting aperatus.
from personal experience scanner steppers are not strong enough to do much with, and the few printers i have stripped used a feed back system with normal pwm controlled motors.
so if we presume you know A, do you know the rest of the factors. my driver and motor were chosen as it would have to move in excess of 4.4kg of camera equipment to a high degree of accuracy without out the complications of rotational or linear encoders.
for what its worth, i am toying with idea of building my own CNC machine at some point, with some nema 17 motors and the same drivers as i am current using, coupled to ball screw drive there will be no issue in regards to strength.
unfortantly it only something you can make a final desicion on once you know A) all of the motor specs, B) the machanical drive set up C) what resistance the cutting material is going to provide D) the mass of the cutting aperatus.
from personal experience scanner steppers are not strong enough to do much with, and the few printers i have stripped used a feed back system with normal pwm controlled motors.
so if we presume you know A, do you know the rest of the factors. my driver and motor were chosen as it would have to move in excess of 4.4kg of camera equipment to a high degree of accuracy without out the complications of rotational or linear encoders.
for what its worth, i am toying with idea of building my own CNC machine at some point, with some nema 17 motors and the same drivers as i am current using, coupled to ball screw drive there will be no issue in regards to strength.
Well, the motors I am using are from old Laserjet printers. As you said, inkjets and scanners usually use (at least in my case) DC motors with some sort of feedback system. As for the motor specs - they are hard to find. One of them is a Mitsumi M49SP-1. Datasheets I can find are for 30ohm and 120ohm. Mine is 1.8Ohm. The other two are PM42L-048-CDC3. And again, I can only find data about higher dc resistance motors. The ones I have measure at 5.8ohm. The weight of the gantry should be no more than 1kg total, as it should just be asmall cnc machine (~40cm x 40cm). This whole thing should pretty much be just a test to see if I can even build one. I will be using screw-drive to move the whole thing, hopefully the friction will be low enough. If this works (and if I have the money) then I might do it properly, with better/bigger motors, ballscrew drive etc. For now, it's something to keep me busy and help learn about many different things.
Anyway, what I'm starting to realise is that both of those drivers will be good enough. If these motors will be crap (and they probably will), I can then buy some better hi-torque motors and re-use the drivers.
One last question - if I were to buy Nema 17 steppers, what characteristic should I look at? Holding torque, rated current, voltage?
Anyway, what I'm starting to realise is that both of those drivers will be good enough. If these motors will be crap (and they probably will), I can then buy some better hi-torque motors and re-use the drivers.
One last question - if I were to buy Nema 17 steppers, what characteristic should I look at? Holding torque, rated current, voltage?
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Holding torque of the bigger motor is 181mN*m. There's no detent torque specified. Pull-out and pull-in torque is rated 62.7 mN*m and 60.8 mN*m respectively. Judging from the holding torque, the "big" motor that I have has less than half the torque of a Nema 17 motor, which is probably too little. The two smaller motors have no holding torque specified in the datasheet. Pull-out and pull-in torque rated at 96mN*m and 92mN*m respectively @ 24V and 400mA. Anyway, I'm thinking of just doing this right and using more... proper motors, probably the Nema 17 that you mentioned - they seem to be at least twice as powerful and don't cost that much. The only problem is that there are a few variations, ranging from 0.8A to 2.5A and also differently rated voltages. I suppose the only thing I should be interested in the datasheet is the holding torque and rated maximum current, correct? As I understand, the higher the current, the more torque a stepper can generate.
for your application current is almost irrelivant on the only provision that you can provide the motor with at least what is rated for and a least twice the voltage
holding torque is the amount of force that will be need to turn the motor while energised against its will, although it may well not affect your application it maybe wortn noting pull in and pull out, but seeing as the machine most likely wont be doing any mega acceleration i doubt that those figures will be of any interest.
dont forget that you will also have the machanical advantage of the screw drive, providing you over come any friction issues of course - i am unable to stop the test setp i had together the other which involve trying to hold the ball nut against the end bearing, i am pretty sure i have far exceeded the 4.4kg i originally specified (i can compress with more than 10kg of force with my hands)
you may also want to look at step size, most are 1.8 (200 steps per rotation) while other are 0.9 (400 steps per rotation). do you plan on making use of micro stepping too
holding torque is the amount of force that will be need to turn the motor while energised against its will, although it may well not affect your application it maybe wortn noting pull in and pull out, but seeing as the machine most likely wont be doing any mega acceleration i doubt that those figures will be of any interest.
dont forget that you will also have the machanical advantage of the screw drive, providing you over come any friction issues of course - i am unable to stop the test setp i had together the other which involve trying to hold the ball nut against the end bearing, i am pretty sure i have far exceeded the 4.4kg i originally specified (i can compress with more than 10kg of force with my hands)
you may also want to look at step size, most are 1.8 (200 steps per rotation) while other are 0.9 (400 steps per rotation). do you plan on making use of micro stepping too
The nut on srew drive im going to use moves around 8mm per revolution, so 200 steps per revolution will give me around 0,04mm of movement per step at 1.8 degree - thats much more than I need, as my goal was to have 0.1mm resolution. There's two possible cheapish nema 17 motors I've found on ebay - the cheapest one has less torque and is rated at 0.9A and the more expenaive one is rated at 2.5A and 470mN*m. My gut tells me to buy the more expensive one. I don't think I should use the steppers I harvested, as they seem to be too weak. I need to order the motors this week, because I'd like to have them by the end of this month (for personal reasons), that's why I'm asking you for guidance - I'm pretty new to steppers. I don't know much about microstepping, but as I understand it from wikipedia it would be something I'd like to use (for the "smoothness").
the choice of motor will be entirely yours, if you get the stronger ones you maybe able to get your machine to to deal with heavier items (a heavier router for cutting denser mateiral maybe). however providing you put the currect controller in place upgrading the motors at a later date should not be an issue.
while yes you would gain smoothnes, you will also increase the time it take to make a single revolotion, but you would also increase resolution (if not accuracy on that resolution). so with the THB6064 set to 64 micro step, you would end up with 12800 micro steps per revolution giving 0.000625mm travel per micro step (i belive it does half step).
of and that another plus side of using proper controllers, you need only to control enable, directin and step andvance, and enable can be shared across all the controllers if need be, this meani if you are ever using it with picaxe or alikes you save on pins
i have attatched a copy the THB6064 data sheet
while yes you would gain smoothnes, you will also increase the time it take to make a single revolotion, but you would also increase resolution (if not accuracy on that resolution). so with the THB6064 set to 64 micro step, you would end up with 12800 micro steps per revolution giving 0.000625mm travel per micro step (i belive it does half step).
of and that another plus side of using proper controllers, you need only to control enable, directin and step andvance, and enable can be shared across all the controllers if need be, this meani if you are ever using it with picaxe or alikes you save on pins
i have attatched a copy the THB6064 data sheet
Do you think it would be a good idea to buy a chinese - made THB6064 based driver board (don't know if I can post an ebay link here) or should I just get the IC? The board is capable to directly interface with mach3 software, also comes with a cooler. I'd pay almost as much buying two THB6064 ICs as I'd pay for a driver board containing two THB6064 ICs and all the extra stuff. Not sure what quality to expect, though.
Well, this is the board I have in mind http://www.ebay.co.uk/itm/CNC-THB6064AH-Two-2-Axis-64-Micro-step-4A-Stepper-Motor-Driver-MACH3-Biaxial-/151052736772?pt=LH_DefaultDomain_0&hash=item232b71d904Boards usually work - and you can post links
This thing has two driver ICs and some extra bits and pieces to work with mach3 (which is the final goal anyway). Although I would still need to use a picaxe to drive the Z axis, this would probably be a good idea anyway. I can always, if needed, run everything from a picaxe. The price is ~ 10GBP higher than two bare THB6064AH ICs off ebay. I don't really look anywhere else, because components in Norway are stupidly expensive (one shop actually asked 50gbp for shipping when components themselves only cost ~25gbp) and the supplier I usually buy stuff from in Lithuania (I'm from there) doesn't have these ICs.
I've already ordered some Nema 17 motors (like these -> http://www.phidgets.com/products.php?product_id=3303_0 ), now just need a proper way to drive them. Usually I'm not very picky, I often buy various parts from dealextreme, but this is something I have no experience with, so not sure if it's safe to buy a driver board or should I just buy ICs and run them from a picaxe.
JimPerry
Senior Member
Oh, cool, thank you.
Well, now it will take some time for the parts to arrive. I gues in the meantime I can experiment with the MTD2003 driver and printer steppers. Thank you for your patience and answers, both of you.