Microstepping Stepper Motor Driver Kit
Questions:
I have several pieces of Vexta PK266M-02A motors which are of DC 2A, 2 phase, 0.9degree/step. Is the linistep driver suitable for it? Also, my router's x-axis is driven by two leadscrews and motors. Can two linistep drivers be synchronized for them and how?+
Thanks,
Raychar
Hi+
I've just finish the linistepper board a, during the test, the stepper motor gets very hot and i've tested only without step signal an the mototers still gets very hot. I use a desk printer motor to test with 12V. This behaviour is normal or do you have any ideia about this problem?
I have four of the old version 1 controllers and was going to use on Taig mill. Thats 20tpi leadscrew. It appears the best speed IPM I can get with Version one is max of 240 RPMs which comes out to 12IPM table speed. Is there anything I can do to improve on that?
James Newton of Massmind replies: Change the sense resistors to provide more current to the motors, assuming they can take it. Be careful to provide enough cooling to the drivers to keep them from cooking off. Good heatsinks really make a difference: I run 2 amps/phase at 12 volts and with a CPU heatsink/fan for cooling, my drivers just get warm.+
I am building a light CNC machine for PCB milling, and plan to use Linistepper contolllers to drive 3 Vexta PK266-02A motors that I already have. I am a little concerned that this controller may be marginal for use with the Vexta motors that are rated at 2A per phase @ 3.6V in unipolar mode. I plan to use a 12V supply yet to be built or acquired. I see this motor on the "recommended" list, and was wondering if anyone has had success with this combination.
Thanks,
Charles K
James Newton of Massmind replies: The Linistepper shouldn't have any problem at all with those motors. You should probably adjust the sense resistors to increase the drive to 2 amps. Running the extra current is unlikely to be a problem since the motor voltage is low, especially if you use a lower voltage supply. I would recommend a 9 volt supply instead of 12 but 12 should be ok.+
Hi, I'm a newbie. I would like to ask could I exchange the tantalum capacitors with the electro-axial one? and also, does anyone has tried to use the linistepper with 4-axis opto-interface from PMinMo? Does it work? Thanks
James Newton of Massmind replies: I would not recommend changing the capacitors. The PMinMO interface works just fine, the only difference is that what PMinMO uses as an enable line, we use as a low power line, so if you "disable" the stepper, it will still step, at low power.+
From the above, I understand that I can use the driver kit with the 555 kit to drive a 6 wire unifilar motor in a stand alone configuration. Am I correct in this? Thank you for your time.
Rick Kernell
James Newton of Massmind replies: That is exactly right.+
I'm having trouble following the supply voltage selection instructions. In one place it says add 5V or 10V to the motor rating and in another it seems to say more volts would be better. I want to control a 1.3A, 4 ohm, 5.2V, 11mH motor (Lin 5718M-15-09). My available supplies are 5V, 12V, 17V, 22V, 29V, 34V, 39V, 46V and 51V. All supplies have plenty of Amps for my motors. Peak load will be at about 600RPM and when accelerating from zero. Assuming I have plenty of transistor cooling, which voltage should I use to get the most oz/in out of this motor? Which step mode should I use for maximum oz/in? Why?
James Newton of Massmind replies: 12 or 17 would be best. Try 12, and if you need more speed go to 17.+
James Newton of Massmind replies: As to the maximum torque: The smothest transition from one step to the next will best reduce the chances of a skipped step. So the 18th over 3600 steps per revolution is the best. On the other hand, that is also the mode where the drivers will heat the most.+
hi,
I am very impressed with the linistep, but it is more than I need right now. The only thing I need is simple 200 steps but with a chopper driver so I can run my 5V 1.1A motors with 12V. I was looking over your schematic and PIC program and I would like to know if I can replace the resistor ladder from pins RB7-6 with a single resistor coming form 5V, just like you have depicted in your 'how it works' page for the 'Operation of the constant current circuit' diagram. There, you have Rp depicted as a single resistor. If I am reading your information correctly this should give me 200 Steps only with current chopper control and I could control the stepper sequence from another source like a pc or other controller chip.
James Newton of Massmind replies: I'm not sure I understand the point of doing that... saving the cost of a few resistors is... usless. The Linistepper, as supplied, will do 200 steps per revolution; just set the mode switches for full step.+
I'm interested in converting my Taig Mill to micro-stepping, but would like to retain the 400 step/rev resolution. Is this mode possible with linistep?
Thanks,
Norm
James Newton of James Newton's Massmind replies: Assuming you use a standard 200 step/rev motor, half stepping mode will give you 400 steps per revolution. The linistepper will support up to 3600 steps per revolution, so 400 is no problem.+
Hi,
I purchased 2 boards and finished constructing the first one, which is bolted to a bracket and large heatsink. While testing with a 3.2v 2A stepper on my mill, the bracket seems to get too hot. I replaced the 1 ohm resistors with 0.5 ohm 10w resistors and am driving the board at 24v. Within about a minute, the bracket the transistors are mounted on, gets so hot I can't touch it with out getting burned.
I have a 42cfm fan blowing directly on the heatsink but it can't cool fast enough. I'm afraid to burn out the board so I turn it off after 1 minute.
While it is working (for that minute) it works perfectly on full-step and half-step. Haven't tested micro-stepping.
Am I doing something wrong or is my setup too power hungry for this board?
Thanks.
Saltiel replies: I guess I'll answer my own question. As documented elsewhere on this site, the difference between the motor voltage and the supplied voltage is translated to heat. I experimented with lower voltages for my steppers, and it seems that 15v will be sufficient. At this voltage, the board remains cool with my heatsink and fan. Kenny.+
hi all,
i have posted this question on another page, and i am posting it here again.
will the source code work with the newer PIC16F628A? anything that i should change in the source code. not a pic programmer myself, just a newbie. what do i need to change in the source code?
also, can i use a 20MHz crystal instead of the 16MHz? do i have to change anything on the source code? if so what will it be?
sorry for asking too much.
thanks in advance.
mel guevarra
James Newton replies: The A is backward compatible so it should work fine. Since nothing is timing critical, the crystal should also be ok.+
Mel Guevarra replies: hi! thanks then. at the moment i am populating my breadboard and will test it with a 555 as signal source like how you are doing things. will post on here the results. thanks again. mel+
Hi! I just built the kit, with the 555 driver kit. I'm using it to (hopefully) drive a 6-wire linear actuator, which will slowly push a syringe pump. The motor is a Hurst SLS custom-jobbie I got from a surplus dealer here in Silicon Valley; the label says 12VDC, 11 1/2W (which, in my newbie brain, means about .96A; 12.5 Ohms...?)
So - what are my power supply requirements/hookup? (Sorry, but I wasted my education on an MBA, and am mostly trying to learn chemistry lately - my EE knowledge is decades old....) TIA!
Andrew
James Newton replies: Motor power supply should be 5 to 10 volts more than the rated voltage of the motor.+
James Newton replies: You can use the form about half way down the page at http://www.piclist.com/techref/io/stepper/linistep/lini_tun.htm to find the sense resistor values to use for your target motor current. I'm a little confused as to why you feel the other resistors must be changed...+
I am using a US Cyberlab Neuractor CNC-4+ kit that I built 10 years ago. My software is DANCAM. My motors/drivers are pretty whimpy. Do you know if your stepper driver has been used to retrofit a CNC4+ kit to provide better torque and speed? Thanks, Durl
James Newton replies: Sorry, I don't know anything about that specific kit. What does it put out? What type and rating are the motors?+
James Newton replies: One lini per motor. I don't know, I pull my steppers from old copiers, printers, and fax machines. If it has 5 or more wires, it will probably work fine.+
The 1 0hm 3W resistors are for 1 ampere current limit. Is it nessecary to change these resistors when i want to use a motor with 0.6 current rating for one phase? Or can the driver with these resistors be used for any motor up to 1 ampere per phase?
Steven from the Netherlands
James Newton replies: I would change them; otherwise, you are pushing the motor past it's ratings and it may cause the motor to overheat and fail.+
How large a stepper motor would you need to use to drive the steering gear of a small ship, producing about 400KNm? Sounds ludicrous I know, but I was just wondering.
James Newton replies: It's a good question... Sadly, it is almost impossible to answer. There are so many things that affect the actual torque output of a stepper motor that estimates are useless. You just have to try and adjust motor size as needed. The actual torque or a specific motor/driver/power supply combination can be measured but is very difficult to guess.
Take a look at the stepper page and the torque page for more general information.
There is an automated tool at http://www.galilmc.com/support/motorsizer/index.html which proports to answer this sort of question. You put in system type, load mass, etc... and it tells you want motor and drivers to use. Does require registration. And that is specific to thier motors and drivers.+
http://homepage.ntlworld.com/janrose Hi to all! I'm very new to Pics, but have had excellent results so far with "burning" the 16f types, using source codes or hex files compiled by the experts "as is". The Linistepper looks fantastic to me, but I need some advise here. The project calls for a 16Mhz resonator. The Pic on the pictures seems to be a 10Mhz type.
1.Is this correct or am I misreading something?
2. Instead of using a 16Mhz resonator, can I use a 10Mhz crystal instead? (Got some in hand).
3. Most of all, I would like to use Pic 16f628, but of what freq? Does the source-code need modifying to suit? If so, what?
Thanks for the patience.. Can somebody please e-mail me directly..Regards, Jan Huyser
James Newton replies: 1. The kit is supplied with the correct part for the resonator. 2. A slower osc can be used, but the unit will have a lower maximum step rate. 3. I would expect the source modifications would be minimal.+
James Newton replies: The caps do a very nice job of smoothing out the high voltage pulses and the remaining juice leaks off quickly.+
James Newton replies: The LiniStepper kit supplies a 16F628 (or compatible) chip which is rated to run at 16Mhz. While the source code can be re-compiled for the '84, it would need to run at a lower speed or be "pushed" (which is not recommended).
In the picture, the brown does look a bit black, but they are 470 Ohm resistors. They were added to improve operation and tolerance for component variation after the design was complete and the boards produced. They are important, and will be incorporated in the next revision of the design.+
Thank you so much for the information on this site and contained in the links! My goal is to use my own program and printer port to control stepper motors. If I use your linistepper boards do I have to worry about Electro Magnetic Feedback from the motors going into my PC? Also, if I used my PC, then would this eliminate the need for a separate timer?
James Newton replies: You should ALWAYS worry about spikes and so on going back into your PC. Especially with high power connections like this one. A good opto-isolated IO board would be nice to have, although I've found them to be very expensive. I personally use an old '286 computer that I really don't worry about frying for all my experiments. People are giving them away all the time.
I am working on a PC interface board with some very low tech, low cost optical isolation for the hobby market and I hope to have something ready soon. For now, just be careful.
And yes, your PC can be used as a timer by sending out pulses from the parallel port. Your accuracy may not be perfect, but it should get the job done.+
Hi, I was wanting to use your driver for a PCB router project. I thought I would use 80 oz/in motors. Do you forsee any problem with this idea. And, also, can you recommend a good source for stepper motors. (Preferably, for poor people.) Thank you for your assistance.
James Newton replies: You really need to look at the amp/phase rating of the motor rather than the torque.
Industrial Junkyards and office equipment repair shops are the best Stepper Motor sources I've found +
James Newton replies: The USPS website says shipping to the UK costs $6.40, plus $7.50 for registered mail (which I have found is necessary to prevent "accidental" loss of things in customs) and another $1.75 for a return reciept. Both our addresses have to be written on each of those and on the customs form (that is 4 copys of exactly the same data... yes, it is a government agency) so I get another few dollars for my time.
Short answer: $20 shipping and handling to the UK (and most other places).+
James Newton replies: That sort of torque is very doable... with a gear train. There is a low power hold mode, but yes, you really do need heatsinks.+
Hi,
Your controller looks like what I'm after, but maybe you could verify. I'd like to control from a PC a roller-blind type projector screen. Rotational speed from the motor would only need to be somewhere between 2 - 5 rev/s, the rod for the blind (being 80" long) would be light and the screen a light material, so I assume a 1A/phase stepper motor would do the job. Would I be able to get away without extra heatsinking/fans considering I'd be only driving the motor continuously for 10 seconds, then nothing for hours (assuming optimal PSU)? Or is heat generated at idle?
Thanks
Simon
James Newton replies: I aways like to err on the side of too much heatsinking rather than too little. Plan on the heatsinks, and if it never gets warm, cut down, but never elimiate them.+
I want to drive a stepper motor at various speeds to a given number of steps, or until stopped by a signal. I have built the linistepper kit, but have to learn how to program the pic. Is it possible, or do I need to go to a more powerful processor?
James Newton replies: Very possible. But learning to program a PIC may be easy or very hard depending on your experience. Try the PICList beginners page for good starting points.+
I am considering this controller for a project that will automatically guide a newtonian telescope. Could it smoothly control a motor down to 1 revolution per hour? Also, with all the heat, does it eat a lot of power? I would like to run a small stepper off of a 6v lantern battery.
Sure, the linistepper can "smoothly" rotate a load at 1 RPM and it does
not "eat a lot of power." Given a 200 step per revolution motor and microstepping
at 18th over, you would have 3600 steps per revolution with a 1:1 connection.
A 2:1 belt or gearing would give 7200 steps per rev. For even smoother operation,
a fluid damper or flywheel mass would smooth the motion. Now, each step will
be imperfect in size but *average* tracking will be perfect. See
Linear stepping with the Linistepper or How smooth
is smooth? for more information.
If you REALLY need micropower, You would be better off with
a DC motor and a good feedback like a
quadrature encoder
to close the loop and allow the precise positioning and rotation OR use a
small stepper and turn the entire driver circuit OFF between each step so
it only uses power while moving a step. The linistepper does not have an
option to turn off the power, but it is an open source project, so anyone
could try to add it. Both these micropower systems will require some clever
engineering on your part. The easy suggestion? Just buy a decent sized lead
acid battery and use a small stepper motor and a linistepper.
I have run a small stepper motor from an old printer (under no load) for
several hours on a 9v battery. A tiny 5v stepper motor from a modern floppy
disc drive will run ok on about 100mA per phase, average 150mA, will give
a few hours use from a decent sized 6v lantern battery. However a larger
sealed lead acid battery will work MUCH better and is rechargeable. Your
mileage depends on the load, the motor, the battery and the phase of the
moon. I can only suggest that you try it. I'll accept the return of a WORKING
unit for a refund less shipping if you find it isn't efficient enough.
We are getting a lot of interest from the astronomy crowed, and I would love
to hear back if this works... One point to keep in mind: The Linistepper
expects step and direction signals from an outside source, so you will need
a computer or a little clock "pulse generator" circuit to activate it. OR,
since this is an open source project; the uController could certainly handel
this internally if someone modified the code.
Hi ref the LiniStepper v1. I take is as it has a pic that all the programing for running the stepper motor is programed on board. Could it therefore be used with a hand controller? I also have a 4 wire Bipolar stepper . How about that?
Seasons greetings and thanks. al
First, Unipolar only... your Bipolar motor needs a different driver. Second,
since the project is open source, the code in the PIC could be modified to
do other things, including (I assume) respond to a hand controller.
How do you hook the motor to the Linistepper board?
Does M+ connect to one end of each phase, or do you connect the center tap to the M+ terminal?
thanks
James
Hi, with most common 5-wire unipolar motors;
With 6-wire unipolar motors;
You may want to check the stepper wiring page.
Very informative and interesting! I have one question regarding the kit for the Linistepper: the PIC chip is programmed already, isn't it? How to go about tools/info on programming these chips? Stan
Thank you! The PIC is pre-programmed. You can find information about PIC
device programmers at the PIC
programmer page +
Hi, I'm a newbie and would like to know what it would take to drive the stepper motor board directly from the printer port--as in, does the software posted here do the trick directly, or do I need to figure out how to make calls to the printer port?Thanks for your time--it's very much appreciated!
You are very welcome! The linistepper software is for the PIC on the actual
controller board. Computer Numerical Control software for your PC will send
signals to the parallel port to activate the controllers. See our
CNC page for some options. The hardware
connection is easy, just make sure the linistepper and the PC share a common
0v (gnd) and then connect the parallel port to the linistepper input pins.
The resistors are already on the linistepper board.
+
In general, the Linistepper can listen to 3 signals; step, direction, and the enable line which selects high or low power. So, for example, you could connect a single Linistepper to the PC Parallel port like this:
Port Pin Axis Signal ---- ----- --------- D0 1 Step D1 1 Direction D2 1 Power
In a production environment, were the boards are being pushed to the limit, the low power hold can be very important. The low power pins of all three axis can be controled from a port pin:
Port Pin Axis Signal ---- ----- --------- D0 1 Step D1 1 Direction D2 2 Step D3 2 Direction D4 3 Step D5 3 Direction D6 All Low Power
Each board (and stepper) really requires only two signals, Direction and Step. The other signals are for configuration of the operating mode can be supplied by manual jumpers. Each printer port has 8 data outputs (D0 to D7) plus some control signals. The standard way of connecting stepper controllers to parallel ports is like this:
Port Pin Axis Signal ---- ----- --------- D0 1 Step D1 1 Direction D2 2 Step D3 2 Direction D4 3 Step D5 3 Direction D6 4 Step D7 4 Direction
This allows for 4 axis control, and is the option supplied with our 4 Axis / +5 Power / Pulse/test / Relay board which really makes the entire thing very easy.
If you need more there are two options: Install a second parallel port (for 8 axis) or combine direction signals.
IF your software supports it, you can wire all the direction inputs to one parallel port pin so that the remaining pins are available to step other axis. The software needs to set the direction for the first axis, then pulse the ONE step signal for that axis and continue repeating this process for each axis. Obviously this takes longer but when you compare electronic signal speeds to the speeds of the mechanical world, you can see that it won't matter much.
Port Pin Axis Signal ---- ----- --------- D0 1 Direction D1 1 Step D2 2 Step D3 3 Step D4 4 Step D5 5 Step D6 6 Step D7 7 Step
So this would allow 7 Axis control from one parallel port.
Actually, most of the software available for PC's will specify which
Port Pin is to be used for what, or will allow you to specify in the software
how you have connected the signals.
Again, see out page on the parallel port
pins for the actual pin numbers and pictures of the connectors.
Bruce M. Stump Says: " Does anyone know if linistepper can be used to control coils sequentially at high speed for a homemade type linear motor " James Newton replies: Hi Bruce it sounds like you want a controller to fire coils in a linear motor? Yes the lini module can do that but you would probably need to re-program the internal PIC software to do it and even then it will only work for 4 (or less) coils. The max speed is determined by the software, since the PIC is crystal resonator locked you could program it to be the firing controller and you could fire the 4 coils in sequence at a very high rate, about 2MHz i think. You might want to look at the 4017 logic chip, this accepts a simple clock input and drives TEN outputs in sequence. It can do the high speed you need and you just need up to ten transistors for your coils. For best results do a search on ("linear motor" controller) as there are commercial modules. -Roman :o)+
Comments:
Hello
I am looking for controlling a stepper motor in 1 or 3 degree stepps.This is for a Comparater dial for my master clock.The stepper would recieve 1 sec and 30 sec pulses from a master clock.The idea of this is to show the differance between master clock time and frequency time.The stepper would go clockwise with frequency and anti clockwise with master time and the dial on the stepper would show the differance between the two.I first have to find away for the stepper to move the 1 or 3 degree from the pulse from the master.
Any help would be great.
Regards Mark
James Newton replies: The Linistepper will NOT do what you want. It needs step and direction signals.
However, the Linistepper is based on a PIC Microcontroller and it is open source. So, you could reprogram it to accept the signals you need. Or an experienced PIC programmer could anyway.+
Hi!
I'm very confident about the linistepper! I made two of them on one board, for driving two floppy drive steppers. It is for use of a dual axis telescope drive (1:3000 gear ratio). I have modified the firmware to support only the microstepping mode and your special halfstepping mode. Microstepping is very accurate and what is more important, there are absolutely NO vibrations, which can be even more distracting than rough step sizes. For controlling the stepper board, I have made a very simple controllerboard, based on an 16F84. It operates the two motors independantly and is also able to be controlled by RS232. It is adapted to be used for a altazimuth telescope. However, it could be interesting for other standalone operations as well.
Kind regards,
Kai Ries
James Newton replies: See: http://www.piclist.com/techref/io/stepper/linistep/mod-maxries.htm for Kai's modifications.+
See also:
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 Peter Todd has released source and sample projects for his artwork, including his 3d wireframe cube renderer for the PIC 18f6520 This includes examples of hardware developed with free software tools such as gEDA/gschem/PCB, SDCC, gputils and picp all on Linux. http://petertodd.ca/art/source-code/ |
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