Microstepping Stepper Motor Driver Kit
Hi, i'm really new to stepper motor and it's drivers, so i hope you could help me with choosing a PSU. My stepper motor is 12V 2A/phase. In this site, it is said that i need to use PSU that supply 4-10 volts more than the motor voltage, but since i can't find a PSU in that range, could i just use a 12V PSU, or if properly cooled, could i use a 24V PSU for the linistepper?
Thanks for your help!
What dc voltage and ampere of power supply are required to push three Linistepper boards and three these motors (1.8ohm and 2A)? Are two 0.5ohm 4W resistors required in each board? Thanks
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?
James Newton replies: Those motors should be find as long as they have 5 or more wires. Any two stepper drivers can be synced, but once they are in sync, the only way to keep them synced is to ensure they never loose a step, and that requires some care. In general, it's been done, and it works, but make sure you have more than enough drive capacity.+
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 become very interested in your Linistepper kits. I have some questions, I intend to build a small(24"x24"x48") 4axis foam cutter, mainly for my RC aircraft hobby. I found some nice looking motors and as I am truly a Newbie thought I'd ask to make shure these motors would work with your Linistepper design. I know the Linistepper only works with Unipolar motors, can these motors be configured as unipolar for the Linistepper? I have sent the seller this question and have not recieved a reply. Also in your opinion would 30.0 oz-in "cut it" I'm only going to be moving the gantry and wire.
Any help greatly appreciated!
Applied Motion Products 5017-013 Stepper Motors
NEMA-17 frame size (Motor length = 1.85in)
Industry standard 1.8 degrees / step.
6-lead motor, performance dependent upon wiring configuration:
42.4 oz-in holding torque
8.5 Volts, 0.57 Amps
Winding resistance: 15.0 Ohms
Winding inductance: 23.2 mH
6.0 Volts, 0.80 Amps
Winding resistance: 7.5 Ohms
Winding inductance: 5.8 mH
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.
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.
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: 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.+
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... unwarranted. 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?
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.+
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?
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.+
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 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!
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
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
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.
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 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).+
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?
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?
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?
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
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.
Hello, can the linistepper be upgraded by the use of FETs of higher power? I'm looking at steppers with 4.6v 2.5a per phase, and 300inlb.
Thanks for your time.
James Newton replies: Certainly, however the engineering of that is left "as an excersize for the student." There is some information available at http://www.piclist.com/techref/io/stepper/linistep/lini_tun.htm+
Bought it, built it, and then realized that my bi-polar motors (painstakingly chosen) will not work on it. The Linistepper seems perfect for my prototype if only it came in a bi-polar version! I need to buy it in a heartbeat.
From the schemetic diagram, I found out there are resistors connected in series: R18 with R19, R20 with R21, etc. In actual board layout, I saw only one resistor being soldered, ie R18/R19 = 150 ohms. Could you please advice? I am confused. Is 150 ohms equal to two resistors in series? Or can I substitute the pair resistors with one resistor only?
http://www.call-mac-then-pack.com/hobby.htm Someone must have already revised these boards to put out 2.3 amp. I can solder and thats about it. Trying to get my motors to work like they should, 2.3 volt & 2.3 amp unipolar applied motion products. If I knew what to get I could install it on my boards. Can you please help me. Bought the boards from you and more sales to me are fourthcomming.
James Newton replies: Please read this web page: "How to tune it for special needs!" especially the section under the heading "Changing Current." It really isn't terribly complex. Changing the sense resistors to one half ohm (or soldering another 1 ohm resistor in parallel) will give you 2 amps. For 2.3 amps, for each coil, you need a 1 ohm (already supplied as R1 or R2), plus another 1 ohm (R3 / R5), plus a 30 ohm resistor (R4 / R6) all soldered in parallel. Make sure your heat sink is a good one!+
I posted before, but I can't find were it is. I was looking in the Mouser catalog and found a PNP power transistor that might possibly be used to get more current out to hungryer motors. The part number is 511-MJ2955 and is rated at 15 Amps at 70 Volts. It is in a TO-3 case which will require special mounting to the heat sink with remote wires to prevent smoking the foil traces. Would this transistor work O.K.? Jack
The parts list and the circuit diagram/board overlay disagree on the value of C4 and C5 - 2.2pF vs 4.7pF
The boards arrived in Australia really quickly! Very impressed thanks :)
I have built two Linistepper module to replace GS-D200S cards who activated a home built PCB engraving machine.
I can whitness that movments now are very smooth and quiet, huge difference with previous drivers. I think that Z axis will be fitted soon with a Linistepper !
I would like to modify resolution to get 1000 or 2000 steps/revolution, do you think that it is possible ?
I have not a great Pic experience but I'm looking your software 'step-by-step' to understand your work and try to adapt it to my use.
Thank you very much to provide me with some answer, and congratulation for this design.
James Newton replies: I'm very glad to hear that the unit worked well for you.
The linistepper already offers 3600 steps per revolution simply by setting the jumpers on the board, so I am confused by your question.
It is possible to modify the code (this is an open source product) for any number of new features, but honestly, it is very difficult. The PIC code for the Linistepper was written by a true genius (NOT ME! The author is Roman Black) in PIC programming and it packs a lot of features in a very small amount of code. Improving on that will be difficult without experience in PIC programming. For someone with PIC experience, it shouldn't be terribly difficult give the existing code as a start.
Excuse me if this question seems a little simple, but I'm not well versed in matters electronic. Can someone tell me exactly which parrallel port pins connect to which pins on the stepper controller? Much obliged.
James Newton replies: Actually you can connect any of the "D" or Data lines to any of the inputs on the Linistepper. Some ideas are listed at the FAQ page and there is a page that shows exactly what pins are available on the parallel port connectors.+
Do you have any parallel port interface or do you know where I can find one.
Just checking before I buy something my software can only drive parallel port interfaces.
I'm dumb or whatever...?! At least, I didn't deal with PIC's in whole my life... :-) Anywhere, I'm trying to find out which PIC is appropriate for the *.hex file you gave to us!? IS that 16F84, 16F84A, 16F628 or 16F628A and do we have to use only 20MHz MCU's? Please be patient and answer these question for dummy!
James Newton replies: I'm not sure what .hex file you are referring to. The source code is available for p16f84A or p16f628 at http://www.piclist.com/techref/io/stepper/linistep/lini_asm.txt. You need MPASM from Microchip to compile it. The clock does not have to be 20MHz, but it may miss very fast step pulses with a clock that is too slow. tratincica-spinter- replies: I reffered to http://www.piclist.com/techref/io/stepper/linistep/lini_01.hex hex file. It's already compiled but I do not know what PIC type I have to use with this compiled file. I have no MPASM neither do I know deal with it. I've just planned to use your hex file... sorry for bad english and thank you for replying. James Newton replies: Actually I'd forgotten about that one.. That file is for the 628. tratincica-spinter- replies: . Thank you for fast and accurate info. I'll post here pictures of my hardware and feedback infos when complete linistep (3x). Greetings from Serbia+
I purchased a stepper motor clock drive that I am planning on driving with your linistepper/ 555 pulse generator. I have no idea what the manufacturer had previously as a driver but I did notice that each common has a precision 3 ohm resistor attached to it (the windings resistance is also 3 ohms - doubling the motor's resistance): is this to draw more voltage and would this increase smoothness or accuracy (the desired features in a clock drive)? I am assuming that these resistors would NOT be useful with the linistepper?
James Newton replies: Those resistors are left over from an old style linear driver. They are replaced by an active circuit in the Linistepper that uses current sensing and transistors to increase the performance of the motor. Remove them before connecting the Linistepper and all should be well.+
Dear Sir, I was wondering why not using a Mosfet instead of Darlington JBT, I mean... Mosfet have a much faster on/off speed an d can produce higher micro steps during low speed and give full power during right speed right?
Hi (hope this is the correct place to ask) i was wondering if this is what i need for my project. Iam building a 4 filter slider for a camera which needs to move to each filter then return to the begining after each photo is taken. I actually know next to nothing about motor control at the moment, is this possible with the kit? i can solder and follow instructions etc i just am unsure if this will do what i need. Thanks for your time. Ryan
James Newton replies: This would work to drive the stepper motor, but you would still have to find some logic to generate step and direction pulses to active this controller. I'm not sure what to say about that, but the 555 kit might help if you could find a way to switch the direction signal and stop the pulses between pictures.+
Is it necessary to use the pic16f84 20Mhz instead off the 4Mhz version ? Is it necessary to use the 16Mhz crystal , because in the circuit diagram it's a little complicated .
/techref/io/stepper/linistep/2b1records.com The linisteper works great. I am very pleased - question though. I have another project that needs 5amp's how would you requmend steping up the output. I guess the Heat sinks would be huge - I could use fans, I could use a dalenton high current maybe TIP41C?. What do you suggest - Boots-2b1
I need to know how long the connection from the computer to the motor can be. I plan to use the linistepper for telescope control from inside the house and need to know which cables need to be short and which can be long - in this case about 50 feet.
James Newton of MassMind replies: Passing on Romans reply:
My suggestion would be to keep the Linistepper inside the house in it's box with heatsink/fan etc, clean and dry, and just run the 5 wires out to the stepper motor so the stepper motor is the only part needed externally on the telescope. The wires can be 50 feet for that with no problems that I can see. The RJ45 cable itself should be fine for 50 feet or more, however you should not use the tiny RJ style connectors, as these are not suitable for motor current. I would use connectors suitable for 5 amps or more, to ensure good reliability. If in doubt you could solder the wiring direct to the stepper wires and heatshrink for weatherproofing, then just screw those 5 wires into the Linistepper terminal block. A photo of your finished setup would be much appreciated, and James may add to the Linistepper open-source web page as telescope use is one of the areas the Lini can really shine! (Is that a pun?) -Roman+
I am using Linistepper with a simple IBC-400 RS232 controller (AMS2000.com) and it works great. The motor is in a Klinger 0.1 micron precision translation stage and it takes 0.125 A per winding at about 20 V in DC, I use 60V power supply to have a decent boost in torque and 8 Ohm resistors as R1 and R2.
The only suggestion (but very critical!!!) - one may need to add 2 diodes to the collectors of each of the 4 output transistors (Q1-Q4) to eliminate very strong positive and negative voltage spikes that occur when the transistors switch coils off and on. In my case with these diodes the maximum motor speed increased several times. Technically I used 2 DF04M diode bridges with the pairs of "~" terminals soldered in the back of the card to pins A1&A2 (one bridge) and B1&B2 (second bridge). The two "~" pin separation in DF04M is exactly the same as the distance between A1-A2 and B1-B2 pins on the board, so it is very easy. The "-" terminals of each bridge go to ground (using extra wire) and "+" goes to M+ terminal. I don't not know if that is critical for any stepper motor, but I found it essential to use limiting diodes for all kinds of steppers I used in past and I believe that is a standard practice with stepper motors.
I have a project that requires driving a 14.5 inch telescope for photometry.
I lack the experience to make a stepper controller myself
I have the programmer and some parts to try and make a pic stepper controller myself.
However, do you have a pic controlled kit
I do not have a parallel port for a printer on my laptop
or do you have a suggestion as to what stepper driver kit you have that I can operate from usb from my computer.
I will want two axis
Hi, I am thinking of building a table of 2 axes but I am zero in electronics. If I have an engine of 2 phases, (0.8 A / phase and 6Vdc) or higher, which should be the criteria for selection of components (C2, 4 C3 C5, 6 D1-6 and the general C1) given the voltage that passes through them. It must be equal to the voltage of feeding the engine or higher. (I know only that in C1 should use a V above) Already now, the site is 100%. The best kind of with open source.
Thank you, I await a response
Thank you very much for sharing this nice design!
To make it even more useful, it could provide a way to hook end-switches to it.
Maybe change the input scheme:
Inputs RA3 and RA4 are used to connect end-switches.
If either of both goes high, further steps in the current direction are ignored.
If RA3 and RA4 both get high, "programming mode" is enabled, and RA2 selects power mode, RA1 resp. RA0 serve as mode bits.
I'm not used to PIC programming, but maybe somebody is willing to implement this...
I see you have the version 2 out. When I click on the .ASM link, it gives me V1 code. Is V2 just a hardware revision, or is there another source file I've missed?
I'm having a strange issue here which I think is the crappy PC I'm on but I'd just like some clarification from a pro. I can run the linistepper where the motor is on 19V of laptop PSU and the PIC and stuff is on USB from the PC. The motor makes a noise but the shaft does NOT turn but at higher speeds the shaft DOES turn but the motor sounds very dirty like there are stray steps everywhere. What might the problem be for this? Would it maybe be the USB supply at less than 5V (4.7 or whatever it is) or something different?
I have already built one linistepper of my own design and will be building a couple more for my CNC machine, but I have a question... will the linistepper run on 36v reliably? Also, I think I might have built it wrong because my 5V steppers at 19V still wont run very fast. Anyway, the most important question is will the linis run at 36v?
James Newton of Massmind replies: As long as the components are rated for double that voltage and you provide enough heat sink, it will run just fine. A 5 volt stepper, however, shouldn't need more than 7 to 9 volts at the most. Speed problems are usually related to resonance (try microstepping modes, solid mounting, and a damper) or the wrong current sense resistors installed for the motor.+
I have a question about the PCB. I am plannin to drive a sanyo denki unipolr motor(6 wires) that runs on 6.5V 1A per phase. I have to use this stepper motor drive board for space application. Would this work for the above rated voltage and current. Should I have to make any changes? I read that the motor supply voltage to the driver must be higher than the actual motor operating voltage. I cannot increase the voltage since that increases my power(which i have limited on my payload). can I supply 6.5V to the linstepper and connect a motor that runs on 6.5V? I have a requirement of microstepping till 16th of a step. Thanks...
James Newton of Massmind replies: Yes, you can run the motor at 6.5 volts, but you will not get the full rated torque as a result. Because the Linistepper provides active current regulation, you will get better performance from it than from other linear drivers, and because it is linear, you will get smother motion and better high speed operation. It may be that a chopper type driver would give you better low speed torque. My best recommendation is to purchase one of each and try it out.+
I am putting together 3 linnisteppers and a 4 axis/555 board with the pcbs and kit that I have just received. (Thank you for the good service)
Now I have one question:
Can I use them directly with a unipolar 0.9 degree step motor, or will I have to change the code?
If so where should I start?
Thank you and best regards from far away Portugal.
James Newton of Massmind replies: The Linistepper doesn't care how many degree's the motor steps, it just moves it to the next step. What ever system is providing the step pulses will need to deal with how far the motor rotates for each step.+
Kai Ries, if your there, I would love to see the code for your alt-az telescope controller!
I can find no link to it :(
Please do post a link here if you wish to share it, you will save me and many others days of head scratching !
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.
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.+
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.
James Newton replies: See: http://www.piclist.com/techref/io/stepper/linistep/mod-maxries.htm for Kai's modifications.+
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