Linistepper update

[OCNC]

Originally Posted by trebby first of all posix for keeping ur design open source. iam following your layout only.but i have some general doubts in it. 1.i found the schematic and layout but unable to get source code for(.hex) for PIC16F628. 2.the board inputs are step and direction.so can we directly connect it to parallel port or do we need any interface board in between 3.the 12v supply for board is just to run the motors? bcz i took my motors from old printers.so not sure at what voltage they work. 4.have a look at the below pic.can u tell the what those terminal stands for. thanks once again for ur help. regards

The page on the piclist that describes the terminals in question is here: http://www.piclist.com/techref/io/st...p/lini_use.htm
The +5V and GND should be obvious, that's your logic input power. The other terminals need to be connected to Logic Hi or Logic Low (+5 or GND). None should be left floating (unconnected). The 'Power' terminal is 'High Power Mode' Logic Hi or 'Low Power Mode' Logic Low. Generally leave this connected to Logic Hi. 'Mode 0' and 'Mode 1' control the drive's step rates. If both are set to Logic Low the drive is in full step output. If 'Mode 0' is set Hi and 'Mode 1' is set Low the drive is in half step mode. If 'Mode 0' is set Low and 'Mode 1' is set Hi the drive is in sixth step mode. If both 'Mode 0' and 'Mode 1' are set Hi then the drive is in eighteenth step mode. For a 200 step per rev motor this equates to '200 steps per rev', '400 steps per rev', '1200 steps per rev' and '3600 steps per rev' resolution.

You can connect directly to the parallel port but usually some kind of minimal breakout board (BOB) is used to facilitate making connections conveniently for example to tie the grounds from the PC and any power supplies together.

[OCNC]

Originally Posted by trebby first of all posix for keeping ur design open source. iam following your layout only.but i have some general doubts in it. 3.the 12v supply for board is just to run the motors? bcz i took my motors from old printers.so not sure at what voltage they work. thanks once again for ur help. regards

You're going to be at a bit of a disadvantage not knowing either the voltage or current rating of the motors. The Linistepper has current limiting but if it's set too high for your particular stepper and you start raising the voltage without using caution you could cook the motors.

[trebby]

thanks for the detail reply OCNC.

i saw lot of posts asking for code and layout for Linistepper made by posix.i put all the info i found on net and in this forum in the below zip file.i hope it will help some newbies.
OCNC pls have a look at it and let me know if there r any mistakes.

if ppl are still working on this famous controller then it will be good to design a break out board(BOB).so the whole project can be presented as a pack.

thanks

[OCNC]

Originally Posted by trebby thanks for the detail reply OCNC. if ppl are still working on this famous controller then it will be good to design a break out board(BOB).so the whole project can be presented as a pack. thanks

Here's one example of a simple Open Source BOB. http://pminmo.com/mhelsinterface/mhelsinterface.htm

[trebby]

well it might need lot of modifications to suit our current circuit.,
so i'll try to built my own board.
mean while if any one else working on this project.pls share ur experiences.
thanks

You're going to be at a bit of a disadvantage not knowing either the voltage or current rating of the motors. The Linistepper has current limiting but if it's set too high for your particular stepper and you start raising the voltage without using caution you could cook the motors

well iam using motors from old jet printers.which use 24v supply as input.below is the pic of motor that iam planning to use.
the only thing that i understood is 7.5degree,13ohms on the motor.so what do u think.
http://img408.imageshack.us/img408/9...89smalltw8.jpg
http://img176.imageshack.us/img176/3...91smallmn4.jpg

[epineh]

First of all nice work Roman, James and Posix

I am in the process of building a couple of Lini's for a tiny lathe retrofit I am doing. I thought I would post a couple of pic's for good measure...

I have used Posix's layout mainly as I am lazy and it is already in Eagle which I use, so I don't have to do much to get it going I also love the layout for heatsinking, I intend to keep everything nice and cool.

I did change the layout just a little though, only by thickening a couple of tracks, mainly the ground track from connector to motor terminal, as this will take motor current, also a little bit thicker on the transistor tracks, not really much difference, just a little "beefed up". I didn't change the motor + supply as I will simply take it straight to the connector(s) and you may notice I left out the connector on the left hand side of the board, as now I won't use it.

Enough talk, on to the photos ! You will be able to see my heatsinking plate, this is about a 12mm (1/2 inch) thick piece of aluminium that both boards will be bolted to (with insulators of course) and on the other side I will be bolting on two of the large CPU fan/heatsinks as close to the opposite side of the transistors as possible.

My motor current will be 1.5 amps so things should be good ! If you read this James you MAY recognize my PCB manufacturing method I included the un-etched board to show the track mod's. I will post the layout if it is OK with Posix and if anybody is interested.

Russell.

[epineh]

Oh yeah and the sense resistors shown will not give me 1.5 amps, I am keeping the current down for testing purposes, in the interest of keeping the smoke in !

[OCNC]

Originally Posted by epineh First of all nice work Roman, James and Posix I did change the layout just a little though, only by thickening a couple of tracks, mainly the ground track from connector to motor terminal, as this will take motor current, also a little bit thicker on the transistor tracks, not really much difference, just a little "beefed up". I didn't change the motor + supply as I will simply take it straight to the connector(s) and you may notice I left Russell.

Any chance you could post your Eagle files?
Also be sure to post some photos of the finished project. Heat sinking is the key to success with the Linistepper.

Chris

[epineh]

No problem posting the Eagle file, but I would like to hear from Posix first as it was his design I modded, I didn't do much more than make a few tracks bigger, the rest is as Posix had it.

Russell.

[epineh]

I have mostly finished the heatsink mounting, I have a little tidying up to do but here are some pics that should give some idea of what I am doing...

Also attached the Eagle file for the layout, I don't think Posix will mind, I am not claiming the design as my own, I just "tinkered" with it

Next is to mount all of this up and test, I will keep updating the results.

Russell.

[epineh]

Fired up one of the boards today...that is one sweet driver on full microstepping

I powered up the lower current board that I made and it has heaps of torque, enough for the lathe and it is running the motor at about 70% of its rated current, I may not even change the current as the transistors didn't really get the heatsink very warm at all.

Unfortunately the other drive is not working, I will start fault finding next, I swapped out the micro's to check but still nothing, it is like the power isn't even turned on. Otherwise very happy with the result !!!

Attached a pic, was going to take a video but not much to show without being in the machine. If I tried these drivers first I wouldn't have chosen to upgrade to servo's on my router

Russell.

P.S. Did I mention that the motion was smooooth ?

[epineh]

If any one is interested, I am thinking of a few more mods to Posix's layout, mainly a buffered and optoisolated input stage, with RC filtering on the step/dir input.

Only downside is a little more cabling required, I am thinking of using a standard USB cable from the PC to the board to provide the 5V logic to the buffer and allow true optoisolation, since the parallel port cannot source more than 2.6 milli amps which isn't enough to fire an opto, and using the 5V logic supply from the driver side defeats the purpose of the opto.

Any thoughts ?

Russell.