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Re: Shinano Kenshi Steppers
Jon Elson
Don Hughes wrote:
From: Don Hughes <pencad@...>The four motors are set up with center tapped windings. An ohmmeter should tell you which groups of 3 are connected to the same winding, then a little more probing with the ohmmeter will tell you which lead is the center tap. (The leads which have the most resistance of any combination are the end 2 wires, the remaining one must be the center tap.) These motors can be used with the half-winding drive, and 4 transistors for the whole motor. You put the DC supply through a resistor to the center tap. Ignoring the center tap, you can drive these motors with 2 full bridges, from the winding ends. This takes 8 transistors, but gives better torque, and higher speed. The other motor has 4 separate windings. This is just a bit harder to decipher, but it has 2 pairs of 2 windings. These can be set up as center tapped, parallel, or series. Running them parallel, with 2 full-bridges gives best torque and speed. That could add up to more power than your driver can put out, although that would only be 2 amps/winding in parallel. You probably have to drive the coils one at a time, and by finding which connection nulls out current in another winding, you can determine which 2 windings are the pairs, and which way they are polarized. Jon |
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Re: Linux EMC project
Tim Goldstein
As far as the stepper controller board goes, I would make a strong
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recomendation for getting it from Dan at Camtronics I am using one I built from his 5 amp kit and am very pleased. Tim [Denver, CO] ----- Original Message -----
From: Buchanan, James (Jim) <jambuch@...> To: <CAD_CAM_EDM_DRO@...> Sent: Wednesday, June 02, 1999 2:00 PM Subject: Re: [CAD_CAM_EDM_DRO] Linux EMC project From: "Buchanan, James (Jim)" <jambuch@...>discussion of shop built systems in the above catagories. |
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Re: Linux vs. DOS
Jon Elson
"Buchanan, James (Jim)" wrote:
From: "Buchanan, James (Jim)" <jambuch@...>Probably not. I don't think MCA systems are supported. Servo control is out, as the supported servo card is ISA. 6 MB is awfully small. Linux would probably run (badly), but it really is too small to do serious work in. The 60 MB hard drive is hopeless. I was not able to put a reasonable subset of linux on a 600 MB disk. The kernel and a couple small utilities can fit on a floppy, but if you want compilers, libraries, help files, kernel source, etc. then it gets very big. Yes, you need the real-time patch for the specific version of Linux you would be running. Most people who have EMC running are using 1 GB + disks, 32 MB ram, and Pentium CPU's. I'm pretty sure you can get EMC running under X windows in 16 MB, but that leaves little memory left over for anything else, like another xterm with emacs. |
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Shinano Kenshi Steppers
Don Hughes
Has anyone got a color coding diagram for Shinano motors?
Also has anyone got any idea of how to decode their serial no.'s? I have received 5 steppers and have no idea of their torque rating. Four of the motors are Ser. No. STH-55D203-02, and the last one is a Shinano 06320-105. All motors are 5V 1A, 1.8 deg step. The first four motors are 6 wire, and the last one is an 8 wire model. Any help is greatly appreciated. Thanks Don Hughes |
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Re: Linux vs. DOS
Buchanan, James (Jim)
Hi:
Just returned form the University surplus equipment sale where I purchased a skid of PC gear for $15 because I needed a new paper tray for my laser printer. Besides getting a Laser Printer which I have not tested yet, I got a PS/2 8555 which is a 386sx 6meg ram and 60mg hardrive. Can I run Linux on this system? If so how do I easly get a copy and what version do I need? What additional tools do I need (compilers)? Do I need realtime code? If so where do i get it? and what version. My plans are to build a stepper motor drive for a small mill. But first I just want to run some stepper motors to get a better understanding of CAM. I design my parts using Autocad. -- James Buchanan Lexington, Kentucky (The Blue Grass State) USA Two Truck Climax Locomotive Operator & Builder |
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Re: Linux vs. DOS
Dan Mauch
I have aslo used paralel port A-B switches with the breakout boxes. That way
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I can select the configuration. Dan -----Original Message-----
From: Tim Goldstein <timg@...> To: CAD_CAM_EDM_DRO@... <CAD_CAM_EDM_DRO@...> Date: Tuesday, June 01, 1999 5:03 PM Subject: Re: [CAD_CAM_EDM_DRO] Linux vs. DOS From: "Tim Goldstein" <timg@...>parallel asport cable and save you from fighting the process of making up a newcable.I think you can buy them at radio shack for $8-9 or at other places forout commandgothe Vector (the CAD/CAM product I am using) is designed to output it's canwithfrom the code. A big pain, but workable. I was considering MaxNC, butbeforeall the talk about EMC on this list I though I would give it a tryashelling out some more $$$ for this hobby.Sorry, my fault there I'm afraid.Not a big deal. Without your help I still would have been mucking around founddonumbers.without involving the software folks such as just changing a fewthe discussion of shop built systems in the above catagories.discussion of shop built systems in the above catagories.anything on setting up the parallel port.discussion of shop built systems in the above catagories. |
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Re: Linux vs. DOS
Dan Mauch
Maxnc
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1M03 2 XS 3XD 4YS 5YD 6ZS 7ZD 8AS 9AD 10LIMIT+ 11M06 12LIMIT- 13hOME SWITCH SENSOR g61 14M7 15M8 DESKNC 2XS 3XD 4YS 5YD 6ZS 7ZD 8AS 9AD 10 X HOME 12Y HOME 13 HOME 15LIMIT 14 16 17 RELAYS DAN -----Original Message-----
From: Tim Goldstein <timg@...> To: CAD_CAM_EDM_DRO@... <CAD_CAM_EDM_DRO@...> Date: Tuesday, June 01, 1999 9:45 AM Subject: Re: [CAD_CAM_EDM_DRO] Linux vs. DOS From: "Tim Goldstein" <timg@...>discussion of shop built systems in the above catagories.From: "Matt Shaver" <mshaver@...>Actually, the DanCAD pinout has provisions for limit switches (All axis's + |
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Re: thermal expansion of mylar
Ron Wickersham
On Tue, 1 Jun 1999, Elliot Burke wrote:
According to my material selection guide, polyester CTE is 4 E-5 /F, cast^^^^^ 6 E-5 /C The situation is somewhat better for stabilized polyester such as used for printed circuit photo-tooling, such as Kodak Estar .007 inch thick material * www.kodak.com/global/en/professional/support/techPubs/ti1814/ti1814.shtml#dimenstab * CTE is 10 E-6 /F compared to cast iron at 6 E-6 /F. (Aluminum is 12 E-6 /F) Using this material for scales works out to 4 E-6 /F, considerably better than the 34 E-6 in your example above. A 1 C change in temperature will cause a 0.001 inch relative movement in 16Using the same 16 inches, stabilized polyester moves .00028 relative to the cast iron. Meanwhile the cast iron itself changed .00019. A change in relative humidity of 1% changes the polyester about the same amount as above. A usual shop environment is not controlled anywhere close to 1 C, yourNot to mention the heat imparted into the work by the machining changes the part's size even if you control the shop. Polyester also has a tensile modulus of around 500 kpsi. Thus a piece 0.004A good suggestion, and making the scale slightly undersized and stretching it to dimension lets you calibrate the machine. For many lengths stretching the scale should be practical, but for larger machines the sag could be a problem. I still believe that constraining the scale with a clamp or simple glue would keep the film scale in sync with the machine due to the small forces required as you point out above. -Ron Wickersham |
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Re: Linux vs. DOS
Tim Goldstein
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-----Original Message-----I have my request in for one of these boards from Dan. So, if you need someone to test a closed loop stepper system I will be available. See:I spent 3 hours messing with this tonight and I still can not get the X axis to move in the correct direction. The Input Scale settings took care of getting the EMC movement distances to match the actual table move distances, but it did not seem to matter whether the OUTPUT_SCALE was set to positive or negative, the X axis just wants to go in the wrong direction. I imagine I could swap the wiring to the stepper for the X axis to get the rotation to reverse, but this sure seems like it should be a software setting. Reduce the DEFAULT_VELOCITY, DEFAULT_ACCELERATION, MAX_VELOCITY andI fiddled with these settings and did get the acceleration rate to be more appropriate, but none of these settings seemed to change the fast move "G0" rate. I also noticed that regardless of the rate I set for MAX_VELOCITY or DEFAULT_VELOCITY the feed rate setting that comes up in Xemc is always 60 and that appears to be the speed it tries to go. Might be easy for your servos, but it sure makes a terrible racket with the steppers!! I tried entering the line as Jon suggested with a M6 command in the sameWhen the program hit a line with a G42 cutter comp entry I got the errorto specify line as the G42 and still don't seem to have the trick worked out. I will hold off on worrying about this until I get the basic parameters worked out. This error is still with me. I don't remember it ever happening with DanCADMajor problem. If I only move the X or Y axis all is fine. If I move theZaxis I start to get random very ragged movement in the X axis and anythe Z axis or DeskNC so I don't think it is a problem with the hardware (Dan M., Any chance this could be a controller hardware issue??). I did try moving the wiring to the controller around a little just to see if it might be some type of cross talk, but I didn't see any difference. Frustrated but hopeful, Tim [Denver, CO] |
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Re: Linux vs. DOS
Tim Goldstein
Dan,
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I was too impatient to wait and find parts, so I hacked up a parallel cable and got it running last night. I will probably end up doing some type of breakout box so I don't have to climb up on my bench to change the cable on the computer. Tim [Denver, CO] ----- Original Message -----
From: Dan Mauch <dmauch@...> To: <CAD_CAM_EDM_DRO@...> Sent: Tuesday, June 01, 1999 7:32 AM Subject: Re: [CAD_CAM_EDM_DRO] Linux vs. DOS From: "Dan Mauch" <dmauch@...>cable. I think you can buy them at radio shack for $8-9 or at other places forout powerthe GUI. This is great!I am running a Shoptask machine with some Superior 550 in/oz bi-polar Stepsterthe CNC stuff from a 24 VDC 20 amp surplus power supply. I have beenrunningit from DeskNC DOS version. I also have DeskNC Win95 , DanCAD, and softwareall set up on the system just to see what I like. Of the group of goproducts DeskNC DOS seems to be the most stable. within and manually draw offset paths and then remove the G42 and G40 command beforeall the talk about EMC on this list I though I would give it a try ashelling out some more $$$ for this hobby.Sorry, my fault there I'm afraid.Not a big deal. Without your help I still would have been mucking around imagination,soldering iron... I'm not a programmer by any stretch of the digand I don't think this is in the .ini file. Give me a little while to justthrough the EMC source directories here and I'll get back to you. I orcooked some burgers on the grill, and I'm going to eat a few and think numbers.dosomething like that. I can imagine it involves some changes that we canwithout involving the software folks such as just changing a few the thissoftware as all the other programs I have installed are configured for seen.particular setup. This particular configuration is what is specified for discussion of shop built systems in the above catagories.discussion of shop built systems in the above catagories.Amazin', ain't it.I'll agree with that. |
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Re: Linux EMC project
Tim Goldstein
Robert,
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----- Original Message -----
From: Robert N. Ash <esccmail@...> To: <CAD_CAM_EDM_DRO@...> Sent: Tuesday, June 01, 1999 6:07 PM Subject: Re: [CAD_CAM_EDM_DRO] Linux EMC project From: "Robert N. Ash" <esccmail@...>up myself. I needed to wait for a stepper version myself. Is it capable ofthat now? I get 2 bonuses, I get to kick Bill and get better software. I just got the current version of EMC loaded up this weekend (good thing it was a long weekend) and it is stepper capable. If you are referring to Linux in the better software part that is debatetable. Amazing that it was created by a bunch of people for free distribution, yes. Offering good functionality, definitely. Easy to use, not. Tim [Denver, CO] |
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Re: Cheaper servos
Jon Elson
Phil Plumbo wrote:
From: psp@... (Phil Plumbo)Glad you didn't take offense.Sorry, but I think you're nuts!Well, Jon, you're not the only one...no hard feelings. I wanted to generate Well, what does the robot do? If it only needs to pick up a 3" wheel andServo motors are designed to have minimalI see, so we rely on the motor characteristics as well as positional put it on a conveyor belt, it doesn't need much accuracy or smooth motion at all. If it is putting IC's on a circuit board with .01mm accuracy required, that is another matter. I'm doing fairly precise machining, and don't ever want to preclude some really hairy work, like making a steam turbine or jet engine blades. So, I want very good accuracy and precise motion. Now, the 'lumpy' servo motors would work fine for positioning, but for smooth motion, the CNC control would have to compensate too much. I'd like to know more about how a DC motor is constructed to have theseOne of the big tricks, for slotted armatures, is to 'twist' the armature laminations as they are pressed onto the shaft, so that the slots are not in a straight line, but have a twist to them of about 1/n. So that at the radial position where one slot starts at one end, the next slot ends at the other end. This way, the pole between the slots does not break out of the field flux all at once, and the wire in the slot doesn't, either. Now, for the finest servo motors, they eschew slots entirely, and the wires are wound onto a smooth mandrel. This is the way many DC tachometers are made. But the whole aim here is to have the same number of current carrying wires in the field flux at every possible position of the motor. Well, maybe you can. But, at some speed, the torque or speed ripple couldMy servo systemSmooth is good, and the range is impressive... I'm still not clear on why, come out at the smae frequency as some resonance in the system, and then it would excite oscillation. Now, maybe you can know that these frequencies will never match up, but on a retrofit, it is hard to know. Do you have any suggestions as to which motors might possibly be acceptable?You just have to test them. Jon |
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Re: Cheaper servos
Sorry, but I think you're nuts!Well, Jon, you're not the only one...no hard feelings. I wanted to generate some discussion. I'm happy to play the role of the guy that asks the stupid questions to that end, if you all won't mind. Servo motors are designed to have minimalI see, so we rely on the motor characteristics as well as positional feedback? My recollection of the gist of the Byte article was that with positional feedback, even cheap motors can give accurate and repeatable positioning. For a robot. My question is really, "if OK for a robot, why not for a home shop machine tool?" I'd like to know more about how a DC motor is constructed to have these desirable ripple characteristics. My servo systemSmooth is good, and the range is impressive... I'm still not clear on why, with good positional feedback, we can't use cheaper motors. Some motorsDo you have any suggestions as to which motors might possibly be acceptable? I am using 1000 cycle shaft encoders. I can't imagine making oneIt would be nuts to use paper for this app, for sure. I mentioned that only to jog the memory about the particular article, and to recall Ciarcia's spirit of "Sure, it can be done". Thanks for the reply Phil |
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Re: Linux vs. DOS
"Ian W. Wright" <[email protected]
Hi Tim,
I've been browsing you conversation woth Matt and its been fascinating as I'm thinking of trying Linux and EMC on a spare 486 machine I have. Just a thought re. your interfacing problem - it would seem easiest to me to make up the necessary short leads to go between your mill leads and the computer and change the pin settings this way. I.e. a lead with a pulg on one end wired for the EMC output and a socket on the other wired for your mill controller. Much easier and quicker than trying to figure out the software! Ian Matt Shaver wrote: Best wishes Ian -- Ian W. Wright LBHI Sheffield Branch Chairman of the British Horological Institute. Bandmaster and Euphonium player of the Hathersage Brass Band. UK. See our homepage at:- or or 'Music is the filling of regular time intervals with harmonious oscillations.' |
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Re: Cheaper servos
Jon Elson
Phil Plumbo wrote:
From: psp@... (Phil Plumbo)Sorry, but I think you're nuts! Servo motors are designed to have minimal 'torque ripple' and 'velocity ripple', meaning that with a constant DC voltage applied, they provide constant torque if the speed is held constant, and turn at constant speed when free to turn. Cordless drill motors, etc. are not built this way, and won't give smooth motion. My servo system moves smoothly down below .01"/minute, and up to 105"/minute. With a little higher DC voltage, it could go faster. Some motors salvaged from appliances might be acceptable, but unless you test it, you won't know. Other motors clearly are unacceptable. I am using 1000 cycle shaft encoders. I can't imagine making one of these out of paper! The 'starburst' pattern of stripes has to be centered on the axis of rotation to an extreme degree of precision to get accurate position readout. Jon |
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Re: Linux vs. DOS
Jon Elson
Tim Goldstein wrote:
EMC does the lead-in to cutter compensation a little differentlyWhen the program hit a line with a G42 cutter comp entry Igot the errormessage "convert_cutter_compensation_on error 43 blah,blah, blah"(OK, Ididn't write it down). This is even with a line in theprogram to specifythe tool (T1). that my old Allen-Bradley system. I have gotten it to work, however. It is very sensitive to any concave corners. (The AB would allow corners with small concavities, EMC absolutely does not!) The only way to do a concave corner in EMC is to have an arc of greater radius than the tool. Specifying the tool with a T1 (or whatever) doesn't do anything. You have to do an M6 H1 to 'change tool' to tool 1. You can do it as M6 G42 H1 while the cutter radius comp is turned on. You then have to have a linear lead-in for the radius comp. The radius comp is interpolated in during the length of the first move. This move should not cause a concave corner. Look in the file ftp://isdftp.cme.nist.gov/pub/emc/emcsoft/RS274NGC_22.doc to see more details, although this is written as documentation on the internals of the interpreter, not as a user document for coding your RS-274D files. I will send a copy of one of my programs that uses radius comp. tonight. Yup, that is a deficiency.I am mighty confused about how to step through a program as the steppause. Any idea Jon |
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Linux Box Setup
Bob Bachman
I'm trying to setup 486 DX66 for Linux. I need some 30 pin sims, 4meg or
larger. Anyone have some laying around they are willing to part with? The machine will not take the later style memory chips. I currently have Caldera 1.3 running on a 486 dx33 with only 8megs of memory. X runs real SLOOOOOOOOOOOOW. Bob |
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