Staggering motors

[viktorcnc]

Hello.
First of all: Thank you for this wonderful site and all the work CNC admin performs.
I've been a member for some time now but this is my first posting. A short background: My electronic knowhow is limited to my radio amature activity and some. Last year I got hold of a 3-axial CNC used for learning purpose at a technical school. The machine was produced in Norway in mid 80's and the company dosn't excist anymore. No drawings, no info of anything just a machine that didn't work. The driver units for each axis doesn't receive step/dir signals. Anyway, after a lot of experimenting I've decided to change the drivers. I bought 3 of this kit: http://www.electronickits.com/kit/co...tor/ck1405.htm to go with the internal power supply, about 15,7 volts. I will run the machine from PC parallell port. The motors are:
Superior Electric, Slo-syn 53oz, 200 steps, 3.8 A, 1,25 volts, 6 wire, type M061-FD08 (hope I remember this correct). I've used a current limiting resistor at 4 ohms ( parallell 6x27ohms, each 15watts ). I haven't been able to find the right drawings for the motors, but measured the winding recistance to 0,4 – 0,8 – 0,4 ohms. I've connected the wires in all possible ways, but the motors won't move the axis. Just a lot of staggering. I begin to think the Kit isn't suitable?? for these kind of motors. I tried a unipolar step motor from a laser printer and it worked fine, think the windings were 12,5 and 25ohms, voltage and ampere unknown. "Fair" deal of torque when the motor was running. The Kit has two options, internal or external pulses. There is a variable resistor on the Kit that allowes variation of the internal puls frequency. I'm obviously doing something seriously wrong here, and my electronic knowledge is not all that great. Anybody have any suggestions to get me started in the rigth dir Why are some motors staggering with little or no torque at all, while some are quite good?

[CNCadmin]

Thanks for joining the site.

[tachus42]

Are the MOSFETs on the driver board hot when trying to drive your motor ?

[snaggletto]

Hey,
The website says it's for unipolar motors only. It appears that your 6 wire motors should work, just depends on how they are wired I guess.

It appears that this driver board you have is not a microstep drive, nor will it allow high motor supply voltages. I speak from experience here. I've got an old Supertech 4 axis stepper cnc system, setup for 12V. It is pathetic. I'm affraid you will not be pleased with the performance of your system, as I wasn't pleased with mine.

The nature of steppers is to loose steps when the load is higher than the torque of the motor. Your 53oz in motors are going to have a hard time driving anything of any weight without loosing steps. For steppers to remain accurate, the motor needs to have more torque available than it will ever need on it's application. Finally, bipolar motors of the same size have much more torque than a unipolar. I'm not familiar with your machine, but I would be looking at bipolar 200oz in + at a minimum. If you need more than one person to move your whole machine, then 300 oz in + would be recommended.

Furthermore, you are going to need a better driver to get any decent performance out of any motor. At a minimum, check out Xylotex bipolar micro step drives or better yet get some Geckodrives. I always hear about people using 20 - 25X the rated voltage on the motor for the DC supply. With Geckos, the right sized power supply for your app, and decent software (Mach2) you will have those motors flying smooth as silk at 60+ IPM, rather than a jerky, rough, unreliable 10 IPM that you might get from your existing setup.

I ditched steppers all the way, and I'm currently building a Gecko DC servo based system for an Emco Turn 120 cnc lathe (big in the educational field as well). Do some research, Geckos and Xylotex have GREAT support for thier products as well as tons of users that can help you. You are going to be on your own with your existing stuff. Good luck.

[viktorcnc]

Thanks for replying folks. Yes I had a problem with the internal puls generator and deactivated it. The motors ran much smoother, but still there was something, and you'll never guess what. In the heat of things I had forgotten something so stupid that I can't believe it's possible. I forgot to grease the threads for the axis. Can you belive it!! I had oiled everything else but the treads. I was so focused on the correct coil windings and the parameters in the TurboCNC that I forgot the basics. I'm learning the hard way

[tachus42]

From the EMC Handbook at http://emc.sourceforge.net/Handbook/Handbook.html
The documentation does hint that you can you can change the mapping - it's probably hidden in a config file some where.

IO Pin Function Function Function Function
Step/Dir Quadrature Two phase Four phase
D0, pin 2 X direction X CW X Phase 0 (P19) X Phase 0
D1, pin 3 X clock X CCW X Phase 1 (P13) X Phase 1
D2, pin 4 Y direction Y CW Y Phase 0 (P19) X Phase 2
D3, pin 5 Y clock Y CCW Y Phase 1 (P13) X Phase 3
D4, pin 6 Z direction Z CW Z Phase 0 (P19) Y Phase 0
D5, pin 7 Z clock Z CCW Z Phase 1 (P13) Y Phase 1
D6, pin 8 A direction A CW A Phase 0 (P19) Y Phase 2
D7, pin 9 A clock A CCW A Phase 1 (P13) Y Phase 3
C0, pin 1 B direction B CW B Phase 0 (P19) Z Phase 0
C1, pin 14 B clock B CCW B Phase 1 (P13) Z Phase 1
C2, pin 16 C direction C CW C Phase 0 (P19) Z Phase 2
C3, pin 17 C clock C CCW C Phase 1 (P13) Z Phase 3
S3, pin 15 X/Y/Z/ lim + X/Y/Z/ lim + X/Y/Z/ lim + X/Y/Z/ lim +
S4, pin 13 X/Y/Z/ lim - X/Y/Z/ lim - X/Y/Z/ lim - X/Y/Z/ lim -
S5, pin 12 X/Y/Z/ home X/Y/Z/ home X/Y/Z/ home X/Y/Z/ home
S6, pin 11 Probe Probe Probe Probe
S7, pin 10 spare spare spare spare

[smoregrava]

Hey Viktor CNC is the mill you got of the type Spes Produkt. SP CNC. If so I got a similar type. Just got in contact with one of the folks that build this thing. And He gave me some information. do you have your old drives for that machine.

[viktorcnc]

Hello and thank you for replying to this thread. Yes the machine I got is made from Spes Produkt and I belive I still have the original drivers some where. Is amazing to hear that someone has got a similar type of machine. Would be very interesting to hear more about that and what kind of information the designers provided.

[smoregrava]

Here is a picture of the beuty.I will come whit more info tomorrow but now I have to leave my computer. You could also send me a mail (Saa kan vi ta det paa norsk)

[Zoriander]

I want to have 3 * stepper motors of 640 oz/ inch (www.homeshopcnc.com) what do you think of it?
Will I be able to cut iron with it?
or any other steel?

tnx a lot
Toon Goris

[smoregrava]

I have not used this machine jet so I'm not shore how bad og good this machine is.
But if any others out there got one of these I Have some real interesting info.
My mill is Serie number 1143-1 model Sp-fres 22.0101 Sp Fres/K boremaskin
If you look at the picture the connection Pin1 is Bottom rigth Pin2 Bottom left...
Pin 10 x direction
Pin12 xstep
Pin14 Y direction
Pin16 Y step
Pin18 z direction
Pin 20 Z step
All is TTL(0-5V)
Pin 23 have to be connected to 0V
Pin 21 have to pulse from 0V to 5V and back again for each step/direction puls
(I don't know why it is like this. He kalled this Latch puls
But the engineer who buildt it belived that The steppers would work If Pin 21 was connected to 0V have not tried this.)
Pin 1,2,25 and 26 is 0V

[ESjaavik]

So this is where the other Norwegians hang out?

Nice to see others joining. That brings the count to 5 that I know of.

@Viktor: 73 de LA8BKA