[SteveS]

I am starting a project using an old Roland GRX 400 plotter from a flea market. The plotter was built quite sturdy and has a 40 inch gantry.

It has three step-syn motors. One has 6 leads and the other two have 10 leads. (I counted them twice and there are 10.) One of the 10 lead motors drives the gantry belt. The other 10 lead motor was to friction feed the paper and drove a shaft going the gantry length. The smaller motor was to change out the plotter pens.

On the gantry to move the pens down is an electrical solenoid.

I have stripped it down from being a pen plotter and now need some information on the motors in order to go any further.

The 6 wire square motor is part number / Type 103-541-0144. It has 24 volt, 0.2a, 1.8 deg/step on it. It does look NEMA 17 size and is 30 mm between bolts. Measuring resistance, I found the following;

Blue White Orange
Blue - 124 0.248
White 124 - 124
Orange 0.248 124 -

Yellow Red Black
Yellow - 0.248 124
Red 0.248 - 124
Black 124 124 -

What type of motor is the 6 lead? I found a Parker picture that seems to make sense of the resistance as a Bifilar winding. I assumed from that article that it is bipolar.

The other two are identical round motors except the plastic gears. They are double ended shaft and seem to have some sort of plastic flywheel on the non-gear ends. They are part number / Type 103-7555-54D0. Ratings are 0.78 volt and 0.6 amps, 0.45 deg/step. These two are bigger at 47 mm between bolts on a side. Measuring resistance, I found that there were 5 pairs of wires that each had 1.2 ohms. No other combination of wires gave a resistance. The pairs were a solid color wire and then a white wire with the solid color spiral on it.

What type of motors are the 10 lead motors? In all of the threads and links, I didn't come across this number of leads.

Is there any decipher of the part numbers? Google didn't get me anything for these part number ranges of motors. One breakdown for step-syn had the initial two digits being the NEMA class, third digit being amps and the next set of numbers being the ounce holding rating.

If the number sequence is correct for this old of motors, is the 0.2a and 0.78a for the voltage they are being used at? If so what is the voltage for the 3 amp use? I have a number of power supplies to choose from

While moving the pen mounting plate across the gantry didn't probably require much, the moving of paper off a roll should have been a meaningful load. It would be helpful to know the ounce ratings for these.

Hope someone can help.

Steve.

[pminmo]

Six wire steppers can be used either unipolar or bipolar, see here: http://pminmo.com/six-wire-motors

Can't help you with the 10 wire motors.

[valeen1959]

I have seen 9 wire motors 1 common and the rest were 8 sequential windings. Trace from the motor connectors back to the driver ICs (if you still have the board). Google the driver number and that should tell you what you are dealing with. I built my cnc out of old printer motors and parts. Even found the driver ICs in them.

[SteveS]

Using an ohm meter, I found there are 5 circuits in the ten motor wires. Each circuit is 1.2 ohms. None of the wires has a resistance to any other wire except the wire that shows 1.2 ohms. It would appear that there are 10 separate coils in the motor.

The motors turn very smoothly with no noticable "ticks" like other steppers that I have had out.

Each of the 10 wire steppers had its own driver board.

ICs on each of the two driver boards are 8311BO (qty 3), 3403AD (qty 4) and AN6912 (qty 2).

There are ten (10) sets of 3-legged devices numbered 81181 and 0173 on each of the driver boards.

Then there are 10 more 3-legged devices numbered C1815 on each of the driver boards.

I googled some of the numbers, but don't know enough electronically to tell their significance.