Stepper motor?

[satchid]

Hi, I have a lot of questions, some of them are below mentioned

I purchased size 23 stepper motors from Deepgroove on Ebay. They have 4 separate coils ending in 8 input pins.

The folowing is marked on them:
1.8° per step
Is(dc) 1.75A Bipolar series Vs(dc: 65V
Po:30w
1500RPM

Mesured 2A with powersuply on 3 volts on 1 coil.

What is this telling?

What is the best supply voltage from the powersuply with a chopper driver from ( www.************* capable of max 3A per channel and 44V)?
What can I set as the maximum curent?

Is there a way of finding the tork of these steppers?

Can I drive a small router whith these, I want to make a router the size of x=12" y=16" Z=5"

What would the preferable pitch of the leadscrew be for a reasonable travel speed with these motors an driver?


I hope that this is the proper place to put these questions, otherwise would one of the moderators move it to the right spot please?

Thank you for the advice,
Satchid

[marvinstov]

Satchid,
I believe those are the same motors that Jeff at Xylotex sells. They are 116 oz/in steppers. I have some on a 14x24x5 home made router using 5/16-18 all thread screws with drawer slides for rails. I get about 50 ipm rapids with them. I also tried them on another machine (12x24x5) I have with 1/2"-10 acme screws with Thompson linear rods and bearings. They would get about 90 ipm rapids on it and cut pretty good too. Mine are wired bipolar parallel (which Jeff recommends with these motors) and work really well for their size. Of course a lot will depend on how much friction your machine has, how they are wired (parallel, series) and power supply voltage.
I don't know about the driver you are talking about and whether or not it has a current adjustment on the board or if you have to use external resistors to limit the current. I suggest that you read the setup papers on the Xylotex web site for setting the current if you are using the Xylotex driver. There was a discussion on this very subject today but I can't locate it at the moment. When I find it I will get you the link.
As for the voltage. With the Xylotex driver, you should limit it to 30V. The board is good for a MAX of 35V but you need some buffer in there for back EMF. The motors should be ok even above the 30V using the board you are indicating. I believe the motors are about 3 or 3.5 volts and you should be able to run them at approx 20 times that voltage without harm using a bipolar chopper drive. I believe the 65 volt rating is a max sort of like just before self destruction occurs. They shoudl run good at 30 - 40 volts as long as you limit the current to what is recommended according to how you have them wired (parallel or series). If I remember what I read today, you should be able to run them bipolar parallel at 2.5 amps without problems. For series, 1.75 amps.
I hope this helps and if I gave some bad information, somebody please correct me. I't still pretty new to this also.

Marv

[marvinstov]

Satchid,
Here is that link I was looking for. It is from the CAD/CAM/EDM/DRO Yahoo group.

http://groups.yahoo.com/group/CAD_CA.../message/73676

Marv

[satchid]

Dear Marvin, thank you, this is a huge help, I was wondering how I could get this info.
Indeed, these are the steppers. http://www.xylotex.com/DoubleStepper.htm I have no connecting wires for these motors. Could it for you posible to look at the motorconnrction, and give me the collor of the wire when the cinnector is in the soccet on each pin. the pinnummers are on the motor.

A question for all:
These motors are markes Bipolar series. They have 8 pinouts for 4 separate coils (mesured). My driver board is a unipolar shopper board from HobbyCnc. would this couse a problem? can I wire these motors in unipolar mode?


Thanks,
Satchid

edit: 11:34 url was not shown.

[ger21]

At the Xylotex site there is a PacSci data sheet willwill havemotor specs and wiring diagrams. The wiring is somewhere around page 50-53 I think. To find the rated voltage for the motors , find the motor in the data sheet and multiply amps x ohms. The 65V is the maximum you can use.

If using these with the Hobby CNC chopper board, the motors will only be 82oz. (Unipolar gives less torque). The rated voltage would be about 2.5V. I'd use themaximum or close to it voltage the HobbyCNC board is rated for. (somewhere around 40V, right?) This will probably give you better high speed performanc than a Xylotex at 24V.

[marvinstov]

Satchid,
Ger21 is right. If your board is a unipolar board then you do not have a choice on how you wire the motors. The PacSci data sheet will give you all the info you need to wire them. The following link is an installation bulletin from the Xylotex web site for the PacSci motors. It is only two pages and has the wiring diagram for Unipolar on it. http://www.xylotex.com/PacSciIB.pdf

The full PacSci documentation is at: http://www.xylotex.com/PacSciDS.pdf

The HobbyCNC site indicated that you do not need external ballast resistors. The current is adjustable on the board.

Marv