[glomagno]

Is it possible to connect a nema 34 stepper motor connected to dm860a driver to a serial servo controller. There is 3 connections on the servo controller which are Data, Ground, +5V. On the DM860A driver the only connections needed to move are (-)Pulse and (-)Direction. Here is the circuit from both. It looks like it can be done but im not an electronics expert. I dont know if the signals are compatible or not. Do i need a dual h bridge to run the stepper like a servo?

[Al_The_Man]

It appears to me that you have step/dir drives and a RS232 serial controller?
If the RS232 is intended for control then you need some way of decoding the RS232 signal into a compatible step/dir signal, also more info on the PIC controller would be needed?
Al.

[glomagno]

HVLabs.com


The pic controllers are listed on this page along with the hex files

[Al_The_Man]

I see now the RS232 is for communication with the P.C. but the data for each servo is only one pic output?
Don't quite see how to get dir indication?
Al.

[glomagno]

The out put for each motor channel is Data, Ground, and +5v. I am assuming the "data" connection is the direction? i don't know. never used a setup like this. a guy on instructables used this servo controller for a robot using dc servos with feedback. I wanted to use steppers because i don't need planetary gears for my rotation and i would like to use the available holding torque instead.

[Al_The_Man]

I would have though that the data was the step pulses, but that still doesn't explain the absence of the dir.
If the commented source code was listed instead of just the HEX file, it would be easier to decipher the method.
Al.

[glomagno]

I see what your saying. The dm860 needs a pulse and direction signal when that servo controller only provides one signal. Can it be jumped? Or if i use a dual h bridge connecting both windings and jumping all the inputs together should that reverse the polarity? Sorry if this sounds stupid i am pretty new to this

[Al_The_Man]

If in fact it is a step signal output, you could set the dir either + or - or manually switch between the two, but that sounds limiting and his P.C. S/W seems to imply direction control?
In his video he just shows a 3 wire connection to the motor control, +V, com and data?

I think I have it, I believe model motors like he shows operate in a single PWM signal, for speed and dir?
Al.

[glomagno]

ok disregard all the previous questions. i want to connect the same serial servo controller to this driver for a brushless dc motor. what connections go where? i am confused because of the labeling.


http://www.anaheimautomation.com/ima...g(800x523).png

http://www.hvlabs.com/Images/serialservo.jpg

[lucas]

That serial servo controller is designed to drive servo motors for model planes, boats etc.. AKA RC servo.
The single data signal contains both the info for direction and position using a special continous PWM signal, there"s a defined pulse width for the center (zero) location, increasing or decreasing the pulse width turns the servo CW or CCW, the amount of position change is dictated by the percentage of pulse width change.

Some info: Servo control - Wikipedia, the free encyclopedia

These type of controls can't be used for real CNC position, they lack the required precision.

Speed control for a spindle is possible, some people use a RC brushless motor as a spindle.

Hope this helps,
Luc.

[Al_The_Man]

The controller you show in post #9 is an analogue input control using a BLDC motor, you would have use one of the PWM to analogue converters as used in some BOB's, or make one up.
If using a Picmicro from scratch, the usual way is to use a digital to analogue convertor from each of the ports.
Al.

[glomagno]

ok this is for brushed dc motor. stupid me. this why im on here asking. thank you

[glomagno]

AL on the analogue input control i posted on #9. what inputs in the wiring diagram are necessary to control the motor?

[Al_The_Man]

It shows a simple pot across 1, 2 & 3, if controlling it from an external source such as a PWM to analogue you would supply a 0-10vdc signal between 2 & 3. Or 1 & 2 which ever is the common, 1 or 3?
BTW, there are some BLDC drives that will control a brushed DC just as well, such as A-M-C, etc.
Al.

[glomagno]

well the reason why i ask and going through all this trouble is because of the software for the board. The software controls each servo with sliders, angular position, record and play functions very easy to use. So i would like to utilize this if possible. Trying to figure out what wires i can put a DAC on from the board i have to the brushless motor driver. i checked out A-M-C products. i think the software is a little over my head considering im still trying to figure out how to wire

[Al_The_Man]

Look at fig 16 simple PWM to analogue.
Al.