3-Axis Stepper Controller

[RobiD]

In addition to the above:

I have changed around the order of the wires and am now getting rotation. It's ok on the z and y axis, but the x axis is a little choppy.
There is also not a lot of torque (not enough to move the axis, but the steppers rotate in-situ without the axis attached (hope you understand what I mean).

I am running the board on 12vdc (or it's probably more like 11.8vdc).

Would the motors be stronger if I ran the driver board on 24vdc, and will that cause any damage?

Sorry about the repeated posts.

David

 

[GreekPIC]

RobiD: more voltage -> more torque, just don't exceed the motors specifications. You might also try different pulsewidth settings, the motor might be stalling.

kanzor: In TurboCNC when you home the axis moves untill it trips the home switch, then resets to 0 or any other preset value (e.g. you wouldn't want Z to home on the table, you would set it to go + (up) and resset to whatever your Z travel is.
It is not neccessary to home every time (the position is stored when you exit the program) but it is recomented for better accuracy.

 

[MP1]

David, I cannot comment on the voltage for your motors without a data sheet. However, if the wiring is not correct, the motors will not move. You should check the wiring a few times to make sure you are connected to the correct winding. If you are sending 12 VDC to a 5 volt stepper, this is not a good idea. Are you sure these are 12 volt steppers?
Another cause for not getting motor movement is to have the speed of the motor set too high. Try setting the delay between steps to a higher number. I am not familiar with KCAM, but there should be a setting for speed or delay. If the motor is getting the pulses too fast, it will jog when you give it a step manually, but it will not run.
It would be nice if you could post a diagram of your setup for the 5 wire steppers for others in the forum.

MP

 

[RobiD]

Thank you MP for your response, in fact thank you everyone who has has an input.

As for a wiring diagram for 5 wire steppers, it was more trial and error after identifying the center tap using a multimeter, connecting this to position two of the individual axis connectors, then connecting the remaining 4 wires into positions 1,3,4,and 6.

Then test and if no good, swap 3 and 6 etc until you get the motor moving in a consistant direction.

In response to your questions about the stepper voltage, they are rated at 12vdc and 24vdc with a higher torque rating at 24vdc.

I am assuming I just attach the 24vdc to the + and - terminals of the driver board (surely I don't have that wrong).

One more question, when I finally get a motor to turn continually in one direction under the control of KCam, the motor seems to make one complete revolution then pause for a fraction of a second then go for the next revolution and so on.

Shouldn't the rotation be consistant and smooth? If not, what have I done wrong?

Thanks for your help.

David Andersen

 

[RobiD]

Sorry, another question.

I may try to build a power supply myself. What sort of amperage do I require to run the driver and motors, or is related to the ratings of the stepper motors only which is 216mA at 24vdc per motor. (data sheet here if needed http://www.mitsumi.co.jp/Catalog/compo/motor/m55sp/1/text01e.pdf )

Thanks again.
David

 

[MP1]

The inconsistency of your motor rotation might be due to not enough current. Setting the speed too high can also cause this.
For a power supply, I usually use an old computer power supply. They are cheap, run cool, and have plenty of current at 12 volts.

MP

 

[RobiD]

I was informed that a computer power supply is switching and not as good as an unregulated supply.

How do I check current supply?

I was using an AT power supply, and I was only getting about 10vdc with load.

Also, I have another AT power supply that has very low volts with no load (about 3vdc) and I am told that it has to have a load to produce the full 12vdc. What is the easiest way to put a load on the supply to produce the full current?

Thanks
David

 

[ante1]

Hi RobiD,

One easy way to load a PC PSU is to put a 4R7 10W on the 5Volts side. This works on most ATX and AT PSUs. If you look at the label on your PSU you can see the ratings on the different voltages.

 

[rdmotors]

My question abou this circuit is: Why are the input lines to the ic have 5v resisted supply on them? The restistors I am talking about is RP1-3. it would seem that you would back feed power into your lpt port? Or am I way off base?

 

[MP1]

Your parallel port data pins are logic levels. The 5 volt through a pull-up resistor insures the lines are tied high until the port pin sets it low. This is a standard configuration for logic. You are not feeding power into the parallel port. However, if your software is setup to read the pins on the parallel port instead of send, then yes, you will be feeding the voltage into the port to read it. This is a bi-directional port. Whether it reads or writes is up to the software in the PC.

MP

 

[madthug]

Uhh... at the risk of sounding stupid, what program can be used to open the "___.ps" file exention?
Thanks,
MadThug ???

 

[GreekPIC]

I open them in Corel Draw. Adobe Ilustrator will do too, and many programs can import it (even Word if you added the appropriate filter during install).

 

[madthug]

I just wanted to thank GreekPIC and MP for supporting this project for free. I'm excited to get started on my own gantry mill.
-MadThug ;D

 

[GreekPIC]

You 're welcome. Good luck with your project and post updates

Nikolas

 

[MP1]

Hope to see the results of your mill.
Good luck!

MP

 

[Dazza]

Hi all,

I have been wanting to make this project for a long time, but had no use for it until now .

Okay I want to start with getting familiar with the software, which leads to my first question, with probably many more to come ;D.

I am a slow learner when it comes to software , so what would be the most user-friendly software to use ???, I prefer Windows based software, anything else will scare me ;D, and preferably freeware/shareware to get me going .

Thanks in advance.

 

[RobiD]

I use KCam at www.kellyware.com

It is windows based, imports dxf plt etc and works out the tool pathways for you. My only complaint it that it doesn't have tool offset yet.

It's shareware.

No matter what software you use, it will take time to understand what you are doing, and lots of test cuts.... you know, trial and error.

David

 

[Dazza]

Hi RobiD,

Thanks I installed KCam , looks like a lot of learning for me, with plenty of that trial and error ;D. My OS is XP so I'm not sure how it will go, I may have to find something else but at least I now have an idea of what I am in for . I only have the one computer to use to get the milling machine set up, then I will buy a cheap computer solely for the milling machine.


I want to use it for milling timber and foam patterns for metal casting, I first want to make a very basic scale model, then make the larger mil that I will need. It's likely that I will need motors that will draw more current then this project can handle :-\, there shouldn't be any problems if I use power transistors or could I use MOSFETs to drive the stepper motors via triggering their gates? Accuracy wouldn't be lost by doing this?

 

[RobiD]

I believe that this driver board can handle voltages up to 35vdc, which should be enough for most larger stepper motors. If you are going to go big, you would probably want to use bi-polar anyway as they have more torque.

This is a nice home cnc driver board which works great.

As for how to use mosfets as switches, I'm not that advanced with electronics but I know others on this forum are...

Good luck, and have fun building it all.

David

 

[Dazza]

I have just noticed that this project calls for, (3 resistor network 770-81-R-4.7K) is there an alternative to using these components. As they are not readily available to me, these are basically resistors configured in a certain way?, can I use resistors if so how do I configure them?