Servo without using software

[racear*2865]

I hope I am on the right part of the forum to ask this question, If not I apologize. I have a mill that I have installed a servo and controller to do nothing but go up and down. I do not want to use software. I would rather just use pre determined push buttons to go down. For example a push button for fast travel and another for go down .005 per touch and one to go down .001. Any help would be appreciated.
thanks
racear

[Al_The_Man]

It depends what type of control is used as input to the drive, whether analogue, digital or step/dir?
This will decide the nature and design of any control set up.
Al.

[mike_Kilroy]

as Al said it depends on your hardware. please list the model and brand so folks can offer ideas.

[racear*2865]

The control is step and direction

[Al_The_Man]

A couple of ways is using descrete logic IC's with say a 555 at the core with shift register or counters.
Or one of the most simplest and compact is to use a Picmicro to do everything together with a couple of push buttons.
The push button for fast jog would be simple but the incremental jog will require some scaling which is dependent on the encoder resolution.
Al.

[mike_Kilroy]

do u know how step & dir work? they are typically 5v differential signals where DIRection tells direction to go and step is pulses where each pulse is a very small distance. so unless you have a computer or other scheme to generate these signals it is not easy to do what you want.

But still, tell us the MODEL and BRAND of this device - a lot of servo drives ALSO have analog command input capability which you then can easily use!

[jasminder]

you can use a mpg or a home made encoder (or buy one if it fits your budget)

[quazga]

Or how about software! HAHAHA!! =D

If you're gonna manufacture these, then yeah, you'd want to go with an inexpensive microcontroller. However, if you're just building a one off then you might be interested to know that a SBC (Single Board Computer) may be able to be used. I wouldn't suggest this normally based on cost, yet the prices for SBCs have gone wayyyy down. You could probably pick up a SBC for around $100 and run ordinary software like Mach3 or TurboCNC.

And why would I suggest this being that you specifically asked for a non software solution?

Well how smart are you? hehehe =D Are you a nerd? =D Are you proficient in low level programming languages that would allow you to develop a program that would run in an inexpensive microcontroller and control your stepper driver?

If not then you're looking at getting a microcontroller that can be programed with a high level programming language and that is if you're able to program in those high level languages. But wait, if you get one of those high level microcontrollers then you're already in the price range where you might as well get a SBC.

It's true that given the simplicity of what you want to do you'll most likely find what you need already programed for whatever microcontroller you want to use, but still, there is lots of development that would need to be worked in even with an off the shelf program.

It would be nice if there were some off the shelf solution specifically designed for stepper motor control, with a microcontroller / driver combination, where you could, basically, add a power supply and adjust some parameters and be done with it. But to the best of my knowledge I don't think there is anything out there that does this as of yet. And if there is, I would love to know about it as I also would love to find an easy non conventional software based motion controller solution for some of my projects sitting on the back burner.

If not, then yeah, I'll be going the SBC rout since I'm not a nerd. HAHAHA!!! =D

[quazga]

ORRRR!!!

"use mpg, you can use a mpg or a home made encoder (or buy one if it fits your budget)"

HAHAHA!!! =D

Yeah, I'll bet that what he's trying to ask about. =)

[mike_Kilroy]

I love these forums! What a great idea to just get a manual hand crank encoder or make one from any old encoder you find around and put a kn0b on it!! Why didn't I think of that!!!! and use a simple switch for forward/reverse into the direction line! How many times I wished I could run a step/dir drive easily and never thought of this!!! Thanks!!!!!!

[Al_The_Man]

The only problem is using just a MPG or encoder unless the drive has any kind of intelligence it would need extra circuitry to step in 5 & 1 thou increments.
e.g. Ebay 300505717760.
Also as a servo was mentioned, there has to be an encoder back to an intelligent drive, otherwise the PID loop would have to be taken care of by the add on circuitry.
Al.

[racear*2865]

I will find the manual on line for the servo drive and the controller that I have with it so that we know what we are working with. But I already see this can be made to work. You guys are fantastic. Man I luv this forum and it great people. Thanks yall
racear