# Is it Possible to "Jog" Stepper Motors?



## toddalin (Jan 4, 2008)

My CNC machine uses stepper motors to move the table and quill when it is under CNC control. However, there is no way to use these motors during manual operations, which are performed using hand cranks. In fact, there is a switch to disconnect the stepper motors to manually jog the machine during a CNC operation.

It takes 115 revolutions of the hand wheel to move the table from one side of the machine to the other. It would be nice if I could use the stepper motors to perform most of this cranking for me using momentary switches.

Does anyone know of such a circuit that would allow me to jog the steppers once I disconnect them from their dedicated drivers?

Thanks


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## Gary Armitstead (Jan 2, 2008)

Todd,

I am really trying to jog my old memory on this one. I believe stepper motors run on a sinusoidal (Sp) wave curve. Are these motors "brush" or "brushless" motors? Thinking back quite a few years, I think we ran a Bridgeport Bandit mill and I beieve it had stepper motors. The Bandit controller DID have the capability to jog both the X and Y axis. If you google stepper motors, there are quite a few circuits shown to do what you want to do. I'm not an electronic wiz, so I can't help.


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## Greg Elmassian (Jan 3, 2008)

When I worked for HP, they made plotters that used stepper motors. There was indeed a high speed "jog" button. 

A common features, so I'm sure you will find a circuit out there somewhere. 

since that time, the steppers have been replaced with servo motors and rotary encoders, otherwise I could probably get you a circuit diagram... maybe even using relays and 555 timers! ;-) 

Greg


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## toddalin (Jan 4, 2008)

These are interesting motors: 2 phase 1.80 Step, 4.30 amps, 0.5 ohms, *2 vdc*, 19 watts, 326 oz-in.

There are plenty of stepper kits on the market. But I don't see any that go down to 2 volts, and even those that can sustain the 4.3 amps are costly.


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## Michael Glavin (Jan 2, 2009)

Todd,

Why not use the software interface to jog the drivers\motors. Generally there is a feature to manually move the steppers about. Albeit if you don’t have the laptop and software yet there is no easy solution IMO. 

Are the motor driver(s) and power supply in place now? You can provide a signal to the driver boards, if I recall it’s a 3 wire configuration for each driver with FWD-REV and common although if memory serves me it’s not as simple as toggling a switch...

You don’t need a 2 volt driver, you indicated bi-polar steppers with a rating of 4.3A the current rating is what’s important here; as steppers are driven at higher voltages typically 12-36 volts.

Michael


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## toddalin (Jan 4, 2008)

I should be able to do this through the software, when it comes. But I really don't want to leave a computer out in the garage and often you just want to get something done quick and easy while standing there. I guess I'll see how easy/difficult it really is to use the computer when it's together.


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## Trains West (Oct 4, 2008)

are you sure on the voltage .... with 2 volts i would not think that there would be enough energy to make it work ..... 12 maybe .... or 24 or 36 

and yes there used to be drivers ..... I know as i have one ..... question is are they still made


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## John J (Dec 29, 2007)

How electronically inclined are you ?

Here is something that may allow you to do what you want 


http://www.ebay.com/itm/CNC-Step-Pu...175?pt=LH_DefaultDomain_0&hash=item4d052e44ef

I was building a CNC machine before the big disaster and I got a lot of stuff from these people 

JJ


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## toddalin (Jan 4, 2008)

Posted By Trains West on 23 Nov 2012 09:43 PM 
are you sure on the voltage .... with 2 volts i would not think that there would be enough energy to make it work ..... 12 maybe .... or 24 or 36 

and yes there used to be drivers ..... I know as i have one ..... question is are they still made


The case says 2 volts and it makes sense. 2 volts x 4.3 amps x 2 phases ~ 19 watts


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## toddalin (Jan 4, 2008)

Posted By John J on 23 Nov 2012 11:00 PM 
How electronically inclined are you ?

Here is something that may allow you to do what you want 


http://www.ebay.com/itm/CNC-Step-Pu...175?pt=LH_DefaultDomain_0&hash=item4d052e44ef

I was building a CNC machine before the big disaster and I got a lot of stuff from these people 

JJ 


I'll check it out. Thanks.


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## Michael Glavin (Jan 2, 2009)

I wouldn’t worry about the laptop and the shop/garage use I’ve yet to have an issue with same. Very dependable IMO, I simply protect them from debris. I purchased a few old working Dell laptops for $50.00 each just for driving CNC equipment their needs are low in the scheme of things and inexpensive to replace if need be.

The stepper pulse control from Brent at Hubbard CNC that JJ linked to would suffice for jogging a stepper motor providing you have the stepper drivers and a power supply in play. Most of this stuff is linked to a computer with an old style “LPT” parallel printer type plug/chord. You could hack an LPT chord, connect the pulse controller and plug into the driver array and then push the appendages around (one at a time) dependant on which driver board was connected to the controller. 

Hubbard CNC is local to me here in Sacramento; I have purchased stuff from them several times in the past, never had a problem. 
The steppers don’t operate at their rated voltage; this specification is used as Vref or reference for tuning the driver to the motor. Elevated voltage and current limiting is the key herein, the higher voltages allow the coils to charge faster and maintain the desired step and or performance levels. 


Michael


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## Greg Elmassian (Jan 3, 2008)

Yeah, I buy refurbished Dell Latitude laptops from Overstock.com for a couple hundred, and they are tough and run pretty much forever. Dual core, couple gigs ram, XP pro... 

Interesting about the low voltage, most are higher, but it the watts that move it one way or the other. 

Greg


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## Kovacjr (Jan 2, 2008)

My friend has a CNC Sherline setup and there is a manual override, also have control of the travel speed if you are doing any cutting.


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## Trains West (Oct 4, 2008)

http://www.ebay.com/itm/Universal-U...256febcc4d 


I kinda like the looks of this one ..... i will go look at mine when it warms up a little .... back shop building is way cold right now


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## Michael Glavin (Jan 2, 2009)

Scott, 

That's a neat gadget for tinkering and testing Unipolar steppers..... It’s an all-in-one solution.

You may need a “Bipolar” motor drive; Unipolar drives can’t operate Bipolar steppers, that said a Bipolar drive can run Unipolar steppers.
First order of business is to verify what type motors are in play, 4-wire steppers are exclusively Bipolar, 5, 6 or and 8 wire motors can be configured as Bi or Unipolar steppers. Stepper motor specifications or needs distinguish which wiring scheme and the associated caveats of same are best suited for the application in play.
Michael


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## Gary Armitstead (Jan 2, 2008)

Todd, 

I have been thinking about your problem regarding "jogging" your mill table. I don't know why I didn't think of this sooner!! This is the simplest way to do this.










I took a look at the G codes this machine recognizes and noticed G0 (rapid positioning). Just give it a G0 and the location. What is the rapid speed on your machine? This should all be explained in the manual for the software.









The nice part about using G0 is that you can move one or two or all three axis at the same time. Unless you have three hands, you can't do this manually! OR as fast!


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## toddalin (Jan 4, 2008)

Thanks Gary. I did not get the manuals for the DRO or CNC with the machine. The PO is looking for them and if he doesn't find them, I'll inquire at the mfg. web site. The laptop and a VFD should be here soon as they were sent out last Fri a week ago.

As I mentioned, sometimes it is nice just to do something quick, and just firing up the software can take as long as positioning the table for a single action. I guess that most time the table will remain under the quill, more or less, so it shouldn't be that big a deal. To move the table from one end to the other takes a lot of cranking and my wrists don't get the regular workout that they did when I was a teenager.


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## Gary Armitstead (Jan 2, 2008)

Posted By toddalin on 24 Nov 2012 12:15 PM 
Thanks Gary. I did not get the manuals for the DRO or CNC with the machine. The PO is looking for them and if he doesn't find them, I'll inquire at the mfg. web site. The laptop and a VFD should be here soon as they were sent out last Fri a week ago.

As I mentioned, sometimes it is nice just to do something quick, and just firing up the software can take as long as positioning the table for a single action.
Todd,

I think that once you receive the software, it should show how to jog the machine. Most of the folks that I know that have home CNC machines, feed them with very cheap, low power computers. However, the time when you PROGRAM your part, will be the time consuming, number crunching part! Just feeding the program to the controller doesn't take a lot of computer power. You can feed the program to your controller from a computer inside your home by DNC (over a cable connected to the controller. We used to feed our Haas mills and a giant Seeburg and Cincinnati mills, by cable. Your programs won't be very large anyway because your controller won't hold more than 1000 lines of code anyway (per Shopmaster's website).


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## toddalin (Jan 4, 2008)

Posted By Gary Armitstead on 24 Nov 2012 12:28 PM 
Posted By toddalin on 24 Nov 2012 12:15 PM 
Thanks Gary. I did not get the manuals for the DRO or CNC with the machine. The PO is looking for them and if he doesn't find them, I'll inquire at the mfg. web site. The laptop and a VFD should be here soon as they were sent out last Fri a week ago.

As I mentioned, sometimes it is nice just to do something quick, and just firing up the software can take as long as positioning the table for a single action.
Todd,

I think that once you receive the software, it should show how to jog the machine. Most of the folks that I know that have home CNC machines, feed them with very cheap, low power computers. However, the time when you PROGRAM your part, will be the time consuming, number crunching part! Just feeding the program to the controller doesn't take a lot of computer power. You can feed the program to your controller from a computer inside your home by DNC (over a cable connected to the controller. We used to feed our Haas mills and a giant Seeburg and Cincinnati mills, by cable. Your programs won't be very large anyway because your controller won't hold more than 1000 lines of code anyway (per Shopmaster's website).





Thanks.

I seem to recall that there is an available upgrade to go out beyond 1,000 lines of code.


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