# Sieg X3 power feed



## ShawnR (Jan 25, 2022)

You know how one project is often interrupted by another project?  Hand cranking the X axis is getting old (albeit, my mill is small, but I am lazy) so a power feed for it has jumped up the list. I started with trying a drill to see how well it worked. Great, so then making an adapter, which turned out well. I then used a small torque wrench to determine what ball park will be and 15 in lbs turned it. I don't trust the torque wrench to be deadly accurate but it gives me a starting point. I wanted to know if my stock NEMA 23 motor might work and it is on the border so all good so far. As most know, NEMA designation is the mounting size so to swap it out with a higher torque 23 should not be an issue.
I did want to confirm the torque values though so cleaned up the adapter shaft and will do a more accurate test today with weights before I cut the shaft off to make the actual adapter.
It has been a while since I did anything with microcontrollers, very little with step motors and I am new to the Arduino platform so I wanted to do some practice/experimenting.  I made up this prototype module. I am thinking I might have a digital display to show set feed speed but practicality says a simple control will suffice. Time and my "gotta get it done" syndrome with a mild case of "the novelty has now worn off"  syndrome will determine how elaborate it gets.  The nice thing about ucontrollers is that you can add or change features relatively easily.


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## David_R8 (Jan 25, 2022)

Nice!


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## ShawnR (Jan 25, 2022)

So I did my torque test. Maybe someone can tell me if my numbers and method is correct?

I wanted to use that bearing in the first post to eliminate any drag on the hub adapter but that did not work due to interference with the bench top so I had to extend the arm. The adapter rotates on the edge of the plate to keep it in line with the lead screw in the table top. Some drag there but the motor I use will be upscaled anyways so I don't think it will be a huge factor. I then took up the backlash and poured sand into the can until the arm moved. From the center of the arm to the end of it is 8.75" and from the back of the adapter to the end, 9.25". Splitting hairs but just curious which is the correct number to use. I think the 8.75 as it is to the center but the rope comes around the back side, thereby lengthening the arm...or does it?

The first test yielded 24 ounces but all of the rest resulted in about 18, give or take. Data attached. If it is correct, my motor is right at the limit being rated for 170 oz/inches. We lost internet here this morning so I could not check on larger #23 motors but I recall them being readily available. @David_R8 , my motor is one of 3 I bought for the plasma cutter, so the same as what you used. I knew this project was on the list so the 3 pack was the way to go.

Am I on the right track or out to lunch?...


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## David_R8 (Jan 25, 2022)

I'd go one size up to a 23 to avoid potentially overworking the motor. But that's my ethos; some good ergo more better


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## ShawnR (Jan 25, 2022)

Yes, absolutely! A quick Amazon search brings up several larger sizes. Always a trade off. One was like 470 oz in but would stick out substantially. One, probably the "next size up" was about 270. I would probably like to double my findings so thinking 340 but will see when I get more into the research. At least, lots of choices in the #23 size so I can go ahead and do the mount. 

Phil Vanderlay did a power feed motor mount, but a wiper motor on the same milling machine. I like his clutch but I don't know if I need it as if the stepper has no power to it, it will not cause much drag. Power will lock it in position though so I like the idea of the stepper over the DC motor.


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## David_R8 (Jan 25, 2022)

I think Lee Peedin (PragmaticLee on YT) also did a slick power feed for an X3-size mill. Might be worth a look for some ideas.


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## ShawnR (Jan 25, 2022)

Yes, that one looks good too. More compact than what I am doing.  I think the same clutch mechanics as Vanderway and with those geared motors, you would want it.


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## whydontu (Jan 25, 2022)

I’ve always been a big fan of the saying ”when all else fails, cheat”. To help you with your cheating, here’s a photo of the motor from my scrapped OEM G0704/CT129 power feed. This was an old version, no longer sold by Grizzly.

The motor struggled at low speed (using a straight DC brushed motor at low voltage is a waste of time). Then the cheap-ass controller board died, so I tossed the whole mess into the spare parts bin.









						775 DC motor with planetary gearbox - RobotDigg
					

RS775 DC motor with planetary gear RS775-12V 7000rpm motor : No-load speed (rpm) :7000 No-load current (A): 760 Rated sp...




					www.robotdigg.com
				




However, the motor info is legit and you could use it to size your stepper system. I’d suggest  going at least 1.5x the rating of this POS motor.


The text at the top of the page is utter BS (400 amp current draw at 24 VDC?) but the chart at the bottom is probably legit.

The current version of the power drive is 90 Vdc @30 watt.



			https://cdn0.grizzly.com/manuals/t23010_m.pdf


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## ShawnR (Jan 25, 2022)

whydontu said:


> I’ve always been a big fan of the saying ”when all else fails, cheat”. To help you with your cheating, here’s a photo of the motor from my scrapped OEM G0704/CT129 power feed. This was an old version, no longer sold by Grizzly.
> 
> The motor struggled at low speed (using a straight DC brushed motor at low voltage is a waste of time). Then the cheap-ass controller board died, so I tossed the whole mess into the spare parts bin.
> 
> ...



Thanks @whydontu  Good information to consider. The motor amps is probably 0.4 A or 400 milliamps, (the mA was lost in translation)  seeing as that spec is a no load current. The loaded currents look reasonable, as you said.


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## YYCHM (Apr 7, 2022)

Susquatch said:


> I keep thinking about a power x axis too. But the price went to hell in a handbasket. So it has to wait a while.


https://www.vevor.ca/power-feed-c_1...110v-5-8-shaft-variable-speeds-p_010206704752 

Ya ain't gonna find no $60 PF out there


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## Susquatch (Apr 7, 2022)

YYCHM said:


> https://www.vevor.ca/power-feed-c_1...110v-5-8-shaft-variable-speeds-p_010206704752  ???????



It's out of stock but I would pay that for it in a heart beat. That would sure delay the last two steps of my DRO install though. I'd like a power X feed and RPM, but not as much as I'd like a power x feed.....

Thanks! 

That price is great. Might not last. I wonder if they will accept an order even though it's out of stock......


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## YYCHM (Apr 7, 2022)

Susquatch said:


> It's out of stock but I would pay that for it in a heart beat. That would sure delay the last two steps of my DRO install though. I'd like a power X feed and RPM, but not as much as I'd like a power x feed.....
> 
> Thanks!
> 
> That price is great. Might not last. I wonder if they will accept an order even though it's out of stock......



Try this one  https://www.vevor.ca/power-feed-c_1...type-milling-machine-0-200-rpm-p_010894769989


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## Susquatch (Apr 7, 2022)

YYCHM said:


> Try this one  https://www.vevor.ca/power-feed-c_1...type-milling-machine-0-200-rpm-p_010894769989



I believe I need the 450 inch pound version Craig. Also, I'm worried about the size. The Vervor website says the screw is 5/8 but there is no way that is right. Mine is huge. Just guessing an inch and a quarter but maybe an inch and a half. I'll have to check tomorrow when I get to the shop. 

I think I'll try calling them in the morning. 

Thanks for helping. It is much appreciated!


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## ShawnR (Apr 8, 2022)

YYCHM said:


> Try this one  https://www.vevor.ca/power-feed-c_1...type-milling-machine-0-200-rpm-p_010894769989


. 
Sounds like a steal!!

 Here is a link to a power feed for my mill, a toy machine next to a Bridgeport!









						Power Feed, X3 & SX3 Mills 5114
					

Mini Mill Accessories 5114 Fits X3 and SX3 Mills, Grizzly G0463 and G0619; Power table feed for the X3 and SX3 mills. This power feed mounts on the l...




					littlemachineshop.com
				




American dollars, about 40% of what I paid for the machine ~ 10 years ago


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## ShawnR (Apr 8, 2022)

I have asked admin to move these power feed posts over to this thread. Forgot I had started it back in January. 









						Sieg X3 power feed
					

You know how one project is often interrupted by another project?  Hand cranking the X axis is getting old (albeit, my mill is small, but I am lazy) so a power feed for it has jumped up the list. I started with trying a drill to see how well it worked. Great, so then making an adapter, which...




					canadianhobbymetalworkers.com


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## Susquatch (Apr 8, 2022)

YYCHM said:


> Try this one  https://www.vevor.ca/power-feed-c_1...type-milling-machine-0-200-rpm-p_010894769989



Not sure where to put this post now. Hopefully @Janger will move this post with the rest.

The leade screws on both my mills are 1-1/4 - 5tpi. (200 thou per turn). So ya, the 5/8 Vervor isn't gunna work......


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## YYCHM (Apr 8, 2022)

Susquatch said:


> Not sure where to put
> 
> 
> Not sure where to put this post now. Hopefully @Janger will move this post with the rest.
> ...



Are you sure it's 1-1/4 at the end where the PF would attach?


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## Susquatch (Apr 8, 2022)

No idea. I've had the end off but don't remember what it looked like. Could be smaller. Can't see why they would do that though.


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## Brent H (Apr 8, 2022)

@Susquatch : the power drives attach where the handles and bearings are.  The lead screws drop from  the 1-1/4” to way smaller


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## Susquatch (Apr 8, 2022)

YYCHM said:


> Are you sure it's 1-1/4 at the end where the PF would attach?



Actually, no I wasn't sure. But @Brent H is right, they drop down to 5/8 at the keyed shaft before the nut that holds the handle on. 






So I guess the question really becomes - do I really need 450 in-lbs?  That question will have to wait for Monday to answer.


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## Brent H (Apr 8, 2022)

@Susquatch : no you don’t. 

150 for X , 135 ish for y and the 450 would be for the Z as you are lifting the knee and what ever part you have up there.


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## Brent H (Apr 8, 2022)

@Susquatch : disregard that for the weekend if you want to wait for Monday


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## Susquatch (Apr 8, 2022)

Brent H said:


> @Susquatch : no you don’t.
> 
> 150 for X , 135 ish for y and the 450 would be for the Z as you are lifting the knee and what ever part you have up there.



I think I just bought an X-Axis Power Feed! 

Left or right side? Thinking left because I like to stand on the right side.


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## Susquatch (Apr 8, 2022)

Brent H said:


> @Susquatch : disregard that for the weekend if you want to wait for Monday




OK ok, I'll wait.


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## Brent H (Apr 8, 2022)

Fits on the right side (you facing the mill) that is the longer spindle end. The left side has a double bearing for thrust absorption- sorry - second glass of wine - I will wait for Monday


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## Darren (Apr 8, 2022)

Make sure that you don't have Vidmar or similar cabinets close to the mill where you could leave a drawer open and have the power feed going and think you have enough time to run outside for a quick pee, and have the spinning handle jam up on the drawer that someone else must have left open and wreck your power feed. Just sayin.


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## ShawnR (Apr 8, 2022)

Darren said:


> Make sure that you don't have Vidmar or similar cabinets close to the mill where you could leave a drawer open and have the power feed going and think you have enough time to run outside for a quick pee, and have the spinning handle jam up on the drawer that someone else must have left open and wreck your power feed. Just sayin.


Sounds like experience...


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## Darren (Apr 8, 2022)

ShawnR said:


> Sounds like experience...


Not my finest moment...


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## ShawnR (Apr 8, 2022)

Darren said:


> Not my finest moment...



Yea, I have a few of those too....I think we all do, whether we admit it in public or not. As long as we live through it, all good. If not, well the old "did not see that coming " line applies.  ( I guess, apparently, I have not crossed that one yet)   

Cheers,


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## ShawnR (Apr 9, 2022)

Well, as Frankenstein's maker said, "It's alive!"

Darn thing actually works! 

As I was getting closer to tying it all together, I wondered how I was going to line up the screw end with the stepper motor, through the adapter and coupler, before I made holes to mount the motor adapter to the end plate. I decided to make an alignment tool (wish I had a cooler name for it) that fit nicely into the mill table end, through the aluminum plate, and into the motor adapter. This seems to have worked out. So I took my prototype out and gave it a whirl. The motor seems to do ok with the mill table. I will put an ammeter on it later to see how close I am to maximum current draw, and, worst case, I get a stronger NEMA23 motor. I hope I understood correctly in that all NEMA23 motors have the same mounting configuration...


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## ShawnR (Apr 18, 2022)

Almost wrapped up. Need to figure out labelling. The motor, as I suspected is borderline so, now that I know it works, have ordered a larger motor.   I find the motor hesitates sometimes, then moves along, then stops. I am thinking that the new higher torque motor will be enough.


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## jcdammeyer (Apr 22, 2022)

I realize I'm coming late to the party but back when I added a stepper motor to my South Bend lathe and then again later to my milling machine knee I used this method.  This clamped onto the lead screw shaft.  Sized for a socket I had that fit my flex handle I now had a lever on which I could hang weights to see how much torque was required to overcome static friction.

I then doubled that value. Totally just because; no science behind that. 






Next step is to look at motors.  I've attached a size 23 286 oz-in motor torque curve.   Notice how at high rate the torque falls of as the speed increases.  What makes it worse is the motor isn't rated in RPM there but in half steps.  No one uses half steps.  It's all micro-stepping.  And we don't really hang weights on the flex handle measured in newtons .

First step then is to google conversions although it's probably best to figure out what our maximum traverse rate needs to be.   Say we want the carriage/table to move at 100 inches per minute (insert your own units here).  Given the lead screw pitch we can come up with a lead screw rpm to achieve that.    We've also figured out what double the static torque is.

So we have a 5 TPI lead screw and we want 100 inch/min.  If I've done the math right then we have:
5 turns/inch * 100 inch/min = 500 turns/min.  The units cancel well.
Now 500 turns per minute is 8 turns per second and assuming we have 1/2 step per step motor driver the:
400 steps/turn * 8 turns /second = 3,200 steps/second. 
Let's look at the chart again which suggests .7nm which is about 100 oz-in.at that speed.

Now back when checking out torque.  Say I put 5 oz of weight at the 10" point of the flex handle and the handle started moving.  That's 50 oz-in and since I'm doubling that value I need 100 oz-in to overcome static friction.  Kinetic friction is lower so easy peasy.  But what about cutting load?  That's where the 2x fact gestimate comes in. 

So theoretically as long as this motor can provide the 0.7 nm at a 3,200 steps per second half step rate it's likely the motor can also drive the mill table at that 100 in/min.  Now if you need 1.4 nm it's time to look at a bigger motor or maybe 2:1 pulleys.  After all twice the speed is pretty linear at 0.35 nm which is 7 nm with  2:1 belt drive.  

If the motor driver can actually run the motor that fast and the torque curve is accurate then that motor works assuming the pulleys and belts are cheaper than a bigger motor with bigger driver etc...


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## Degen (Apr 22, 2022)

My power feed was about 130in/oz handled the feed no problem, my current setup now has about in excess of 200 through the entire 100% duty cycle, 100% rpm range on the servo's.

My machine is bigger and is pushed. If you need more than 130 on you small table you have issues  on the machine you should address.


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## ShawnR (Apr 22, 2022)

@jcdammeyer  and @Degen Thanks for the input.

In post #3, I show the procedure I used to determine the torque required. Not too scientific but figured it was a start. As commented, the motors I had in stock were about 170 oz (actually 178 oz) motors and so I was going to be borderline. But, seeing as learning the Arduino code and trying to recall programming skills from many years ago, this whole project was an adventure/gamble, for me.

Fast forward to post #31 and the motor was pretty much exactly as expected. It would move along, then skip, idle, pulse. I could put a slight bit of pressure on the crank and it would pick up again. But at least the electronics was working out so I looked for the largest motor I could find in a NEMA23 mount and came up with this one. There was higher torque, but my controller only went to 4 amps or so, and I figured at 2.5 x the one that was borderline, it would be adequate.



			https://www.amazon.ca/gp/product/B08BF6HLJ3/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&th=1
		


At 425 ozin, I thought it was quite a step up. As expected the mount was perfect, being a 23. I drilled out the coupling mount to accommodate the larger motor shaft size, rewired the new motor in, this time incorporating a connector instead of directly wired to the control box.

Seems to work well now. If you watch the video closely, you might pick up a slight hitch once per RPM. This is when the controller paints the display. I might rework the code to see if I can reduce the write time, but at a higher pulse rate, it should not affect the milling.

As to the feed vs RPM, my mill x lead screw is 0.100"/revolution. I just went with that. The display, due to the math, only shows even RPMs, but the feed rate is variable between. It would be an excuse to continue looking at the code to see how to display the speed with a higher resolution. In my shop, with this small mill, not necessary, but it would just be an exercise in learning. As is, it spins up to about 120 rpm, iirc. I played around with the pulses setting on the controller to find one that yielded an adequate top end, yet smooth "enough".  800 pulses/step seemed to be the magic one. The "top end" is really only used to position the table. I have never really paid much attention to feed rates before, despite reading them. I went by finish, chatter, etc. I don't think these small mills can do the feed rates/depth of cuts that engineering books suggest for the proper cut. ie, If my DOC was 0.120", as recommended yesterday for a cut,  I would either break the mill or the motor would just stop. Having said that, now that I have a convenient feed display and consistent feed rate, I will be able to explore those settings more.

I should clarify, the motor spec sheet is the old motor and the chuck is coupling that was being modified for the new motor. 

Thanks for the interest.


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## Degen (Apr 22, 2022)

Respectfully, Civil 101 years ago taught Torque (bending moments) if you didn't get it God didn't want to become an engineer.

If you have readings this high, you have some issues in slide binding, bad bearings or lead screw/nut issues.  Check this.

Secondly, steps vs servos big difference in ratings.  Steps peak holding, servos at duty cycle.

YouTube Clearpath SDSK vs Stepper big difference, eye opening by NYCNC


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## jcdammeyer (Apr 22, 2022)

What I was trying to say in my rather long winded explanation is that the torque curve is more important than the motor rated torque.  Try and find the torque curve for that particular model motor.  That will tell you how fast you should be able to run the motor before the torque falls off and you get skipping.  

ShawnR: I think you meant 800 pulses per revolution?

And yes, with the servo, the rated torque, which is way lower than a stepper motor of equivalent physical size, is the important value because that torque value stays the same throughout the entire RPM range which is generally 4x that of steppers before they are inadequate.

And AC brushless servos are better than DC brushed.  The DC one turned out to have a different coil resistance from the one on the X axis and tended to loose position in one direction.   At first we thought it was the encoder so that was changed.  Didn't make any difference.  Finally just gave up and changed to the smaller size but identical RPM+Torque rating AC servo.






With 3:1 reduction and max 3000 RPM on a 5 TPI (0.2" per rev) lead screw I get 180 ipm.  Which is scary fast.  And it's oh so quiet.  Rated torque is 1.27 nm x 3:1 = 3.81 nm (~540 oz-in) with a peak torque of 3.9nm x 3:1 = 11.7 nm (~1650 oz-in).  





So to match that with a stepper motor requires a motor that can do 540 oz-in of torque all the way up to 750 RPM.   That would be one huge stepper motor.  The catch though is cost.  Way more expensive with belts_pulleys+mount+servo.


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## ShawnR (Apr 22, 2022)

Degen said:


> Respectfully, Civil 101 years ago taught Torque (bending moments) if you didn't get it God didn't want to become an engineer.
> 
> If you have readings this high, you have some issues in slide binding, bad bearings or lead screw/nut issues.  Check this.
> 
> ...



Maybe my data, as presented, is incorrect. It does not feel hard to move at all. And, since I took those measurements, I installed the DRO. When I did that, I disassembled the table and did some deburring, cleaning, etc on the ways, so perhaps that was all a contributing factor, back when I got my data. Or my gib screws are too tight. But using the small hand crank at the end of the table, it moves ok, I think. But I will look into your recommendations. 

Thanks


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## jcdammeyer (Apr 22, 2022)

ShawnR said:


> Maybe my data, as presented, is incorrect. It does not feel hard to move at all. And, since I took those measurements, I installed the DRO. When I did that, I disassembled the table and did some deburring, cleaning, etc on the ways, so perhaps that was all a contributing factor, back when I got my data. Or my gib screws are too tight. But using the small hand crank at the end of the table, it moves ok, I think. But I will look into your recommendations.
> 
> Thanks


See if you can find a torque curve for that motor.


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## ShawnR (Apr 22, 2022)

jcdammeyer said:


> See if you can find a torque curve for that moto


I found this one for that model, although not the same make. 
Attached  is the image of the curve with calculated oz in (from an on line converter)

The way I read it, since my top speed is about 120 rpm, it should be good. (unless I am still not getting something) 
Granted, I am running at 800 pulses/revolution, not 3200 and 24 vdc, not 36 so maybe the chart is irrelevant. It appears that down around 100 rpm, most motors are in the peak of their torque curve. And that is where I will be mostly




			https://www.exp-tech.de/media/pdf/ce/c1/30/23HS2430B-Datasheet5cb48ea253436.pdf


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## jcdammeyer (Apr 22, 2022)

Excellent!  BTW, like a DC motor, the higher the voltage the more likely you can reach higher speeds.  
It has to do with how a stepper motor works which is why the torque curves are that way.

The motor winding voltage for this motor is rather high at 4.8V.  The driver applies your 24V until the current reaches the max 3A per phase and then switches on/off (Chopping) holding the voltage at 4.8V and current at 3A.  

The next full step requires the voltage across the winding be reversed.  However, it's an inductor in a magnetic field so that takes time.  By applying a higher than 4.8V value across the windings it helps change the direction of the current faster and build the new magnetic field faster so the rotor can move faster.

The second reason for the higher voltage is that like a generator, the motor when turning also generates a reverse voltage.  Back EMF it's called.  A simple brushed DC motor produces the same back EMF as the applied voltage and that's why the motor turns one speed at 6V and a different speed at 12V.  The back EMF is the limiting factor.  In simple terms.

With the stepper it's the same issue.  Got to get current flowing in the windings in the opposite direction.  If you can't do that fast enough before the next direction change then you never get full current through the windings.  And since Torque is Amps x Turns if the Amps aren't high enough you don't get the torque.  And there's the reason the for the shape of a stepper motor torque curve.


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## jcdammeyer (Apr 22, 2022)

ShawnR said:


> Maybe my data, as presented, is incorrect. It does not feel hard to move at all. And, since I took those measurements, I installed the DRO. When I did that, I disassembled the table and did some deburring, cleaning, etc on the ways, so perhaps that was all a contributing factor, back when I got my data. Or my gib screws are too tight. But using the small hand crank at the end of the table, it moves ok, I think. But I will look into your recommendations.
> 
> Thanks


BTW if you are into reading C code here's my ELS Source code. I do the micro-stepping for the Z axis myself. Or if the internal stepper driver is disabled the step/dir pulses are on the parallel port output for X and Z.  

If you have issues with downloading with this link through the forum you can also go here to get it.


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