As you guys probably know I keep preaching the mantra that bigger stepper motors do not always equal better stepper motors. I use and recommend 166 oz-in motors for Taigs and some folks always insist that you have to use 270 to 387 oz-in motors or a Taig just won't work properly.

I was doing some feed-rate testing tonight and though I would see how fast I could get my Taig going. I am using the 166 oz-in motors I sell, with a G540 and a MeanWell 48V power supply, and a SmoothStepper. Generally I have the motors tuned to a max velocity of 40 IPM as nothing I do requires any faster rapids than that.

I first tried 100 IPM and the mill worked fine. I upped the X axis to 150 IPM, then 200 IPM, then 250 IPM, finally at 300 IPM it quit! 250 IPM is kind of scary as there is a lot of vibration from the lead screw.

The moral of the story is that choosing components that are well matched will always work better than just slapping on the largest motor you can. I made a short crappy video with my cell phone, I'll shoot a better one at a later date: http://soigeneris.com/Documents/Taig_250IPM.3gp .

Jeff-Birt,

Are you sure it is running at 300 ipm?

I don't think that is possible, the stepper would need to be turning 6000 rpm.

JoeyB

I think he's saying that he tried 300, but it didn't work. 250 was the fastest it would go.

250 seems extremely fast to me too, but what do I know?

It 'will' do 250 IPM but the imbalance of the lead-screw causes a lot of vibration. 100 IPM seems very comfortable. These speeds would not be possible with a larger (270 oz-in) motor as the inductance is too much higher to get the stepper moving that fast (given that you hold all other things constant; driver, power supply, etc.)

So I will loudly proclaim that "bigger motors != better motors". You MUST size the motor to fit your machine.

It 'will' do 250 IPM but the imbalance of the lead-screw causes a lot of vibration. 100 IPM seems very comfortable. These speeds would not be possible with a larger (270 oz-in) motor as the inductance is too much higher to get the stepper moving that fast (given that you hold all other things constant; driver, power supply, etc.)

So I will loudly proclaim that "bigger motors != better motors". You MUST size the motor to fit your machine.

I'm still new to all this, but from what I can tell, anything greater than 50 IPM just isn't very important to most folks. What I'm interested in, more than achieving ultimate rapids, is the ability to hog out metal at lower speeds without losing steps. That would include cutting various thicknesses of steel plate in circles and arcs, and vigorous Z-axis movements through the metal as well. Unfortunately, there's no standardized test for comparing different motors this way. The hardness of the metal, type of cutter, motor RPM etc. all come into play. Empirical (statistical) data from multiple users seems the only way to really get a handle on this for a newcomer like myself.

but from what I can tell, anything greater than 50 IPM just isn't very important to most folks.

That has been my point all along. Just because my mill will do 100 IPM does not mean that I will run it there; just like my truck will do 100 MPH but I don't drive it at that speed.

The motors/drive/power supply need to be matched to the machine. All I'm proving with the crazy speed is showing that the 'small' motors are a better choice for a Taig. Acceleration takes torque, so being able to accelerate to crazy speeds shows that the combination I am proposing has more than adequate torque and speed for the true operation range of the machine. A larger motor simply won't perform as well.

Based on Joeys comment, then that means you're spinning the stepper reliably at 5000rpm?

That has been my point all along. Just because my mill will do 100 IPM does not mean that I will run it there; just like my truck will do 100 MPH but I don't drive it at that speed.

The motors/drive/power supply need to be matched to the machine. All I'm proving with the crazy speed is showing that the 'small' motors are a better choice for a Taig. Acceleration takes torque, so being able to accelerate to crazy speeds shows that the combination I am proposing has more than adequate torque and speed for the true operation range of the machine. A larger motor simply won't perform as well.

All you are proving is that SMOOTHSTEPPER (http://www.youtube.com/results?search_query=SmoothStepper)is wicked awesome.
If the point is that people don't need faster than 50 ipm and you can get that with just the motors at 25kHz,
why in the world would you spend an extra $155 for something that you never use?
An extra parallel port card is cheaper.
People tell you that they get better performance with slightly larger motors (jalessi) but they are dismissed
because they spent $30 more for speed they don't need in your opinion.
Sounds a bit more logical than $155.
Hoss

All the smoothstepper does is generate pulses. If the PC could generate pulses as fast then the LPT would work just as well. You can continue to doubt but I've shown I'm correct with both the theory and by empirical evidence.

If a car engine could generate it's own nitrous oxide then you wouldn't have to add a bottle either.:rolleyes:
It doesn't happen in the real world.
Ignore whatever jalessi or anyone else tells you that they do in the real world
and believe what you want to believe in your world.
Hopefully the newbies can sift thru the detritus.
Have a good holiday, Hoss

Real world empirical evidence would be rapid speeds, material hog, and at the end come back to home 0,0 showing no lost steps. If it can't machine or accelerate without losing steps, what good is speed? If it does do all of the above, then you've made a great point.

Hoss2006,

Dinoflagellate's eat detritus for dinner, some may even believe it is a delicacy.

Have a most awesome Fourth of July.

Jeff...

Makes me wonder if the vibration described was in fact the stepper motor losing steps.

The smaller motor can do the job, but there's no proof the bigger can't, nor that there aren't some things the bigger motor does better.

Personally, I like my mill to be able to move over 100 IPM, but then it has quite a bit more travels than the Taig.

Cheers,

BW

Folks the whole point is that the motors, drive, power supply etc needs to fit the machine. On the TAIG larger motors than the range I'm talking about offer no additional benefits. They only cost more and use more power and would most likely harm performance.

The noise was most definitely the lead screw. It is not supported on both ends so it can whip around. At 100 IPM I did several repeated sweeps across X and indicated at zero and was dead on. The 250 IPM speed is way out on the edge and I am certain that it will loose steps at that speed.

For larger mills larger motors and faster speeds may be what is called for. That is exactly the point I have been trying to make. Some folks are under the impression that on a TAIG you need to put a 270~370 oz-in motor for the machine to work properly. That is clearly not the case. Then the argument was "well it will be too slow", so I decide to see how fast it will go and when I prove emperically that it is is certainly 'fast enough' the response is 'well that is just the SmoothStepper".

I hooked a a LPT cable and set Mach to a 60 kHz kernel as that is as fast as my shop PC will go. I could run 90 IPM just as well on the LPT as I could the SmoothStepper.

I took some new video of the mill doing 90 IPM with the SS and LPT and a better one of the @%) IPM. I'll get them on you tube tonight and add links here.

Here is a better video of 250 IPM: YouTube - 250 IPM SS

Here is 90 IPM on the SS: YouTube - 90 IPM SS

Here is 90 IPM on the LPT: YouTube - 90 IPM LPT Machine

The 250 IPM speed is way out on the edge and I am certain that it will loose steps at that speed.


If even you are certain it will lose steps at this speed, then please don't claim it will "do" that speed. For a speed to have any use, it had better not lose steps otherwise what is the point? No operation, including rapids between feed moves is any good if it loses steps.
Just because one motor "will" do something, it also does not disprove the fact that another motor can do the same thing.

I feel like I'm in an episode of 'Who's on first?" I am not claiming that 250 IPM is advisable or reliable or anything of the sort. As I stated in the very first post, I wanted to see how fast it would go. I have to admit being a bit amused at all the flack I'm getting by simply trying to present some factual information about motor sizing. If you are happy with your motor choice than I am happy for you.

If anyone is interested in learning the facts about motor sizing get yourself a copy of this book: http://www.copperhillmedia.com/ServoSizingBook.html.

All I can say is I have ~280 oz·in motors (Keling KL23H276-30-8B) and there have been a few times my machine has inexplicably lost steps. I have to guess that less powerful motors would lose steps more often.

My motors wired in bipolar parallel have a lower inductance than the inductance listed on the spec sheet for those 166 oz·in motors (but I don't know how those motors are suppose to be wired). My rotor inertia is 480 g·cm² compared to the 166 oz·in motors that are 271 g·cm².

The max speed I can get my Taig to move (reliably, and with my ways and nuts properly adjusted) is around 75 IPM. I limit the machine to around 60 though as I figure that's fast enough.

I think I'm going to pick up a SmoothStepper. If it doesn't give me anything else it'll let me use USB which I prefer over parallel anyways.

All I can say is I have ~280 oz·in motors (Keling KL23H276-30-8B) and there have been a few times my machine has inexplicably lost steps.

What driver are you using?

All I can say is I have ~280 oz·in motors (Keling KL23H276-30-8B) and there have been a few times my machine has inexplicably lost steps. I have to guess that less powerful motors would lose steps more often.

Lost steps can be from a variety of reasons:

1) A running process can interfere with Machs generation of the pulse stream.
2) Noise in the system from spindle motor, wiring issues etc
3) Running a machining operation that is right on the edge.
4) Using backlash comp in Mach.
5) Improper motor tuning.
6) Power supply not keeping up / driver issues.

I would probably suspect noise or PC issues as I think you probably have a good handle on feeds/speeds. With the Taig I recommend using a line filter mounted up by the spindle motor to eliminate it as a problem. Motors are noisy and it will cause problems. I just added some good line filter to my site that work well on the Taig spindle.

What driver are you using?
Sorry, I have a bad habit of editing my posts 20 times, one of those times I had put the driver, but I must have edited that part out.

I'm using Gecko G203v drivers with a Keling 48 volt 12.5 (IIRC) amp PSU.

Lost steps can be from a variety of reasons
...
Yeah, it could have been a few of those things, most likely 3 (which I took to mean: "right on the edge of being too much for the motors to handle). When I was more of a beginner I would try to push the machine too hard. But, the last part I made (which was also used the most operations of any part I've made) didn't have any issues.

I have my suspicions about noise in my wiring too. If I keep using the AC spindle I'll have to look into getting a filter.

now I'm not familiar with the taigs and at the same time I'm not sure I understand how those small motors can be reliable on a mill ? like you I have 166 oz motors that I sell too and they work great for small diy routers and such but they are absolutely worthless for my x2 mini mill , Ive tried them on the x and y and I will not use them because there is very little torque to handle any worth while cutting . In order to get any decent movement I had to go light on the overall tightness of the machine which leaves too much play and is a massive sacrifice on rigidity . Ive come to the conclusion that I will not put anything less than 201 geckos and some high torque motors (700 oz min) before I can consider it reliable enough for my liking . Now the comparison of a truck running at 100 mph but not being used may be half correct , a Jetta will probably run even faster but it will never pull a 5th wheel trailer . also in my opinion the faster the rapids (reliably) the better , rapid moves are just that , rapid in rapid out and over , less time air cutting is best , so don't buy the fact that it wont get used . Ive experimented with a number of motors when i built my router table , the high torque motors have won in power and speed hands down , when my new power supply arrives next week I will have rapid movements above 2000ipm and i don't want to be in its way

So you've got my sincere curiosity , is there some that I'm missing here :) ?

So you've got my sincere curiosity , is there some that I'm missing here :) ?

I think what you might be missing missing is gear reduction. taig has 20tpi screws. I don't know about a converted x2 but IIRC its 5tpi or so I've seen mentioned. A motor on a taig has to spin 4x as fast for the same ipm. A 700oz motor has high inductance and so can't deliver torque spinning as fast as a taig demands enough to move a taig at more than a few ipm without missing steps. its good for low, slow grunt. A 166oz motor just can't deliver the torque at low rpm on an x2 to get it to move more than a few ipm without missing as well, it is good at keeping small steady torque at very high rpms which then gets a leverage effect from the higher screw pitch.
Fast motor for slow screws and slow motor for fast screws is the recipe for success. Given 5tpi and 20tpi, and so four times the torque multiplier, a 166oz on a taig actually delivers pretty much exactly the same torque and ipm range as a 700oz on an x2. Essentially they are the same thing. They are both the right motors for each of those mills but wont work at all if you swapped them. The bigger is better idea is just stupid with drive motors, screws have got to be matched to the motor for the machine to work right.

I think what you might be missing missing is gear reduction. taig has 20tpi screws.

A 700oz motor has high inductance and so can't deliver torque spinning as fast as a taig demands enough to move a taig at more than a few ipm without missing steps. its good for low, slow grunt. A 166oz motor just can't deliver the torque at low rpm on an x2 to get it to move more than a few ipm without missing as well,



The bigger is better idea is just stupid with drive motors, screws have got to be matched to the motor for the machine to work right.


my lead screw is mm16 1.5 (16.09tpi) so no huge difference , i neglected to meantion that I also reduced the gearing 3 to 1 in a last ditch attempt with those motors , I also tried some 400 oz motors and had much more success and once they were geared down i still had greater success , these are the same motors that could perform half of what the 770 oz and 1350 oz motors that i have on my router table which dragged my son across the table at a few hundred ipm when i asked him if he could hold it back:D

i have to disagree with the bigger is STUPID idea !
because so far I have not found anything with all the different motors and screws that i have used to prove different , i have no doubt that if i put my 770oz motors on that mill it will haul , and i have no doubt if i wanted to I could easily snap an idle 1/2" carbide with a slow or fast travel ( anything less is worthless for me ) , a 166oz can't compare to the screws and coupler that Ive broke with the high torque motors

I'm used to working with real cnc's large and small so overall performance and reliability is important to me . speed is cool but for me it boils down to torque , if i want to cut on a mill then i want to take a decent cut , and when i was able to hold back the table with my hands then that said it all to me that it was a complete failure ,

I'm not dismissing what has been done and that is why its gained my curiosity but what will convince me is to see it take a decent size cut at a decent speed

Cameraguy,

Welcome to the CNCZone, I see you just joined today.

Your first post is quite a doozy, are you sure the bigger motor wont work on the Taig?

I would bet several dozen chocolate frosted doughnuts that the bigger motor would work very well on the Taig.

Have a great holiday,

JoeyB

My mill is a bit bigger than a taig. My screws are 10mm pitch. I found that the 270's I tried first with a Xylotex just weren't up to snuff. Then I installed 201's. Much better but still not doing what I needed.
I then installed 425 oz motors. Again better, but still not getting the holding torque I needed on these large helix ball screws.
Ultimately I went with 495's, 203V's and a 72 VDC PS. I get great rapid's and holding torque now, but wasn't good enough on my Z axis. I wound up gearing 2 to 1 on it to get the torque I needed.
Direct drive on X and Y.

I could have gotten away with the smaller motors if I was just cutting aluminums and plastics, but when you start cutting steels, you need the best holding torque you can get for the budget. My machine easily rapids 300 IPM, but I generally cut with it set at 180. It would only reach the 300 IPM on long travels anyway. I try to adjust the code so there are very few long rapids.

I consider my machine semi production, though now it runs even more that before. It is almost constantly running 8 hours a day 6 days a week.
Any lost steps means lots of lost time and materials.

IMO, usage as well as machine stats and budget determine the best or at least usable motors. Drives, PS, SS etc all add to the mix, but I find what works for one, may not ultimately do the same for another unless all the above are identical.
In my case, bigger was indeed better. Now is bigger than 495's better in my case? Sure it would be, otherwise I would not have needed a belt on the Z axis. Would smaller motors work? Not really. Not when cutting steels using a higher helix screw.

Just thought I'd correct something I said earlier...

I realized that I have actually got my Taig to rapid at 120 IPM, reliably, but after putting a fair amount of weight on the bed I dropped it to 65 IPM to keep it reliable. I figure if it's reliable at 65 IPM with 65# on the bed it's good enough for me.

If anyone's interested, look for my posts on this thread...
http://www.cnczone.com/forums/showthread.php?t=75417
There's a downloadable video on page 2. Sorry it's blurry at the beginning and end.

I'm glad to see that this has turned into a good honest discussion...

An larger mill, like an X3, is much heavier than a Taig. You have much more mass to push around so you need more powerful motors to do so (as the desired speeds.) I would not suspect that the motors I use on Taigs would be any good at all on a machine of that size. That has been my whole point, size the motors to fit the machine.

The motors, power supply, and drivers all have to work together. Keeping the power supply voltage the same and switching to a larger, higher inductance, say from a 166 oz-in double stack to a 276 oz-in triple stack, motor will only gain you a little more torque at low RPMs (which on a Taig or Sherline with 20 TPI screws does not help much), then the torque will drop off sharply and be about the same as the small motor. Using a higher drive voltage will allow you to take better advantage of the larger motor. Keep in mind that larger motor = larger power supply = larger drivers = more $$.

Hirudn, on a small machine like a Taig I think rapids in the 40~60 IPM range are all that is needed for the vast majority of folks. It is a small table and it is not a powerful or rigid enough machine to be doing high speed machining. I have been cutting parts out of 0.065", 6061 Al with a 1/16" carbide cutter at 10K RPM and 11 IPM the last couple days. That is about as fast as metal can be reasonably be done on the machine. Wax or something else could be done faster, working in steel would be slower as you will be limited by the available spindle HP and the rigidity of the machine.

Based on this discussion, I see I should buy motors with a rating between 166 oz-in and 700 oz-in. :D Seriously, should I just pick something in the middle, say the Keiling 387s, or is their inductance too high? It does fall outside the range Gecko recommends as optimal for the G540. Also, much of my work will be cutouts and pockets in 1/4" and 1/2" 6061 plate. Will a pump and recirculating coolant system be essential for this work?

Based on this discussion, I see I should buy motors with a rating between 166 oz-in and 700 oz-in. :D Seriously, should I just pick something in the middle, say the Keiling 387s, or is their inductance too high? It does fall outside the range Gecko recommends as optimal for the G540. Also, much of my work will be cutouts and pockets in 1/4" and 1/2" 6061 plate. Will a pump and recirculating coolant system be essential for this work?
What machine are you using?

I'm certainly far from being an expert, but if you've decided to use the G540 it seems to me that you'd want to max it out. The Keling 318 oz-in steppers (discussed in this thread (http://www.cnczone.com/forums/showthread.php?t=75417)) were apparently designed to get the most out of the G540, so in my opinion it stands to reason that these might be the best motors.

Based on this discussion, I see I should buy motors with a rating between 166 oz-in and 700 oz-in. :D Seriously, should I just pick something in the middle, say the Keiling 387s, or is their inductance too high? It does fall outside the range Gecko recommends as optimal for the G540. Also, much of my work will be cutouts and pockets in 1/4" and 1/2" 6061 plate. Will a pump and recirculating coolant system be essential for this work?

I run the 387's on a Gecko 540, as do a lot of folks here. They run fine to me, but then again I'm not running them at 250IPM, missing steps, or anything else foolish like that.
I can say that I cut reliably at 40IPM when contouring mold work, without missing any steps. This is not a TAIG machine, it's travels are similar, but it uses 5TPI screws and linear rails.

The motor needs to fit the machine. Trying to use the biggest motor the drive is rated for is a common mistake. Either the 166 oz-in or 276 oz-in (out of stock for another week or so) I sell work great on the Taig. The larger motors just don't offer much/any advantage. If you were going to do something crazy like put an X2 head on the Taig then the 276 oz-in range would be better as the little bit of extra low end torque will help getting the much heavier X2 head moving.

Keiling also has motors in this range as do other vendors.

What machine are you using?



I bought a Taig lathe last month, and I'm planning to order the CNC-ready mill within a few weeks.


I'm certainly far from being an expert, but if you've decided to use the G540 it seems to me that you'd want to max it out. The Keling 318 oz-in steppers (discussed in this thread (http://www.cnczone.com/forums/showthread.php?t=75417)) were apparently designed to get the most out of the G540, so in my opinion it stands to reason that these might be the best motors.


The recommendation from Hoss in that thread was "If I were building one I'd just use the $33 185 oz/in motors for the X and Y, they are 50v motors so the g540 would get everything out of them." That's what I was thinking about doing (with maybe a larger motor for Z), but then Jalessi said that the 185s (KL23H256-21-8B) run out of torque too fast. Jeff likes the 166 oz-inchers that he sells, but I don't have a torque curve to compare.

I realize there are probably a number of motors that will work well, and maybe no single model that's actually the "best" choice. I just don't want to buy the wrong one (or to spend money needlessly).

Here's the chart for the...
KL23H256-21-8B: http://www.kelinginc.net/KL23H256-21-8BT.pdf
Soigeneris 166 (STP-MTR-23055): http://soigeneris.com/Documents/surestepmotors.pdf

The ~31v curves (the only voltage the Keling pdf shows) look pretty similar to me.

So, how to choose between the two?
I just put in my first order with Jeff_Brit, so I can't comment on this order, but I've been pretty unhappy with a couple Keling orders* in the past (you gets what you pay for sometimes).

* nothing so bad that I wouldn't consider buying from them again. One time I ordered and paid for a servo, only to find out it wasn't in stock. Keling gave me an upgrade to a larger motor, but that motor had two different screws holding it together ("refurb" sold as "new"?). A power supply I bought from them had fingerprints all over it underneath the shrink wrap (again, maybe a "refurb" for "new" price?). Also, the shipment packing hasn't been the best I've ever seen.

I run the 387's on a Gecko 540, as do a lot of folks here. ... This is not a TAIG machine, it's travels are similar, but it uses 5TPI screws and linear rails.

Doesn't this imply that the Taig's 20 IPS screws should produce similar torque at the table with much smaller motors?

Doesn't this imply that the Taig's 20 IPS screws should produce similar torque at the table with much smaller motors?

Yes and no, there are plusses and minuses to the 20TPI screws on the TAIG. While it's true that there is a 4x difference in the "reduction" given by the screws, the linear guides and ball screws are significantly advantaged in the friction department.
In order to get the rapid speed with a 20TPI screw, you have to speed up the stepper, and therefore lose torque. Too much and you're losing steps. Couple this with ways and screws that can be adjusted to various levels of "tightness" (not so much with a ball screw/linear guide machine) and you might have a problem.
If it were me, and I were to have "upgraded" my original Sherline machine (instead of building a whole new linear guide system for the Sherline spindle) I would have used motors in the 280 range, and accepted the fact that it was not going to rapid that fast. I have more mass to move too, so I wouldn't recommend the 387's to you, but you asked if they were too much for the G540, which I was trying to report that they were not.

Just out of curiosity, I reset my Taig to 60 kHz and 300 IPM. It did it easily and could have done more but that's too fast for me. I reset it to the usual 80 IPM.

BUT, I have 5 TPI ball screws. 250 IPM with the stock 20 TPI screw is just plain scary.

More to the point of the thread, my Powermax II steppers are rated at 161 - 253. I assume the range reflects how much voltage you give it? I'm running about 52 volts so I suppose I'm near the top of the range. If it crashes, it has enough power to move the column and require re-tramming.

In my opinion, if you want more power than that, get a bigger mill.

Cheers,
Walt

Got my SmoothStepper Jeff_Brit. It looks like I wont get to hook it up til next week though.

Thanks

Wow, less than three days, that was quick! Just give me a shout if you have any questions.

Motor inductance does NOT necessarily go up with size. There are high inductance small motors and low inductance LARGE motors. The spec sheet describes that.

Not that it's likely to come up, but note that the G540 has a MINIMUM inductance requirement. That's needed to keep current smooth as the PWM pulses.

The parallel port will NEVER step as smoothly as the SmoothStepper, and that compromises torque capabilities since any "late" step edge will make an inconsistency in the speed, making a deceleration-then-acceleration demand on the motor torque.

People have said the Taig will wear out if run "too fast", but no one has attempted to justify what that is. I suspect leadnut/leadscrew wear is fixed per total linear inches traveled, until the motion results in heating of these parts (which might take a lot). I noted what you did though- if you run the Taig leadscrew too fast, it wobbles violently, increasing as the leadnut approaches either end, the worst being the motor end since it leaves the far end unsupported. The leadnut being at the far end leaves the middle unsupported too though, leading to "jumproping".

With a SmoothStepper controller, is it possible to help large files with maybe skipping steps or is that all computer related?


Why not just add one more nut on like bearings to keep the leadscrew from wobbling.


-Jason

Motor inductance does NOT necessarily go up with size.

Of course. I was trying to make the same point like this 'larger motor (higher inductance)". But looking back through the thread I can see that I forgot to make that distinction all the time. The main point I was trying to make though was choosing the motors/driver/power supply as a set to match your machine. Holding everything else constant and just swapping in different motors can give you drastically different results, i.e. a larger motor is not always a better motor.


With a SmoothStepper controller, is it possible to help large files with maybe skipping steps or is that all computer related?

The SmoothStepper produces a much smoother pulse train with no jitter w.r.t. the parallel port. Some computers will not drive a parallel port properly for our uses with Mach. The issues can range from old/slow computer HW to the chipsets used on the motherboard simply not allowing fast enough access to the parallel port registers. When you have problems with the parallel port driver your pulse stream can get a bit 'distorted' making it hard for the stepper driver to do its job. At higher speeds you can often hear a 'tick' type sound or even have really rough running motors if you have an parallel port issue.

I really, really like the Smoothstepper as it lets the PC do what it is great at: crunching numbers, accessing files, providing a nice UI. At the same time the SmoothStepper does what dedicated HW is really great at: providing a really smooth pulse stream with lots of I/O. You get the best of both worlds. If your missing steps due to a poorly performing parallel port it will help with that, if your loosing steps due to motor tuning or mechanical issues it can't help with that.


Why not just add one more nut on like bearings to keep the leadscrew from wobbling.

The problem is that the screw is only held in place at the stepper end and by the bronze nut. The tail end of the screw is in free space. For normal sane speeds on a Taig it is not an issue.

Well in theory you could add a bearing to the end and attach the pillow block to the Taig table, but the leadscew is threaded out to the end, there's no finished surface to add a bearing to.

And again you can only go so fast in *most* materials. Especially with a spindle limited to 10K rpm. I've not needed to go faster than 30 ipm in anything. Now rapid transit time when it's above the material is another matter, that doesn't have any tool-vs-material-based limits, but that usually isn't a lot of the total job time.