Yes, check your wiring.
Might have been a rodent.
A kitten chewed mine.

Will do guys, Thanks. I havent been back at since last post, I'll let you know.

Ok, I finally got around to checking all my wiring and connections and all had 0.0 resistance. I then swapped out my bigger X motor to one of the problem motors and same issue. I then swapped cables around and the problem stays on the same two gecko drives (Z & A ( two Z slides)). I then swapped out transistors, which made no difference.

could it be software?

here is a link to a video of the issue.
https://youtu.be/EmDsn9ra1Mc

are you sure your wiring is correct as far as phasing on the motors

Have you checked your spring dampeners to make sure they are ok? Does the motor work ok off of the machine? Sounds like if this is on your Z axis only your lift cylinders may need replacing.

In the audio of that video, it sounds like the motors are actually spinning. I wouldn't expect to hear that accell - run - decell sound if the motor was unable to move. From that angle I can't see the motor shaft, but it sure seems like a loose pinion grub screw to me.

From the video it appears you can move in one direction and not the other. Is that correct?

I have heard whining and grinding before at work when either the motion in the one direction has reached the end of travel or the weight is too great to move, you can hear that sound. If you are moving down ok but not up then I would ask, does it move up ok if you assist by helping lift when it is trying to run? Mike already made mention of the spring pressure. Also if the spring was installed with the rod up it has a greater possibility of the seal drying and relieving assist pressure needed for the lift if your gear reduction and stepper is not sized for a dead lift (which it should not be).

Any more info, even the smallest detail that may not seem relevant will usually provide the data to resolve a complex problem. I also recommend writing down everything you have done and the finding. This helps with forming a picture to pin down the problem or other issues that may need to be address.

Last but not least, with the motor not engaged in a gear or pulley. Will the motor turn both directions with no problems? If you are using a gear reduction method, attach the motor to the gear reduction but not to the Z slide and test the movement. Does it move in both directions? If these two tests pass then it is something in your Z slide.

I hope that helps.

Hello Bilal,
Can you put somewhere an acceleration parameter in your machine software?
When I started up my machine I played with this parameter. If your acceration parameter is to high, your motor can't handle and wil stoll. put it significant lower (each time 10x lower) and looks how it works.

for setting the acceleration parameter a had the following approch. I put it lower and lower, and when you start a movement from a certain axis you axis will move. when you have an very low acceleration parameter your acces will still move a couple of milimeter. the I raised the acceleration parameter a little. I repeted this until I reached a value when I stop the movement from an axis, the axis is visualy stopping. Your machine will run smoot.
when your acceration value is to High and you stop an movement from an axis, it looks like it's stopped by an hammer. and you will feel the frame shaking.

also check if you turn the motor by hand (when power is shut of) the axis is moving, it can be that your bearings are put too tight and the slide has to much resistance.

One thing folks should keep in mind, just like on cars, over time and with use these dampeners wear out.

Hello all, thank you for all the replies.

Finally back at it again, I did check the motor phase wiring and its correct.
The dampers are still good.
Brad, at first the audio confuse me as well, I thought the same thing. But the motors still make the same noise whether they are moving or not, remember its digital signal, not just a blast of power. Signal accelerates and decelerates.
Pete, it was just easier on the motor going in that direction that's why it moved.
No gear reduction yet. The motors do rotate both ways when disengaged and I think I figured out what's going on with them.
They have been weakened for sitting for two years+, they became demagnetized.
The bigger pk299 are affected as well but not as much, they still move the X & Y fine. But I can actually stop both the pk296 & pk299 from spinning with one hand, glove on. I shouldnt be able to do that should I? Especially the pk299?

I did call OM and they said this is possible if they've been sitting for that long.

I also plugged in the pk299 into the Z axis (pk296) and it did seem weaker, but I'm assuming from the different transistor.

Accel parameters are not perfect but seem to be fine for testing purposes.

Another video of me holding motors.
https://youtu.be/d0hd5qaL9qs

Please let me,know what you guys think.:)

I may have missed it in the threads, but have you looked at your Geckos? Also check the resistance of the limit resistor on the Gecko. Also try switching Gecko's and then the PMDX 133's. If this issue is on two motors step back to the next point in line to test.

Hi Mike,
Geckos are all green, I will swap motors again along with their correct resistors to see if it has the same power from one gecko to another. and check those resistors.

Well, I made some assumptions at first.... regrettably.

I assumed that only the two Z axes were the problem because the other axes were fine, or seemed so.
All 5 steppers are weak, just not weak enough to skip steps on the X and Y axes. I can stop all 5 motors with one hand, each on their own gecko.
The gears should jump out of the pinion if it is a over weight issue, correct? it just doesn't seem right that I can hold the steppers from turning with one hand.

resistors on the pk299-4.5a are @ 240k(x & y), and the pk296-4.5a @ 82k (Z x2)

Do you have a degaussing coil?

http://www.cnczone.com/forums/genera...s-quickly.html

Post #9 was interesting about remagnetization.

But I have seen quite a few threads on demagnetization killing torque on these motors.

We may be on our way to a sticky thread in Motors Section.

Also may be time to consider switching to a cheaper type motor that matched the design of your electrics.

Import steppers have come down in price, so at this point I think one should order one to see if that is the fix considering all other elements seem to work fine.

Like capacitors, stuff does get "used up" over time. Of course in this case due to sitting.

Interesting Mike much appreciated. I don't have a degaussing coil, but might be cheaper to try an import stepper first to be 100% on whats happening.

Also adding gear reduction might fix my problem as well, which is next on the list.

any particular brand of stepper you would recommend? KL34H280-45-8A? in place of a pk296-f4.5a

What voltage are you running at the motors?

Using the AN-10440, I have 57vdc out from the caps.
I still havent refamiliarized myself with the electrical requirements.

ok, just finished going over voltage requirements. looks like I'm a bit over the recommended 20%, should i be concerned? although it will match the KL34H280-45-8A @2.2mH inductance much better.

I ordered 2 of them tonight. will post what happens when i get them installed.

Ok, I failed again.
Impatience and assumptions + MM = fail.
I'm assuming once again that these motors should tear the meat off my hand if I attempt to hold them.....
There definetly was a difference in the Kelling being 200+ oz. More powerful, but still didn't do the job.
Dampers seem fine. If I go with a heavier or lighter capability I will probably end up in same scenario but in opposite directions.
So I'm hoping gear reduction should be able to handle it.

So are you saying you got your motors and still have an issue?

also remember that 200 in-oz is 200 ounces at 1 inch at maximum torque or 12.5 lb at 1 foot.

I use a 880 oz-in motor for my z. I use a ball screw for mine and it is overkill but I already had it. Still even with that I have a extension spring to equalize the weight of the Z so it will not free fall. Re-familiarize yourself with the properties of a stepper motor. It sounds like it is a weight issue to me. That is why I asked if you helped assist the motor if it would rise. You are using the same computer/program/settings right?

If you swapped the motor to your X or B axes (assuming they are the same motors) and they move that axis fine I would lean toward a weight issue. If you can't swap it with one of those then use the Y.

Yes Mike, same issue although not really an issue, I'm just expecting too much out of the motors.
Pete, first thing I should of done is refamiliarized, but my time is limited and I got impatient.
It would rise if I assisted it, but seemed way too weak of a motor, again just expecting much more, which is my fault.
I'm going to try other then McMaster Carr for a damper in closer range..
Pete, other then that, I'm gonna work on some reduction boxes using your files, just try and make them look sexier.;)

Just so I understand. These motors move X & Y just fine?

Yes Mike, the pk299 move the x & y fine, but fairly close to skipping steps( very heavy gantry tubes + y-car stuff). Pk299 wasn't tough enough for the Z's either, that's why I thought I had motor issues. And the Z,s didn't seem too tough to pull back up/ push down... Again just complete ignorance on my part about the motors.

Hello all,

I've got the spindle spinning from mach3 through a PMDX-107, but cant change RPM through mach3. I used warpd9 smooth stepper settings for mach and set main parameters in VFD, setting PD013 first, then 5,4,3,6-12 & 140-145.
I think that it is a parameter that is set incorrectly, but not sure.
I'm using the Haunyang HY04d023b w/ 4kw spindle.
PD005 - 400
PD004 - 400
PD003 - 400
PD006 - 2.5
PD007 - 20
PD008 - 220
PD009 - 15
pd010 - 8
Pd011 - 120
PD014 - 12
PD015 - 12
PD141 - 220
PD142 - 10
PD143 - 3
PD144 - 3000
PD070 - 0

I also customized Pete's Z-axis plates, just put a couple curves in them. I was hoping someone could quote me on cutting them out. local quotes seem too high, but then again I'm not sure what a decent price is for something like this.:confused:

I use a Hitachi drive so I would not be much help with confirming the settings but modbus can be tricky to set up in mach, I did have pics in my thread with the setup I used that could be for reference, also search cnczone for info

The more complex the part, the more it costs to make. A part that can be made manually that is quick and easy to make is less than one with complex curves. Changing the rounded rectangle to 1.5" radius or boxing it to use only a 0.500" endmill reduces cost to make as well. Most machine shops will work with you if you ask him what you can do to the part design to help lower the cost to get it within your budget.

Thanks Pete, it seems most people go the modbus route. is the only reason RPM accuracy?

I got the part quoted both ways, modified and unmodified and he wanted $30 more per.

anyone willing to cut it?

If I'm looking at the right online manuals, you need to set PD-163, PD-164, PD-165 to an address, baud rate, and type of modbus protocol you want to use. Also PD-002 for what source controls frequency - probably value 2.

I can't tell if this article is obsolete or not in terms of setting up the Mach3 side.

Thanks Brad, it doesn't look obsolete. same parameters as what my manual shows, but I'm not going modbus route. I believe those parameters are modbus only?

and can someone tell me what is a decent price to pay for those plates?

Thank you.

Whoops, I missed that. So you're trying to PWM to control the frequency, and you're wired from the PMDX-107 to that input? Do you have PD-002 set to 1 ?

Get quotes around your area and online with RFQs, they will vary much, figure cost of material plus standard cut rate plus tolerance fee. The lowest I have heard of is $50/hr but most will be a lot higher than that.

Brad, correct and PD-002 is set to 1

does $225 per plate sound fair?

If the tolerance is +- 0.005, that is inline with most quotes I receive at work. But like I said, don't be afraid to shop around.

Thanks Pete, most guys around here (Toledo) wont bother with the one off part.

next question might be silliest on the forum but...
When I'm standing in the "front" or "Material feed" end of the table, my spindle home is at the back right corner and when I bring my X forward, the DRO will read in the negative. So once i got my soft limits set, it wouldn't allow the X to budge from its home position. Y axis is fine as it goes into a positive reading from home.
So how do I flip the + and - readings on the X? I'm hoping software only solution...

Change the wiring on the driver to the motor for x and b to reverse the direction it travels