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Z-axis overshooting sometimes
I am having an intermittent issue with my Fineline machine. When I go to run a program it will start with the z all the way up to the safe Z height, and then drop to the piece. Randomly sometimes it will make a barking noise and just plunge all the way into the piece like it gained a bunch of steps and dropped through the leadnut. I have since learned to hold my hand on the Estop button and listen for that when starting a new program, but would like to fix it permanently. I tried lowering the safe Z height and lowering the velocity and acceleration of the axis, thinking it would be a decent bandaid, but it still happens starting 2.5" lower. It only seems to be an issue in the top half of the Z travel. Before I start tearing it apart to figure it out, could it be something else? Are the ACME leadnuts a wear item that needs regular replacement?
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Re: Z-axis overshooting sometimes
Sounds like it's binding. HAve you oiled the screw/nut?
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Re: Z-axis overshooting sometimes
Hmm, I can definitely say that I have never oiled it. I figured its some sort of plastic piece so it would need it. Its from here: https://www.finelineautomation.com/p...ly?taxon_id=39
Wouldn't binding make it lose steps, not gain them and plunge into the table? Or is the binding making it skip teeth and drop?
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Re: Z-axis overshooting sometimes
compare the rated voltage of the z motor with the actual supply voltage, perhaps.
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
Stewey
compare the rated voltage of the z motor with the actual supply voltage, perhaps.
It's not an issue with the motor for once on my machine! I upgraded to Clearpath servos and am utilizing the closed loop portion so the machine will shut off if the servo isn't behaving correctly.
Could the backlash nut be spinning in the housing? I guess that would actually make it appear to have missed steps, not gained them.
Hmm... Maybe the fast acceleration at the higher location is overcoming the spring tension. Would increasing the spring tension help overcome this?
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Re: Z-axis overshooting sometimes
If you have Clearpaths, then you can't be losing steps. The coupling may be slipping? Yes, you should definitely be lubricating the nut.
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
ger21
If you have Clearpaths, then you can't be losing steps. The coupling may be slipping? Yes, you should definitely be lubricating the nut.
Exactly my thoughts. Its almost as if I am gaining steps, not losing them though. Like the lead screw is falling through the nut at the top half of the Z travel. This happens only in the top half and in the down direction. When running actual code the Z is dead nuts accurate.
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Re: Z-axis overshooting sometimes
The nut still may be binding, causing the couplers to slip.
The motors should fault if they lose position, so you aren't gaining or losing steps at all. Must be a mechanical issue.
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
drxlcarfreak
I am having an intermittent issue with my Fineline machine. When I go to run a program it will start with the z all the way up to the safe Z height, and then drop to the piece. Randomly sometimes it will make a barking noise and just plunge all the way into the piece like it gained a bunch of steps and dropped through the leadnut. I have since learned to hold my hand on the Estop button and listen for that when starting a new program, but would like to fix it permanently. I tried lowering the safe Z height and lowering the velocity and acceleration of the axis, thinking it would be a decent bandaid, but it still happens starting 2.5" lower. It only seems to be an issue in the top half of the Z travel. Before I start tearing it apart to figure it out, could it be something else? Are the ACME leadnuts a wear item that needs regular replacement?
It could easily be lost steps, caused by binding or EMI noise problem that could cause lost position also, if it is not going to the command position in the program, can you cut and paste the G-code where this is happening, there could be something in your program also
Remove your Z axes motor and see if the Z axes move up / down freely, this will eliminate anything mechanical problem with the Z axes
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
drxlcarfreak
I am having an intermittent issue with my Fineline machine. When I go to run a program it will start with the z all the way up to the safe Z height, and then drop to the piece. Randomly sometimes it will make a barking noise and just plunge all the way into the piece like it gained a bunch of steps and dropped through the leadnut. I have since learned to hold my hand on the Estop button and listen for that when starting a new program, but would like to fix it permanently. I tried lowering the safe Z height and lowering the velocity and acceleration of the axis, thinking it would be a decent bandaid, but it still happens starting 2.5" lower. It only seems to be an issue in the top half of the Z travel. Before I start tearing it apart to figure it out, could it be something else? Are the ACME leadnuts a wear item that needs regular replacement?
I used to have a Fineline machine with the ACME screw and had exactly the same problem you are describing. The machine worked fine for quite some time. Then, suddenly the problem manifested. Had me scratching my head for awhile, but I finally tracked down the problem. On mine, the coupling part that clamps to the ACME screw was slipping. When I assembled the parts, I used a product called Vibra-tite as a thread locker. Big mistake. It is not designed for such small clamping screws. I should have used blue Locktite. Anyway, the clamping screws loosened just enough to allow the screw to slip. Messed up a few pieces and made some bad cuts into the spoilboard before tracking down the problem. Dollars to donuts, you have loose clamping screws. I suggest looking there first. While you are at it, you should also check the clamping screws on the upper coupler.
Note: Even if you used blue Locktite, it may be that you didn't get the screws tightened down enough. They are so darned small, that there is a real risk of stripping out the hex. In fact, when I retightened the screws, I managed to strip the hex on one of the screws. I was never able to get it back loose. I no longer have the Fineline (I built a better machine), but when I took the Fineline apart, I wasn't able to get the coupler off the screw. I could have cut the screw with a dremel, but didn't bother. I wasn't going to reuse it anyway. I mention it as a caution. My advice: GET NEW SCREWS.
Gary
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Re: Z-axis overshooting sometimes
I actually sprayed the acme screw with silicone last night and it seems to have fixed the issue, now when I power the machine off there is so little friction the z axis noticeably sinks into the table, so I may wipe some off.
Hmm, I will take a look at those bolts as well to see if I can crank them back down. Hopefully I don't strip them out!
Thanks guys!
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Re: Z-axis overshooting sometimes
I still think the coupler is loose, and the lack of lubricant caused it to be noticeable. Adding lubricant lowered the torque requirement, so it's no longer slipping. But, it's still loose.
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Re: Z-axis overshooting sometimes
Coupling slippage is a huge issue with the lower cost clamp types. However you wouldn’t hear the slippage thus there was or could still be lubrication or binding issues. In any event considering previous posts I suspect that your whole machine could use a bit of maintenance.
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Re: Z-axis overshooting sometimes
Is this a Chinese machine? I ask because you often find that the Allen head screws they use inside China are rather soft. The hex hole burrs around and the tip of the bolt squashes. Strangle, the Allen head bolts I have bought from China/eBay have been good.
So ... try replacing the bolts with a better brand, and tighten them up.
By the by: I have a small Chinese lathe. It goes OK now that I have replaced just about every Allen head bolt in it! Especially in the QCTP!
Cheers
Roger
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Re: Z-axis overshooting sometimes
I took the z axis off tonight to check it out, there were a couple loose nuts there. I tightened it all back up and it seems to be working like a champ now. I think the threads are slightly stripped on one of the couplers, I may at one point do a through bolt drill through both the coupler and acme screw just so that I know it'll never slip on me.
Regarding maintenance, what all maintenance needs to be done other than cleaning off and oiling the cold rolled steel and the acme threads?
It is a fineline automation machine,
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Re: Z-axis overshooting sometimes
I thought I had the issue sorted out, and went to try again today and the bit dove right into my piece. I took the Z-axis apart to install a new anti-backlash nut, and noticed when tightening down all the bolts that one of the acme coupler screws was broken. Not sure how I missed that before, but instead of messing with a screw, I tig welded the acme thread right to the coupler, there is no way that they will slip now. Honestly, I really doubt that it was slipping before because I tried spinning the other end of the amce rod with pliers hard enough to torque it a bit and mar up the threads and it wasnt budging.
I tried started a gcode (the same one that gave me trouble this morning) about 10 times and the Z seems to have stuck for me. On one run though, it looks like I lost/gained about 1/16" in the X&Y axes as I never touched their offsets when repeating the code over and over. I double checked the tension on the R&P drives, its nice and tight. At this point I think I may be having a computer issue. Is that possible? I am running the newest software 1.2111 with your 2017 screenset Ger, because I was having an EMI issue with my VFD so I run 2ms debounce ignore so the spindle doesn't trip the limits.
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Re: Z-axis overshooting sometimes
2 mS is awfully long. With that sort of filtering you could even miss encoder pulses.
How about setting the speed and acceleration to painfully low values (5%) and rerunning the test programs? If the system is then OK, your filter length may be a problem.
Cheers
Roger
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Re: Z-axis overshooting sometimes
The encoders go directly to the drivers, so wouldn't be affected.
As I mentioned before, you shouldn't be able to lose position with servos, as the drives should be faulting.
Also, keep in mind that 1.2111 is a test version which may contain bugs. If you are having any issues, you should be trying the stable release.
And I don't think any computer issues would cause a loss of position.
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Re: Z-axis overshooting sometimes
Quote:
The encoders go directly to the drivers, so wouldn't be affected.
As I mentioned before, you shouldn't be able to lose position with servos, as the drives should be faulting.
Also, keep in mind that 1.2111 is a test version which may contain bugs. If you are having any issues, you should be trying the stable release.
And I don't think any computer issues would cause a loss of position.
That's true, and I don't see these motors losing position at all with their strength and the speeds I have dropped them to.
True as well, unforunately, I need a version with the debounce option otherwise my vfd is tripping the limit switches.
Quote:
2 mS is awfully long. With that sort of filtering you could even miss encoder pulses.
How about setting the speed and acceleration to painfully low values (5%) and rerunning the test programs? If the system is then OK, your filter length may be a problem.
Hmm, I guess that is a decently long time. Unfortunately the software doesn't allow for decimals and 1ms was still tripping occasionally.
UGH, all this is starting to sound like I need to just pony up and buy a new VFD instead of trying to limp this one along. Are there any decent 2.2kw VFDs out there for the money? My spindle still seems to be operating 100% fine.
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
drxlcarfreak
I was having an EMI issue with my VFD so I run 2ms debounce ignore so the spindle doesn't trip the limits.
Quote:
Originally Posted by
drxlcarfreak
T unforunately, I need a version with the debounce option otherwise my vfd is tripping the limit switches.
Unfortunately the software doesn't allow for decimals and 1ms was still tripping occasionally.
UGH, all this is starting to sound like I need to just pony up and buy a new VFD instead of trying to limp this one along. Are there any decent 2.2kw VFDs out there for the money? My spindle still seems to be operating 100% fine.
New information we didn't know before. As you've already identified, you have a noise problem.
1. Have you been using dust collection, and if so, do you have it grounded with a bare braided ground wire in the hoses. If you are using PVC anywhere in the system, the static buildup goes way up. I have typical 4" clear hoses and some PVC in my system. The amount of static buildup was incredible. If I got anywhere near the hose with the dust collector on, my hair stood on end. I had limit switches tripping from static within less than a minute of running time. Properly grounded (to earth ground) and the problem went away. I have a ground wire inside the PVC and wrapped abound the outside. Ditto for the hose running from the PVC to the Z axis.
2. Mactech suggested EMI filter on your incoming power line to the VFD to reduce noise. With the problem you are having, it makes sense to try it. The filters are pretty cheap. I admit that I don't have one, but I'm not having problems with too much noise.
3. What wire are you using from your VFD to the spindle? Is it grounded at both ends? Improper wire (it needs to have a braided shield) and improper grounding can/will cause noise issues. Igus makes some great cable for VFDs. I'm using IGUS CF6, which is flexible and well shielded.
4. Is the wiring to your limit switches shielded? If not, it probably should be.
I wouldn't be too quick to blame the VFD for your noise issues. I believe virtually all VFDs will put out noise. Some just put out more than others. If you are using an HY VFD (one of the more popular Chinese VFDs), you should be able to get the noise down to a usable level. Even if you buy one of the very best/most expensive VFDs, you could still have noise issues. The trick is to filter out/shield out/ground out the noise.
If you want a lower noise VFD, you might consider an Hitachi model. The WJ200 is popular and gets good r=eviews, although it costs a lot more than the Chinese models. In any event, if you don't take the precautions noted above, you many not solve your limit switch tripping problem.
Maybe mactech54 will stop by with some pearls of wisdom. He knows way more about VFDs than most of us.
I still think your over-travel issue sounds mechanical.
Gary
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1 Attachment(s)
Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
drxlcarfreak
That's true, and I don't see these motors losing position at all with their strength and the speeds I have dropped them to.
True as well, unforunately, I need a version with the debounce option otherwise my vfd is tripping the limit switches.
Hmm, I guess that is a decently long time. Unfortunately the software doesn't allow for decimals and 1ms was still tripping occasionally.
UGH, all this is starting to sound like I need to just pony up and buy a new VFD instead of trying to limp this one along. Are there any decent 2.2kw VFDs out there for the money? My spindle still seems to be operating 100% fine.
Another VFD is not going to change anything they all make EMI, if it is not wired correctly will play havoc with your whole system, a good test if you have everything wired correct is no debounce is needed, so need some photos of your wiring
Do you have a input power filter in front of the VFD Drive this can help a lot with the EMI here is one that I think is best suited for your VFD TDK Lambda RSEN 2030L this would be a starting point
Next is your cable from the VFD Drive to the Spindle 4 core Shielded or Double Shielded is required , and the shields correctly terminated at each end
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1 Attachment(s)
Re: Z-axis overshooting sometimes
Yes, sorry I forget that not everyone knows what I have been going through and forget to mention everything. The machine was running fine for about 2 years, then all of a sudden I got a weird issue where starting the spindle would occasionally trigger a limit, if I jiggled the spindle cable it would work. I just assumed that the wire for the spindle was too close to the Z axis inductance sensor. Then one day no matter what I did I couldn't get the spindle to turn on at all without triggering a limit. The only way to get the spindle to run without tripping a limit was to unplug everything from the control box minus the spindle, but then again when I did that, it was running in limit override mode because the servos were showing as tripped, so it may very well have still been tripping a limit. It was mentioned on the UCCNC forum that the cheaper chinese VFDs main capacitors dry out quickly and increase the noise. Updating the software to get the debounce parameter fixed it, but I think it possibly has introduced other issues.
1. I do have dust collection, but with my issues, I use it very rarely, but, I will try grounding it to see if that helps with anything.
2. I am looking for a decent EMI filter. For a 2.2kw spindle, will a 20amp filter do? Doing a quick calc at single phase 220v, the max it will pull is 10amps, plus losses in the VFD.
3. I am using shielded and either 18/4 or 16/4 wire. Inside the case is a different story. For some stupid reason I stripped all of the wires to make it easier to terminate the wires so there isnt any shielded cables inside the case. I do plan to get clamp on ferrite rings to try and reduce the EMI in there as well. The grounding I will have to check, but I believe that I wired the ground to the spindle. and the other ground to the case.
4. Looking at the webpage I got them from (https://www.automationdirect.com/adc..._cables/evc179) again, it doesn't look like it is shielded. Would ferrite rings on either end help out here?
I only blame the VFD because it seemed to be the root of my other issues forcing me to update the software to an alpha release. Another problem I can think of is I put everything in one case and the breakout boards and directly above the VFD. When wiring it up, I had read to keep everything away from the power supply because it has noise, but heard nothing about a VFD until after everything was wired in. Would moving it out, or maybe adding sheet steel/aluminum between the top of the VFD and the control boards help keep noise separated?
Attachment 427482
If you think it is mechanical, what other items could it be? Losing steps I totally get in every direction, but gaining steps doesn't make sense to me, at least mechanically wise. The Z sort of made sense since if the coupler is slipping the weight on the acme thread just allows it to keep going into the board when the motor stops. I don't think it was slipping because before I welded the coupler to the rod I had the motor holding steady and used vice grips to try and make the rod slip, I put a ton of force on it and the rod didn't budge. That said, I am totally willing to have my horizons broadened.
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7 Attachment(s)
Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
mactec54
Another VFD is not going to change anything they all make EMI, if it is not wired correctly will play havoc with your whole system, a good test if you have everything wired correct is no debounce is needed, so need some photos of your wiring
Do you have a input power filter in front of the VFD Drive this can help a lot with the EMI here is one that I think is best suited for your VFD TDK Lambda RSEN 2030L this would be a starting point
Next is your cable from the VFD Drive to the Spindle 4 core Shielded or Double Shielded is required , and the shields correctly terminated at each end
I was only saying a new VFD based on the assumption from another forum thread that this one is on its way out (https://www.forum.cncdrive.com/viewtopic.php?f=2&t=2092).
I have no input filter yet. I was planning on picking one of those up as well as some ferrite rings for the VFD output and the stepper motor outputs.
Sure, here are a bunch of pictures from when I upgraded to servos.
Attachment 427502
Attachment 427504
Attachment 427506
Attachment 427508
Attachment 427510
Attachment 427512
Attachment 427514
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
drxlcarfreak
Yes, sorry I forget that not everyone knows what I have been going through and forget to mention everything. The machine was running fine for about 2 years, then all of a sudden I got a weird issue where starting the spindle would occasionally trigger a limit, if I jiggled the spindle cable it would work. I just assumed that the wire for the spindle was too close to the Z axis inductance sensor. Then one day no matter what I did I couldn't get the spindle to turn on at all without triggering a limit. The only way to get the spindle to run without tripping a limit was to unplug everything from the control box minus the spindle, but then again when I did that, it was running in limit override mode because the servos were showing as tripped, so it may very well have still been tripping a limit. It was mentioned on the UCCNC forum that the cheaper chinese VFDs main capacitors dry out quickly and increase the noise. Updating the software to get the debounce parameter fixed it, but I think it possibly has introduced other issues.
1. I do have dust collection, but with my issues, I use it very rarely, but, I will try grounding it to see if that helps with anything.
2. I am looking for a decent EMI filter. For a 2.2kw spindle, will a 20amp filter do? Doing a quick calc at single phase 220v, the max it will pull is 10amps, plus losses in the VFD.
3. I am using shielded and either 18/4 or 16/4 wire. Inside the case is a different story. For some stupid reason I stripped all of the wires to make it easier to terminate the wires so there isnt any shielded cables inside the case. I do plan to get clamp on ferrite rings to try and reduce the EMI in there as well. The grounding I will have to check, but I believe that I wired the ground to the spindle. and the other ground to the case.
4. Looking at the webpage I got them from (
https://www.automationdirect.com/adc..._cables/evc179) again, it doesn't look like it is shielded. Would ferrite rings on either end help out here?
I only blame the VFD because it seemed to be the root of my other issues forcing me to update the software to an alpha release. Another problem I can think of is I put everything in one case and the breakout boards and directly above the VFD. When wiring it up, I had read to keep everything away from the power supply because it has noise, but heard nothing about a VFD until after everything was wired in. Would moving it out, or maybe adding sheet steel/aluminum between the top of the VFD and the control boards help keep noise separated?
Attachment 427482
If you think it is mechanical, what other items could it be? Losing steps I totally get in every direction, but gaining steps doesn't make sense to me, at least mechanically wise. The Z sort of made sense since if the coupler is slipping the weight on the acme thread just allows it to keep going into the board when the motor stops. I don't think it was slipping because before I welded the coupler to the rod I had the motor holding steady and used vice grips to try and make the rod slip, I put a ton of force on it and the rod didn't budge. That said, I am totally willing to have my horizons broadened.
Yes you have a problem, the VFD Drive cable must be shielded all the way to the VFD Drive and the shield clamped to the metal case which would have a Ground connected, Twisting the wires can also help with noise, by your photo you have a lot of problems
Yes you could put a Aluminum cage around the electronics, it really is a big problem the way it is, the power supply will be nosy as well, you may be able to move the electronics into another smaller cabinet on top
Ferrite rings are not going to help with your cabinet layout
Your VFD will be drawing Double the Amps that the spindle max is so you need a 30A EMI filter
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4 Attachment(s)
Re: Z-axis overshooting sometimes
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
drxlcarfreak
You should not take to much from what you read, they are all in the same boat as you are, they try different things instead of doing the build how it should be done from the start, what I can see by your photo's is wiring plugs Etc which are all problems for a system like this, a layout like this will always have a noise problems
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
mactec54
Yes you have a problem, the VFD Drive cable must be shielded all the way to the VFD Drive and the shield clamped to the metal case which would have a Ground connected, Twisting the wires can also help with noise, by your photo you have a lot of problems
Yes you could put a Aluminum cage around the electronics, it really is a big problem the way it is, the power supply will be nosy as well, you may be able to move the electronics into another smaller cabinet on top
Ferrite rings are not going to help with your cabinet layout
Your VFD will be drawing Double the Amps that the spindle max is so you need a 30A EMI filter
Ok, so:
1. No ferrite rings
2. 30A EMI filter
3. Redo the VFD cable with shielded cable inside the cabinet.
4. Faraday cage separating the top half from the bottom half of the electronics?
5. Twist signal wires
Honestly, looking at the wiring, I may not have the case grounded at all. I will need to look at that.
I'd like to get away with not having to rewire the entire case if possible. This sounds hokey, but if I wrapped the bundle of signal wires running from the board to the quick disconnects in aluminum foil and somehow grounded it to the case, would that mimic shielded cables?
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
mactec54
You should not take to much from what you read, they are all in the same boat as you are, they try different things instead of doing the build how it should be done from the start, what I can see by your photo's is wiring plugs Etc which are all problems for a system like this, a layout like this will always have a noise problems
What is a preferred layout? Are plugs not good to have? Are there other quick disconnect options?
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
mactec54
You should not take to much from what you read, they are all in the same boat as you are, they try different things instead of doing the build how it should be done from the start, what I can see by your photo's is wiring plugs Etc which are all problems for a system like this, a layout like this will always have a noise problems
I saw that you said that this cable was a requirement for a 2.2kw spindle in another thread: https://www.automationdirect.com/adc...ed/cf6-15-04-1
Should I replace my current cable with this and run it directly from the VFD right to the Spindle, no disconnect in between?
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2 Attachment(s)
Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
drxlcarfreak
I saw that you said that this cable was a requirement for a 2.2kw spindle in another thread:
https://www.automationdirect.com/adc...ed/cf6-15-04-1
Should I replace my current cable with this and run it directly from the VFD right to the Spindle, no disconnect in between?
Yes. And you cut off a small section of the outer cover inside the box, exposing the shielding. Using some sort of fixture, ground the shielding to the box's ground plane. Although not idea, you can take a copper plumbing mounting strap shaped like this:
https://www.cnczone.com/forums/attac...d=427524&stc=1
Then, flatten it out and reshape to look this this:
https://www.cnczone.com/forums/attac...d=427526&stc=1
Be sure that the circle fits the cable shielding, i.e., when the screw is tightened down on the ground plane, the circle closes tightly over the cable shielding.
As I indicated before, I'm a fan of Igus CF6 cable. That's what I'm using.
Gary
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
GME
[SIZE=4][FONT=times new roman]
Yes. And you cut off a small section of the outer cover inside the box, exposing the shielding. Using some sort of fixture, ground the shielding to the box's ground plane. Although not idea, you can take a copper plumbing mounting strap shaped like this:
Then, flatten it out and reshape to look this this:
Be sure that the circle fits the cable shielding, i.e., when the screw is tightened down on the ground plane, the circle closes tightly over the cable shielding.
As I indicated before, I'm a fan of Igus CF6 cable. That's what I'm using.
Gary
Fair enough I ordered the input power filter that Mactec recommended, I will buy 30' of that shielded cable that you recommended, abandon the plug and run the wire directly to the VFD. I also plan to wrap the low voltage signal wires in the case with EMI shielding tape and possibly, put in a faraday cage around the controller and breakout boards. Is there anything else I should look into doing before I put it back in service?
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8 Attachment(s)
Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
drxlcarfreak
What is a preferred layout? Are plugs not good to have? Are there other quick disconnect options?
Plugs are always a source of problems, direct wiring as it is done in CNC machines Etc is less work and less problems
Start with the filter and new cable, a shield would be very beneficial in your case as every thing is very compact
Some Ideas on how to Ground the Shields
Some VFD Drives already have built in Shield Ground clamps snips below
EMI Glands perform the best for through Cabinet mounting and Spindle mounting for Shield Grounding
So lots of snips for you to look at
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5 Attachment(s)
Re: Z-axis overshooting sometimes
Some more as there are many examples of how to do things better if you know what is and can be used
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4 Attachment(s)
Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
drxlcarfreak
I saw that you said that this cable was a requirement for a 2.2kw spindle in another thread:
https://www.automationdirect.com/adc...ed/cf6-15-04-1
Should I replace my current cable with this and run it directly from the VFD right to the Spindle, no disconnect in between?
Yes that is the cable to use from the VFD to the Spindle, make sure the Spindle Ground is attached in side the Spindle to the 4th pin of the plug the other alternative is to not use a Spindle plug and use a Gland for Shield clamping built in this is the best for EMI protection, you crimp all 4 wired joining them to the Shielded cable
Cable prep is also important that you only expose enough wire length to do your connection, make sure all wires and shield are cleanly trimmed
Twist all wires where ever you can Filter to the VFD Do not twist in the Ground wire only Power wires, a photo of Twisted wires
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Re: Z-axis overshooting sometimes
If I ever get that far where I'm using a VFD I'll be putting it in it's own separate case as far as poss from both the PC and controller case.
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
mactec54
Yes that is the cable to use from the VFD to the Spindle, make sure the Spindle Ground is attached in side the Spindle to the 4th pin of the plug the other alternative is to not use a Spindle plug and use a Gland for Shield clamping built in this is the best for EMI protection, you crimp all 4 wired joining them to the Shielded cable
Cable prep is also important that you only expose enough wire length to do your connection, make sure all wires and shield are cleanly trimmed
Twist all wires where ever you can Filter to the VFD Do not twist in the Ground wire only Power wires
Fair enough. I will have to look into my spindle to see if the connector will come out easily enough to do that. I also need to find a wire gland that is actually metal inside, and hopefully available on amazon prime so I can get it in the next couple days to get this thing back up and running again.
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
dazp1976
If I ever get that far where I'm using a VFD I'll be putting it in it's own separate case as far as poss from both the PC and controller case.
Good idea.... When I put mine in I didn't read about it anywhere and tried to mimic other cases that I had seen that apparently didn't have issues. I am actually beginning to wonder if my old nema23 steppers were not an issue and were powerful enough, but because of the added drives in the enclosure I was getting random EMI issues with lost steps...
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
dazp1976
If I ever get that far where I'm using a VFD I'll be putting it in it's own separate case as far as poss from both the PC and controller case.
It is not a problem if everything is wired correctly, a separate cabinet does not always solve an EMI problem, so using a separate cabinet in most cases it can create other problems
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
mactec54
It is not a problem if everything is wired correctly, a separate cabinet does not always solve an EMI problem, so using a separate cabinet in most cases it can create other problems
When you say wired correctly, what do you mean exactly? Shielded cables, no disconnects to the case but emi shields instead, all grounds go to one spot, keep shields on wires inside case especially low power signal cables. What else am I missing? Is there a picture of a perfectly wired control panel with a VFD out there to reference?
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Re: Z-axis overshooting sometimes
Quote:
Originally Posted by
drxlcarfreak
Good idea.... When I put mine in I didn't read about it anywhere and tried to mimic other cases that I had seen that apparently didn't have issues. I am actually beginning to wonder if my old nema23 steppers were not an issue and were powerful enough, but because of the added drives in the enclosure I was getting random EMI issues with lost steps...
Most likely where not the problem as many use steppers without problems, it all come's down to wiring in most cases, steppers also are noisy and need shielded cables and good Grounding practice for Shields and Ground wires
Simple Aluminum shields around noisy parts like stepper drives , VFD Drives low voltage Electronics can save the day, the Shield needs to be Grounded