Machsupport Forum
Third party software and hardware support forums. => SmoothStepper USB => Topic started by: Hood on November 01, 2010, 08:23:37 PM
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I have 4 SmoothSteppers on machines and have not suffered from noise issues on three but the Beaver Mill would have problems in two distinct areas.
1. If the E-Stop button was pressed on my control panel then 90% of the time the SS would hang and I would need to restart Mach. My E-Stop not only sends a signal to Mach but also drops out all the contactors on my mill so things like AC power to the servo drives get cut.
2. If sitting for extended periods with Reset flashing the SS could hang.
I read with interest this thread and also the discussion on the Yahoo group http://www.machsupport.com/forum/index.php/topic,16186.10.html
I decided I would remove the capacitor and resistor that are on the SmoothStepper at the side of the USB socket, they are C4 and R5 and since removing them I have tried hard to make the SS hang by repeatedly pressing the E-Stop button and also have left Mach sitting for long periods with the rest flashing. I have not had a single hang and its now been 5 days of trying.
So it might be well worth users that have issues trying this. Its quite easy to remove the capacitir and resistor if you have two soldering irons, you just melt the solder at either side and then lift off with the irons. I actually just used one but had to go from side to side quite a few times easing the cap up slightly each time and after a while it came off. I also tried crushing the components with needle nosed pliers on a spare SS I had and this too was easy and worked well but I would recommend desoldering rather than crushing, I just did it that way as a test to see if it could be easily done. Greg has also mentioned another way, if your soldering iron can bridge the ends of the component you can drop a blob of solder on the top to bridge the component and this will then melt the solder pads and allow you to lift it off with tweezers.
So although my problem was not a serious one as it only ever happened at an E-Stop or whilst sitting doing nothing, I still want to thank David for his testing and findings as they have cured a minor niggle that I had.
Hood
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I put together a quick PDF a few days ago that details this modification. You can download it here: http://www.soigeneris.com/document/smoothstepper_board_modification.pdf .
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If you are dropping the contactors it maybe an idea to
place a varistor across the coil.This will contain the voltage spike
from the deenergizing coil.
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If you are dropping the contactors it maybe an idea to
place a varistor across the coil.This will contain the voltage spike
from the deenergizing coil.
They have snubbers ( or whatever they are called) already.
Hood
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Thanks Hood and Jeff for sharing your findings and solutions. Jeff's solution of cutting the trace is a fine one. Just beware that the ground plane is close to the surface (about 0.0073 inches below), and that if you cut into it there is a chance that you could short the outer trace to the ground plane and you won't accomplish anything. I don't want to make it sound like cutting the trace is risky, but I just want to point out something you might not be aware of. Like Jeff suggests, use an ohm meter to make sure the connection has been severed. To see if the shield was accidentally connected to the ground plane, ohm from the outer shell of the USB connector to the ground of the board. You can find ground on the external 5V connector or pin 5 of port 3 (green screw terminals). The distance from the ground plane to the power plane is huge, so there is no worry about shorting the ground plane to the power plane unless you really dig deep! The distance is about 0.039 inches.
For those of you that would prefer to desolder the components, I took a before and after shot of that area of the board:
Before:
(http://warp9td.com/files/SS_C4_R5_mod/SmoothStepper-C4-R5-Before.jpg)
After:
(http://warp9td.com/files/SS_C4_R5_mod/SmoothStepper-C4-R5-After.jpg)
Thanks,
Greg
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Hi,
To desolder the components R5 and C4, lay the tip of the soldering iron along side R4 (in between R4 and C5 is best). Most iron tips will be large enough to bridge both ends of the component. If not, alternate the tip back and forth between both ends in a rocking motion. If necessary you can also add some solder to help it reflow.
When you see that both ends are molten, wipe the component off the board with the iron.
Then do the same for C5. Note the capacitor will take a little longer, but the process is the same.
A lot of people think that you need a really fine tipped iron for SMT work. The problem with a really fine tip is that the heat gets sucked out of it too easily.
For most of my work I use a 1/8" chisel tip.
Cheers,
Peter.
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I have a new Smooth stepper that I received last week and the "offending" components have been omitted from the new ones.
Don
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Yes Greg said he was going to remove them on any he sent out and on the new batch they wouldnt be soldered on.
Hood
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When I first installed a SS I had hangups every time I started my VFD. I fixed this by making some alterations to my grounding system.
This involved bringing computer and VFD ground to a common point.
Out of curiosity I removed the before mentioned resistor and capacitor and reverted my grounding system to what it was when it used to hang.
I could not get it to fail. Seems this fix was enough to rectify my original issue.
Greg
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Is removing these two components effectively the same as removing the ground shield on the USB cable going into the SS as discussed originally on the Yahoo group?
Tom
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Yes, it has exactly the same effect.
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Well thank you very much.
I was having some very intermittent problems, nothing i could easily reproduce.
So i did this modification.
Now i get lots of problems, but its the same problem in that Mach locks up, the ST light change and the only way out is to cut power to the ST
There is no error message from the ST until i cut power.
Any Clues
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Sounds like you have noise problems. Often the culprit is the spindle motor or the wiring layout. Electric motor put out a lot of interference, especially when starting or stopping. A relay switching an inductive load, like a motor, will also produce a lot of interference. Try running your machine without the spindle motor running and see what happens.
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Jeff,
Is there a way to supress the noise of a 3ph 2HP induction motor? I know you sell some motor line supressors, but will those work on my motor or might there be something else?
Tom
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Sounds like you have noise problems. Often the culprit is the spindle motor or the wiring layout. Electric motor put out a lot of interference, especially when starting or stopping. A relay switching an inductive load, like a motor, will also produce a lot of interference. Try running your machine without the spindle motor running and see what happens.
Thanks Jeff, the point i was making doing the mod to reduce noise actually made things worse.
I looked at my code at the point of lock up and it is the motor and coolant turn off point M5 & M9
So what would i need to fix it, my wiring is very neat there are no power and signal wires running together.
Thanks
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There are three phase line filters as well, they will cost about $100 USD or so. How are you turning the motor on/off? Are you using a VFD on it?
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Phil
what size motor is it, or rather whats the max current?
I have a 3 phase line filter here that I could give you a loan of to see if it helps, would save you buying one to find out it doesnt.
Hood
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There are three phase line filters as well, they will cost about $100 USD or so. How are you turning the motor on/off? Are you using a VFD on it?
Yes, VFD, Hitachi SJ200 sized for my motor. I'm just trying to figure what might be causing Mach3 to eStop VERY randomly. I run a 60k line program and it runs for an hour and a half and suddenly it estops. No M5 or M9, nothing near where it estops, just a bunch of X/Y/Z moves. Last two times it did it it happened near the end of those 60k lines!!
Not trying to hijack the thread, was just wondering about these noise filters.
Hood, if you were asking me and not Phil (?), it's a 6.2 Amp motor, but I'm wondering if Jeff is pointing me at the fact that the VFD is doing this filtering already? Besides, shipping to the US from Scotland would seem prohibitive. Thanks for the offer. I'd just buy one if I need to.
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VFDs are even noisier than a regular induction motor. Wiring layout is VERY critical, you can even get 'VFD' cable to run from the VFD to the motor that is really well shielded. Go here: http://www.soigeneris.com/Documentation-content.aspx (http://www.soigeneris.com/Documentation-content.aspx) and look for the 'Installation Tips' in the SmoothStepper section. Also make sure you are NOT pulling the file from a USB drive, a network file, etc...
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Hood thanks for the offer.
Hood & Jeff i think the problem is only related to the Coolant pump 240v single phase its the original pump maybe 20+ years old.
It only seems to happen when turning off the coolant pump. The Spindle motor and VFD are new and not the usual cheapo stuff
I have no idea of the amp draw of the pump its not listed in manual and its too difficult to see without dragging the machine out
The pump is turned off by Mach3 using a 10amp relay
Hood if it may help my problem i would be willing to try it
Can i just put a cap across the motor if so what would i need
Thanks
Phil
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Can i just put a cap across the motor if so what would i need
Bad idea. You can cause a very dangerous situation by not using power rated caps when trying to filter an AC line.
There are two different things at play here. One is that when the relay switches it will create heaps of noise, the other is that the pump motor itself will create a lot of noise. If you are controlling the pump with a 10A relay I would guess it is a 1 HP or less pump so a line filter like I carry, and an arc snubber across the relay contacts would help a tremendous amount.
I was trying out a few different brands of arc snubbers a while ago, I may still have one laying around. If you want to try the line filter I'll throw in an arc snubber to get you fixed up.
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Can i just put a cap across the motor if so what would i need
Bad idea. You can cause a very dangerous situation by not using power rated caps when trying to filter an AC line.
There are two different things at play here. One is that when the relay switches it will create heaps of noise, the other is that the pump motor itself will create a lot of noise. If you are controlling the pump with a 10A relay I would guess it is a 1 HP or less pump so a line filter like I carry, and an arc snubber across the relay contacts would help a tremendous amount.
I was trying out a few different brands of arc snubbers a while ago, I may still have one laying around. If you want to try the line filter I'll throw in an arc snubber to get you fixed up.
Jeff thank you for the offer but i am in the UK the warmer part so i think send parts to me from the USA would cost too much.
I am quite willing to buy them but only if i know what to buy, if you Jeff or anyone else can point me in the right direction of what i need
I will clarify i am using a 10amp rated relay but doubt if i am drawing that amount of current
Phil
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VFDs are even noisier than a regular induction motor. Wiring layout is VERY critical, you can even get 'VFD' cable to run from the VFD to the motor that is really well shielded. Go here: http://www.soigeneris.com/Documentation-content.aspx (http://www.soigeneris.com/Documentation-content.aspx) and look for the 'Installation Tips' in the SmoothStepper section. Also make sure you are NOT pulling the file from a USB drive, a network file, etc...
Hmmm......I've printed and read your Installation Tips for SS and consider it the gospel.
Now, pulling from network. I DO have my G-code files on a Windows Home Server. I'll stop doing that and store them locally. I'd NEVER consider THAT and might should have as I've only had it do this lately doing lithopanes with a .040 ball endmill and 60,000 line files. Local only for me now, thanks a million for THAT tip!!
OH, and a tip on where to get this VFD specific wire?
Tom
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Do a search for VFD wire. I found this right off the bat: http://www.houwire.com/products/belden.asp
The not running files of a network or thumbdrive is a general Mach 3 tip, it is true no matter if you use the parallel port, a SmoothStepper or any other motion control device. Networks and tumbdrives can cause unexpected read delays for Mach which will throw it off.
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Phil
I was thinking it was your spindle motor, the filter I have is three phase, its meant for the AC servo drives I have, although likely it could be used single phase as well. I may have another filter that my Beaver mill came with, there was one on each motor and as I only have the original coolant and knee motors and have done away with the spindles induction motor I should have it kicking around in the store, will look it out tomorrow if I remember.
Hood
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Phil
just remembered I have a smaller line filter here, single phase 10Amp rated that I could loan you. Its one of these http://uk.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=246-3699
PM your address if you want to give it a try.
Hood
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Interesting... I haven't been here for a while since my router hasn't been getting a lot of use and I thought I'd mostly solved my noise/smoothstepper lockup issues but I had a job fail twice after a couple of minutes of cutting on Monday (which is odd since it was running fine the previous day). My router has a chinese vfd controlled, water cooled spindle which is quite noisy and it wouldn't run for more than 30 seconds before the smoothstepper would freeze with a "normal" usb cable.
Anyhoo - my original setup isolated the smoothstepper board with a shielded 5 meter usb extension cable (which actually has a 1port usb hub in the end). This was coiled up in the enclosure the smoothstepper was in and seemed to be 90% reliable.
After reading this thread I decided to try cutting the shield from the smoothstepper end of a 1m USB cable to see if it would "work" and, so far, it seems to be stable. I'll kick off a couple of real jobs tomorrow and see if it stays going...
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Hi Guys ,
When you say hang ups do you mean the SS rand out of data warning message>?
As I am getting this sometimes when my spindle shuts down for a tool change ( or I move around in the graphic screen when running ) and I end up loosing my position and having to unplug/re-plug the SS usb as well and re-starting mach 3?
Would removing the c4 and R5 Possibly help this issue?
Cheers
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As I am getting this sometimes when my spindle shuts down for a tool change
This is a sign you need an arc snubber across your relay contacts. When switching inductive loads relay contacts will arc which produces quite a lot of RFI and can drive many things crazy. Also, using a line filter on the spindle motor is a good idea (mounted as close to the motor as possible), it will help prevent the electrical noise generated by the motor from making its way back down the power cord into your controls.
or I move around in the graphic screen when running
This is a different problem and stems from Mach being single threaded. Mach can have this same issue with the parallel port too. It all depends on your file size, graphics card, and CPU speed.
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Thanks jeff, not to sure what an arc snubber is or how to fit one but I will have a hunt around for more info , would you recommend taking off the capacitor and resistor on the SS board also?
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Not out of the woods yet.
Dell Vostro, newish, USB keyboard and mouse - never any problems with those.
All excess SW stripped off machine, no network, etc etc.
RC combo removed from SmoothStepper.
Latest driver V2.08.02 installed and checked.
Still getting 'The smoothstepper has not communicated for a while' error message and Mach hanging.
Help ...
Cheers
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Not sure if it will help or not but some people reported that unchecking the power option in your USB hub helped, see pic.
Hood
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You also have to check the other things in your power profile, screen saver, HD shutdown, etc. On Win7 there is an advanced option in the Power Profile to disable the USB Selective Suspend, that is the place to change it rather than on each root hub (the way you do it in XP).
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Hi Hood and Jeff
You also have to check the other things in your power profile, screen saver, HD shutdown, etc. On Win7 there is an advanced option in the Power Profile to disable the USB Selective Suspend, that is the place to change it rather than on each root hub (the way you do it in XP).
I will check, but I doubt that is the problem. My reasons include:
I was reading a plain text file when it hung, so the system was quite active.
The load due to Mach is under 5% of capacity, so no problems there.
The USB port was very active of course, so I doubt that the system would have tried to power it down.
The hang was identical to previous failures: Mach was in the same infinite loop as before.
I recovered the system by unpluggging the USB cable.
No hub anyhow, and WinXP SP4, but no matter.
I would be fairly sure it's a software problem caused by noise and not handled by the driver and Mach.
I will try a big earth link between the SS and the PC chassis, run parallel to the USB cable. Should not be needed as everything is earthed (tight wiring requirements in Oz), and that does raise the possibility of an earth loop, but it's worth trying.
Cheers
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The USB port was very active of course, so I doubt that the system would have tried to power it down.
The USB device can be put into Selective Suspend if there is a 1ms lull in USB traffic from the device. (It might be 3ms I don't recall exactly, but it just a handful of ms.) I have done a lot of research on this and found cases where it would happen to some people with their mouse (what a PITA that would be.)
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Hi Jeff
The USB device can be put into Selective Suspend if there is a 1ms lull in USB traffic from the device. (It might be 3ms I don't recall exactly, but it just a handful of ms.) I have done a lot of research on this and found cases where it would happen to some people with their mouse (what a PITA that would be.)
Erk! Where does one find that? Win XP SP4
I have been through all the USB hub settings for the computer and set them all to 'no powerdown', but didn't see any mention of Selective Suspend'.
I have also just upgraded Mach from V3.042.040 to the latest version.
I haven't installed an extra earth strap yet as everything IS fully earthed fairly well ... and it would mean drilling a largish hole in the solid steel cabinet for the earth wire and the USB cable, and ... I'm am lazy ... but it may still happen.
Cheers
Roger
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I would like to say a big thank you to all who have contributed to the solution of this frustrating issue.
I was on the point of ditching my SS as it was more trouble than it was worth, but it is now working a box of fluffy ones.
The SS would error simple by turning on the Dust collector or even my vacuum cleaner. I was too scared to go near the dam thing while it was cutting in case it failed and even then it still stopped for no apparent reason. >:(
I did the removal of the Capacitor and resistor from the board and there was an instant improvement. I could still trip the SS with my Dust collector but it was now hard to do and I had to flick it on and off in a way it would never be used to do it. In real world testing the SS would still fail intermittently but nothing like it did previously and I was able to work in my workshop again without fear.
Just before I found the mod I had ordered some ferrite cores for my USB cables and they turned up in the mail 2 weeks after I did the mod. I had nothing to loose so I clamp a ferrite coe on every end of the USB cables and 2 on the one going into the SS. If it's worth doing, it's worth over doing.
That was a month ago and I haven't had a single failure since. ;D
I passed my findings onto a few other people who were having problems and it has fixed their issues as well.
I can recommend the mod to anyone have issues and also adding Ferrite cores for good measure
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:)
Brett
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Is it still a good idea to remove the mentioned components? Or should I just see if everything is going to work first? Is there a reason to not remove the components?
I bought my SS last year, but am just now beginning to put it to use.
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I would not remove the resistor/cap unless needed. There are a few PCs where it helps but others it causes more problems. There are also better ways to isolate the USB signal now (if needed).
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Thank you