Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: halfmill on November 12, 2017, 05:40:58 PM
-
So the situation is this: I have a mach 3 running a cnc gantry style and I have added a forth axis (A axis) It has its own power supply and control board.
My spindle runs separately and it is not controlled by mach 3. I turn it on manually. There are no wires running from the inverter vfd that runs the spindle, and control board--none!. So the vfd, spindle electrical cable, and spindle are not wired to the control board that runs a-axis or to the other control board that runs any other stepper motor!. A-axis lathe is run by a stepper driver and stepper motor.
But the following happens: When the spindle is activated by turning on the vfd ---the A-axis rotary starts turning, but it sounds like its grumbling badly as it spins up to rapid. Its not suppose to do anything. If I disconnect the usb cable between the A-axis control board and the computer, and then start the spindle running, then A-axis does nothing. Plug it back in with the spindle already running--and a-axis revs back up, grumbling. Actually its sounds like a growling cat or something tearing itself apart. If I disconnect the energy cable from the spindle motor, a=axis still turns (vfd still turned on).
IF I EXIT MACH 3 ALTOGETHER... AND THEN TURN ON THE VFD, THE A-AXIS still SPINS UP!!
Hitting the emergency switch, stops x-y-z movement, but the *7!@# lathe keeps on turning...(its alive!!)
Hitting the home switch for a-axis does nothing... still keeps turning.
Ok you wizards... where did I f*** up. bob
-
You need proper shielding and grounding on your VFD and cables.
-
I have good grounding all the way back to the main panel of the building... checked it with a continuity meter.
have to think about shielding my cables and vfd
liked your advertisements, not sure how they apply to my current issue... bob
-
Has anyone out there had a similar issue...
-
Simply, and I mean very simply stated, your problem us that you have a transmitter creating interference and something that acts as receiver of the interference.
There may be no single simple solution but what Gerry said is a start.
Most folks just don't understand interference and there are many books written on the subject. Hopefully the electrical and instrumentation folks will give you specifics on what to do.
Will not go into any detail, but, resolution of the problem is something like this:
- Identify the source of the problem
- Eliminate, isolate, reduce, contain the source of interference
- Provide protection from interference to any device
I have good grounding all the way back to the main panel of the building
That may be true from a purely electrical code point of view.
For interference, ( term used very loosely for the sake of simplicity) one
may want to provide a seperate ground system.
----------------------------------------------------------------------------------------
Simple things to do and try:
- Make sure your wires are all shielded
- Provide a ground system for the shielding
- Move the electrical plug of the VFD to different outlet that is not part of the circuit
used for the PC or electrical supply to the router.
- Move the VFD as far away from the router as possible
- Keep wires to and from the vfd away from other wires
- Any control boards etc for the vfd should be enclosed
Only do one change at a time and see if it solves the problem
RICH
-
In the past I have had similar issues with Freq drives. I had both ends of the shield grounded. This proved to be a mistake. When I would unhook one end of the shield .
The issue would go away. It is kind of like an antenna. Dont know a better way to describe it.
-
All good info fellas.
Tweakie has a very good write up on noise somewhere. I think it was on his website.
This is to a post in members docs..... http://www.machsupport.com/forum/index.php/topic,25616.msg180583.html#msg180583
-
I want to thank everyone who responded to my issue with the vfd interference... I replaced the cable from the inverter to the spindle motor and with a shield cable and that solved the problem immediately... so thank you very much... bob
-
Glad you got it sorted. Mitigating EMI is a lot like black magic. There are common practices (which is a good place to start) then there is the thing that actually fixes it. Which may require some nose twitching, a crows foot and other ingredients. Consider yourself lucky if your first attempt fixed it.
-
I spoke too soon... Earlier today I put in the shielded cable and it worked beautifully... no turning of the 4th axis lathe when the spindle came on.
Later this evening I came in and decided to run it again before I tried to cut some stuff... but upon spindle spin up, the lathe started turning???
Now when the lathe comes on under these conditions, I notice that it is trying to turn both directions at the same time. Does this trigger any ideas in anyones mind?
All thoughts appreciated... bob
-
As I mentioned earlier, that the 4th axis lathe which is controlled by mach 3, comes on when the spindle spins up even though the spindle is independent of mach 3 and is manually turned on when it is being used.
Now I tried an experiment earlier. I disconnected the power cable from the inverter to the spindle at the spindle end of the cable... then turned on inverter... the lathe still would come on!
If I reconnnected the cable to the spindle end and disconnected it from the inverter end, and turned the inverter on—then the 4th axis lathe (a-axis) does not come on. So I figured it had to be the cable itself as it was not shielded and so I felt that was the problem. So I bought a shielded cable and put that on... that worked for an hour and then the problem re-occurred. So this time I did the same procedure of disconnecting the cable at one end and then the other... and the 4th axis lathe did not spin up either way... so that’s an improvement... but if I connect the spindle, and turn the spindle on, the the lathe activates and starts grinding along. Does this trigger any thoughts about what might actually be happening?
-
Hi,
there are a number of mechanisms that will allow electromagnetic noise in one circuit interfere with another. The radiated 'transmitter/receiver'
idea is reasonably well understood. Another is conducted noise.
If you have a VFD plugged into a 230V socket and have another power supply also plugged into that same socket the noise 'referred to the input' of one
device can propagate to the output of another device.
As an experiment supply your VFD from a remote socket with an extension lead. Does it make any difference?
Craig
-
This triggers lots of thoughts in my mind but none that have not been covered by previous replies or links in those replies. You're just gonna have to dig into it (following the previous replies) and experiment until you can remove and repeat the problem at will. When you can do that you can be pretty confident you know what to do to eliminate at least one of the problems (you may have several).
Separate wires (put some distance between them), change ends the shields are grounded on, float or bond commons, etc.
The best tools to use to fight noise issues are detailed wiring schematics and component layout drawings. Those 2 are the first steps in mitigating noise issues. Assuming they match the machine exactly you can use them to check for ground loops, star ground, proximity of components, etc. Without those the best anyone can do is make educated guesses. That route usually ends being way too much wasted effort and time to guess down problems that should have never existed in the first place. Not a game most will take time to play.
-
Hi Halfmill,
It’s an illusive problem and no one solution cures all. When I fitted my VFD the manufacturer’s instructions regarding grounding were well over the top of what was actually required but the fitting of an RFI mains filter and shielded cable between the VFD and spindle also VFD and controller (shields only grounded at one single point and at one end only) was essential.
A couple of years back I did a basic wiring tutorial (for beginners) and this may be what Chaoticone was referring to (a couple of posts back). If it’s of any assistance it is here: https://openbuilds.com/threads/electronics-101.693/
Tweakie.
-
Hey Guys, thank you again for the suggestion above... I will slowly work through this.
bob
-
One thought I had is "How close is the drive that is picking up noise to the other drives? Are the step and direction durations set the same for all the motors in motor tuning".........
-
Chaoticone Hi,
The stepper driver is right next to all the other drivers. See attached photo. There is three feet distance from the inverter to the box that houses the stepper drivers and power supplies. But usually its five feet as its stored under the work table.
I will go into mach 3 and check your other suggestions...
bob
-
One thing to consider is fitting some resistors across the input pins of the drive board if this isn't already done. This will drop the input impedance of the board and help dissipate any spurious signals while allowing the more powerful signals from the PC to get through uninterrupted. The resistor value depends how much current you can get through from the paralell port or controller board. Equally you can fit pullup resistors to pins that are grounded to activate, reducing their susceptibility to spikes and noise and of course coolant leakage. Gotta keep them angry pixies in check.
Edit: If all this is in a wooden box you may want to consider a metal one, this will help a lot.
Be scrupulous when grounding things, bring everything back to a single point, no loops.
-
You just received a PM from me.
RICH
-
Just a suggestion...
I think you need to sort out some of your wiring - each drives supply (+ & -) should be wired directly back to the PSU and not a star and daisy chain as you have at present.
Tweakie.
-
Tweakie, thank you for the suggestion, I need to order things better. when I first started I knew nothing about cnc electronics, so of course I am making all the typical beginners mistakes...so its been quite a learning curve and it continues.
-
Rich HI
I took your radio idea to locate the heavier sources of noise in the system. The inverter itself produced very little static on the radio. The control box of course produced a lot of noise, but nothing produce static as much as the spindle itself... it was very strong around the junction where the shielded cable inserts into the built in plug on the spindle motor. The shielded cable itself had no static along its length. I purchased an 8 foot copper grounding rod and will drive it into the ground today or tomorrow and then "earthground" the spindle, control box, the base is alumn., and anything else I can ground it to--as you suggested.
-
Hi,
that might work but may also cause problems.
Your household electrical installation will have an earth rod somewhere. If you go and put in another somewhere near your machine an hook it to the frame of the machine
you will have created an earth loop. By earth loop I mean: frame of your machine to new earth rod, through earth to existing earth rod, to the earth conductor of household
wiring, to the socket you have your machine plugged into, to the metalwork of your machine, a loop. Any alternating magnetic field passing through that loop ill induce
a voltage in the loop potentially causing problems.
You are working the strategy that you wish to reduce the sensitivity of your installation from radiated and/or conducted electrical noise, its a worthy strategy and lots of little
things you can do to make it effective.....BUT there is an even better way.....stop the electrical noise from being generated in the first place. If you never turn your
spindle on then you get no interference....not very helpful. Why is your spindle motor so noisy? Is it a DC motor and if so are the brushes in good order? Are the brush
springs providing the require engagement force?. Are they the right brushes, not some that you found and filed down to fit your motor (yes I've done it)? Is there a RF choke
in series with each brush or could you put one there? Is there suppression capacitors on the motor or have they broken off? If they've been replaced have they ben replaced
with ceramic or silver mica caps? It may be as simple as correcting a fault with your spindle motor and all the noise issues recede into the distance.
Craig
-
Thanks Craig for the loop information... the spindle is brand new and has less than 2 hours of actual running time.
I guess if I installed a new ground rod some distance from the house and then if after grounding the spindle to the rod, and then of the lathe didn't turn on by itself anymore, then we would have fixed the situation. So I will try your suggestions. But an earth ground loop at this point seems unlikely as the rod is grounding to the whole earth which would seem to offer much less resistance than the loop... you disagree??? bob
-
Hi,
to have a second earth stake is to have an earth loop...thats pyhsics.
It may be troublesome but then again it may not. My experience is that earth loops can cause control circuit faults
particularly in industrial situations where large machines can produce large magnetic fields and work on earth loops.
Craig
-
I now follow your thinking. I will let you know how the experiment works out... I don't think a 1.5kw spindle can compete with big industrial machinery.
bob
-
Hi,
it does seem unlikely that an earth loop will cause you any issues in a home situation.
If you ever talk to an Audio engineer or a sound technician for a band...ask about earth loops and they will give you chapter
and verse. Don't overlook earth loops they WILLl cause grief and are hard to solve if you don't keep your eyes/mind
open.
Craig
-
ECHO.......
"Only do one change at a time and see if it solves the problem"
That includes the earth grounding also. Then if there is a connection at the spindle wrap some wire mesh/ braid around the
the connection and attach the wire to the mesh. The mesh acts as a shield.
I must add "makes progress" to improving the situation.
See if a fix can be improved.
Then add another fix in addition to the original.
Ideally one would quantify any fix, or analyze the field, but, unfortunately most don't have the equipment or knowledge to do that.
Note that once a signal is mixed with another it may be impossible to resolve the matter, simply.
RICH
-
Rich, thanks, good points... step by step, record all experiments. bob
-
I have a variable speed wood lathe... a small one... at last resort I can simply use that and have the Cnc spindle do the millings in conjunction with that... but I would like to be able to do indexing... so I will take the time to figure this out.
-
Bob,
Not to be harsh, but your pictures give me an OH MY! moment as I have been building control panels for about 50 years. It is really easy to see why you are having noise problems. A couple of things really need to be done. The step and direction wires from the breakout board should be shielded or at least twisted in separate pairs of signals and commons. Same with the DC power to each drive. If the stepper motor wires are not shielded twist the four wires into a cable of sorts. It actually helps if different pairs of wires are twisted in opposite directions and even different twist per inch rates. Totally separate the DC feed and the motor wires from the drive signal wire. If they have to cross one another try to do it at right angles, don’t put them parallel. The number one mistake that everyone makes, including me way too often is a panel that is simply too small for all the stuff that needs to fit. That often leads to noise problems.
-
Hi Gary, nice to hear from you again. I am going to replace everything with shielded wiring...so I will take your advice. Now can I have 4 wires in a shielded cable etc., or do I need to have each individual wire in a shielded cable all by itself?
another question as someone said I might have mis-configured the a-axis. For instance if I put in a360 f10, the stepper motor just clicks turns a partial mm. Mach 3 is set for inches. To get the lathe to do one rotation in say 7 seconds, it has to be set at f 5000. So I am thinking I have mis-configured something. Also, could mis-configuring a-axis cause it to be super sensitive to interference, so that if it is reset properly, the interference may not be a problem?bob
-
^ Put each pair of wires in a shielded cable, so if you have a switch or a DC motor, use 2 core shielded. A block of 2 switches can use 4 core shiielded. A 3 phase motor uses 3 core shielded and so on. The idea is for the current on one conductor to cancel out the magnetic field produced by the other while the shield reduces the effect of external influences. Equally, external RF and noise will affect both conductors equally and oppositely, reducing its harmful effects. Just twisting pairs together goes a long way towards this, shielding increases your margins even further.
This goes both ways - shielded/twisted wires will radiate less trash signal than loose single cores. ;)
-
To Rich, Chaoticone, Gary,
I did an experiment which got a different result. I took my x-axis stepper driver and switched it out so that it is now the A-axis stepper driver. I left the X-axis simply unconnected for this test.
I took the wiring from a-axis and wired it to the new stepper driver. The problem ceased. The spindle when activated did not active the lathe. So could I have purchased simply a defective stepper driver??? The stepper driver that I bought for the A-axis and seems to have the problem is a Microstep brand driver STM5045. I am ordering a new stepper that is the same as all the original steppers as x-y-z axis use. I redid this test 4 times and got the same results, so it appears to be duplicating either the malfunction if I use the Microstep driver, or no malfunction when using the original x-axis driver. I am afraid to put the Microstep driver on the x-axis as it might do something weird... what are your thoughts on this? Do you think this may be the problem?
To BluePinnacle--thank you for your advice on the wiring. Bob
-
Bob,
To get the lathe to do one rotation in say 7 seconds, it has to be set at f 5000. So I am thinking I have mis-configured something.
I will be covering feedrates in the next lesson.
RICH
-
Bob,
What brand drives are used for the x,y,z axes?
I suggest you not buy another drive. The problem may have to do with control box wiring and the box itself and not the drive as others have implied. Sorry I didn't look at the pic's you posted earlier and more closely.
Keep it connected as it was.
It looks to me that you controller box has bottom and two sides metal and the other two sides wood.
Don't know what your using for the top of the box. Simply said the box is not shielding anything.
ie; Wood does not keep the "rain" from getting in!
Consider how any connections are made when they penetrate the controller box.
ie;No seal around the pipe penetrating the wall allows the water outside the foundation wall to leak in. A hole thru the box with wire running through it does not allow for continuous shielding. ie; wire shield on cable bonds to box at connector and the rf ground system provides a path for noise from the box to ground which presents little resistance to the noise.
On the end of the radio's antenna you can wrap a coil of wire. You cover the coil and also some length of the actual antenna with something non -conductive. The allows you to get very close to a spot, not make an electrical contact, and inductively pick up the signal / noise.
Go "sniff" more at any wire penetrating the box. In particular sniff the the A axis wires.
If noise mixes with output wires to the stepper it can be the equivilant of sending pulses to the stepper.
Gary was nice in his post......
I express the condition in this way:
All dishes and utensles are washed and dried before putting them neatly and orderly on the dinning room table in preparation for the meal. This is done before the guests arive for dinner. ;)
RICH
-
Rich HI, ok I get the picture... will start on this. Thanks bob
-
Rich the stepper drivers are DM556D.
-
Question:
the info on the stepper motor for the lathe says 3.0 amps, the stepper driver which causes the lathe to move when the spindle is turned on is set for 3.0 amps.
The other drivers are all selected for 3.2 amps. Now as I said and I tried it again this morning. When the wiring for a-axis is set on another driver beside the one that has problems, then the problem of interference stops. So could it be that my selection of 3.0 amps on my mal-functioning driver should be set higher... its next choice is 3.5 amps... it does not have the choice of a 3.2 amp setting.
Also the ST-M5042 driver (the malfunctioning one) cost about $35 bucks. and the best price on the dm556D driver is like $50 off of ebay. So maybe there is a real quality difference???
-
Also on all the drivers there is a note about switch 4 being on = half current and switch 4 being off, equals full current. What does this mean??? bob
-
Hi,
I don't have the manual for your drivers but guess that setting reduces the current to the stepper when it is stationary. It is a means of reducing the
heat build up in the stepper and a common strategy of driver manufacturers.
Craig
-
Hi,
it is the inputs to your A axis driver is sensitive to noise, not the outputs. Changing the output current to 3.2 or 3.5 amp will make it somewhat more powerful
'transmitter of noise' but wont change its input sensitivity.
Have you tried some ceramic capacitors on the input terminals?
Craig
-
Craig Hi, Ceramic capacitors?? Nope, will have to go to the electronics house and see what they have... what capacity capacitor do I need? I assume that these input wires are that ones labeled V+ and COM from the power supply. Would I put the capacitor "inline" to the driver connectors? Thank you for your half-current explanation.
bob
-
Hi Bob,
no, I mean the Step and Direction inputs, between the terminal and earth. Ceramic capacitors are commonly used in RF applications and are preferred in high frequency
situations but not mandatory.
Given that the capacitors are 'shorting' out the input then a large capacitor would stop the driver, not very helpful. A very small capacitor will present insufficient
load to high frequency interference and not work. Its a bit of a balancing act. I would recommend about 470pF. At that size they will almost certainly be ceramic.
Its highly probable that the driver has a capacitor of this description built in to its input circuit but may be insufficient or the manufacturer left it out to save that extra
few cents to make it for the price people are willing to pay.
Craig
-
Craig Hi, thanks for the heads up... attached are a couple photos of the driver and one with the lid off... bob
-
sorry it would not import the other photo...
-
Hi,
just guessing, but suspect the upper left hand connector is the input and looks like two input buffers/Schmitt triggers or similar with little in the way of input signal
conditioning. I think a couple of capacitors are worth trying, I mean they're only cents apiece. As Rich has suggested do one thing at a time so that you can truly
evaluate each idea you've tried.
Craig
-
Ok Craig... thank you... will pick these up tomorrow if they have them. bob
-
Craig I have tried 3 times to post photos to the forum but it rejects it each time. If you will send me an email to me at anchorite@socal.rr.com then I will send you the 2 photos I would like to talk about. I need a picture drawn showing me how to do this ceramic thing. can you send me a photo please?
bob
-
Gary, Gery, Craig, joeaverage, Chaoticone, and those others helping me, including the moderator and administrator.: I did another experiment. I swapped the supposedly malfunctioning drive from running the A-axis to running the X-axis. I took the X-axis driver and put it on the A-axis. So X and A have been swapped. The stepper motor to the X-axis did the same crazy movement, growling sound as the A axis used to do. The A-axis behaved beautifully, no problem at all. I also went on the web and found youtube videos of higher end drivers malfunctioning... one guy bought 4 and 3 were bad. So I am beginning to think I have a bad driver. Each time I do something, I go ahead and switch any non-shielded cable to a shielded cable. bob
-
The X axis growling sound occurred only when I turned on the spindle.
-
> Craig I have tried 3 times to post photos to the forum but it rejects it each time.
That just means the site already has a file of that name. You need to rename your file.
Cheers
Roger
-
Ok lets try this
-
Roger thank you...bob
-
Hi,
just put a capacitor between Dir+ and Dir- and another between Puls+ and Puls-
Craig
-
Graig.
HMM....at least the drives were not 3040, 30x0, etc. series that some purchase.
Will make an exception for the drives being Chinese and continue with support.
Some info on them attached.
RICH
-
Hi Rich,
yes they do look better than most.
I am coming to the same conclusion as you, 'don't get involved supporting junk'. I got rather short with another poster where he refused to consider a G540
as opposed to the rubbish BoB that we'd already wasted so much time on. He'd bought the whole machine second hand for $200 so even if he stumped
up for a G540 he would still be well ahead. He was rather curt with me, which I understand nor even blame him. The upshot is that if I don't try to support
those types then I wont get the grief either.
Bottom line, if someone buys Chinese junk without doing any research, don't expect any help from me.
Craig
-
Bottom line, if someone buys Chinese junk without doing any research, don't expect any help from me.
And if they buy Chinese junk after doing the research ... even less urge to help?
Cheers
Roger
-
Sounds like your father may have been very unforgiving Roger. bob
-
Nothing to do with fathers.
Rather, a realisation that my life is finite and that I have better things to do with it than repeatedly trying to help some idiots who have shown every sign of not wanting to listen to advice from many experienced players. Yes - idiots. I don't mind a novice who LISTENS carefully, but too many idiots seem to want a magic wand to solve all their problems at zero effort.
How often do you see a plea for help along the lines of "I have only $500 but I want a precision 4-axis mill" ? It just ain't possible, but there seems to be no telling them. So I don't.
Cheers
Roger
-
Bob,
Just for your understanding, nothing personal in any way to you.
After years of support, we find that so many folks buy junk, get no support from the seller or the Chinese mfg's.
The Chinese laugh at us fools as they go to the bank because we are doing their work for nothing.
They send their customers to places like this forum because they gave them a free PIRATED copy of Mach so they can further take advantage of
of this forum's spirit. That really tick's me off, and personally have zero tolerance for the tactics or someone's politically correct view on it.
Let me be very clear on something, NOT ALL CHINESE !
Enough said......................we off topic,
RICH
-
Hi Bob,
I have been using Mach for several years but in the last few months have tried to re-invest the help that was given to me when I started.
By and large I've found it very satisfying and have helped a few guys along the way. There are exceptions too....one of the most common is
blokes who have very poor equipment with no documentation, or at least documentation worth a damn, no manufacturers back up and apparently
little intrest in learning the means to dig themselves out of that hole.
Following your posts you are not in that category.
While I take satisfaction/pride in helping others I can't help but feel there are some who take the piss as well. According to the stats I've been logged on
for something like 900 hours, no doubt not all productive, but a large portion has been devoted to posting for others benefit. I find myself less inclined
to spend my time with idividuals who can't be bothered to help themselves.
Craig
-
Now that is 3 accurate post if ever there was.
-
O Roger, well leave it at that. bob
-
Ok, I went back over the past few posts and it seems that I hit (unknowingly) a nerve in the community. Certainly not intentional on my part. I am "slowly" proceeding through all the suggestions that have been given to me and it will take some time to internalize fully what has been offered. I can see that many of you are highly knowledgeable. I wish to honor that and it has not slipped by my awareness---the authenticity of the gifts that all of you have been making on my behalf. Please hear me when I say I am committed to bring myself to some level of real functionality and that I am aware it really does come from hard work and applying oneself over and over until it sinks in and can be accessed in a fluid and creative manner. My career is that of a therapist and I see, quite well--this very issue that has gotten under the skin of those trying to help others here on the forum. That is--many clients come in demanding a magical solution and that they will just be given the golden key to success in life. In fact, some have literally demanded it! My position is to work their assumptions, that life is magically easy, to the realization that one can be "eaten" in any moment, and that waking to this fact often produces that crises of identity that is the wound of so many--yet is essential for anything "worthy" to really come forth in life. I wish to gain your respect over time thru application of your suggestions to the point of some real clarity in myself about how the CNC world really works and thus can participate in something that most do not have access to... and in the final stage yields the tools that the creative mind must have. Once again, thank you for your honesty, time and efforts.
Bob Campbell
-
Hi Bob,
the efforts your taking to master this stuff are noted and applauded.
I certainly, nor I suspect Rich or Roger really intended to 'air the dirty laundry'. Also it must be put in perspective, I choose to invest my time on a public
forum, and if I find some aspects less than satisfactory I have a choice dont I. I have read comments along these lines on a number of occasions and
admit that at the time thought them rather petty or griping. Now here I am doing exactly the same thing! Often the persons whom are being somewhat
less than realistic rather resent the truth, and I have that unfortunate tendency to 'call it as I see it' thereby earning some rebuke. My problem not others.
Craig
-
Craig Hi,
I have been wondering about the moderator, the administrator, and others that have some authority in the forum...are these people paid by Newfangled etc.? Kind of how does a forum work politically...this is kind of a separate topic... but a few words would be appreciated... perhaps others, especially newbies do not have much of an image of what it takes to work "a forum"... I am open to hearing people' stories. Bob
-
Hi Bob,
There are a couple of Administrators here that work for Artsoft / NFS but all the Moderators are unpaid and are their own men.
Tweakie.
-
Same is true for any post made by anyone on the forum. 100% voluntary. No one is paid to participate. The forum is hosted and maintained by Newfangled to give the DIYers a place to work together.
There really shouldn't be any political workings in a forum. The only thing I have seen over the years is truths yielding to political correctness. This usually helps no one and at best is like going around your elbow to get to your thumb. Myself, I'm a call it like it is kind of guy and I think most of the people that post the most accurate information are as well. I can't tell you how many post I have seen where someone ask a question and in short order have the exact fix by someone yet the post go on forever because the person looking for the answer did not like the answer. I don't waste my time on such nonsense anymore. Life is too short for that. I think all of the most knowledgeable here feel the same way. I know lots of others did but you won't see them posting at all........... they gave up.
-
Chaoticone said:
I can't tell you how many posts I have seen where someone asked a question and in short order have the exact fix by someone, yet the posts go on forever because the person looking for the answer did not like the answer.
Bob's response: I see what you are saying. It makes sense. What I wish to offer though is that for someone new often it is not that they don't take and use the exact "fix" that was offered (that was in fact accurate), but that their level of understanding does not allow for them to realize that what is being described actually is "the fix". If there is a big cat in a tree in the jungle, any child of the tribe will quickly see the cat and bring it to all concerned... but if a grown adult from the city goes into the forest... he is likely to be eaten because he does not have the context to differentiate cat from tree. So in my explanations to people, I have to re-image to them in different ways--how cat is not tree. (How what they are going thru is the manifestation of some way of perceiving life that lacks differentiation -- like when they blame what happens on everyone else, even when it was them that caused the problem).
I picked up a bull snake once in a dense patch of wild gourd. But when the end of the tail came out of the leaves it had a rattle on it, so I slowly lowered it back down and it went on its way. Seeing the tail was a true "aha moment". My differentiation increase at light speed! I don't say it was pleasurable--that is I didn't like the answer...like the learning curve to the vast realm of electronics/computer. Hopefully some of you are smiling now. Bob
-
their level of understanding does not allow for them to realize that what is being described actually is "the fix".
A nice simplistic answer, but not really an accurate one.
In so many cases a novice has asked a question but not supplied enough information for an answer. That's OK: we understand that. So someone (knowledgeable) has offered to help and asked the novice to do steps A, B & C and to report back with the results. Sadly, only too often, the novice has not bothered to take any notice of the offer of help but has gone off in a useless direction. Can you wonder that so many of us have simply given up trying to help as a result?
Many of us are still willing to help, provided the dialogue is genuinely two-way.
Cheers
Roger
-
Roger, yes I agree, no problem. bob
-
What I have been asked to do, but have not yet finished, but will are the following:
proper grounding-- some say put in an earthgrounding rod or similar, othesr say watch out for earth loop... but will do as an experiment.
change to the driver type that did not get activated when the spindle came on, other say don't change driver but do these other things... I will do both as an experiment.
rewire everything more in line with good electric principles... will do this...and get rid of stars etc..
Ceramic capacitor fix--I got them today
Shielded cables--I will do this, have started already.'
Put electrical devices in a larger and all metal grounded box as opposed to where I have all of this located now... I will do this.
I am forgetting 3 or more other things mentioned... but I have printed out all suggestions and will get to them in the order received.
This will all take some time and some money, though not that much...new alum case is $65 or so... the new driver was $58 and has been ordered. So I am guessing a couple hundred bucks...this is manageable...fixed income--you know...
I appreciated the help you have given...so here we go step by step... bob
-
I do wish this forum had an edit button, so that after you've posted something and realize you mis spelled...you could go back and correct...
-
Actually, I thought it used to have an Edit button - but not now. Odd. Someone has done something ...
Cheers
Roger
-
Note for Craig.
Craig Hi,
On an earlier post you said:
Hi,
just put a capacitor between Dir+ and Dir- and another between Puls+ and Puls-
Craig
So as not to burn something up, I interpreted your statement to mean one of the two options attached... so is it Option C or Option D, or just the big buzzer!!?? bob
-
Hi Bob,
option D, B would work too but D is what I had in mind.
Craig
-
Thanks Craig...bob
-
Actually, I thought it used to have an Edit button - but not now. Odd. Someone has done something ...
Cheers
Roger
This changed years ago. Now you have a set time that you can modify your post. After that time a mod or admin would have to modify it for you.
Funny this comes up now. One reason this was changed is we actually had some....
Posting questions.
Getting the correct answer.
Not liking (or not understanding) the answer.
Realizing later (usually much later, after lots of post just to clear up their misconception) they got the right answer to their question right off.
After volunteers educating them enough that they now know the question to ask editing their post to be the question they thought they were asking to begin with.
The chain of post went a lot like this.....
Question asked
Answer given
Lots more questions and answers
Finally get it fixed
Well, why didn't you ask "x" instead of "y'
I did ask "x"
No, you asked "y"
Post modified
Did not, go read it again
Hmmmm, that's odd. Could have sworn you asked "y"
Nope, never did. How dare you insult my intelligence. Thank you for wasting so much of my time on my hobby, my problem and my machine.
(Take special note of the me, me, me on previous line)
Hey, wait a minute...... Screenshot shows you did ask "y"
Silence........... ;D
This would be flat out funny if not so sad.
-
Wow... it certainly got complicated and also their egos could not afford to acknowledge that they were changing their story. I see that being a moderator has its real price in terms of putting one into situations of being left with a bad taste in one's mouth. My personal experience is that the type of narcissistic individual you are describing is actually fairly common in all cultures. I definitely hear that your lament has a strong basis in fact. I would guess that the existential question now comes to the personal value one derives in taking on such a task of helping others in the face of this narcissism. It throws one into a crises and forces us to reassess what we are doing. And what is our psychological stand on helping others in general. Kind of, "no-pearls-to-swine" versus giving to those where some real help would be accepted and highly valued by those individuals. Now when you identify the person who would value your real capacity to help...well then, that is where you would gain a deep sense of meaning for the time you are expending. In this instance, the sense of meaning you derive from helping the other person kind of "makes our effort nourishing to both them and ourselves". Do you agree with this? And in this way we build a net of relations in the world that gives us a strong sense of connected-ness and that the world is not "just-an-abyss" of one atom bouncing off another. The narcissist on the other hand, would project the barren-ness of their own inner experience onto you, so that you would carry the raw pain of their inner state for them. They do this by giving you their problem, then blaming you for their confusion, and then they take the credit for the solution...round and round. You get what I am saying...
This is what is happening in your description above, to you and other mentors on the forum. This process of your getting handed their piece of **** while you are also expected to process it for them and then hand it back to them as a piece of gold, is the basic strategy of narcissistic behavior. Now since I have to work with these types of individuals often enough, and as I have gone through your experience on a regular basis... I have been forced to adopt some ground rules to bring an individual to a point where they don't get to hand me the entire piece of their emotional wound. I take a part of it and then let them struggle with that. I do "modify" some of their "issue" and give it back to them. After all, that is part of my job and under the surface we are dealing with scare and terrified people...to which I have a commitment to help... but you do not have that obligation. But hopefully my description of their behavior and why--can help to bring meaning into a difficult situation and help you to establish boundaries against invasive behavior. Thank you for letting me explain this... bob
-
To Craig and others...
There appears to be some progress. The capacitor that I believe Craig suggested that I put across the PUL+ and PUL- contacts, and then another across the Dir+ and Dir- contacts---well this seems to have worked. To check, the capacitor was first removed from the PUL+/PUL- connection and then the spindle was turned on. The A-axis lathe remained still and did not move. But when I removed the 2nd capacitor, the lathe started right up on its own as the spindle turned on. So both capacitors were put back in as before, and the lathe did not turn on again. Now I have to turn run a bit of testing to see if A-axis will index properly and other things... but Craig, you had a great suggestion and thank you. I will continue to clean up system will the list that was shown a few posts earlier...this is to have a thorough way of approaching working in this environment. It would be good to go thru the proper motor tunings with someone for how the A-axis lathe should be set up... it seem to be mis-configured. Thanks again, you really helped... bob
-
Also a thank-you to Blue Pinnacle... you original suggestion was right there.. bob
-
Rich, now that things are clearing up, I will go back to your list of what I should learn and process... bob
-
It would be good to go thru the proper motor tunings with someone for how the A-axis lathe should be set up... it seem to be mis-configured
Just follow the lessons as they build on each other and will cover the lathe.
RICH
-
Alright Rich, got it...bob
-
Yup Bob, spot on and I do agree. I would be willing to bet many members do to.
Glad your making progress. Hopefully the caps will have you sorted. They are acting like shock absorbers on those input signals of the drive.
-
Hi Bob,
is common electronic practice to have signal conditioning and limiting elements protecting an input terminal. Among
the things that manufacturers will omit to build a device to a price is these very same conditioning/protection elements,
could be the case here.
Note that adding the capacitor has reduced the sensitivity of that input but the radiated electromagnetic interference still
exists. The ultimate solution is to prevent the interference from being generated in the first place and is easier said than
done. Ask any electronic engineer who has tried to get a device past the FCC or EEC emission controls.
Craig
-
Craig... so you are saying your solution is a kind of effective Band-Aid...and that I should take whatever corrections showup over time to keep "cleaning the system". I understand that causal condition still exists even though we have a kind of "fix". bob
Chaoticone--thanks for your support.. bob
-
Well said Craig. Most would never see the potential effects as a negative but in the right conditions it would not be an option.
Is your main concern pulse freq. Vs charge time? Its the first one I think of but never done the math to know for sure one way or the other if that is a possible shortcoming. I know in theory it is.
-
In an ideal world we would not have any radiated RF interference.
Yeah, right.
So we reduced the RFI as much as possible AND harden the digital signals.
Cheers
Roger
-
ideal world we would not have any radiated RF interference
That's why you have "Part 15 of the FCC Rules" plastered all over electrical items stuff.
does not apply to some countries though. >:D ;D
RICH
-
Hi,
you're right in some countries they just don't care. In others they just print conformance notes and attach it to their equipment without being
anywhere near a testing lab.
There is to my knowledge one accreditated testing facility in Christchurh and to have IEC schedule tests done can be tens of thousands of dollars.
Such testing and conformance costs are passed on to the buyer making well designed and made equipment expensive. A lot of the chinese compliance
marks are just plain fraudulent. Some of their gear is just plain electrically dangerous.
Then there is all the shortcuts we as consumers take. We all buy VFDs but has anyone bought the matching line reactors? I bet not, after all the device works
without spending all that extra.....so why bother.
Craig
-
For large (20 kW+) I can see line reactors being necessary, but are they really needed for little hobby-class VFDs? I ask because I do not know.
Cheers
Roger
-
Hi Roger,
yes and no...Small VFDs have input filters in them already, usually just, and I mean JUST comply with reflected noise requirements and no more.
Large VFDs the user is expected to select the reactors/filters to suit. Thus if you have your own transformer then line reactors become redundant, you
use the leakage inductance of the transformer. If sharing a distribution transformer with other users will require reactors and if your neighbhour has
some sensitive equipment you will be required to install them.
The amount of noise a VFD produces is proportional to its output power. Ten 10kW VFDs produce as much hash as one 100kW unit. The smaller units
will have some filtration but some cheapskate will install the 100kW unit with nothing if he can get away with it. Does it really matter to you if the hash
interfering with your machine controls is your own 10 kW unit or the neighbhours 100kW unit?
I don't know whether you listen to AM radio much, I do when I drive and in certain rural areas the interference drowns out even the strongest stations.
Craig
-
OK, I understand both the theory and the economics. Fully.
Cheers
Roger