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Help please. Dip switches and mach 3 settings
Hi,
The items in cause are Nema 34 motor 5.6A, 1200oz-in, and driver DQ860MA.
Dip switches set as OFF OFF ON ON OFF ON ON OFF , which sets the thing to 4.9A Peak, 3.5A RMS, Full Current from SW4 (i don,t really know how to set this), and 2000 pulse/rev. The next current setting is 5.7A peak.
In mach 3, in ports and pins, motor outputs, checking only the enabled column does nothing, as I,ve seen in some tutorials. Checking only step low active will get the motors running, and also checking both dir and step low active, seems to work.
In config, motor tuning, I,ve set a few different speeds and acceleration just to see the difference. What exactly should I set in there?
Now, I,m new to this, and I,ve surely missed something, as the motors get relatively warm after a 1-2 min of running a test gcode from the default mach3 folder.
The motors are not connected to the ballscrews, so there isn,t any load to carry.
What have I done wrong?
Regards,
Andrei
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Re: Help please. Dip switches and mach 3 settings
I can not see any thing wrong with how the stepper driver is set up
with stepper motors the motor current depends on what you set by the DIP switches - sw1 to sw3
not the mechanical load on the motor
so the current does not go up when you mechanically load the motor as you may of expected
depending on which manufactures data sheet you look at
the motor can safely run at 70 to 80 degrees C - too hot to touch !
a quick look on line did not find clear instructions for the setting of sw4
but going by a photo of your DQ860MA driver
I expect sw4 sets the current reduction when the switch is set to OFF and the motor is idle ( not being stepped )
set to ON the motor will run hotter but should be OK
setting the motor current to 4.9A instead of 5.6A will do two things
1) reduce the motors temperature
2) reduce the motor torque
if the room temperature is not too high
then I expect you can safely set the motor current to 5.7A
the extra 1.7% current should not be a problem
especially with sw4 OFF
John
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Hi John,
Thank you for the reply.
It seems the problem then is my lack of experience with how this equipment runs in normal conditions. Besides others which might come in the near future.
I,ll adjust the settings a bit then, as you,ve recomended, and proceed to mount the motors on the machine.
Regards,
Andrei
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Re: Help please. Dip switches and mach 3 settings
General recommendations for stepper motors on CNC routers - set the DIP switch to reduce current when motor is stopped. You do not need as much torque to keep the motor in position when not moving, so you can safely reduce the current and therefore motor heating. Then adjust the motor current based on the motor temperature. Select a current setting, and check the motor case temperature with your hand after, say, 30 minutes. If you can hold it comfortably, try increasing the current. If it is too hot to touch, reduce the current. Aim at a motor temperature of about 60degC, which is about the maximum you can hold. Stepper motors are designed to run at these kinds of temperatures. Current ratings, specification sheets, etc, give you a first guess, but in practice you just want as much current as possible without the motor becoming too hot.
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Hi Neale,
Thank you for the info.
As soon as I,ll get the machine going, I,ll post some photos, and some detailed info about it, to get some feedback and advice.
For example, the gantry weighs apx 250 lbs (100 plus kilos), and even if the motors are capable of moving it fairly easy, and the ball screws 2005 seem ok, surely there is an ipm limit, to avoid any problems from the inertia. It,s a wood router design, 5x5 feet, steel tubing frame.
I,m reading as much as I can online, but surely there will be some things which I.ll not be able to figure out and I,ll have *to contact someone who knows what he,s taking about* as someone from youtube nicely put it.
All the best,
Andrei
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Re: Help please. Dip switches and mach 3 settings
According to the photo of the drive at http://www.wantmotor.com/product/dq860ma.html SW4 changes between full current and half current.
As has been said, stepper motors can run pretty hot. If they're getting too hot to touch within a couple minutes, something is wrong, but 80deg after an hour or so of running is perfectly acceptable.
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5 Attachment(s)
Re: Help please. Dip switches and mach 3 settings
Hi again,
Here are the photos I.ve promised 4 weeks ago.
It is a 5/5 machine (1.5m/1.5m) made of 2.3 inches (6cm) steel tubing, and aluminium plates.
Rails and ballsscrews of 20 mm. Nema 34 motors (overkill for z axis, but i.ve bought a kit of 4 a few years ago, I.ll get a nema 23 kit sometime in the future). The part of the gantry moving left and right weighs apx 65 pounds (30 kg), while the whole gantry apx 240 pounds (110kg). I did not have any problem so far with the supported rails and bearings, or screws and motors, just a limitation in speed, as a hard stop at a high speed will shake the whole thing. Adjusting each motor to a certain speed seems to work fine.
The project was designed at first with 2 motors on the y axis, and it weight apx 200 pounds, but the fact that I could not mecanically sync the two ballscrews involved, had me worried and I.ve decided to go with one screw in the middle, as any kind of failure does not have the potential to break or bend something.
It is this large, as I need this mainly for carving soft and hardwoods, for cabinet making, and this size let me fit 6 door panels at once on the table.
This is where i.ve got so far with the project, and once again I ran into an issue which I.m not able to fix. Everything was going fine, until I.ve wired mains for the vfd, then I had a surprise when I almost crushed the z axis as it did not stop when I released the keybord. After I.ve wired the spindle, evrything went nuts, as the steppers make a strong noise, and move back and forward quite fast. It.s a chinese 1.5 kw air cooled kit.
As it can be seen in the photos, my idea was to put eveything in one box, including the pc.
I.ve decided to make another enclosure for the vfd and move it a bit further away, and it did not fix the problem. When I turn on the power for steppers (with a contactor) and the vfd (cam swith), even if the pc and mach 3 are off, or even if the vfd is off, the steppers go mad until i hit reset in mach 3, then they stop and work fine, until i turn on the vfd and/or the spindle.
The wires are shielded, 4 wire cable for all steppers and spindle (18 and 14 awg). I did open the cap of the spindle and connected to the case a ground wire (the 4th one) and connect it to a steel rod in the ground. I did this because it says in the manual to avoid having a common ground with a welder. And I do use one quite often. I did not connect the shielding to anything. I.ve only tried yesterday to connect one end of the shielding at the vfd end to see if it makes any difference, and it did not, and also disconecting the spindle ground from the vfd did not do anything (as by default there is not a 4th wire available). No shielding it connected at any end for the steppers or the limit switches. The only non shielded wires are the mains for everything, pc, sources, drivers, breakout board and vfd.
All the wires go togheter in a cable drag chain.
So this beeing one issue, the second is how to wire and configure the limit switches. From what I know so far, I can wire all of them in series, normaly closed, and connect then to the breakout board (DB25-1205 in my case), to one pin from P10 to P15, and to GND. Well, I did something like that, only that I.ve separated each axis 2 limit switches to separate pins. So P10,11,12 to X,Y,Z and P13 to Probe, P15 to Estop, and all grounds together. And it does not work, as the RESET button from mach 3 stays on emmergency limit swicth all the time, when I enable the pins in cause.
So 3 issues,
1. How to fix the stepers issue? I though I.ll ask first here, and then call an exorcist. (it looks a lot like in the movies) :P
2. How to wire and setup the limit switches?
3. Opinions, reviews, criticism, potential problems and solutions for this particular design, if you may. :)
It.s a long post, so before anything else, thank you for taking the time to read it.
Regards,
Andrei
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Re: Help please. Dip switches and mach 3 settings
Quote:
nd. I did this because it says in the manual to avoid having a common ground with a welder. And I do use one quite often. I did not connect the shielding to anything. I.ve only tried yesterday to connect one end of the shielding at the vfd end to see if it makes any difference, and it did not, and also disconecting the spindle ground from the vfd did not do anything (as by default there is not a 4th wire available). No shielding it connected at any end for the steppers or the limit switches. The only non shielded wires are the mains for everything, pc, sources, drivers, breakout board and vfd.
All the wires go togheter in a cable drag chain.
It is important to connect all the shields to a star point at the control box. Including grounding the router frame.
Only ground one end of the shields. Also make sure the various mounting plates are also grounded to the star point.
With a gantry that wide I think you will need two screws to stop it racking this can be done with one motor and a long belts or two motors one each side.
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Re: Help please. Dip switches and mach 3 settings
Hi Clive,
Thank for your reply.
What do you mean by a star point?
So I should connect all the shieldings at one end for the spindle, the steppers and the limit switches, to a common point in the case. The frame has a common ground/earth with the spindle, which goes into the vfd and from there into one iron rod in the ground. Everything else, has the ground wires sent into the main electrical grid.
After all the shields are connected to this star point, where should this star point be wired to?
Regards,
Andrei
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Re: Help please. Dip switches and mach 3 settings
Quote:
Originally Posted by
Radu_Andrei
Hi Clive,
What do you mean by a star point?
So I should connect all the shieldings at one end for the spindle, the steppers and the limit switches, to a common point in the case. The frame has a common ground/earth with the spindle, which goes into the vfd and from there into one iron rod in the ground. Everything else, has the ground wires sent into the main electrical grid.
After all the shields are connected to this star point, where should this star point be wired to?
Regards,
Andrei
OK I am not familiar with how you receive you incoming mains in your country In the UK the electric company supplies a ground point (that in general is also connected to our neutral) But in Spain in the country areas the supply does not include a ground So you have you use an earth rod in the property.
In your case I think I would connect the shield of the cy4 core going to the spindle to the star point at the control box end only. Ie don't connect the other end to the earth in the VFD.
Thee start point is connected to the main ground (if that is a earth rod then that)
What you are trying to achieve is not to get any ground loops.
Do you need to take the mains for the VFD into the control box.
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Re: Help please. Dip switches and mach 3 settings
The mains is of 3 wires, live. neutral and earth, the earth going to the utility pole as well.
I did run a separate earth metal rod, because it said in the vfd manual to avoid having the same ground with a welder, and I do weld quite a bit these days.
From what I understand so far, I.ll unite all shieldings from all components in the utility box, and only at that end, and run everything into an earth, be it back in the mains or the metal rod.
If I got it right, I.ll do so in the next days and come back with the results.
Thank you.
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Re: Help please. Dip switches and mach 3 settings
Quote:
From what I understand so far, I.ll unite all shieldings from all components in the utility box,
By utility box do you mean where your incoming mains is or your control box?
The star point should be in the control box and then connected to your incoming mains earth.
There are plenty of people that use welders without problems ( it is possible that the ground rod is creating a loop)
I use cat5 cable for signals as it has twisted pairs, but you can use any small screened cable
edit: there are other methods to get rid of EMI using ferrite rings on the incoming mains to the VFD
Good look with the mods
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Re: Help please. Dip switches and mach 3 settings
Sorry, my mistake. I meant the box where all drivers and sources are, I assume control box it.s the name for that.
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Re: Help please. Dip switches and mach 3 settings
Quote:
Originally Posted by
Radu_Andrei
Sorry, my mistake. I meant the box where all drivers and sources are, I assume control box it.s the name for that.
Yes.
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Re: Help please. Dip switches and mach 3 settings
Hi Clive,
I did what you said with the shieldings and it works. Almost perfect. The only thing left, is that my pc behaves a bit weird sometimes, for a few seconds, when I turn off the vfd, weird meaning the cursor is dancing on my screen for apx 10-15 sec and them returns to normal.
I'll try to use a ferrite ring as you mentioned, for the vfd mains, as that cable is not shielded.
The motors are working fine so far.
So THANK YOU!
I.ll keep in mind your suggestion about a double ballscrew drive and one motor, if any issues will come up with this design. This change on it.s own takes a long time, as I.ll need to build and buy a quite a few extra parts to make it work, so maybe wishful thinking might work this time and function ok as it is.
Even if I have the hardware to add two motors, I.ll avoid this method, as in this last problem I had with noise, the motors were spinning in random ways, not to mention other possible hardware failures which might get them out of sync, and it looks problematic to a point of damaging some expensive parts.
A 5 feet belt might cause some trouble as well, but with enough patience I think I can make it work.
So once again thank you.
As for the second issue, with the limit switches, any idea what I.m doing wrong?
All 6 limits are wired in pairs of two, in series like in the photo, NC, where one wire goes into a numbered pin, and the other into the ground pin. P10 to 12 being used in this case for limits. How should I set this in mach3?
I.m new to this forum and not sure what.s the proper way to post questions. Should I separate the questions and post them in certain categories or ask all the quesions in one thread?
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Attachment 24552
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Re: Help please. Dip switches and mach 3 settings
Ok I would keep all the questions in one thread as it helps to see the history.
Re the twin screws I use two motors with out issue. I think it is about half and half ie some use two and others one motor. There are pro's and con's for both.
Do you have homing switches ? generally on the Z axis it only needs a switch at the top. I would set that up as a combined home and limit switch .
You can wire all the limits in series to one pin. ( set that up in ports and pins in Mach) and also set up soft limits as the machine when homed should never hit a limit.
There are plenty of vids on the net:- https://www.youtube.com/watch?v=ma7lMocQbv0 if that helps
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Re: Help please. Dip switches and mach 3 settings
Quote:
Originally Posted by
Radu_Andrei
As for the second issue, with the limit switches, any idea what I.m doing wrong?
All 6 limits are wired in pairs of two, in series like in the photo, NC, where one wire goes into a numbered pin, and the other into the ground pin. P10 to 12 being used in this case for limits. How should I set this in mach3?
In Mach3, Go into Config, - Ports and Pins, - Input Signals, - Automated Setup of Inputs and follow the instructions.
If you don't get a response from the change of state of the switch, then you have a wiring problem. If you get a response it sets the input for you.
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Re: Help please. Dip switches and mach 3 settings
Hi again.
I wired the switches and e stop did the setup as cropwell said. All fine until I power up the steppers, and then I get noise problems again, limit switches triggered, external estop requested message which sometime does not reset.
I disconnected the vfd and still no good.
As adviced by Clive S, I did more research on this topic, and ironically, that raised more questions.
1. is it a bad grounding practice to pigtail for example the stepper shieldings, and then run a ground wire to the mains earth, or should I run a separate ground wire from each shield to the earth. Does it make a difference?
2. as the spindle is set on conductive material, it.s ground wire becomes the framework.s ground as well, and running another ground for the frame will only create a ground loop. is that correct?
3. does the fact that having all components in one enclosure, raise this kind of problems, even if all wiring and grounding is done correct? should I have 3 separate ones, pc, stepper control, and vfd?
4. all wires run in the cable drag chain, meaning I have low and high voltage right next to each other. so from all I found online, the easiest way in my opinion is to add a relay next to the breakout board, and have the limit switch wires at 12 or 24 v. or should i physically separate them a couple inches apart, or improvise a separate carrier for the low voltage wires?
5. for estops and limits, I have an "hardware" and a "software" estop, one to a contactor, one to mach3, is it useful or necessary to approach the limit switches in a mechanical way? (like some relay which kills the power to the driver, or source)
6. in the vfd manual it says that you should not use a contactor as a switch for the vfd. So i use a cam switch to turn it on, but wired after the contactor, so hitting the "hardware" estop, will kill power to everything, turning just in this cases the contactor into a switch. The I reset the cam switch to zero, power up the contactor again, and turn on and off the vfd from this cam switch. Is there any problem in this wiring method?
7. except the vfd main, where else should ferrite accessories be used? sources mains, between sourced and drivers, breakout board 5v wires.
8. does the breakout board, being close to the drivers and/or vfd, can cause noise issues?
I.m considering taking all the electronics apart and start from scratch, a better cleaner design, easier to troubleshoot, and would appreciate very much an advice on how you would do it. Assuming you have in front of you all the parts involved, how would you design it, in order to never, or at least most of the time, not encounter this kind of problems.
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Re: Help please. Dip switches and mach 3 settings
Hi,
Having typed a long and laborious answer to some of your points, I then lost it all because this forum software is crap.
Here we go again :-----
1. a: Pigtailing - no problem, just remember shields should only be earthed at one end or you may get earth currents to make your shield as the primary in a transformer with the secondaries as your signal wires.
1. b: Single earth point in control box, all earths and shields and mains earth to it. Topographically, earth connections are a star, however spur connection is allowed as long as it is a single line spur chain earthed at one end only at the star point.
Attachment 24580
2. Yes.
3. The VFD is usually the main culprit in creating electrical noise and it is common practice to keep it out of the main enclosure (which should be an earthed, shielded box I.E. not plastic).
4. DC voltage supply lines are normally no problem in a steady state, switching transients can be a nuisance, but these would only be when there is an inductive load, like a pump motor, so these are best shielded. Homes and limit switches are normally in a steady state, but it wouldn't hurt to shield them against stray EM crap.
5 and 6 - whatever !
7. I hate ferrites and their nasty little cousins - slugs. Design out the problem if you can.
8. Noise from the BoB, not usually (only when it gets drunk on a Saturday night) but seriously - I refer you back to 3 above.
You should test each earth connection by continuity checking from the central earth point to the earthed appliance. Disconnect the appliance earth and check that the continuity between the earth point and the appliance then disappears. If it doesn't - you had a loop. :beer:
Hope this helps !
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Re: Help please. Dip switches and mach 3 settings
As Rob said. But I hate timber boxes and think of the fire hazard. If you can go with a metal box with the VFD external to it.
edit: something like this could help https://www.jaycar.com.au/iec-emi-po...6-amp/p/MS4003
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Re: Help please. Dip switches and mach 3 settings
Quote:
Originally Posted by
Clive S
As Rod said.
Hi Clyde, who's Rod? :devilish:
Cheers,
Rob
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Re: Help please. Dip switches and mach 3 settings
Well spotted now edited.:dejection:
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Re: Help please. Dip switches and mach 3 settings
Thank you Rob for the detailed answer.
Got it. Metal box at least for the vfd, ideally for everything else.
By shielded box, do you mean just an earthed metal enclosure, or aluminium foil :P or like a faraday cage with chicken wire?
Out of curiosity, Clive, about the fire hazard, how hot do this components get?
I did it from particle board cause it.s easy and fast, and I put all components on a metal plate, actually on the side panels of the pc enclosure, as I dismanteled it. All panels beeing raised half an inch from the wood.s surface. I could not wait to have the cnc running, and was planning to upgrade after a few months of use, and yes, I.m aware it.s a crap and unprofessional design, but it seemed to me a resonable prop at the time.
And should I add an enclosure fan to the drivers as well, as I already have 2 for the vfd enclosure.
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Re: Help please. Dip switches and mach 3 settings
Hi,
If you don't want to replace the control box with a metal one, you could line it with aluminium foil (https://en.wikipedia.org/wiki/Tin_foil_hat) but to be any use it would need to be earthed. I don't think the guy in the wiki is grounded (I apologise if you don't get that joke straight away, it is a little play on the vernacular - in this instance 'grounded' means connected to reality).
LIDL sells adhesive backed foil tape, when they have it.
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Re: Help please. Dip switches and mach 3 settings
I just googled what vernacular means. :stupid:.
Thank you for sharing the joke. Jokes actually, as the noisy bob was funny as well.
And for the extra description. :)
May I, in exchange, share a simple one with you. Did not hear it in english as yet, but I might be wrong.
John speaking to his son in an encouraging manner.
- Come one son, take a step, come one, another one, yeah... yeah, that it, like this, smaaall and slooow. MARRY!!!, bring the camera quick!!, our son has come from the prom.
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Re: Help please. Dip switches and mach 3 settings
Quote:
Originally Posted by
Radu_Andrei
John speaking to his son in an encouraging manner.
- Come one son, take a step, come one, another one, yeah... yeah, that it, like this, smaaall and slooow. MARRY!!!, bring the camera quick!!, our son has come from the prom.
Jokes rarely work in translation, this is no exception :-(
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Re: Help please. Dip switches and mach 3 settings
True. But worth a try. :beer:
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Re: Help please. Dip switches and mach 3 settings
Probably a adapted translation would have pointet out better the initial assumption that a father is teaching his child to walk for the first time, and the pun, that actualy he.s son was just drunk, and faced the same challenges as a toddler.
Non verbal humor tends to work best for an international audience. Mr Bean, Charlie Chaplin, Benny Hill etc
Here.s not the place for that. We.ll stick to technical discussions.
Although, magiciner, I would be glad if you would post a link with the type of jokes and humor appreciated by yourself. Just to have a read, without bothering any admin by posting random unrelated topics.
We.ll get back with the cnc progress soon, as it takes a bit of time to implement Rob.s instructions.
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Re: Help please. Dip switches and mach 3 settings
Hi again.
Just to test to see if it improves anything, I used some zinc sheet metal to shield the control box.
Earthed and everything, it did not make much difference.
So I started to disconnect components, and removed the vfd from his own shielded box, and then unplugged the limit switches fom the breakout board, and all was left was the pc with the drivers, sources and steppers.
The steppers are earthed at the driver end, everything at a star point as recommended. Checked all shield with the multimeter, and it.s all good.
The only thing done questionable is that I have one stepper cable, which I measured wrong, and had to join it to another bit, each of the 4 wires twisted and taped, and did the same with the shield, put some aluminium foil on top, and taped all over it. Not great, but it should not be a bigger deal than any other type of connection.
Also the limit switches are the cheap lever type. Even if not the best, they are not connected to anything now, and still have issues.
I removed all flexible couplings, and have the motors running without any load.
THE PROBLEM: randomly, the motors stall, all 3 of them, some a more often than others. Simply keeping pressed the keyboard arrow keys, they run ok, for 5, 10 even 30 seconds, then at least one stalls.
I,ve loaded a default g code, those coming with the software, and the same problem. I changed the motor turning config to acc 50 and speed 300, 400, 500, still have the problem.
I.ll remove all steppers tomorrow and connect them directly to the drivers. At least to exclude the cables as well.
The motors are 5.6A and the drivers set to 4.9A Peak, 3.5A RMS.
The drivers are DQ860MA and wired like this: +5v to PUL +(+5v), and bridged to DIR+ and ENBL+, then PULL- and DIR- go to the pins 2 and 3 for example on the BoB, ENBL- is not wired. The other 6 terminals are 2 for the source and 4 for the stepper.
The breakout board is db 25-1205.
I.m working on the metal cases, control box and vfd box, suggested by Rob and Clive, but I can not go further with the design and construction, until I figure out the cause of this stall.
I.ve already tried to separate the components and to shield all boxes and ground them. I rechecked all wires, including the drivers, and rewired those with twisted cables inside the control box. This wires between the sources and drivers and the BoB are not shielded. Everything else is.
I had a touch plate fitted and disconnected it as well, as it concerned me that the wire connected to the spindle, and to the chasis as is all conductive materials, sends a ground signal into the input pin of the BoB and might cause problems. Does it?
I.ll even remove tomorrow all other wires from the drag chain and leave only the steppers. It might exclude something else.
BUT I higly suspect the BoB.
What do you think guys? What am I missing?
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Re: Help please. Dip switches and mach 3 settings
I am sorry you seem to have all these problems but keep at it as it will be worth it in the end.
What power supply are you using for the drives?
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Re: Help please. Dip switches and mach 3 settings
the ones that came with the kit, individual for each motor
S-350-60 +60V 5.85A
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Re: Help please. Dip switches and mach 3 settings
Quote:
Originally Posted by
Radu_Andrei
the ones that came with the kit, individual for each motor
S-350-60 +60V 5.85A
60V is a bit low for nema 34 but you will be limited with the drives you have.
What micro step rate do you have the drives set at. And what max velocity are you using in Mach (under motor tuning)
This might just be the cause that you are trying to turn the motor too fast
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Re: Help please. Dip switches and mach 3 settings
Dip switches set as OFF OFF ON ON OFF ON ON OFF , which sets the thing to 4.9A Peak, 3.5A RMS, Full Current from SW4 (i don,t really know how to set this), and 2000 pulse/rev. The next current setting is 5.7A peak.
Nema 34 motor 5.6A, 1200oz-in, and driver DQ860MA.
motor turning: acc at 50 velocity at 300 for the y axis (whole gantry), cause at a full stop, it does not shake the whole thing, and 400-500 velocity for the x, seems to not cause trouble.
I took apart the whole thing, and have it on my desk right now. I connected one stepper only directly to the driver and it works ok, but still it seems to lose a few steps here and there, at various speeds.
I.ll use it next with the long shielded cables and see how it works.
Will post some results, photos, videos soon.
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Re: Help please. Dip switches and mach 3 settings
Quote:
Dip switches set as OFF OFF ON ON OFF ON ON OFF , which sets the thing to 4.9A Peak, 3.5A RMS, Full Current from SW4 (i don,t really know how to set this), and 2000 pulse/rev. The next current setting is 5.7A peak.
This might be to high try sw 5,6,7,8 set to off/on/on/on = 800 p/rev set sw 4 to off = half current when idle
setting the above will alter the distance travelled but that can be sorted later when you get the motors working
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Re: Help please. Dip switches and mach 3 settings
Ok. I tried it like this.
From left to right in the photos and video, drivers set at 800/1600/2000 with motor turning acc 50 and velocity 400.
There is a difference, as the 800 one runs smooth without vibration when touched. The noise difference exists even between steppers with exact same settings so not sure if it matters.
https://www.youtube.com/watch?v=dsHN_Botomk
Also, changing the pigtail connection with a terminal one, seemed to improve a lot, but still sometimes it does like in this video https://www.youtube.com/watch?v=4nHuNHK4fLA
What still does not seem ok, is that when I run DriverTest in Mach3 folder, I get the first time ..Pulsing to fast and then pulsing to slow.. messages and then runing it again, I get System Excellent (apx 25000 pulses per second, 25 khz), straight line.
Everything is taken apart like in the photos, so design wise, I got the fact that the vfd has to be somewhere outside the control box, or in it.s own box, but what about the pc? Any issues with the motherboard being close to the Bob?
As I shielded the boxes with sheet metal, it seemed to get warm inside, which did not before ,with just the wood ones. So, the new box will be a cleaner version of what I did, and I have two 12v fans. How would to mount this, in order to avoid dust collection, as much as possible and overheating? Blow in or our, from above, from beneath? I.m asking about the control box.
How do you suggest , I should test the steppers to make sure all iss good, and proceed with building the metal box?
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1 Attachment(s)
Re: Help please. Dip switches and mach 3 settings
Also I found this wiring diagram online, and it.s quite different from what I.ve done.
I go to BoB from Pull- and Dir-and this one goes from +.
Enbl+ is daisy chained and wired to the Vdd, while mine is bridged to Pull+ and Dir+.
Do this small differences matter in any way?
Attachment 24610
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1 Attachment(s)
Re: Help please. Dip switches and mach 3 settings
going by your photo in post 35
without circuit details of your breakout board
I expect the opto isolated BOB NPN outputs will be connected
so they can output sinks more current to GND
than it can source current from the +5V supply via a pullup resistor
If I am correct
I would connect the BOB to the stepper drivers like this :-
Attachment 24611
the + step & +direction going to the +5V supply and
- step & - direction being connected to the BOB outputs
John
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Re: Help please. Dip switches and mach 3 settings
This is the one. Db25 1205. https://www.ebay.com/itm/CNC-6-Axis-...sid=m570.l1313
I don.t know any more details that it says in the lower side of this webpage.
The multimeter reads 5v at the VDD terminal, without bridging it.
I did it like in the photo you.ve sent, but bridged ENBL+ as well.
Thanks for your reply. :)
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2 Attachment(s)
Re: Help please. Dip switches and mach 3 settings
going by the photo linked to in post 38
it looks like the BOB is as I expected with pull up resistors on the outputs
Attachment 24612
unless you connect the - enable to a BOB output
having the + enable connected to +5V will have no effect
what could be a problem is having the BOB's output optoisolator being connected to another optoisolator inside the stepper driver
having the step signal passing through two optoisolators could distort the pulses too much at high step rates
John
PS
in the photo of the BOB you can see two links that connect the +5V in to Vdd and connects the two GND's together so you don't need the external wire link as in post 37
PPS
a while ago I produced this circuit diagram from photos taken from the net
Attachment 24613
what I need to confirm is the connection of the 10K resistor connected to the 74HC14 input
it was not clear from the photos if the resistor was a pull up to +5v or pull down to GND
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Re: Help please. Dip switches and mach 3 settings
Hi John,
ˇˇwhat could be a problem is having the BOB's output optoisolator being connected to another optoisolator inside the stepper driver/having the step signal passing through two optoisolators could distort the pulses too much at high step ratesˇˇ - does this mean I should remove the bridge from enbl+?
ˇˇwhat I need to confirm is the connection of the 10K resistor connected to the 74HC14 input/it was not clear from the photos if the resistor was a pull up to +5v or pull down to GNDˇˇ - how exactly can I help in confirming this?
P.S. although I have some general knowledge about diodes, capacitors and resistors, I.m struggling to wrap my head around schematics, so I.m sorry if my replies are quite banal. I very much welcome reading material to avoid pushing the limits of anyone.s patience. :)