New to this although a bit long in the tooth, so any help appreciated.
I had the Arduino working away on my self made cnc machine although it was making a lot of strange electronic noises. Anyway it came to a stop and I assumed I had burnt out the drivers. As it was as cheap to by an Arduino, shield and drivers I purchased them. Loaded grbl on to the new Arduino and away we go all ok, although some strange noises still.
Carried out various experiments to try and find out what went wrong to discover that all the existing drivers and the engraver shield are ok and work on the new Arduino ???
Did some test with the original Arduino and am able to load Blink, Sweep etc.which suggests that it is ok Wiped the Arduino with an empty sketch and successfully loaded grbl however when I apply 12 volts to either shield the steppers just freeze. Any ideas?
shortcircuit48:
Also any ideas why I am getting musical noises?
The frequencies used to control stepper motors tend to be in the audible. So you'll hear the coils in the motor resonoate.
shortcircuit48:
when I apply 12 volts to either shield the steppers just freeze
The starting point would be what kind of protection circuits did you use for the motors. They throw off a lot of EMI. It is possible something was damaged.
Thanks for the information. Not quite sure what you mean by protection circuits a steppers have simply been wired to the drivers as shown in multiple examples, should there be something else?
My initial description was not very good as it is the steppers that freeze and simply go rock solid as soon as power applied to the shield.
The musical noises from cnc are annoying..... but are normal and expected.
As for steppers going rock solid .... that's normal as well. The driver is then meant to produce the right amount of currents in the stepper coils to move the stepper shaft around. If the stepper is rock-solid, then it's likely that whatever is upstream isn't working properly (assuming that the stepper is ok).
So..... are you trying to say that the cnc system works fine with the new arduino....... and the issue occurs only when you swap the new arduino with the old one again...... right?
After a bit further research it suggests I have built a guitar which is amplifying the stepper frequencies.
With the new Arduino all the steppers are working and are not going solid as you suggest as being normal. The fault appears to be within the old Arduino although it does run the various sketches and loads grbl,
Beads? They do nothing, only fit for putting round you neck.
You need ceramic capacitors for high frequency and large electrolytic for lower frequencies. The whole power to the motors would also benefit from a seriese inductor, like I said before.
After a bit further research it suggests I have built a guitar which is amplifying the stepper frequencies.
Does that mean your casing has resonate frequencies that are excited by the steps in the motors? If so a micro stepping driver will help reduce these.
Spent a bit of time today to see if I could narrow down the problem. When using the A4988 driver there is very little torque from the steppers and they are easily stopped. I rigged up a couple of L298N drivers and ran a simple sketch and it is like night and day as impossible to stop the stepper. Should there be any reason the torque is so low with the A4988? They work but could they be faulty? I have been very careful today to ensure all power is removed before making adjustment.
I have adjusted the A4988 but saw very little if any difference. Was using a 12volt psu and just now changed it to another unit giving out 30 volt but no difference as the steppers move but soon stop with various tones being given just like they are overloaded.
The fault only appears on the Y axis where I have two steppers and have made A a slave of Y.
The L298N is a simple switch where as the A4988 is a controlled current driver. You have to adjust the current correctly. You have to adjust the current to match what the motor needs.
The higher the voltage the more torque and speed you get because the current gets into the winding quicker. In general the L298N is far inferior, it looses more voltage through its transistors and has no current control.
shortcircuit48:
Spent a bit of time today to see if I could narrow down the problem. When using the A4988 driver there is very little torque from the steppers and they are easily stopped. I rigged up a couple of L298N drivers and ran a simple sketch and it is like night and day as impossible to stop the stepper. Should there be any reason the torque is so low with the A4988? They work but could they be faulty? I have been very careful today to ensure all power is removed before making adjustment.
You probably need to define the initial conditions linked to the things you did above. Eg... which arduino you used..... new one or the old/original one. Also.... what problem are you trying to narrow down? The problem with the old arduino? Or something else?
I have NEMA 17 steppers and adjusted the voltage on the A4988 for 0.62 volts and have tried different settings. For all the adjustments I have made I have got no where near the torque that the L298 gives.
Is there a sketch that will allow me to test the individual A4988s on a breadboard?
Southpark, I gave up on the first Arduino and have laid it aside so as not to cloud the issue. The main problem I am trying to tie down is torque as although X & Z operate ok they are no where near the output that the L298 gives and Y stalls.
That tell us nothing useful about the motor apart from the size of the mounting.
and adjusted the voltage on the A4988 for 0.62 volts
I thought you adjusted them for current not voltage. No wonder it does not perform if the output voltage is 0.62 volts. Unless you meant reference voltage, but you did not say. Have you read the instructions?
Is there a sketch that will allow me to test the individual A4988s on a breadboard?
Bread boards are most unsuitable for carrying such large currents.
You keep us short of relevant information, what libraries are you using?
Look under the File-> Examples menu for that libiary.
As a novice I thought the type of stepper would have been of use.
I have looked at numerous posting as to how to set up the drivers and my indication of the voltage and type of stepper was hopefully to get advice on setting up.?
I have learned from your comment regarding breadboards.
If I keep you short then that is my lack of knowledge as to what I should have posted.
I have loaded grbl on to the Arduino and then using easel.
Most grateful for advice and looking at the numbers that have viewed this topic, it must be of interest to others, who will hopefully learn from my inabilities
Got to thank you Mike, you pushed me in the right direction. I have adjusted the reference voltages and steppers are now working more or less how they should.
Tomorrow is another day
Thanks to all.
Away for a couple of months so now happy that I have made progress
Just to conclude my ramblings. Set up drivers, as per advise and the excellent video, which used a breadboard, and then connected a bench power supply, giving me 30 volts. All run excellently now.
Another success was to adjust the travel in grbl to suit my lead screws so that when I jog 10mm I get 10mm movement. A bit daunting at first but so simple and over the moon with the results.