Very loud stepper motors
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I use those same motors on my corexy at about 1700ma during printing and I can't say they are overly loud. But I also use some cork pads and printed motor mounts which dampen them. A big part of the noise is going to come from resonance with the frame, so if you can decouple the motors it can help a lot. A simple cork pad works ok, and there are purpose made nema17 rubber isolating mounts.
As for the corexy max speed attained when using a single motor, this thread may be helpful.
https://forum.duet3d.com/topic/8697/corexy-speed-constrained
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@N3XT3D said in Very loud stepper motors:
Would it make sense to buy motors with different specifications?
If you can hit the speeds you want with the lower current, no.
Motors with different current rating will also have different torque etc. Its not unusual to have a current rating higher than you are actually setting for the driver.Also, your steps-per-mm in X and Y... seem odd. Are you running printed pulleys or something? I would expect with a coreXY machine that they would be identical (and unless you are running MXL belts, whole numbers).
If you are looking to increase speed, going to larger diameter pulleys is the most effective choice. I don't believe anyone is getting even close to the precision that 200 steps/mm is promising.
Isolate, substitute, verify.
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@Phaedrux thaks for your answer!
I have already thought about such rubber dampers, but I also imagine a weak point in the accuracy, because the motor shaft no longer remains exactly in one position due to the rubber. Or whether the shaft is not even crooked due to the tensile load on the toothed belt.
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@theruttmeister I use 16 teeth aluminum pulleys. With these values of steps / mm I get the best dimensional accuracy of the printed parts. I also find it strange that these values are not identical. They are nominal 6mm wide GT2 belts.
The speed of the printer is a nice to have for me, but the main thing for me is to reduce the noise.
I thought that if I lower the amperage of the motors, I only lose the motor's holding power and not my speed. Ok, as the speed of the motor increases, the holding force also drops a bit, but I think the effects are not that big.
What would be more sensible to install a large, powerful, new motor like this 65Ncm and operate it with lower amperes (because of the volume and still maintain the holding power) or to provide the current motors with dampers and maintain the 1600 mA? It would be important to me not to lose anything in accuracy. I don't know if the motor in the rubber damper can't move too much.
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@N3XT3D said in Very loud stepper motors:
I don't know if the motor in the rubber damper can't move too much.
It's actually quite stiff rubber. I don't think you'd get much more flex then you would from belts.
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@Phaedrux said in Very loud stepper motors:
@N3XT3D said in Very loud stepper motors:
I don't know if the motor in the rubber damper can't move too much.
It's actually quite stiff rubber. I don't think you'd get much more flex then you would from belts.
Thank you. I will buy and try such dampers. At the other end of the motor shaft I have a ball bearing for stiffening. If the damper is installed, the motor shaft will probably no longer reach into the ball bearing. But I will definitely test and report it.
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@N3XT3D said in Very loud stepper motors:
I will buy and try such dampers.
They work very good on my HEVO and significantly reduced the noise. You can estimate the expected noise reduction by removing the belt and then running the motor, once attached to the frame and once held in your hand.
BTW, I like your printer.
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@zapta said in Very loud stepper motors:
@N3XT3D said in Very loud stepper motors:
I will buy and try such dampers.
They work very good on my HEVO and significantly reduced the noise. You can estimate the expected noise reduction by removing the belt and then running the motor, once attached to the frame and once held in your hand.
BTW, I like your printer.
Many thanks. I will install the dampers tomorrow as soon as they are in the mail. I will then link a video with the current status. I hope that the dampers bring the hoped-for success.
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@N3XT3D said in Very loud stepper motors:
@theruttmeister I use 16 teeth aluminum pulleys. With these values of steps / mm I get the best dimensional accuracy of the printed parts. I also find it strange that these values are not identical. They are nominal 6mm wide GT2 belts.
I suspect you are actually either compensating for something that isn't square in the machine, or you are in the noise of your measuring equipment.
Larger pulleys might produce slightly different results just because you will be spreading any potential error over more teeth. Or it might even be variability in the motors...
Either way, not important.The speed of the printer is a nice to have for me, but the main thing for me is to reduce the noise.
I thought that if I lower the amperage of the motors, I only lose the motor's holding power and not my speed. Ok, as the speed of the motor increases, the holding force also drops a bit, but I think the effects are not that big.
What would be more sensible to install a large, powerful, new motor like this 65Ncm and operate it with lower amperes (because of the volume and still maintain the holding power) or to provide the current motors with dampers and maintain the 1600 mA?
Ok. Holding torque is only important for holding position, torque during moves is pullout torque and is the relevant thing.
Torque is a product of both current and motor speed, as speed goes up, torque goes down. Its because it takes time for the magnetic field to generate the torque, increasing the voltage helps because higher voltages form magnetic fields faster.
That motor is also generating more torque because its 1.8 degree, not 0.9. That means the teeth inside the motor are larger (because there are fewer of them) and so you get a stronger field.
The holding torque is misleading, its 50% higher... But if you look at the torque curves (there's a link on the product page) and compare the two motors, you'll see that the pullout torque at 450 rpm is very similar: 3500 vs ~3750 gf.cm.
Part of that will be because one motor is being driven full step, the other half step.
And if you reduce the current limit, you reduce the pullout torque. Reduce it enough and you'll lose position.Which is all a long way of saying, maybe.
The windings are not wildly different, but there are 3 potential outcomes I would expect:- Not noticeable change. None. The function just the same as the first motors.
- The windings are different enough that the motors resonate at the wrong frequency and make a nasty noise.
- They generate enough additional torque that you can under-drive them and they are quieter.
Your call on if its worth the cost to see, but there's no better answer than testing them out.
If you are working on noise its hard, because changes that seem simple may well cause the motors to make noise at a much more annoying frequency.
I once helped modify a printer's electronics to make the stepper drivers run at 16kHz. Don't do that, its a horrible sound.The quietest printer I have built so far uses NEMA23's. When you push it, it will move at speeds and accelerations that are genuinely dangerous. But if you are printing at normal speeds the loudest thing by far is the 40mm fan cooling the head.
If you really want to get the noise down as low as possible, I'd suggest going that route, NEMA23's under-driven. Not a drop-in option though.
I suspect that the lower noise is mostly because that printer is dense, all milled parts and big extrusions. Its an old CNC maxim, if you want to reduce vibration, add mass.The dampers are by far the best first option.
Isolate, substitute, verify.
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@theruttmeister I also believe that these minimal deviations from the 200 steps / mm are negligible.
Thank you for the detailed and very instructive explanation!
So I'll try the motor dampers first. If that does not bring the desired success, I will test the other motors.
The NEMA 23 motors are a bit too big for my printer. Even if it is processed relatively sturdy, it would not be able to withstand the resulting forces without the printing result suffering.
It doesn't have to be whisper-quiet, but you shouldn't be able to hear the printer 3 rooms further at 200 mm/s.
In a rented apartment, printing overnight is so completely impossible, which I would like to do. In addition, the loud noises of the printer in the apartment are very disturbing in the long run. I would be absolutely satisfied with a normal noise level.In any case, thank you for the help and the effort with the explanation. Really great. I will report what the change brought with the dampers.
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@theruttmeister so the problem with the noise no longer exists.
The dampers have had a huge impact. But the change from the 0.9 ° step angle to the motors with 1.8 ° step angle had an equally great effect. Many thanks for the help. Here is the video with the current state.
The printer is now quieter and faster, with the same current for the motors.
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That's a substantial difference!
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@Phaedrux said in Very loud stepper motors:
That's a substantial difference!
Absolutely. This is really crazy. Thanks to all for the help. Now I am happy.
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@N3XT3D
Exellent.
With Trinamic drivers, that's what you should be able to get to!You are lucky you missed the bad old days of Gen3 reprap electronics... Makerbot Cupcakes were LOUD.
