Camiel told me on IRC that the horrible idle noise on batch1 was fixed in batch2. Could I get details on the actual issues and the fix applied? I've been told it's gone when printing, so theoretically couldn't it be solved in software-side? Thanks.

Do you already got some answer on the noise issue? I received a board a week ago and it has the same problem. It's driving me crazy.

No, that's what I want to figure out. I'm almost certain it should be solvable through software, considering that while connecting to the gen6 sometimes it stops making noise for a while. It really does drive me crazy also and is totally something that seems possible to fix.

Waiting for Camiel's electronics partner to show up and answer this with some authority... but the Pololu can squeel too... just not at such an annoying frequency.

It''s caused by the PWM (used in microstepping the motors), in the stepper drivers... it causes some motors to emit noize.

One way to solve it in software is to hack 5D so that you can disable the motors when you aren't printing... Like you can in Tonikip's... or Hack Tonikips to work with Gen6... (not perfectly straight-forward)

Or you can try different motors.. (if listen carefully, you will see the noise is coming from the motors).

But to solve it properly, I belive you need to change certain electronic components on the board to lower or raise the frequency of the PWM so you aren't hearing it or it's low enough not to annoy. This will likely involve surface-mount surgery.. but I'd love to hear from the authority exactly what changes are required.

It's not as if noisy stepper motors is a new thing with Gen6...but I agree it's at a pitch that particularly annoys.

Al...

Posted by Elmar at viewtopic.php?f=19&t=68 .



However when talking to the PC it is sometimes silent, so it should be fixable in sw to avoid rework, which would be interesting to try first.

In batch #2 there is almost no audible sound left now, here I will try to explain how this is achieved. If you have some experince soldering SMD components it is not that hard to fix yourself.

What we've done is we increased the chopper frequency of the motor`s current regulating circuit so that you will not hear it any more. Also by increasing the frequency the mechanical vibration (thats in fact what you hear) decreases in amplitude.

However the electronic switching losses are a bit increased also resulting in a bit higher temperature of the stepper drivers. I advise you to place some small heatsinks on it (about 50 - 70 K/w). Gen 6 batch #2 has it already preassembled. See picture.


How to change the frequency:
Replace the resistors R36...R43 with 68K ohm resistors. This will change the fixed off time of the drivers.

That`s what we've done in batch #2.

When you want to alter your existing PCB, I suggest you just stack a resistor of 100K (in a 0603 SMD package) on R36...R43 (you`ll need 8 pcs of them) and solder it. This way you don`t have to remove the existing resistors.

(why 100K? 1/(100K^-1+220K^-1)=68,75K ohm)

Now check your board for functionality by trying every axis on your machine to control it by software. If it works, stick/glue on the heatsinks and congratulations: now you have a silent Gen 6 machine!

Please note that this change to your hardware could result in damage to your board, only do it when to feel confident you can do this.
Also note that this change will void your warranty!

Any problems, you can post em here!

Does it make a big difference when printing? With the M84 command and "motors off by default" the printer is completely silent unless printing, when it's pretty noisy. If it doesn't really make it much quieter when printing I'm thinking there may not be a need for changing the chopper frequency and thus increasing heat output.

I have both a batch 1 and a batch 2 here at the moment.. the first thing I did was plug them both in (in my quite silent playroom.. I only have a couple of quite fans running in here)

Batch2 is much quieter than Batch1.. I had to move my ear to within 20cm of the motors to hear anything out of it...

I have some of the resistors here, and will try to do a tutorial on adding them to the Batch1 board...

I have to say that I'd do it myself as I find the pitch of the motors bothersome even when printing.. not as bad as when between prints, but still enough to make me want to.

Al...