Definitive TMC2208 Vref settings

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I've upgraded my Anycubic I3 Mega (Trigorilla) "S" to the TMC2208 drivers. I've found on forums various guidelines for the reference voltages: 0.85V, 1.06V, 1.2V, with someone saying 1.5V needed on E0.

After installing the TMC2208's and with the motors removed, I've checked the reference voltages and found them to be (X,Y,Z,E0, E1)= (1.11, 1.11, 1.09, 1.18, 1.11)V and left them like that.

Now, when fast extrusion or retraction occurs, there's a nasty noise from my extruder motor. Can it be that 1.18V is too low for E0?

Note that I have the newer/upgraded "S" extruder from Anycubic.

Is there any generally agreed opinion on what the Vref's should be for TMC2208's in Anycubic I3 Mega (Trigorilla)?

Im trying from 2 weeks to change my Anycubic i3 mega stock drivers with TMC2208 V3 DIY version but i have some problems....can someone explain me please how to change them...one problem is that the motor coil pins are rly different and the 360* rotation of the plastic plugs will not work....i cant find firmware for v3 tmc2208

In my case with V2.1 (bigtreetech) vref 1.1V on E0 was too small.
1.4V heated the motor quite a bit, but was usable.
With 1.3V works fine, - no problems at all.
I left the rest on 1.1V.

I have the same issue. yet no matter if I used 0.88 1.33 or 1.1~ i had the same issue. did it just go away for you? I went back to stock for now for the extruder

my tower with tmc


EDIT: wow you aligned the labels perfectly. I can NEVER do that xD I have a label printer and can never make the cable labels look that pretty

It did go away after I've reduced my retraction speed, please see comments below

I actually ended up using mine in UART mode only for the extruder. there was a pinheader there already and it was super simple for me (tho might be harder for others depending on their skill)
it fixed my issue completely! i have stealthchop enabled and hybrid threshold set to 30 I think (default)

Can you give more details about this, please? I have TMC2208 v2.1 and v2.0 from BTT.

As I'm a newbie on this Mega hack I would like to know if you need to do extra physical wiring for the UART mode.
From what I read so far for UART mode I need to do some soldering on the TMC board joints but I'm afraid there are other things to be done like re-arranging some of the pin head from bottom to the top and the extra wiring.

you do. but lucky for us 3 of the wires are already tehre with the headers. so you only need to solder a cable to the TMC(I don't recommend a header but a direct cable so it allows one of those beefy heatsinks! but that's just me.

the file i attached is a pinout I found somewhere (super huge thanks to whoever manged to figure this out :P)

I"m a hobbyist so keep that in mind but afaik D15 D14 D20 D21 D11(Already used on mine for Bltouch) etc can be used for the uart that already have a pinheader pre soldered. otherwise you can use d4 too but you need to solder a pin there and that means you have to take the board out of the printer which is like a huge pain in everywhere so I rather just not :P

tbh I only use uart for e. I do plan on making the uart available for X and Y too but I mean z is barely used and it's a super slow axis so I will keep that one in standalone.

PS: you can connect both the Z axis "Z and E1 are used for the z axis" to the same pin. since it's both a tx signal and they both are going to share settings

I got the TMC 2208 V3.0 which have 3 pins already soldered on top.


In the v3 manual at page 6, is mentioned that an 1k pull resistor must be also connected to the RX line thus D15 RX and D14 TX seems to be a good choice. Is this resistor needed, did you use it in your setup?

Second question is about pins: do I need to remove the 3 bottom pins and let only the UART top pins? Is it safe to let all the pins as they come from the manufacturer?

Thanks for this, they erased everything about ramps config in october 2019, couldnt find any info about the resistors.

I have no idea if it's safe but I didn't /shrug I think yo uneed the other pins on the bottom. only the uart. also I'm confused why you have 3 pins. it's supposed to be 2 :?

again I have no idea if you have to cut the ones on the bottom or not sorry! probably best to ask the manufacturer but it feels scary to leave them on the bottom

thanks, about the pull resistor I think in your case is not installed.

I think it's just for the TX of (out from tmc in to the MCU)

Wow, thanks a lot.
If I got it well, the only thing to be done for E is to:

  • connect the D14 (for TX only) to the UART of the TMC
  • modify the firmware as in pins_trigorilla14.h below?

Yes! i included my .h file below as an example ;)

did you have to make changes in pins_trigorilla14.h or was that not necessary?

I did but it was very simple and short honestly.

Could you send me a link to that file so I can use it for comparing?

https://pastebin.com/bWrFJuGf this is what I added to the pins_trigorilla14.h or whatever file!

What version of Marlin are you using? I am getting a compile error and am trying to figure out what the issue is.

In the end, I've settled for 0.95V for all Vref, including the extruder driver. The printer works fine.

Very useful post!
Just received my TMC2208 v2.0 and wondered about a decent default settings for Mega-S (Trigorilla1.1).

Hi, sorry a little bit offtopic: can you post the thingie link of the PSU case?

No problem, it is this: https://www.thingiverse.com/make:443749. Note however that there are a few remixes out there now, that might be better.

Anycubic I3 Mega quiet !

I got the exact same issue after changing to TMC2208. The sound from the extruder was vastly reduced when raising the voltage on its TMC2208. The extruder does get a lot hotter though but I think within reason.

In your picture there is no heatsink on the driver, You do have heatsinks on them when mounted in your printer I hope?

Yes they do, the picture is to show make and version. See attached for installed drivers.

Do you have the original, or the upgraded 'S' Anycubic extruder? What Vref's have you used?

The upgraded S. And I actually run my extruder driver at 1.4V now.

Still... there is something fishy here, so maybe a real solution will eventually pop up.

I've now actually adjusted the extruder spring force and lowered the voltage/current to the extruder :-)

Ah, ok. I've now changed Vref to 0.95V (+/- 0.003V, else I'd fiddle with the potentiometers all day) and to 1.22V on E0. I notic a bit less grinding noise at fast retraction, so I might bring it up to 1.4V as you did. Otherwise the printer works well and is very silent.

Now the fans are deafening. I'll now try changing the extruder fan to a Noctua A4x10 FLX but this fan draws 0.03A wrt 0.16A the stock one. Can this be a problem?

I've changed the extruder fan to a A4x10 with no issues. I also removed the metal obstructing air flow to both fans on the extruder.

And changed the horrible motherboard fan.

And finally the PSU fan to a thin Noctua 90mm fan but that depends a bit on what PSU you got, Anycubic seem to ship different PSUs over time...

What a difference it is!!!! :-D

Yes, I've also replaced the PSU and drivers fans (see first photo in this thread).

However, when I put in the Noctua and turbofan (see picture below) they don't turn at all (before you ask, they work fine when hooked directly to and external 12V supply).

I've swapped the old and new heads a few times, and always the same: old fans ok, new fans nothing. Am I missing something here?

That's very odd. Especially since it's a real common mod... strange.

When I swapped it I was first worried that it didn't start but that was because it wasn't turned on by the motherboard yet :-D

Just to mention it: The PSU fan starts after a while when the temp reaches a certain threshold (I think it's 40°C), it is not running all the time.
The radial fan for the part cooler has to be turned on in the sliced gcode (cura settings) or with octoprint.

What I'm trying to say is that both fans will not just run when plugging them in and turning the printer on. Some conditions have to be met :)

Indeed, I had to wait a bit ;) All fine now. Thanks!

Now the part cooling fan is the noisiest, perhaps I got a cheap one. Bah!

Same here, I went for a Sunon 5015 from Amazon, it is not super quiet but it's OK when running it at 60% or so. The radial fans are louder by design. I am also using the marlin firmware from David Ramiro which has the 12V mod and that also requires to run it with a lower percentage if I understood that correctly :)

Could you upload an audio recording of the sound? I also have a sound post upgrade to the TMC2208 drivers but I'm not sure if it was always there and I just didn't notice it amidst the loud, old drivers. My sound happens about mid way through X axis and not on all moves. It's annoying because otherwise the printer would be totally silent.

It's hard to catch. It happens only when a fast retraction occurs. Otherwise the printer runs fine (and much quieter).

Try running the filament removal, that runs it in reverse until the filament is completely out of the tube.

That works fine, without any unusual noise.

I have mine all set to 0.85V with the extruder set to 0.9-0.95V or something aand it runs fine and doesnt get hot

Thank you for your reply! Do you have the original, or the upgraded 'S' Anycubic extruder? Do you have the same Fysetc v1.0 drivers?

mine say V1.1 or so but i took a look at your video and i feel like you need to turn down your retraction speed a bit. my extruder makes noises too you just cant get it noiseless

That was a good point. Thanks!
I've reduced my retraction speed to 30mm/s and the distance to 4.5mm and it's much better!

After viewing your video, mine does the same thing. I have a Titan extruder as well with the 3:1 gear ratio. So the motor has to spin extra fast to get similar retraction speed as a 1:1 (stock) extruder. I had also turned down the retraction speed a while ago and that helped. I feel like there is a vibration component to the noise as well. If I hold the motor during retraction, the sound is further reduced. So I messed around with printing some dampning pads using flexible filament and quieted things down even more.

I already see two opinions in this discussion: 0.95V and 1.2V for E0 Vref. How can such different settings work? Can it actually be that Vref does not actually matter if within a certain interval? My drivers are these: https://wiki.fysetc.com/TMC2208/, where they actually say that Vref<1V

I have heard Vref 3.0v if i don't get myself wrong. If so, can i use it and does it need me to reverse the wires?

I'm planning to install the same to my mega-s this evening. The ones I got have some comments on Amazon saying it should be set to 0.9 and 1.2 for the extruder.

Do you have some missed steps in the prints (probably over or underextrusion at some parts)?
I think calibrating the esteps might also be a good idea after replacing the drivers. At least I'm planning to do that.

Prints ok, except for suspect noises from extruder. I suspect Vref too small.

Just installed mine (f.. awesome, so quiet) and testing now. All set to 0.9, extruder to 1.2

That was fast! ;) What cooling option did you use (old fan will not fit in now)?

I'm using a noctua 40mm with this.fan duct: https://www.thingiverse.com/thing:2878826
Works great, the whole thing is super silent now. The clicking from the extruder upon retraction is the loudest noise. I never expected how well these tmc2208 work. Great stuff.

Other mods I did is a noctua 92mm fan for the PSU
Noctua 40mm fan for the hotend
Igus bearings on all rods
Sunon 5015 radial fan

Super happy now :)

Anycubic i3 Mega UltraBase fan duct for stepper drivers (Remix)

Ok, same fan duct. Thanks!
But do you think the clicking noise from the extruder is ok?

I think it is, yes. I am pretty sure it has been there before but I couldn't hear it as good as I can now as the motor was louder than this. The clicking seems to be just the retraction when the filament is pulled out and the gear changes direction. The motor is as cool as it was before (checked it with a infrared thermometer, it is around 34 C

I am still amazed how well these TMC stepper drivers are working.

Did you not have this noise coming from the extruder before you switched to TMCs?

Nope, there was no such noise before the driver upgrade.

Now, listening to my (quieter now) printer, maybe it was not so evident behind all the other noises ...
I'm not so sure anymore, see video linked above

I have the original Mega since almost two years with the tmc. All drivers set to 0.9V according to a calculation I did based on somebody else work.. and since then no fancy noises at all. I do not get why you should raise the ref value for the extruder motor. Can somebody explain?
I also have a noctua for the extruder, what a pleasant upgrade. In the PSU I have a more silent one than the original, but not a Noctua, since the flow was almost the half of the original and I did not want to risk overheating the PSU. The part fan is the original, works like a charm. Just set them to 70% and not 100% if you use this:


It may require you to adjust it a bit with a hot gun or hairdryer but it works great!

I am printing quite a LOT and did not have a single problem yet. Happy printing!

Anycubic i3 Mega fan duct 2-sided
by H_Run

Thank you. How does one calculate the Vref, based on what?

Thanks! I was aware of the Fysetc wiki (see previous comments); they say Vref should be kept just below 1V.

The problem I have with the Vref calculator is that I don't know where to get the RMS current for a given motor? Would you be able to clarify that?

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