Eddy Duo

This has worked amazingly. It does suffer from heat drift, but that shouldn't matter for most people. I have a sv08 with a pretty warped bed, and I use this for a mesh and "tap" automatic offset calibration. As long as I move the head away from the bed while I heat soak the bed (up to about z 100) it works every time. If I leave it too close to the bed while it heat soaks, it fails tap calibration due to heat drift, but this is fixable by just cooling down the print head by moving it up again.

I will preface this with stating I have done no high temp ABS/ASA printing with this yet. This is running on a K1M with Simple AF software and it works really well. First layer is very nice every time. This probe is not ready to install out of the box it needs firmware and the correct version of Klipper to work. Bed mesh takes seconds and adaptive meshing is lighting fast. It is super important to get the calibration correct for this to work for you. The best way to confirm the calibration is to go through the process and then home everything and take the nozzle to Z 0. If you have a nice paper compression you will have nice first layers.

I'm really surprised to find myself the Eddy Duo 5 stars. I fought for a couple months with Eddy Coils and gave it up as wasted time and money. I decided to try the BTT Eddy Duo on a Ender 3 V2 by adding a steel bed sheet and simply tie-wrapping the Eddy probe's USB cable to the toolhead cable. Getting it setup is not as easy as the other probe but it seems solid and reliable. I'm using the homing and z-endstop functions and am delighted with the automatic layer offset.

I have had many BTT products in my life, but this one by far has the worst instructions for the actual wiring of the probe. Going off their own instructions you would think this means it is plugged into usb on a RPI, but that is not the case. It is plugged into the CAN to USB port on the BTT RPI, which if the little red line was labeled CAN to USB I would still have my RPI4 ....... Yea, it killed it and my microsd card. now I have to order the BTT pi because in 2025 they still can't make a proper set of instructions. There is no mention of this anywhere, and the ONLY instructions you get for wiring it in this configuration is this picture. Clear as mud, par for the course with BTT documentation. 1 star for the lack of 5v warning.

In regard to the hardware and how it functions, I'd give that five stars. Regarding getting it installed and functional, probably two stars, which is why I suspect it's a frequently returned item according to the listing. Your mileage on this may vary and experience with 3D printer hardware and Klipper especially will play a major role in how well it goes for your specific situation. The rig I have this installed on is an Ender 3v2 running Klipper from a Raspberry Pi 4B and a BTT SKR E3v3 motherboard instead of the stock Creality 4.2.2.2. The Eddy is connected directly to the Raspberry Pi via the included USB cable instead of directly to the SKR like a CR Touch normally would be. So, basically the Eddy talks directly to the Pi and Klipper. Where this gets tricky is in figuring out the correct bed boundaries and proper calibration. Calibration is crucial for anything on a 3D printer, but especially so with the Eddy. Not only do you have to set a Z offset via the paper method, but you have to calibrate an array of thermal values as well so the Eddy can adjust its thermal compensation. Something else noteworthy is that once you have it calibrated, you don't adjust it on the fly like you would a normal Z Probe. For example, in order to make sure I have my Z Offset adjusted properly with a BL Touch, I'll print a large square and adjust the Z height in Klipper until it's just right. That (by default) doesn't work with the Eddy making it (as mentioned above) very important to spend the time during the initial calibration in order to get it as accurate as possible. There is a beta feature that can be enabled that will let you do this but I wouldn't make a purchase decision based on that. It seems as though their goal was to prevent us from having to bother with this but I'm guessing some users have had issues getting the initial calibration correct and want to be able to manually adjust the Z Offset value. I tried this out and once I had the offset adjusted, it worked great. The problem I had was that the adjusted value wasn't storing properly or something, so after a restart the calibration would be way off and I'd have to adjust it again. This caused me to spend a couple of days figuring out why it would work and then not. Ultimately, I went back to the default calibration method and just spent more time with it and now it works great. Once you have it working though, bed probing is so much faster and smoother than a touch sensor. I've read that it's not as accurate but I've not (and am no qualified to) tested this.

It took a little bit of work to get the firmware updates and config changes done, but the mounts and guides are already out there so it’s not too bad. First layers are noticeably better since installing this Eddy, and bed mesh scanning is significantly faster, especially for larger prints.

The BTT Eddy was a terrific upgrade to the stock inductive sensor on my Sovol SV08. While it required installing the mainline version of Klipper on the machine, it makes bed mesh leveling so much more accurate and quick. Be prepared as you will likely have to adjust some config files and do some calibrations but the github repository has good documentation on this. And yes, you also get a duck.

Very good product, liked it so much I bought extra for my other printers