So I didn't notice that this unit requires the filament hub connector in order to work with the Kobra S1, and I ordered it to use with my Kobra S1. I don't know if they edited the listing after I ordered it, or if I just screwed up, so . . . it sat for a couple of weeks waiting for the adapter to arrive from Anycubic (it's available on their website for around 25 bucks, when it's in stock). Once I received the adapter kit, I installed the Ace Pro - which takes about five minutes - and printed my first 4-color print. The little gnome came out prefect! Pros: The unit works well and is simple to install. There is no need to update firmware or anything - it just works out of the box. In addition to 4-color printing, you can use the Ace Pro to automatically switch over to a new spool when one spool is used up, or to print with multiple different filaments on the same models. So you can use PLA for support on your PETG print, and the supports will pop right off. Loading filament has never been easier. Just set the spool on the rollers and feed the filament into the guide until the Ace Pro picks it up and starts feeding it. The Ace Pro has a built in filament drying system. You can even set the dryer to run while printing, but I don't recommend it (see below). Anycubic support is first rate. It may take a day between each email, but they will take great care of you if you have issues. They even sent me a new extruder at no cost when I accidentally broke the one on my Kobra S1, even though the damage was my own fault. Cons: Multicolor printing with this system produces a LOT of waste. There are methods for minimizing the amount of waste (just search for "reduce waste in multicolor 3D printing"), but each color change requires a purge to clear out the nozzle before loading the next color. There are also some videos on YouTube showing potential uses for the purged filament - most recommend melting it into molds, which I'm going to try some day . . . The Ace Pro HATES some cardboard spools. And it's not too fond of some plastic spools, either. Some cardboard spools work fine, but others just will not turn when the machine tries to rewind filament. And if a plastic spool has a flat spot (I'm looking at you GST3D), it can get stuck, too. You can print adapters to help alleviate this, but finding the right diameter is a pain because each manufacturer uses a different sized spool, and the plastic rims don't always work. I keep a couple of empty spools in case I have to wind the filament onto a plastic spool, but for the most part I just avoid using cardboard spools in the Ace Pro. When I tried to dry some PLA while printing, the filament actually softened a little and jammed inside the feed mechanism. You can adjust the drying temperature to prevent that, but I just decided not to use the dryer while printing. Clearing jams inside the Ace Pro can be a nightmare. The filament buffer is on the bottom of the unit, so you have to turn the whole thing over to remove the buffer, then disassemble whichever part is jammed (be very careful you don't lose the internal spring or break any of the plastic parts), and remove the wadded up filament. Fortunately, I've only had one jam, but that nightmare is why I don't dry filament while printing any more. Some spools don't fit with the lid closed. I've had several 1kg spools of filament that are too large to fit inside the Ace Pro with the lid closed. Simple solution - print a lid prop to hold the lid partially open when using those spools. There are a LOT of models for them available online. Conclusion: The Ace Pro is a great way to get into multicolor \ multimaterial 3D printing. It's works well, it's easy to use, expandable by adding more units, and the price is comparable to similar machines. There are some weaknesses - which are common to these types of filament changers - but it's a great, inexpensive way to get into color printing. Read more

got this for my kobra 3 works amazing easy set up just follow the instructions and the set up is simple Read more

Jamming constantly breaking the pla.Following all the instructions to the letter and still not working right. Read more

Nice unit Read more

I bought this as a second ACE for my Kobra 3 Combo. Plugged the cable into the other ACE and it works perfectly fine in my setup to provide another 4 filament colors without having to physically change spools. Read more