I'm going to have a new baby in my family, and people recommended these Comotomo bottles pictured. For breast milk or formula feeding from the fridge, some people claim you really need bottle heater, other people say it's a waste of money. Of the bottle heaters people like, the water-bath style seems the safest and the quickest. Since I already have an older ANOVA sous-vide heater (not pictured), and some 4-quart cambro containers (these: https://www.amazon.com/Cambro-RFS4PP190-Polypropylene-Storage-Container/dp/B001E0FNMK) , I figured I may as well make my own bottle bath !

The only problem was… keeping the bottle in the bath steady and from tipping over as it warmed in the water bath. Commercial baby bottle heaters are designed around the bottle form factor, but are only good at that one task, and seem like a wasteful purchase. In order to avoid buying such a few-time-use product, I figured I'd design a little hanger to keep these Comotomo bottles upright.

After a few design tweak iterations it works quite well at keeping the bottle in place, even with an empty air-filled bottle that would normally WANT to tumble over due to buoyancy.

How to print

I printed this in polycarbonate, but ABS or Nylon or something heat resistant would be good. PETG might be pushing your luck it unless it's CF-PETG. On the other hand, most of the model won't be submerged. Anything that can withstand the 60-65 C needed to quickly heat baby bottles up. I used no supports and a 0.16 mm layer height to maximize strength, but i'm sure 0.2 would be fine.

STEP and Fusion360 files are included, so you can adjust this for your own bottles if you need.