In a perfect world, everyone would use a well-calibrated lab oven capable of reaching temperatures up to 350C. However, a variety of equipment can be used for 3D printing purposes, even as simple as a 55C filament drier.

Ovens can be used for filament drying, which means they need to get to 55-90c

Ovens can be used for annealing, which means they need to get to 120-200c

Ovens can be used for turning your filament into a melted mess, which can happen up to 400c or even as low as 230.3c

There are a few different types of ovens commonly used in 3D printing for drying, annealing, remelting, and more, each with their own advantages and disadvantages.

Off-the-shelf, purpose-built filament dryers are generally only really useful for low-temperature materials (PLA, TPU, etc.). There are a few exceptions, such as Sunlu's E2 dryer, but most are effectively overpriced food dehydrators. Many of these options don't fully reach their advertised maximum temperatures and/or don't have sufficient airflow internally to be effectively remove moisture from the filament. They can be a decent solution for storage while printing, but are not recommended for actual drying. Annealing is not an option with these dryers.

An increasingly popular option for filament drying and annealing is an air fryer. Some popular models include the Ninja AF101 and Gourmia GAF716. These provide a compelling balance of affordability and maximum temperature. Since they are forced convection ovens, airflow is also quite good as well. The main drawbacks of a stock air fryer are usually the preprogrammed “cooking” profiles having short maximum durations with no option for full manual control.

While using your standard kitchen oven for drying and/or annealing may seem logical and convenient at first glance, the downsides end up outweighing the convenience heavily. Most kitchen ovens are prone to having large temperature swings (sometimes +/-20C or more), as well as relative temperature inaccuracy. These qualities are important to have in an oven for drying and annealing, where temperature precision is important. Another concern with using a kitchen oven is contamination. Since polymers release various VOCs (volatile organic compounds) and particles when heated, it's generally not a good idea to mix that with food.

A great way to increase the accuracy, stability, and controllability of a basic air fryer or toaster oven is to add a PID controller in place of the original electronics. This will allow for more precise temperatures, smaller temperature swings, and also unlocks the ability to program specific heat-up and cooldown curves over time. Some popular options for these projects include PIDKiln, the Controleo3 convection oven kit, and this project on Hackaday.io.

Lab ovens will be the best off-the-shelf oven option for drying and annealing. They're known primarily for high temperature precision and stability. A relatively affordable option for a convection lab oven would be this one from Amazon. Out of the box, it is able to hold temperatures within +/-1C and is well insulated. This oven is capable of up to 300C and will run for as long as the user needs at any temperature. The only real downside of cheaper lab ovens is the lack of ramping/soaking programming. Instead, the user needs to manually control the heat-up and cooldown rates.

When replacing the stock control unit in an oven with an aftermarket PID controller, there are two main paths to consider.

Utilizing a Raspberry Pi (or similar SBC), Klipper/Kalico can be used as control software for an oven. The chamber temperature is essentially controlled in the same manner as a standard bed heater in a 3D printer and can be programmed in various patterns and profiles.

For a less DIY solution, there are a number of off-the-shelf PID controllers on the market that can be used on their own to add ramp/soak functionality to various oven types. Some popular options are the DIN 1/16 form-factor Auber Instruments SYL-2353P and DIN 1/4 form-factor Novus N3000. The SYL-2352P is also available in a WiFi-enabled version (AW-SYL-2352P) that allows for profile, settings, and program changes from a smartphone app, instead of directly on the controller itself.