The housing consists of two parts – a front and a back – and is made of PA6-GF. It is mounted on the right inner wall without restricting the movement of the build plate. The images shown are simplified, as my prototype was a bit over-engineered.
Important Notes:
The distance between the bottom edge of the housing and the plastic floor of the chamber should be at least 5 cm. If the heatbed/built plate is within the area of the warm air outlet, the heater should be switched off as a precaution. Such a DIY heater may only be operated if applicable technical and legal regulations permit it.
I tried something similar to this with my p1s. I ended up having a very difficult time keeping the temperature consistent. I was using a pi to control a heating element and fan speed based on 2 temperature sensors at the top and bottom of the case.
Oh, that sounds like a sophisticated solution on your side. Unfortunately, I’m not an electronics expert – what exactly is a Pi?
Here’s how it works for me: The fan motor in the heater is rather weak and produces only a mild, barely noticeable airflow. Therefore, there’s no need for throttling. In fact, I consider the weak airflow an advantage — the air coming out is certainly well above 212 °F.
The temperature controller is very simple: when the set lower limit is undershot, it switches the heater on; when the upper limit is exceeded, it switches it off again. A more elegant solution would be dynamic control of the heating element, but that’s beyond my skills. So the real “art” is positioning the temperature sensor correctly inside the chamber. Based on gut feeling, I placed it a little higher on the left side next to the housing so it sits in the intake airflow. The picture shown in the post is misleading — the housing also has ventilation holes on the left side. With my setup, the control loop works very reliably.
I designed this pretty spontaneously – and to be honest, it’s hopelessly over-engineered. That’s why I simplified the views using AI. Once I have a clean, presentable version, I’ll be happy to share the STL files here. My post is mainly meant as inspiration for anyone considering building their own chamber heater.
One more note: I’m based in Europe, but I tailored my post and the links to the US, since I assume most forum members are located there. I made a mistake with the link to the temperature controller – I’m actually using the version where the control unit is not integrated into the plug.
The DIY heater idea is creative, but there are some clear risks to keep in mind:
The exhaust stream is “well above 212 °F,” which risks hot spots on the bed and parts. A diffuser or deflector would help.
Simple on/off thermostat control with a loosely placed probe can cause big temperature swings. PID control or at least tighter hysteresis would improve stability.
Weak airflow reduces noise, but it also means poor mixing and strong gradients. A small circulation fan could balance this out.
Safety margins matter: keep clearance, use heat-rated wiring, and add a thermal fuse as a fail-safe.
One idea could be to take this further and turn it into a “bentobox” style unit: a compact module that not only provides chamber heating but also integrates a HEPA/carbon filter and circulation fan. That way you’d stabilize chamber temperature, improve air quality, and manage airflow in a controlled and enclosed system rather than just blowing hot air into the chamber. Carbon filters don’t perform well at higher temps, so efficiency might be limited in such a setup — but still worth trying.
I see that you took great care to place a piece of Kapton(polyimide) film on the bottom. Was that to protect the printer floor plastic from heat damage?
I hadn’t considered Kapton - that’s actually not a bad idea. In reality, though, it’s a 0.5 mm copper sheet. The main purpose was to spread the heat more evenly and reduce the temperature spikes measured at the outlet. The housing sits slightly above the chamber floor, and I was hoping convection would carry the hot air upward on its own. But in small enclosed spaces, relying on natural convection can be tricky.
The images show the housing parts from both the outside and the inside. The red area on the inside indicates a copper plate that can be inserted from above. It prevents the plastic from being exposed directly to the hot air. The cutouts in the housing halves are designed to prevent heat buildup.
Earlier I suggested that a 100-watt heater might be sufficient instead of a 200-watt unit. That was incorrect. In fact, even 200 watts is rather insufficient. At higher chamber temperatures, a lot of heat is lost through radiation from the aluminum housing. If you don’t want the heater running continuously but instead at about a 50% duty cycle during printing, you’ll only reach a chamber temperature of around 128 °F. However, this is already enough to noticeably improve print quality with ABS, ASA, and similar materials.
