Precision incense heater (aka subitism) build with details
I built this precision heater (aka "subitism") a few weeks ago and it's been working great. Total cost was $85. Here's all the details on how I built it. Feel free to ask questions.
##0. Safety
These DIY heaters (or even commercial ones) are inherently unsafe. Don’t be dumb. Keep away from children, pets, and anyone that can’t be trusted. Remember to shut it off (use some kind of automatic shut-off timer if you have trouble with that). Don’t use a metal tool to place incense on the heater as you could accidentally short the heater and damage the power supply. Build and use at your own risk.
##1. Educate yourself
This entire build is based on the design by Kyarazen. Do an internet search for "how to build an electric incense heater" and read the blog post. He provides a lot of good information, but also leaves out some key details. There are some posts here in the subreddit that I found helpful as well. Once you understand the basic idea of the build, this post will help you fill in the gaps.
##2. Shopping list
Holder
- I used a small 5" bowl from a china set I own.
- Something with 2" of flat space at the bottom is ideal
Raw Mica Sheets (2x3")
- Two sheets for the build and one sheet to heat on, which can be used multiple times but will need to be replaced from time to time
- Only place I could find raw mica was Etsy
Nichrome 80, 32 gauge
- You'll only need 27cm for the build
- Purchased from Amazon as a 33' roll
DC Variable Power Supply
- Adjustable voltage is key, the one I purchased is 3-24v
- Check cord length before you buy to make sure it suits your needs
- I purchased the "Shnitpwr" brand from Amazon, works fine but the voltage drifts down over time, also the control is very sensitive
Female power plug with leads (2.1mm x 5.5mm)
- Purchased from Amazon
M3 brass standoff kit
- I used four 20mm stand-offs with studs, four 10mm stand-offs with no studs, 8 screws, and 2 nuts
- Purchased from Amazon
Small neodymium (rare earth) magnets
- These are used to secure the heater to a ceramic dish and to secure your heating mica sheet on the heater
- Purchased from hardware store
2” metal fender washer
- Placed under the ceramic dish to hold the rare earth magnets to the dish
- I like this solution as it allows me to secure the heater without using glue
- Purchased from hardware store
M3 washers
- Used for clamping ring terminals and nichrome wire to the stand-off studs
- Purchased from hardware store
Ring terminals
- Crimp these to the leads of the power supply plug and then you have something that can be cleanly clamped to the stand-offs
- Any basic wire stripper tool should have a crimping tool on it
- Purchased from Harbor Freight, but auto stores probably have them, just make sure they include small enough ring terminals for your stand offs
Awl
- Very simple, cheap tool to put holes in mica
- No need to mess with a dremel/rotary tool, a sharp nail would probably work well too
- Purchased from hardware store
##3. Build Notes
Punching the holes for the stand-offs
- This is where you are most likely to break the mica sheet, so do these first before punching the much smaller holes for the nichrome wire.
- Go very slowly with the awl and test to see if the studs/screws will go through the holes before making the holes too big.
Connecting power plug leads to nichrome wire (see image #3)
- I stacked everything on the stud of the bottom stand-off post in this order: mica sheet, washer, power supply lead with ring terminal crimped on, washer, nichrome wire with a little hook to secure around stud, washer, top stand-off screwed down tightly. Overkill perhaps, but I like clean connections.
- Do this on one stand-off, then thread the nichrome through the mica sheet, and then repeat on the other stand-off.
Threading the nichrome wire through the mica
- The awl just barely needs to go through the mica to make a hole big enough for the wire.
- I made a template based off of the Kyarazen design on a piece of paper, then taped a piece of mica over the template and made my holes.
- The passes were 25mm long and 3mm between each pass, you don't want the passes touching each other.
Do you need a precision (subitism) heater?
- No, you don’t. A simple electric ceramic heater works just fine and is available for cheaper than the parts to build this precision heater. You can get an adjustable tea-light heater for even cheaper, which also works great.
- The main advantage of the precision heater is it gives you instant and precise control over the heat. This is nice as you can much more easily play with the heat and see how it changes the experience of the incense.