DIY Heated Bed for the Tiertime Cetus 3D Printer

The Cetus mark 1 didnt particularly get a great heated bed option. You need to first buy an add on module thats quite expensive before you can even look into having the heated bed option, so, I looked into other routes.

Some people have made heated beds in the past for the Cetus that involved power resistors bolted or epoxied to the bottom, but, I wanted something a little more polished. Initially I wanted one of those stick-on heatpads for the cetus' existing bed, but no one seems to make them anymore. So instead, I combined a little bit of each of the projects I have seen. I used an external STC1000 temperature controller, and two 100x50mm silicone heat pads made for engine blocks or something for 28$ and wrapped it all up in a nice 3d printed enclosure for far less money than I would have otherwise needed to spend for the official bed upgrade!

Warning!!1 The following involves connecting and or interacting with wires that will be live at mains voltage! Please do not attempt to use my exact method if you are not comfortable with that, and be aware of the hazards if you do.

So, first I needed to whittle down my options, I considered the 8 power resistor route but that felt so janky and seemed like it would only produce hotspots, I had also seen precut silicone heat pads for other printers like enders and prusa likes, but the only one that was made for the cetus and its special bed with the support in the middle made this not an option either. I briefly considered PTC heat blocks, but, they were either too low wattage or just, I wasnt sure how to make them work right. I even considered getting a custom PCB heater made with a pcb service but I eventually stumbled on engine block heaters.

Now, I dont own a car with a combustion engine, especially not a diesel one, so I've never used one of these. But hey they are the perfect size at just 50x100mm, that covers both halves of the print bed fairly well, and leaves space for wiring too :o

So what I ended up using was;

• one STC1000 temperature controller with thermocouple
• two 100x50mm 120 volt adhesive backed silicone pads
• some aluminium tape
• a rocker swith
• various lengths of wire
• a small square of bare PCB material

So after I recieved the heat pads, I put them on the underside of the bed, and found a nice neat location to route the wires along with the thermocouple. I then covered the whole thing in aluminium tape, cut the wires up, connected them to the controller for testing, and proceeded to print with it in this state for over a week, as you can see in the attatched pics.

I did Identify an issue however, or a potential one, anyway. The print bed is attatched by screws into a bracket that is directly ontop of the linear rail. Now, I dont reaaaaaally feel super comfortable putting a bunch of heat into a linear bearing like that, nor the PLA belt mount that also is attatched to this piece of metal. In the official heat bed you get an upgraded bracket with cooling slots in it, but, I figured I would just use an insulating spacer. This is where the small square of bare PCB material comes in, I wracked my brain for something I had laying around that would work as a perfectly flat insulator, and after considering sheet plastics, layers of kapton, I finally thought of PCB material and found a suitably bare pcb with no traces or vias on it to cut a rectangle out of.

After printing with it just laying on the table for over a week, I figured it was time to put it in a case and not have bare mains wires just, around. I got some cable sleeving and got to making a 3d model in CAD for the case. I decided on mounting it under the bed, next to the y axis rail. This includes mounting wings that attach to the existing bolt holes on the printer, as well as a modified belt tensioner cap that allows screws to mount on the front.

And now it's done! I can finally print with a heated bed, goodby lifted prints and hello materials other than PLA! I'm not sure how helpful this Instructable will be, but if it is, let me know with a comment or a make! It always makes me happy when something I made can help someone with an annoying problem like this.