Don’t bother with normal mk2 beds in such a size. The best option is to use Solid state Relay and Silicon heaters.
You will need DC to AC Solid State Relay (SSR) and AC silicon heater pad (you will find the sizes you need like 300x300mm ) (one/relay). They heat up much faster than mk2 beds and usually include a 100k thermistor inside.
Keep in mind that it might be a good idea to include a switch on the SSR-s so if you don’t need all the print surface heated than you can switch off the heaters witch not required.
I have a coreXY in build 90% functional that uses 4 200mm sq heated beds for a total print area just over 400mm sq or roughly 17in on each side. Height is only limited by the rigidity of the frame. I run my beds from 18v so you can either run to beds in series and the pair in parallel drawing about 500w or you can run two beds in parallel and then in series with the next two beds in parallel; 1000w. These are 12v beds. At 500w you can reach PLA printing temps, at 1000w you can reach ABS printing temps. That will be 10A draw from a 120v outlet just for the beds. I am currently wired for 500w myself as printing an abs print that large with the issue of warping is unreasonable. Ian running off board (externally mounted) FETs to overcome the large current draw as the single one on a ramps board is not enough.
Yeah I primarily print abs, thank you all so much for the replies and ideas! When I referred to the alligator board I meant it with the upgrade attachment as well, if that makes any difference. I’m hoping to do it the most cost effective way as possible, may I ask what the price ranges for your alternatives are?
If you had multiple power supplies or one very large one you could probably get away with it but do you need a heated bed at all? Some types of plastics like ABS don’t require one. PLA does but I’ve read that you can print without it if you use things like blue tape and/or hair spray. Then there’s the option of making your own. I’ve seen Indestructibles on this.
Ummm, sorry, but this is completely wrong… You ABSOLUTELY need a heated bed for ABS parts of any size… It has way higher warpage than PLA (1.5%-2.0% vs. 0.4%) and will peel off the buildplate if not heated (to between 90 and 110 degrees C) and coated with some film or adhesive.
Conversely, PLA almost doesn’t need a heated buildplate, but it becomes necessary for larger parts (typically a bed temp between 30 and 50 degrees C is good).
A lot of this could be your nozzle offset for the first layer as well. Try printing a calibration cube (here’s one: 40mm Cube Test Object by bre - Thingiverse 3) and making sure it’s actually the height it’s supposed to be. If it’s a little off, either lower your bed a bit, or correct for it in your slicer’s gcode offsets and give that a shot!
And if you want a way lower maintenance coating than painter’s tape, try purple Elmer’s glue stick! It works more consistently, is friendly with a better range of temperatures, is simple to recoat, and washes right off! Just make sure you apply it to the whole bed and you’re set
If your printing Pla on a heated glass bed… My advice is take off the blue tape, clean the hot glass with cider vinegar and print on the clean glass (works every time with no mess) if your bed is heated aluminum I suggest printing on heated kapton tape washed with rubbing alcohol. I’ve never had to use glue or any other messy techniques
Only use use the blue tape on non heated beds as the adhesive will soften and release from your bed at printing temps.
I primarily print with ABS, I do have a heated bed and when I do print in pla, ive never had an issue with the adhesive of the tape, I normally run the bed at 50-60*C With abs, I find using kapton tape with a layer of white Elmer’s glue from a glue stick does the job
Wouldn’t you be best off just heating it with electric underfloor heating? That way you get separate electronics and heat controller, its really cheap and you can just use a levelling compound over the top and some cheap IKEA mirror tiles. Think bathrooms more than 3d printers for really super massive size
