This is copied and pasted from my blog, I thought it may help some people on here with its simplicity. If you would like to see pictures visit my blog at: [
boxedrr.blogspot.com] also part numbers for the heaters are a few posts down in blog.
So over the past few days I have worked on my heated bed, and have finally completed it and tested it.
My heated bed consists of:
1 .25" x 12" x 12" piece of 5052 Aluminum
2 130w 110v flexible heaters rated to 300F wired in parallel
K type thermocouple
Solid State Relay
PID controller
Adhesive backed PET film
I wanted to maximize my build area on my bed so I decided that I would not have any obstructions on the top of the bed. With this design specification I really limited my options of mounting the heated bed.
What I decided to do was drill into the sides of the plate, and tap a 1/4-20 hole for the thermocouple, and drill over sized tap drill holes for the legs. The legs of the bed are held on by 8-32 self taping hex head screws with stainless washers between the bed and leg to help minimize heat transfer into the legs. The bed is run at 220F on my pid controller since there is a little lag between the actual temp and the location of the thermocouple, actual bed temp stays between 225 and 235 which is perfectly acceptable to me.
After mounting this up I attempted a build using painters tape, this was a failure, parts would just rip off the bed once they got about 1" high, so I moved on to the PET film. I haven't printed anything over an inch yet put the objects really stick well to the PET.
I have now started work on my version of wades extruder, which is printed I just have to put it together and see if it works. I need to create a filament dispensing solution (have the parts, need to design/print some additions), increase my resolution (stepper pulleys), and lastly I want to go ahead and make a new extrusion head for my MK5 hot-end that has a .34mm orifice aka #80 drill. I have alot to do, and so little time, Im also thinking of picking up 2 high resolution steppers and looking into new electronics, but thats just me thinking.
