Glass Heated Bed Mounts Brackets - Magnetic, Folgertech 2020 Prusa i3

thingiverse

This is my effort at making my build glass removable. I've tried several other methods, none of which I liked, I love magnets and seeing make many offer manufactures use them I figured out a way for me to adapt them to my Prusa i3. It's a pretty simply concept, make the glass long enough to overhand the heated bed and make brackets to hold small magnets. I have uploaded only one STL file, you will need four brackets two opposite, so simply mirror two of them. I used these magnetic from Harbor Freight, the are really cheap (10) for $2.99 and should be easily accessible for most. I have included my method of assembling this (see "Instructions"), I'm sure there are many suitable alternatives, but I wanted to at least give one. NOTE: If you don't want to use magnets you can simply use binder clips to hold the glass to the brackets. This sets the binder clips well out of the way of the hotend...no more flying clips LOL Update (2-29): I finally got both glasses finished and I have to say I love this upgrade. No more binder clips to get in the way and a super easy way to change glass when my Kapton Tape gets jacked up, you can also pull off the hot glass and start a new print right away (no more waiting for cool-down)...win/win if you ask me ;-) Instructions/BOM BOM Glass: Size: 200mm x 250mm x 3mm. Type: Window Glass 1/8" (3mm) thick Source: Ace Hardware, cut to order ($2.50 per sheet) QTY: ~2 (you buy as many as you want) Magnets: Source: Harbor Freight Type: http://www.harborfreight.com/10-piece-rare-earth-magnets-67488.html QTY: 2 pack (12 required for two glass sheets, 4 for each additional glass sheets used) Printed Parts: Source: You QTY: 4 (2 Mirrored) Adhesive: Type: General Purpose JB Weld Source: Just about anywhere QTY: The smallest pack you can find will most likely work Instructions: Glass: Edges: I used a soft grinding wheel to sand the edges of my glass, if you don't have a means to debur the glass edge see if the place you purchase the glass from can (my Ace Hardware does not). Most "Glass" Shops can do this for you. Prep: Prep the four corners of the .75" X .75" for bonding the magnetic. I used a laser engraver to etch these areas, but a firm hand, some time and sandpaper should give similar results. The surface just needs to be roughed up a little to promote a better bond. Magnet: Prep: Sand one face of each of the 8 (initial) magnets, be sure to sand the opposite faces on four of them. Installation: Printed parts: Prep: I left the holes in the corner brackets small so they will need to be tapped to M3. This is so you can secure the brackets to the heated bed. If you don't have a tap you can open the holes up with drill, but leave them small enough the the screw threads itself on. Assembly: -Remove you heated bed from your printer and install the four corner brackets as seen in the photos. -Reinstall heated bed Bonding: Prep: -Use tape to cover the face printed parts (this is to keep the glass/magnet from bonding to the corner brackets) and cut out the magnet holes. -Clean and wipe all bond-able surfaces of the glass and magnets with your preferred cleaning solvent. -Mix up a small amount of JB Weld (very little is needed) -Place pairs of magnets in each corner bracket, I made sure they were all going in, in the same direction. This will allow all of your glass beds to mount in any direction. -Apply a small dab of adhesive to the tops of each magnet...this should a very small amount as it will spread out when the glass goes on. -Set your glass in position, be careful to get it right the first time, if you move it it will smear the adhesive and make a mess. Curing: -I use the heat from the heated bed to accelerate the cure of the adhesive, it should cure in about 2 hours at 80C (your time may very), but it's best to leave the extra adhesive on top of the glass while curing, once it's cured it okay to assume the magnet adhesive has cured as well...it never hurts to give it come extra time though. -If you don't want to use the heat from your bed you can let it cure overnight. Clean up: -Carefully remove the glass, remove any excess adhesive from the glass and brackets. Bracket Bonding: -At this point you magnets are still not bonded in the brackets...simple repeat the bonding process but apply adhesive into the pockets of the brackets. make sure you use the glass to set the magnets in the brackets, it does two things for you. Insures the magnets are properly located, and more import, they are put in the proper direction. -Repeat the cure for the brackets NOTE: You could cure all magnets at the same time, but I prefer to do them separate to make sure all goes well on the glass first, it also allows me to clean up the brackets a bit if needed prior to bonding in those magnets!?!?