Taz Magnetic Bed System

thingiverse

(parts are listed at end of this) I have been using a auto level probe for while. At first I clamped a .4" thick sheet of aluminum with a 1mm sheet of PEI over it, using 12 clamps to clamp the the glass bed. It worked okay but was a pain because of the clamps and the center of the PEI was a little flexible. For the most part, the nozzle prevented any serious bow. I had to use a large 18mm inductive probe because the aluminum cuts the probe sensing gap in half. Then I tried a piece of steel sheet metal and was able to switch to a smaller 12mm probe and get the same gap distance. I have now graduated to a magnetic bed and am very happy with it. The concept should work on any similar machines. This is my latest bed for my Taz-enstein 4. It is a sheet of 285 F (141C) phenolic cut to 300x300mm on my slide miter saw. I routed 25 holes spaced at 60x60mm. The magnets are high temperature 3/8" x 1/16" N42SH. The metal removable bed is a piece of zinc plated sheet metal, 12"x24"x26ga, from Home Depot. I live far from any metal supply house or I would have gotten something that was tempered. This was about $5 and enough to make two plates and works better than I expected. The top layer is a .2mm 300x300mm PEI sheet with pre-applied 3M adhesive I got on Amazon. In order to cut the plate you should use a cutoff wheel, not tin snips, to avoid kinking or creasing the plate. It needs to be handled with care and kept as flat as possible. On my first try I used a Dremel type tool with a 1.5" cutoff wheel. On my second try I used a small circular tile saw with an edge guide and a 4.5" metal cutoff disk. Methods worked fine. My miter saw has a 5% reverse hook thin kerf blade and cut the phenolic accurately with no burn or kickback. The only thing that might be difficult without a CNC machine are the circular pockets for the magnets if you don't have access to that. The pockets leave .83mm (.033") of material between the magnet and the metal sheet. That's not easy to do by hand. The placement does not need a lot of accuracy, but the depth does. The bed corners are based on the stock bed corners. The springs are removed and screws reversed to mount the modified corner. The old finger is still used. I have some 3 mm inserts I got on Amazon. They are 3x4x3, small, so you will probably need to modify the hole in the stl file if you have large inserts. Or redesign the corner. Note that the pocket depth for the glass heater bed and phenolic is about twice as deep as it was on the stock corner. I had intended to use some high temp silicone to hold the magnets in the pockets, but I found it was not necessary to use any adhesive at all. You turn the phenolic upside down (pockets up), place all the magnets in the pockets, place the metal plate under the phenolic plate, and the magnets will stay put while the plate is there, and until you have the magnets against the glass bed. (It is very cool taking the metal plate on and off and hearing the magnets jump to the top of the pockets, or fall away when the plate is removed). the metal plate need to be close to 300x300mm also, but it can be a little smaller. The edges top and bottom need to be dressed with a file, and the corners ground off to clear the clamps. Make sure to get rid of all sharp edges and burrs before thoroughly cleaning both sides with Windex and alcohol before applying the PEI sheet. The corners of the metal sheet are removed to clear the bed fingers so the plate can be removed without releasing the corner fingers. Parts: 25, 3/8 x 1/16" D61SH (N42SH spec), neodymium magnets www.kjmagnetics.com 1, 887480015379 Sheet metal zinc, 24x12x26ga Home Depot Wisamic PEI Sheet 300x300mm with 3M Adhesive Tape www.amazon.com/gp/product/B079FQPFXW/ Phenolic Sheet, Tan, 0.125" Thickness www.amazon.com/gp/product/B0013HKZD6 4 Bed corners