Anyone make their own 3 point bed leveling system? New build and need to make my own.

Anyone make their own 3 point bed leveling system? New build and need to make my own. Looking for ideas from other builders that have gone through this before. I will be using (unless you talk me out of it) 2 8mm rails with 3 bearings for the stage to be supported on, I want to be able to attach a 12 or 16 inch hot bed (they sell these on ebay) with glass above it and need to have access to the 3 points preferably with knobs at the bottom so I can level the bed the best possible way and make small changes while running if needed during first layer. Ideas? I would love to see pictures of your solutions. I am not entertaining the idea of auto bed leveling at this point, I am using 2 inch aluminum D channel extrusion to make my frame. I wanted to make it stronger than it needs to be for repeatability to increase over my current plexiglass frame prusa i3.

I have a glass bed on top of an aluminium plate with heating on the plate.

I Countersunk the aluminium plate from the top in 3 places. Put csk screws through and tightened with nuts below to keep them captive on the plate

The screws poke through springs, then through my support frame below. Adjustment is with a nut on the bottom, with a locknut to stop it moving when set.


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You mean something like this?



I originally used springs between the bed pcb and the bed support, with just 1 nyloc nut on each screw underneath the bed support. But that didn't give enough support, and I didn't have any stronger springs that were also small enough to fit in the space. The supports rarely need adjusting anyway.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Here's the underside of my bed:

The plate is 1/4" cast aluminum tooling plate, milled flat. You can see 3 holes- top, bottom, and right edge. The top and bottom holes are in line with the Y axis. One is used for the fixed reference. The other adjusts "pitch" in the Y axis. The hole at the right edge adjusts "roll" around the Y axis. These are the only two adjustments needed to level the bed.

Here's the top side of the bed with Kapton tape:


The bed is stood on flat head SS screws (the top side holes are countersunk so there's no danger of the extruder nozzle crashing into the screws) that screw into teflon blocks for heat resistance. There are strong springs on each screw that keep the bed pushed up against the screw heads. There are knurled thumbwheels on the two adjustment screws under the bed.

Here's what it used to look like:

That was when I was using belt drive so had to make level adjustments with a screw driver from the top side of the bed. I recently changed to screw drive in the Y axis and now have the knurled thumbwheels as described.

Leveling is simple- first adjust the pitch, then the roll, and takes about 1 minute (after allowing everything to heat up to print temperature). This system works perfectly, and with fully supported linear guides under the bed, doesn't require any readjustment for leveling or zeroing unless I change the extruder.

There is one problem, however. Standing a cast aluminum plate on three screws at its edges makes it into a bell. An it rings, but not in the pleasant way of a wind chime.

Awesome Ideas guys, thank you for sharing!