Which format has the most robust and accurate bed design?

I've owned a Monoprice maker select for several years now and have modified it extensively. I've come to find that among other things the bed is a weak link in these printers. I've upgraded to a better carriage and an anycubic glass bed with piezo underbed sensors but even with unified bed leveling I have trouble with the pla prints sticking at the corners. The bed is leveled mechanically pretty well with a max deviation of -.248 at the worst corner. I get to a certain point in the mechanical leveling and I'm just chasing the errors. So which format has the best bed design? Because the flatness/trueness of the bed is a requirement for layer adhesion I will be placing a high priority on this in the selection of my next printer. Your thought on this?

how many screws in your bed?

Four one in each corner.

That's one too many

.25 mm is a rather large gap that will mess up your prints. If you can't get a more even printbead you should use automatic bed levelling to compensate.
The number of mounting points is not realy an important factor in this. As long as the plate is not planar 3 or 4 mount points make no difference. If the plate is planar it is easier to adjust the level with 3 mount points, but it is perfectly possible and not much more difficult with 4.

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yeah but its better to master 3 and then move onto 4 if you need or want to.

I favor cast aluminum tooling plate beds with same-size, line powered heater on the bottom and a thin layer of PEI on top. I put the plate on a 3 screw kinematic mount so it is stable and does not require releveling. The bed is flat, heats evenly and quickly, and prints stick from edge to edge.



For bed moving in Z, here's what I did.

For bed moving in Y, here's what I did.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Thats some very interesting reading TDD. It sound like you have access to machine tools, lathes,mills etc and know how to use them. I unfortunately I don't have that luxury. Thanks for posting, reinventing is never the best way.

When you're trying to make things really good, you have to try to think about what needs to happen without thinking about the tools you have available. Once you've found something that works really well, then start thinking about how to make it happen with the tools you have access to. For example, it isn't necessary to use machine tools to make a kinematic mount for the bed plate. You can do it with a drill, a saw, and a couple taps. The reference hole doesn't have to be chamfered- you can simply drill a hole in the plate that is too small for the leveling screw to fit through. You don't have to use a spherical head screw- put an acorn nut on a the end of a screw instead. The slot is only slightly trickier. You can make it by screwing down two pieces of metal spaced apart to create the equivalent of the slot I milled. Alternatively, you can just cut a slot in the plate with a saw. I milled the teflon blocks with antirotation tangs that allows them to be held in place with a single screw and t-nut each. If you can't do that just use rectangular blocks and two screws and t-nuts each to hold them in place and keep them from rotating. It isn't as neat as using machine tools, but it will work just as well.



Machine tools are nice, but aluminum can be drilled with any drill, and can be cut with a hacksaw.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]