Autolevel Idea

Call me crazy, but wouldn’t it be easier to put simple microswitches on the corners of the build plate and have the nozzle click them one by one to do the autloevel/tramming? Seems like everyone is trying to figure out the best way to mount a sensor on the carriage next to the hotend. Wouldn’t it work better to mount switches on the build plate and not have to worry about the probe and such? just wire them so that clicking any one of them closes the circuit and reads as a touch.

Just thinking out loud here… but it seems to be a simple solution.

Except, that you’d want them to be well registered to the height of the build plate, so if one was up even a little, it wouldn’t be worth it.

Plus, in my configuration, I am sensing 9 points and it’s creating a mesh. You wouldn’t want a switch in the middle of the plate. And if you’re going to have a sensor might as well have just one on the carriage.

Also, there are a lot of reasons to not do autolevel, which you can find Ryan’s post about in the FAQ. I use it and I like it, but I don’t print very often.

I like the idea though. It’s clever. Thanks for sharing.

I print on glass, and it’s “even enough” for my needs… so if I have three points level I’m good to go. I am actually using the MPCNC, but this seemed more printing related than the MPCNC area.

Leveling isn’t a regular task for me, but seems like an area many people are focusing on. Also, I like to reduce the weight and complexity of the carriage as much as possible.

As I said, I was just thinking out loud…

Thanks for the feedback

How about a hardware levelling solution?

Let’s say I mount my build surface on 3 height adjustable points, creating a plane which can be angled independently from the plane of the gantry.

If these 3 mounts were able to be either tightened off, or left so that there is enough friction to overcome gravity and momentum, you could simply mount say a roller ball attachment and visit the points of the mounts to level with respect to the gantry plane, then tighten.

The problem I can see is that for larger builds, the build surface would need to be very rigid, or well supported so that it can span the mount points without deflection from gravity.

No substitute for a well engineered machine obviously. The gantry plane is created by 4 points, so you might have something far from a plane to start with, so your Z would be non-perpendicular until that is fixed.

@James, isn’t that what you already have? Three screws to adjust the plane of the plate, trying to make it parallel to the gantry. If your build plate is a perfect plane, then you should be able to adjust it perfectly, assuming your gantry also moves in a plane. On my MP3DP, I have an inductive sensor that will read the distance from the Z=0.0 plane at 9 points. Then, when printing, it will bend the print around the bulge in my build plate. This will compensate for some odd errors in the plate, or the gantry, but it adds complexity to the hardware and the software, and it adds the problem of having the Z axis constantly move around while putting down a layer. It’s a pretty common setup.

I fail at reading posts :confused:

I jumped from reading about turnbuckle legs on the MPCNC somehow to this thread without noticing it was about the MP3DP.

I am interested in Dui’s implementation of a drop table, and converting to a large z 3d print envelope, so very interested in levelling the MPCNC without software.

I use Repetier firmware on my 3d printer and have a z-probe based levelling. Not with a sensor like you, but with a detachable microswitch dialed in to the height of the nozzle.

I just use the 3-point approach rather than the grid. After going to all the trouble with software levelling, I find myself using a piece of paper and turning the thumbscrews to level the bed over z-probing.

I’m glad it’s working for you, I might go back to again if I ever go back to the 0.4 mm nozzle. First layer adhesion is much less of an issue with a 1.2mm hose on there :smiley:

James, this was probably better suited to the MPCNC thread since it IS an MPCNC that I’m using… but since it’s specific to printing I started it here…

Aha, good to know.

I’m still mulling over leveling the MPCNC, since I heard Ryan suggesting cutting a bit of surface flat as a solution to having a really flat surface to mill PCBs. That’s the advantage over a 3d printer, you have the nuclear option of routing the entire spoil board flat!

You could also just mill some holes for the legs. If you cut 3/4" holes to -5mm in 3 spots, then you could put feet on your print bed, and have them in those holes and it would be nearly as level as if you surfaced the spoil board. It would save you an hour or more of milling, perhaps.

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Yes the idea of having 3 adjustable mount points for the bed was the mental step from milling it flat every time.

So you’re thinking of a print build surface that sits on the spoil board on feet, which sit in holes in the spoil board. Sounds like a good way to level the print surface without losing too much z-height, right?

But I am also thinking of plotting and drag cutting, so I was more thinking of a quick leveling solution for all applications in a system with a droppable build surface, like Dui’s. I appreciate you can spring load pens and cutters to reduce any level problems, but that will create pressure changes which could show up in pen thickness changes, etc.

Yes, that’s what I’m saying.

If you’re making the area pretty big, then the feet idea breaks down. For one thing, you want the surface parallel to the XY plane, and that plane isn’t perfectly flat. Milling the area first will make it parallel, as long as it’s rigid and consistent. At some point, your going to have some error.

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