3D Printing Basic Question

[Enough!Participant @enough]

Why does the recommended method of levelling the bed always seem to involve shenanigans with paper sheets (standard thickness of course) or perhaps, for people here, feelers? With the attendant difficulties of "feel".

Why wouldn't a better method be to bias the bed upwards until it touches the nozzle (spring loaded piston) in four corners, lock it up there then set an appropriate gap in the software (where you could actually treat it as a variable)?

[Enough!Participant @enough]

Levelling/aligning the bed

[Paul LousickParticipant @paullousick59116]

A sheet of paper is a convenient feeler gauge.

The bed is not always perfectly flat and can deflect slightly when heated and the nozzle could scratch the surface of the bed when you move it from one corner to the other. (don't ask me how I know).

Paul.

 

Edited By Paul Lousick on 08/12/2017 23:53:36

[Neil WyattModerator @neilwyatt]

I came across a new method that mounts the hot end on a piezo sensor and recognises the 'tap' of it on the build plate. This is used to build a model of the surface with a few or many points.

Other ways are to use capacitative proximity sensors or swing away microswitches.

I must admit I use a super advanced and highly specialised technique called 'eyeballing' the reflection of the nozzle in the build plate…

I find setting the plate level is a rare exercise, while adjusting the z-height needs to be done every week or two – or if you do something like change a nozzle.

Neil

[Enough!Participant @enough]

Posted by Paul Lousick on 08/12/2017 23:52:51:

A sheet of paper is a convenient feeler gauge.

The bed is not always perfectly flat and can deflect slightly when heated and the nozzle could scratch the surface of the bed when you move it from one corner to the other. (don't ask me how I know).

 

I can see that on an aluminum bed (uncovered at that) but is that really likely to be a problem on a glass bed with a brass nozzle? And if there were slight scratching of the glass, so what? Typical glass beds seem to fail sooner rather than later by "de-laminating" (not the right word – peeling off the surface). Particularly with higher temperature materials. I've already had to replace mine and others have done the same. And given the junk we put on them such as glue-stick etc which dries unevenly, the effect on the part isn't likely to be great (although I've found a better way with glue sticks).

To each his own on the paper feeler gauge. To me, it's like a wet noodle …. not to mention that local sources of (copy) paper bear no relation to the thickness that the printer manufacturer claims.

Edited By Bandersnatch on 09/12/2017 19:45:49

[Enough!Participant @enough]

Posted by Neil Wyatt on 09/12/2017 08:04:37:

I came across a new method that mounts the hot end on a piezo sensor and recognises the 'tap' of it on the build plate. This is used to build a model of the surface with a few or many points.

 

Hmm … bit complicated for my addled brain really. I just wish I could find some reasonably straightforward slicing software that would let me set an initial gap so that I could at least experiment …. it may be out there and I haven't run across it yet – I just don't want something that will involve me in more time learning the software than actually doing anything.

Edited By Bandersnatch on 09/12/2017 19:48:29

[pgk pgkParticipant @pgkpgk17461]

If it's the whole machine you need to level (as opposed to the bed within a stand) then for something with this size footprint couldn't one just float a thin epoxy into a tray and let it self-level?

[Neil WyattModerator @neilwyatt]

Posted by pgk pgk on 09/12/2017 19:57:32:

If it's the whole machine you need to level (as opposed to the bed within a stand) then for something with this size footprint couldn't one just float a thin epoxy into a tray and let it self-level?

It is the bed within a stand, the beds usually have an adjustable three or four point fixing. My printer sits on six medium density foam pads to keep the noise down.

Neil

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