Home position problem + goos skirt, but then pants :-(

Hi all,

I just got my first printer; a AnyCubic i3 Mega S, and I'm using Cura 4.71

Aside from the test print (the owls), yesterday I did my first print of something of my own design using the same settings as the test print. It went really well and I was chuffed to bits. The end products are two supports that will clamp onto either side of my large, but slightly unusual dining table, and will hold a table-tennis net across the table. Today I started to print the second identical support. I made no changes. I used the same g-code file.

The original "home" position of the nozzle was over the plate at the bottom/left corner (where the nozzle would go down and then back up again to de-splodge itself). Now the "home" position has shifted to off the bottom off the plate. So now the de-splodging doesn't happen, because the splodge doesn't touch the base when the nozzle comes down. I have read and looked everywhere I can , but can find no instructions on how to tell the printer where home is. The Z limit switch is solidly fixed.

In addition to the above problem, something else odd and frustrating is happening now. The skirt prints well (the splodge at the start notwithstanding). After that, the first layer of the actual peice is pants :(. The printer seems to want to print the lines super-thin/non-existant. I haven't changed anything. Why would the skirt print (and adhere) perfectly and not the rest? I have re-checked the plate level and it is fine.

I've upload a short video to show what I mean about the pants first layer - https://youtu.be/HB2Mzcri6ts.

Thanks in advance.

Sud

Did you check the axis correctly?

you re calibrated way too close to the printbed.

cura is not good and certainly not easy to use or adjust.

try pdownloading prusaslicer.
https://www.prusa3d.com/prusaslicer/

Also unless you change the bed levelling nuts for locking nuts - bed calibration tends to be a constantly ongoing thing with i3's .

Quote:

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Originally Posted by mikahawkins

Did you check the axis correctly?

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Hi,

Thanks for your reply.

First off, I apologise. I just now realised that the vertical axis is the Z-axis in 3d printing. I naturally assumed it was the depth (back-to-front).

When I first printed the sample owls, the HOME position of the nozzle was over the bottom left corner of the plate. Now, for some reason the HOME position has shifted to just off the bottom edge. The X and Z axes are fine (the nozzle is close to the plate level, and the nozzle is inside the left edge of the plate), but the plate travels too far towards the back, and so the nozzle is then below the bottom edge. See attached drawing.

The only thing that I can check, and alter, is the plate level, but that doesn't mpact the HOME position of the nozzle in the Y-axis.

Quote:

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Originally Posted by curious aardvark

you re calibrated way too close to the printbed.

cura is not good and certainly not easy to use or adjust.

try pdownloading prusaslicer.
https://www.prusa3d.com/prusaslicer/

Also unless you change the bed levelling nuts for locking nuts - bed calibration tends to be a constantly ongoing thing with i3's .

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Thanks for the advice.

I have swapped over to Prusaslicer now. The first layer is still not great, but it may be, as you say, due the constant atteniton the bed-level needs. I haven't been checking that.

On the whole though, de-splodging notwithstanding, the 3D printing experience is a fulfilling one :)

Many thanks.

The first thing I do with a new machine is to change the bed level nuts for printed ones with nylock locking nuts inserted.
Pretty much solves the bed levelling. I level Maybe once a year, maybe less :-)

The other thing you can do is to adjust the z-gap in the slicer. So you can try making the gap larger or smaller.
in prusaslicer it's here:
Attachment 15457

I usually adjust by 0.1 mm increments. so positive numbers to make the gap larger: 0.1, 0.2 etc and negative valuse to reduce the gap: -0.1 etc.

And yep 3d printing is pretty amazing.
Still blows me away that i can think of a widget and design it and hold one in my hand an hour or two after thinking of it.

Thanks for the tips.

I'll check the bed level before I print the bed-level nuts :)