Trachsou
Posts: 1
Joined: Sun Dec 23, 2018 5:35 am

First layer height setting

Sun Dec 23, 2018 5:47 am

Hello everybody!

My problem is that when I tweak the first layer setting going under 100% it will still change the extruded amount of the first layer (checked in gcode). Although, S3D says : "Percentages under 100% will reduce the height of the layer being printed (with no change to the extrusion amount)".

Anybody got an idea what I'm doing wrong?

Thank you

Trachsou

S3D-Alex
Posts: 449
Joined: Thu Aug 30, 2018 1:23 pm

Re: First layer height setting

Thu Dec 27, 2018 1:12 pm

This has changed for Version 4.1. The First Layer Height will no longer keep the extrusion rate consistent. It will now alter it accordingly depending on your layer height as it does for all other layers. If you want more extrusion in a smaller first layer then you will want to use the g-code offset going forward. This is a more consistent way of handling first layer settings going forward. Please let me know if I can be of any further assistance.

wirlybird
Posts: 1243
Joined: Sun Jul 17, 2016 1:32 pm

Re: First layer height setting

Thu Dec 27, 2018 1:17 pm

How about an example or more details on the "gcode offset" you mention.

S3D-Alex
Posts: 449
Joined: Thu Aug 30, 2018 1:23 pm

Re: First layer height setting

Thu Dec 27, 2018 1:29 pm

Thank you Wirlybird,

The setting I was referencing is known as the Global G-Code Offset. It can be found in the G-Code tab of the Process Settings in the lower left. This allows you to set offsets for your X, Y and Z axis.

If I am printing at say .2mm layers and I set my G-Code Offset to have a Z Offset of -.05mm then my first layer will print at .15mm with the same extrusion amount it would usually use for a full .2mm layer.

wirlybird
Posts: 1243
Joined: Sun Jul 17, 2016 1:32 pm

Re: First layer height setting

Thu Dec 27, 2018 1:39 pm

Ok, I wondered if you were referring to the Z offset.

airscapes
Posts: 374
Joined: Tue Mar 06, 2018 10:35 am
Location: Philadelphia PA Area

Re: First layer height setting

Thu Dec 27, 2018 7:47 pm

Have not downloaded the new version for obvious reasons, but currently I leave he first layer height set to my printers default which I think is 95% then print and measure calibrations squares to tweak my firmware Z offset to achieve the proper height part.
I assume from your statement that when I do move to 4.1 I would set the first layer height to 100% and proceed as I always did in tweaking my starting height as it is no harder to do than the global Z offset. Is that correct?
Thanks

User avatar
dkightley
Posts: 2366
Joined: Tue Mar 10, 2015 4:09 pm

Re: First layer height setting

Fri Dec 28, 2018 6:40 am

An unconfusion is required...…

In settings in S3D, there are a total of three different settings that have X, Y & Z offset in their name....and surprisingly, each has a different purpose...

Lets start on the G-Code tab....the right hand side to be more accurate. There's an ORIGIN OFFSET for each of the axes. These values adjust the "origin", ie the point x=0, y=0, z=0 for where the slicer starts from. My printer (MakerBot Rep2) has the origin in the centre of the bed...so the X-axis and y-axis offsets are half the x and y bed size, and the z-axis offset is zero. Printers vary, so don't take my values as gospel for all printers. These values are the ones that can be written to your printer firmware....and are the STARTING POINT for every printer of the same type (in my case, MakerBot Rep2s and Rep2Xs).

Now let's move to the left hand side of the same setting tab. Here we have Global G-Code offsets for each axes. These effectively do the same as the three offset settings...BUT are for tweaking the starting point for YOUR printer...and your printer only....by a small amount in either a positive or negative direction. Invariably, you'll only ever need to adjust this offset for the Z axis. The effect of this would be to move the printer head up or down in relation to the bed so as to tweak the first layer height or to increase/decrease adhesion to the bed.

The third and final set of offsets are in the Model Edit window...at the top. These adjust the position of the origin of the model in relation to the STARTING POINT for printing. Adjusting the z axis in a negative direction will move the model downwards, the result being that the very bottom of the model, being "below" the z=0 point, will then not print.

Looking at the changes in the latest release.....nothing affects what I have described above! What has changed is the "first Layer Height now reduces the amount of plastic extruded when you reduce the value below 100%...whereas before it didn't.

I hope this allows your questions to be answered.....
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net

airscapes
Posts: 374
Joined: Tue Mar 06, 2018 10:35 am
Location: Philadelphia PA Area

Re: First layer height setting

Fri Dec 28, 2018 7:31 am

Thanks Doug, it is a real shame this type of information is not properly documented for each and every setting in the software and updated with each release. Thank you very much for the full and properly detailed explanation of the Gcode page. The Mod should make you post a sticky!

And yes this answers my question regarding my printer and the way I mange the starting height when I change layer heights or hot ends. The answer to my question, about my printer only, is "Yes". Set the first layer height to 100%, then set the machines internal Z offset using the terminal as I have always done.
Have a happy new year!

S3D-Jake
Posts: 948
Joined: Wed Jun 20, 2018 12:45 pm

Re: First layer height setting

Thu Jan 10, 2019 12:19 pm

The changes to the first layer height % setting were meant to limit confusion within the software, as the previous function of that setting meant that there were two areas of the software where you could effectively accomplish the same thing. Now there is only a single way to lessen the gap to less than 100% of the layer height and still extrude a non-scaled amount. Our marketing team has planned a few updates to our web resources that will help educate newer users on the new best practices for perfecting their first layer.

The G-Code tab behaves as it has in the past and is fully documented in a stickied post in the general discussion sub-forum. The exact topic where the G-Code tab is explained is tip of the day 26: viewtopic.php?f=8&t=2366
"A bird does not sing because it has an answer. It sings because it has a song."

lnquang
Posts: 1
Joined: Wed Jul 28, 2021 10:45 am

Re: First layer height setting

Wed Jul 28, 2021 10:48 am

i just set first layer height to 10% and extrude width to 1000%, so I dont have to adjust print bed every time I change print layer height from 0.12 to 0.3mm. Suggest new version allow ignore first layer height or allow set to 0.

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