maddavo
Posts: 14
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Re: First print layers density question

Fri Dec 18, 2015 9:31 am

CompoundCarl wrote:If you have to adjust the extrusion amount for the first layer alone, then your print isn't starting at the correct height. There's no other reason you would need to adjust the first layer flow rate unless the nozzle was not starting at the correct height.
Well, no - not in all circumstances.

Whilst you may not have reasons, and that is completely fine, I encourage you to consider that others may have reasons why they may want to extrude more material on the first layer even if the nozzle is the correct height and the bed is level.

Really appreciate your advice, but bear in mind that other slicers have the option to do this and it works for certain situations and should be an option in S3D.

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jimc
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Re: First print layers density question

Fri Dec 18, 2015 10:48 am

If your not getting a solid first layer or your layer is over extruded and you need to change the flow rate then your bed gap needs to be changed either tighter if not solid or looser if over extruded, plain and simple. There is no reason to have a different flow for the first layer. If so then your just compensating for the gap being set wrong. If you have been using that feature in another slicer then the other slicer has got you into a bad, unnecessary habit.

CompoundCarl
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Re: First print layers density question

Sat Dec 19, 2015 6:35 am

jimc wrote:If your not getting a solid first layer or your layer is over extruded and you need to change the flow rate then your bed gap needs to be changed either tighter if not solid or looser if over extruded, plain and simple. There is no reason to have a different flow for the first layer. If so then your just compensating for the gap being set wrong. If you have been using that feature in another slicer then the other slicer has got you into a bad, unnecessary habit.
I couldn't agree with this more. Well said.

jeevesme@hotmail.com
Posts: 28
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Re: First print layers density question

Wed Dec 30, 2015 10:41 am

The settings should be fairly straight foreword. It shouldn't be this difficult to figure out. I didn't pay $150 to try and guess what settings do what. I'm contacting S3D to see if they can explain it.

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dkightley
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Re: First print layers density question

Wed Dec 30, 2015 11:43 am

Having read through this topic, I can see a level of confusion here. S3D has the ability to vary the extruded width and extruded height of the first layer. Taking exactly what I have said....and nothing else.....the following has to be true:

* With the first layer width set at 50%, the individual extruded lines are laid down at half the pitch as compared with 100%, and the rate at which the plastic is extruded is reduced accordingly to maintain the same layer thickness.
* With the first layer width set at 150%, the individual extruded lines are laid down at one and a half the pitch as compared with 100%, and the rate at which the plastic is extruded is increased accordingly to maintain the same layer thickness.
* With the first layer height set at 50%, the height of the extruded layer is reduced by 50%, the nozzle being at half the height compared with 100%, and the rate at which the plastic is extruded is reduced accordingly to maintain the same layer width.
* With the first layer height set at 150%, the height of the extruded layer is increased by 150%, the nozzle being at one and a half the height compared with 100%, and the rate at which the plastic is extruded is increased accordingly to maintain the same layer width.

None of the above variations will affect the amount the first layer is "squashed" onto the build plate. One way of doing this is by varying the nozzle height by either mechanically raising/lowering the build plate, or by adjusting the global position of the z axis. Another way would be to vary the extrusion multiplier....the more plastic extruded the more the plastic is "squashed" into the plate. A third way that can improve things...and this is where the issue is....is to adjust the first layer height/width. This doesn't add or remove the "squashing", but it can alter the area of plastic touching the build plate....giving in some cases, the same effect.

So, there you have it. Which goes to show that there's not always one adjustment that cures one issue.....it's a combination of things. Well....that's how things seem after looking at it with a logical point of view!
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net

jeevesme@hotmail.com
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Re: First print layers density question

Tue Jan 05, 2016 11:05 am

After a couple emails to the Simplify3d Team, I got some answers that were pretty helpful. Here were my questions and the answers given:

EXTRUDER Tab
Overview
1. When using Manual, and decreasing the EXTRUSION WIDTH below the actual nozzle diameter, does it decrease the amount of filament extruded? For example, if I have a .6mm nozzle installed and put the EXTRUSION WIDTH at .50 so I can get the level of details I want in the print, does it extrude less filament or does it just tell the program to use .5 and leave the amount of extrusion alone?
The extrusion width influences the amount that is extruded at all times, including when you lower the extrusion width below the nozzle diameter.

LAYER Tab
First Layer Settings
1. If the First Layer Height is Under 100%, does it just decrease the layer height and does not change the amount of filament extruded?
That is correct. This setting is typically lowered below 100% in an attempt to squish the layers a bit more and get better adhesion through a better bonded first layer that should completely fill the extruded area without issue.
2. If the First Layer Height is Over 100%, does it increase the layer height AND extrude more filament?
Also correct. This is done so that if you're using a fine layer height that doesn't put down a thick enough first layer you can use a thicker first layer height without needing to use a second process for a single layer.
3. If the First Layer Width is Under 100%, does it decrease the amount of filament extruded?
Correct again. Width adjustments always affect extruded amounts.
4. If the First Layer Width is Over 100%, does it increase the amount of filament extruded?
Yes, indeed. Width adjustments always affect extruded amounts.

INFILL Tab
General
1. Infill Extrusion Width – Does increasing/decreasing this modify the amount of filament extruded, or simply increase/decrease the distance between each extrusion line?
This setting affects the actual amount of extrusion done for each infill line. The way to adjust the gaps between the lines printed is to alter the overall infill percentage. Width adjustments always affect extruded amounts.
I.e. Will percentages above 100 increase the extrusion amount while keeping the extrusion lines equal distances apart or will the extrusion amount stay the same and simply decrease the distances, essentially overlapping the extrusions?
Percentages above 100 will increase the amount extruded, just as percentages below 100 will decrease the amount extruded. The lines will stay in the same positions and simply adjust their thickness, this is implied through the name including the word "width." Width adjustments always affect extruded amounts.

Heisenberg
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Re: First print layers density question

Fri Jan 15, 2016 9:08 pm

Hi guys, I've read this topic carefuly to set my 1st layer and now it's clear for my small mind.
But I didn't notice something about the total measurement of a printed part if I set my 1st layer at eg. 60%.

If my part is 10mm height and my layers are 0.2mm, I should have 50 layers.
But if my first layer is set at 60%, I should have (1X 0.12) + (49X0.2) = 9.92mm.
I'm correct ?

And by the way, is there an easy way to compensate this gap ?

Sorry for my English language, and happy new year from France ;)

pcman
Posts: 43
Joined: Sun Dec 27, 2015 10:50 pm

Re: First print layers density question

Sat Jan 16, 2016 11:04 pm

dkightley wrote:* With the first layer height set at 50%, the height of the extruded layer is reduced by 50%, the nozzle being at half the height compared with 100%, and the rate at which the plastic is extruded is reduced accordingly to maintain the same layer width.
...
None of the above variations will affect the amount the first layer is "squashed" onto the build plate.
jeevesme@hotmail.com wrote:1. If the First Layer Height is Under 100%, does it just decrease the layer height and does not change the amount of filament extruded?
That is correct. This setting is typically lowered below 100% in an attempt to squish the layers a bit more and get better adhesion through a better bonded first layer that should completely fill the extruded area without issue.
This really reinforces the need for some decent documentation for S3D. If someone as knowledgeable and experienced as Doug can get it wrong, what hope is there for beginners?

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dkightley
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Re: First print layers density question

Sun Jan 17, 2016 5:07 am

This really reinforces the need for some decent documentation for S3D. If someone as knowledgeable and experienced as Doug can get it wrong, what hope is there for beginners?
Errare humanum est sed in errare preseverare diabolicum.* :oops: :oops: :oops:

Which links in nicely with this thread:
viewtopic.php?f=9&t=4236&p=18499&hilit=wiki#p18499


* ps I'm not trying to show off by quoting Latin....I had to look it up! Apparently it means "To err is human, but to persist in error (out of pride) is diabolical."
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net

pcman
Posts: 43
Joined: Sun Dec 27, 2015 10:50 pm

Re: First print layers density question

Sun Jan 17, 2016 6:17 pm

A user-generated wiki is just a let off for the publishers. It would be acceptable if this was free software but it isn't. I still don't think it would solve many of the documentation problems anyway. When I first read your post about the first layer settings, I thought 'yes, that makes sense.' That could have reasonably been added to the wiki and probably nobody would have challenged it without word to the contrary from support. Also, I've found from my own postings that there is disagreement over whether certain behaviours are bugs or features. Who would mediate? We need to understand the philosophy of the software to get the most from it and that's something that only the developers can tell us because anything else would be speculation. We put up with it for now because we're enthusiasts but as soon as 3D printers are ubiquitous enough, one of the big companies (probably Autodesk) will do it properly and steal the market. That would be a shame for S3D.

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