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Topic: slic3r Question And Help with top versus bottom layer

I am trying to figure out why slic3r produces a different top and bottom fill. The bottom is nearly gap less while the top has more voids.

Would someone(s) be willing to take a look if I posted some pics and the files that go with it?

Thanks!

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Re: slic3r Question And Help with top versus bottom layer

Take a look at your extrusion width settings.

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Re: slic3r Question And Help with top versus bottom layer

I have the first layer set to 200% width, but I'm having issues with thin walls as well.

If you look here:  http://support.3dverkstan.se/article/23 … #wallspace

That's the more annoying problem right now. The extruder head is 0.4mm and the article recommends to use wall thicknesses of that multiple. While it makes logical sense, its not practical at all. Surely there are some slicer settings that can be used to help fix the issue.

If I post pics will that help with troubleshooting?

4 (edited by lueman 2015-02-01 15:19:02)

Re: slic3r Question And Help with top versus bottom layer

Make sure you use a predictable  space when setting z-home I use a flat razor (.22mm) and set z-offset at between 50% to 70% of my extrusion width so at .3 layer hight I use -.14 z - offset , finally make sure your width calibration is spot on.  If all else fails run a print and very flow rate , once you find what works for you, modify e-steps  by that percentage. Don't be surprised if e steps are way off especially when using an E3D hotend.

SD4 with E3D V6.

Those who don't know ask, those who don't care comment,  those who comment without answers  hide ignorance for fear of asking. Be fearless!

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Re: slic3r Question And Help with top versus bottom layer

Do you have suggestions for ensuring my widths are accurate? Any posts or sites you can point me to?

Is there a direct relation to width versus layer height? Since the nozzle is 0.4mm then I know that's the minimum width. If I use a layer height of 0.4 versus 0.2, does that change the width at all? The flow rate would be different for both.

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Re: slic3r Question And Help with top versus bottom layer

Here is a sample of before and after some setting adjustments:

Sample Gears

I changed: Top Solid Infill from 0 (Auto) to 125%.

I also have it set to 4 top and bottom Horizontal Shells. It looks like its extruding too much and making a bit of a mess on the top now.

Can anyone comment?

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Re: slic3r Question And Help with top versus bottom layer

Definitely looks like over extruding. The width is determined by the amount of mush (TECHNICAL TERM) the material is squishing sideways so a  .4 mm head is said to produce the best print when the filament is extruding .48mm that's the single wall thickness in the calibration  box. The layer height   or layer resolution is determined programmatically to get between .1 to .4mm (max for a .4 nozzle)  Having said that you really need to look up calibration before you go any further.

SD4 with E3D V6.

Those who don't know ask, those who don't care comment,  those who comment without answers  hide ignorance for fear of asking. Be fearless!

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Re: slic3r Question And Help with top versus bottom layer

Thanks so much for the reply.

What exactly do I need to look into calibrating? The extrusion width? I have the bed calibration down pat, IMO at least. (No issues with prints sticking straight to the glass. No problem with printing taller objects.)

Here are the specs for my setup:

- DaVinci 1.0 printer running 0.92 repetier host firmware
- Slic3r version 1.2.5 beta
- ABS filament
- Running heated bed at 105c and extruder at 215c

9 (edited by lueman 2015-02-04 02:12:43)

Re: slic3r Question And Help with top versus bottom layer

Check me previous posts, but once you have extrusion width & e-steps , then you can
An start experimenting with z offset to get the smooth top layers..

Ie:Make sure you use a predictable  space when setting z-home I use a flat razor (.22mm) and set z-offset at between 50% to 70% of my extrusion width so at .3 layer hight I use -.14 z - offset , finally make sure your width calibration is spot on.  If all else fails run a print and very flow rate , once you find what works for you, modify e-steps  by that percentage. Don't be surprised if e steps are way off especially when using an E3D hotend.

SD4 with E3D V6.

Those who don't know ask, those who don't care comment,  those who comment without answers  hide ignorance for fear of asking. Be fearless!

10

Re: slic3r Question And Help with top versus bottom layer

DrAnonymous wrote:

Thanks so much for the reply.

What exactly do I need to look into calibrating? The extrusion width? I have the bed calibration down pat, IMO at least. (No issues with prints sticking straight to the glass. No problem with printing taller objects.)

Here are the specs for my setup:

- DaVinci 1.0 printer running 0.92 repetier host firmware
- Slic3r version 1.2.5 beta
- ABS filament
- Running heated bed at 105c and extruder at 215c


The most important thing is to make sure your esteps are correct. To test this, mark a known measurement such as 10 or even 100mm from the top of the extruder input. That would be that small plastic tube. Then open Repetier host. Heat the extruder to normal temp then click the extruder control to feed 100mm. If your esteps are correct then the mark you made should be right at the top of that plastic tube.

If they are wrong then you need to change the value in the EEPROM settings using Repetier host. If the feed is too little then increase the steps. if it is too much then lower the steps. You will need to experiment with how much to change it to as well. I would start with maybe a difference of 100 and see where that gets you. Then adjust from there by going back the the original value and adding more or less depending on the change.

Once you get that dialed in then you can worry about the software adjustments as they depend on and assume a proper calibration. I have not adjusted mine but me Da Vinci 1.0 is wrong and I need to do it. It is just some what of a PITA to do and is not that far off on mine.

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11 (edited by frito 2015-03-19 02:37:29)

Re: slic3r Question And Help with top versus bottom layer

If you want to avoid guessing, you can use this formula:

S1 = D1 / D2 * S2

where
D1 is the distance you tried to move
D2 is the distance you actually moved
S1 is the correct extruder steps per mm (what you want to set the value to)
S2 is the current extruder steps per mm


Example:

I send a command to extrude 150mm of filament (D1 = 150) but the filament actualy moves 160mm (D2 = 160).
My extruder is currently set to 700 steps per mm (S2 = 700).

To correct the movement I need to set the steps per mm to S1,

S1 = D1 / D2 * S2
S1 = 150 / 160 * 700
S1 = 656.25

So setting the steps per mm to 656.25 will give the correct movement.

This would also work for configuring you axes steps/mm.