Extrusion calibration

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jimc
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Re: Extrusion calibration

Post by jimc » Sat Mar 07, 2015 5:01 pm

inches

Vprints
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Re: Extrusion calibration

Post by Vprints » Wed Mar 11, 2015 9:34 pm

Finally got some calipers. I've got two questions:

1) The thickness varies a bit, from .38 to .5, as I go around. This is PLA from esun and seems to be fairly consistent thickness (around 1.73).

2) The height is consistently 1.94 -- what's the height *supposed* to be? (Using the box linked to at the top of this thread, with 0 infill per instructions.) I just used Ye Olde Business Card method to set the Z stop when I got it, haven't dug up my real tools for the job yet...
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jsc
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Re: Extrusion calibration

Post by jsc » Wed Mar 11, 2015 9:40 pm

The thickness will vary, especially in the corners. Try to get several consistent readings from the middle of the walls and average them. Calipers are tricky things, and when using them in a soft material you can affect the reading just by the amount of pressure you apply when closing them. Try to use a consistent, light force, and make sure the jaws are perpendicular to the wall, and try to measure with as little of the jaws as possible.

The height should be 20mm, did you mean 19.4mm? It seems difficult to imagine how it could be .6mm too short, that would have it starting three layer heights below the bed. What is your layer height and extrusion width settings?

Vprints
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Re: Extrusion calibration

Post by Vprints » Thu Mar 12, 2015 6:58 am

Layer height is .2, extrusion width is .4. And, yes, it's reading 1.94 (i.e., a little below 2mm high.) But I can confirm the nozzle is not dragging through the glass on the first layer. :)
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jsc
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Re: Extrusion calibration

Post by jsc » Thu Mar 12, 2015 7:55 am

Sorry, you're right. It IS 2mm high. That means your first layer is .06mm too high, about a third to a quarter layer width off. Your first layer should look visibly flattened, and you may be getting a thicker first layer. Make sure you measure off the top and not the bottom.

Vprints
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Re: Extrusion calibration

Post by Vprints » Thu Mar 12, 2015 6:26 pm

OK, that makes sense given how I adjusted it originally. Guess it's time to break out the real gauges...
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jdacal
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Re: Extrusion calibration

Post by jdacal » Sat Sep 19, 2015 11:33 pm

I just printed the cube

Nozzle Diameter: 0.35
Extrusion Multiplier: 0.83
Extrusion Width (manual): 0.44
First Layer Height: 100%
First Layer Width: 100%
First Layer Speed: 50%

When I print it the cube wall reads right at .44mm and the height is at 2.0 using a 0.15 offset.

Now when I try printing a print using these settings, except for Layer Width set to 115% this is what I get:
2015-09-19 18.16.39_1.jpg
2015-09-19 18.16.39_1.jpg (451.96 KiB) Viewed 14962 times
This print is set for two outline layers and as you can see there is a gap between the two layers. I am also getting gaps at the circles, I've been getting these for a while even using different settings. So I'm wondering if this is a calibration problem of if there's something I may need to do to calibrate the stepper motors? Or do I just need to play around with the extrusion multiplier in order to get rid of the gap in the outer shells even though the cube is printing at the correct .44 wall thickness?

Even the solid area has the gaps so would the Infill extrusion width help with this?

Thanks for any feedback
jdacal

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jimc
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Re: Extrusion calibration

Post by jimc » Sat Sep 19, 2015 11:36 pm

bed gap is too big.

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jdacal
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Re: Extrusion calibration

Post by jdacal » Sat Sep 19, 2015 11:59 pm

jimc wrote:bed gap is too big.
Thanks Jim. So even though the cube walls are coming out to the correct measurements, my gap would still be off?
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Re: Extrusion calibration

Post by jimc » Sun Sep 20, 2015 12:05 am

Yeah sure. Gotta remember its only affecting that first layer or first couple layers

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