Cellular Lamp / Week of Aug 28 to Sept 10 2012

Looks like so far we have four completed prints. I'll wait until after tomorrow to judge. I'm happy there was significant participation this time though, I think the two week limit helped. Maybe whoever wins should pick a challenge part that is a bit easier to print for next time.

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I'm just about to post my final versions and some things I have learned over the last week printing this object.

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[richrap.blogspot.com]

My first prints of this lamp object were not great due to speed and layers curling up. (PLA)

It's an easier print in ABS, but for anyone wanting to print this or objects like this in PLA this could help.

I made a few more prints and found a solution that worked for me -

I'm using Slic3r V 0.9.1 for the below.

My normal nozzle diameter is set to 0.42mm, this gives me nice results for most 'normal' and many organic objects, but this lamp caused some issues.

Normal settings below (used for first print, seen earlier in the thread)

; layer_height = 0.3
; perimeters = 10
; solid_layers = 0
; fill_density = 0
; perimeter_speed = 45
; infill_speed = 75
; travel_speed = 290
; scale = 1
; nozzle_diameter = 0.42
; filament_diameter = 2.86
; extrusion_multiplier = 1
; single wall width = 0.47mm
; first layer single wall width = 0.80mm

To get a decent print using PLA I ended up using the following settings below –

; layer_height = 0.2
; perimeters = 2
; solid_layers = 2
; fill_density = 0
; perimeter_speed = 37
; infill_speed = 37
; travel_speed = 200
; scale = 1
; nozzle_diameter = 0.48
; filament_diameter = 2.86
; extrusion_multiplier = 1
; single wall width = 0.67mm
; first layer single wall width = 0.80mm

Slower print, and slower travel speed, but the main difference was telling Slic3r of an increased nozzle size (forcing slic3r to space the filaments slightly further apart)


Two new prints using the new method - 0.3mm layers on the left and 0.2mm on the right. (only printed one at a time!)

You can tell when Slic3r is doing this by looking at a ‘Brim’ when the nozzle size is increased each ring of the ‘Brim’ only just touches the next, and you can pull them apart. If the nozzle is set ‘correctly’ the ‘Brim’ will be joined and only pull off the object not apart in rings.



When you now print the outlines of each island the filament is just (not quite) touching the last, so instead of them warping up, they just slightly sag down instead, for me this provided a better result than anything else I tried, including fans and just reducing temperature.






These two close-ups above are showing the slight filament sag in the most extreme overhang on the Lamp, same spot on each print, the 0.2mm one looks a little nicer.


I expect you could get a similar result from reducing the E steps/mm in firmware, but nozzle size increase worked well for me.



I’m not sure if anyone else uses this method? Or something similar for printing things with great overhangs in PLA? Any other solutions?

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[richrap.blogspot.com]

@Richrap Very nice print and well observed. Looking closer at my print I think I'm seeing a similar effect with the drooping, I might try backing of the line width a bit and trying it again.

Right now it's looking pretty close between richrap and rhysjones. Overall, rhysjones' print looks a bit nicer to me, but the fact that PLA is a bit more difficult than ABS for a print like this adds a few points to richrap. I'll wait till tomorrow to announce who I've chosen, to see if we get any last-minute entries.

As a reply to richrap:
Increasing the nozzle diameter in Slic3r will have a different effect than decreasing E steps/mm. With the volumetric math, increasing the nozzle diameter should still produce the same total volume of extrusion, whereas decreasing E steps/mm will decrease the total volume extruded. That is, unless Slic3r is doing some funny math with the nozzle diameter...

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I guess I'm the last minute entry


So there is my attempt, unfortunately not as good as rhysjones or richrap especially on that spot :


Printed in transparent PLA
Layer height = 0.2mm
Speed = 50mm/s
Printing time : 3h57

I've recorded the printing, I will upload the time-lapse tomorrow.

@Richgain, Very nice - is that ABS?

Edit: I swear Rich had a completed print up a minute ago - I must be losing my mind!

Edited 1 time(s). Last edit at 09/10/2012 06:07PM by rhysjones.

rhysjones Wrote:
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> @Richgain, Very nice - is that ABS?
>
> Edit: I swear Rich had a completed print up a
> minute ago - I must be losing my mind!

He does have one up [forums.reprap.org]

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@NewPerfection I think thats a sign that I need to go to bed!

Yes, I switched from PLA to natural ABS to try and get at least one successful print.
Thanks to the great advice on this thread I hope to carry on improving the tuning and see if I can succeed with PLA as well.

@NewPerfection Thanks Cameron, yes, you are right, you should see different results with just esteps reduction, in the past reducing esteps has helped me print a few more tricky things. I think messing with the nozzle size is quite a good trick for many prints, especially if you are trying to match object wall perimeters with multiple filament widths so you don't get tiny bits of infill. I have no idea if that will work for all Slic3r versions? And I'm still not exactly sure what Slic3r is doing with that value, but it seems to do the trick with filament spacing.

@Rhys - Thanks, I don't normally print with plain white PLA, but this print helped me notice that my X bars had become loose (un-clamped) from both the Z ends! (not using lock nuts) so that could be the source of my slight Z wobble on recent prints. That's where the Huxley is better than the Mendel/Max - much less fighting of vertical registration. Mendel90 also seems to have resolved the Z wobble

@richgain - looks nice in transparent, what temperature are you extruding at? I drop back by 10 degrees when printing things with low flow of material. Your's was a faster print - my 0.2 layer one was just over 5h 10mins - that's the longest print in months for me.

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[richrap.blogspot.com]

I wanted to get mine in as well, even though it is after the 10th. I had a lot of failed prints and problems with breakage. A combination of Z lift and the increased nozzle size trick seems to have worked for me.

This is printed with a Solidoodle 2 in ABS. The S2 has a 1.75 Makergear hot end with a direct drive extruder.

; layer_height = 0.2
; perimeters = 3
; solid_layers = 4
; fill_density = 0
; perimeter_speed = 20
; infill_speed = 60
; travel_speed = 80
; scale = 1
; nozzle_diameter = 0.38
; filament_diameter = 1.66
; extrusion_multiplier = .91
; single wall width = 0.42mm
; first layer single wall width = 0.60mm

195C with a fan
Z Lift = .5
Retraction Distance = 1
Retraction Speed = 50

I've uploaded the time-lapse of my print : [youtu.be]

This is a tough one. Both rhysjones' and richrap's prints were very good, and richgain's and IanJohnson's looked pretty good as well. I'm glad we got some good competition here.

I think I have made my decision:


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rhysjones is the winner this time around. Although it seems that ABS is slightly easier to print with for this model, his result was just so nice. So, rhysjones gets to pick the next competition piece and judge it. Good luck!

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Good decision.
Congratulations Rhys. Well deserved. Already looking forward to the next one.

Well done Rhys, a very nice print indeed.

It's really great to see so many prints, this was a tricky one, if anyone else tried and failed, still post them up, it's all good information, and you will get some help.

Looking forward to the next one

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[richrap.blogspot.com]

Thanks guys. Overall the standard of prints was really high this time around, despite the tricky model - it's good to see print quality on the rise since the early competitions.

I'll try to get something up by the weekend

Posting here just in case, like me, you signed up to get notifications on forum updates for this thread.

The new competition is up.