Iphone case print

[ajdulion 0]

Hey guys

for some reason I just can't print iphone cases that ''fit'' to the iphone..

i tried doing them fast/slow 0.1mm and 0.25 they all seems to ''work'' but the phone just won't sit into the case.

no one seems to be sharing there settings on how to print them..

i tried printing this one http://www.thingiverse.com/thing:241258

my settings are :

 

another problem is when i use retraction (standard 4,5mm and 45mm/s settings) it seems that after a while the printer does not extrude any pla and the prints fails, this wasn't an issue before but now it seems that it happens all the time.

 

Also, the gold pla I got with my ultimaker 2 is at 50% and I now already have had 4 breakings of the pla on the spool wich meant having to manually guide the filament into the extruder to keep the print going is this due to the fact the spool was wined up to tight ?

 

 

I also did do the extrusion test and it seems to pass everything

 

http://dump.ajdulion.nl/IMG_2224.JPG

 

made a link due to large size

 

(i know there is a line at 6mm/s but this was due to the spool once again breaking and me having manually feeding the cable in)

 

[gr5 2,224]

1) I don't know why PLA gets brittle. Mine has been fine - all colors, all brands. I think it gets too dry maybe? I haven't heard any good explanations. I recommend you somehow mount the spool on the floor. Maybe make something with knex?

2)

 

when i use retraction (standard 4,5mm and 45mm/s settings) it seems that after a while the printer does not extrud

 

Very strange. This would make complete sense if your rear fan is broken. There is a 3rd fan on the print head at the back. Look carefully. Does it spin? It should start up when you power on the machine - even before the lights come on.

3)

 

cases that ''fit'' to the iphone..

 

Is it too small? Do you have calipers to measure exactly? I would measure very accurately the "error" and increase the model by that amount. Or you can just try 3% as that usually works - maybe change the scale in CURA to 1.03 (3% larger).

Or you can scale in only X and Y if those are the problem dimensions. If it is more complicated maybe you have to post a picture?

 

[ajdulion 0]

1) I don't know why PLA gets brittle. Mine has been fine - all colors, all brands. I think it gets too dry maybe? I haven't heard any good explanations. I recommend you somehow mount the spool on the floor. Maybe make something with knex?

2)

Very strange. This would make complete sense if your rear fan is broken. There is a 3rd fan on the print head at the back. Look carefully. Does it spin? It should start up when you power on the machine - even before the lights come on.

3)

Is it too small? Do you have calipers to measure exactly? I would measure very accurately the "error" and increase the model by that amount. Or you can just try 3% as that usually works - maybe change the scale in CURA to 1.03 (3% larger).

Or you can scale in only X and Y if those are the problem dimensions. If it is more complicated maybe you have to post a picture?

 

1: pla might be stored wrongly not sure i've bought 6 new rolls so i'll see what happens.

2: fan is working no problems there... it's just really strange.

3: it seems to be to small, i've been to a 3d shop in Rotterdam and they had allot of cases laying around and those seemed to be much smaller at the edges mine are very thick.

it seems my fifth and sixth attempt at printing a case worked, only downside one of the 2 models broke after removing the iphone for the second time so this one might need to be printed in flexibel pla the second one didn't break yet after removing twice.

now I should have to figure out how to get my retraction working...

is there a test file i can print to test retraction I know there is pyramide that seems to test this very good.

 

[closedcircuit 1]

Could it be linked to your fill density? It seems low at 5%. I generally use 20% or more.

[ajdulion 0]

Could it be linked to your fill density? It seems low at 5%. I generally use 20% or more.

 

I actually printed 4 more cases that all seem to fit after chabing from UM gold to abother brand pla black..

I even turnd on retraction and now problems.. I will test the hollow cube soon after I finished the fifth iphone case and post the results

 

[ajdulion 0]

so..I did the hollow pyramid test.

seems the conclusion is the filament was messed up..

same settings just changed the filament (and i went from 230 > 220 > 190 c on the top to keep it from deforming)

 

[gr5 2,224]

Some stringing tests I did. Different color filaments (and different brands) need different temperatures (see very first photo in this thread):

http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/

 

[ajdulion 0]

and i'm back again..

0.1mm prints seem to work fine but now when i try to print 0,06 or 0,02 i seem to get underextrusion.

when i ramp up the extrusion rate to 400% it starts flowing again but that shouldn't be good ?

the first layer goes on without a problem but the second one seems to underextrude and after that it seems to speed up the print process the next 2/3 layers.

 

It also seems the first layer isn't 0,06/0,02 but a thicker layer (looks like a 0,1mm to me) is this normal ?

 

i'm trying to create the smoothest surface on the first layer so that i can sand it better in post but for now all I seem to be able is to print 0.1mm cases but once i go down that layersize the prints starts to fail with underextrusion..

 

[gr5 2,224]

In cura, the first layer defaults to .3mm. This is good because...

When you extrude the first layer if you want it to not over or underextrude by more than 20% then you need to level to an accuracy of the first layer thickness times 20% or .06mm accuracy. This is about half the width of paper and difficult to do. If now you make the first layer .1mm it's extremely hard to set the first layer leveling that perfect.

However, many people make the first layer .2mm or even .1mm and spend an hour leveling by trial and error until it is perfect.

Anyway - the point is that is a Cura setting.

The slower first layer is also a Cura setting. This is a good feature because it allows the PLA to flow better and stick better to the glass so you get a nice smooth first layer. Alternatively you can print the first layer hotter. But for quality, nothing beats slow.

For an iphone case, personally, I would print the whole thing slow - it's not so big - will only take a few hours at 20mm/sec. So why not?

 

[gr5 2,224]

I think you should print this test print to see what your cubic print speed is at 230C. 230C is strongly recommended for this test print. At 230C you should be able to get to 7mm^3. At 200C maybe 2mm^3 (not sure - I have a graph somewhere on this forum):

http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/

Do the above test so we can see if you have a fully functional UM2 or if instead you have some issue.

 

[gr5 2,224]

Are you printing PLA or ABS?