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Simon
(@simon-16)
Estimable Member
Printing issues

Hello to all!

I've a little problem. Sometime I got prints like this:

What could be the cause?
Room temperature? (around 18-19°C)
Wrong gcode?
Missing supports?
PLA quality?

I know they could be different causes, but would like to know which are the common causes.

Another example is my first print: the supplied FROG with the MK2.
I have not the picture here, but I've printed the frog and one of the leg was missing with the paw printed but the leg in part missed and the wire thicker, like this in the picture above. The wire is bigger than the 0.2mm print.

Thanks for the help!

Printer: MK2
Material: PLA
Quality: the above example in 0.2mm, the frog was in 0.1mm.

Posted : 29/11/2016 3:54 pm
StephanK
(@stephank)
Reputable Member
Re: Printing issues

I'll give it a shot: The object in the picture is upside down, right? Or in other words, the top side was on the print bed when you printed it?

If that's correct then we're looking at "overhangs". Or "Missing supports" from your list of choices.

The printer can't print into "thin air", it needs something to support the line it is currently printing. Otherwise the line will "droop" down to the bottom. I think that is what happened to the text on left side and the round hinge in the middle of the picture.

To avoid this, the Slicer software has a "Support" feature that prints additional "pillars" everywhere needed (ideally).

One exception to this is "Bridging", the printed line lands on another piece already printed and just has to "bridge the gap" for a short distance.

Now, adding support structures to the object is one way to fix it, sometimes rotating the object before printing solves the problem as well. With this object, try printing it so that the text is facing up.

Hope this helped a bit.

Posted : 29/11/2016 8:14 pm
Simon
(@simon-16)
Estimable Member
Topic starter answered:
Re: Printing issues

Thank you @stephan.k for the answer.
That makes sense. I've tried to print it with supports and the result is much better.
BTW, I show you another case wich gives me issues even with supports.
The item is this spinning top:

http://www.thingiverse.com/thing:23686

I've followed the printing instructions, also enabled the supports (simplify3d).
I've tried to print it 3 times:

- 1.st try: Complete print with default supports

Result:
The bottom of the spin is poor in quality. Here I've already cutted some filament.

- 2.nd try: Partial print with supports / infill specified by the item instructions

Result:
This time I've observed what happens during the printing process. The first layer is a simple dot. Then it makes a little circle filled and for the next layers the circle becomes thicker to create the bottom of the spin. What happes is that after 3-5 layers the extruder, writing on a layer which has only a little dot as support makes the base unstable. So the base fails on aside and for some layers it prints in the the air. As soon it gets a minimum base, it's able to print again.

- 3.th try: With supports and raft enabled.
Always same result.

In this image you can see the bottom of the spin.

Looking on the GCODE created, you can notice that the first layers are without support for the spinning top. I thing thats the issue:

What could me help?

Thanks,

Simon

Posted : 02/12/2016 10:05 am
David T.
(@david-t)
Noble Member
Re: Printing issues

Cut the object in half, print each half separately and then glue them together. You will get way better result. The bonus is no supports needed.

Posted : 02/12/2016 10:28 am
Simon
(@simon-16)
Estimable Member
Topic starter answered:
Re: Printing issues

Thank you, could be a way!
But, I would be know how the other poeple have printed it. I've seen in the comments one has cutted it as you suggested. Possible the author was able to print it anyway in one shot? 🙂

simon

Posted : 02/12/2016 10:34 am
mavu
 mavu
(@mavu)
Estimable Member
Re: Printing issues

Try slicing it with the Prusa version of slic3r.

This looks a lot like the slicer you use is doing something wrong, probably due to the very shallow angle at that point in the print.

If you want to keep using S3D, you can place manual supports all around the point that gives you trouble, but I'd be interested to see what Slic3r does with the model.

Posted : 02/12/2016 11:18 am
StephanK
(@stephank)
Reputable Member
Re: Printing issues

Since you're using S3D, you could manually add support where it is missing in the center - just "paint" the additional supports in. You could also try adding a "dense support layer" or two in S3Ds Support Settings and finally, check if "upper vertical separation layers" is set not higher than 1.

In general, to improve performance of overhangs, try printing a cooler (and slower)

This is a difficult print, i would cut it in 2 parts as well.

Posted : 02/12/2016 11:22 am
David T.
(@david-t)
Noble Member
Re: Printing issues

But, I would be know how the other poeple have printed it. I've seen in the comments one has cutted it as you suggested. Possible the author was able to print it anyway in one shot? 🙂
I'm sure there is a way how to print it in one piece. But it won't work without supports and without massive overhangs, which never (or almost never) look nice. I usually like (and try) to use the way which consumes as little material as possible (thus no supports, no rafts) and the result looks as good as possible.

Posted : 02/12/2016 11:30 am
mavu
 mavu
(@mavu)
Estimable Member
Re: Printing issues

Upon downloading and slicing the model with slic3r, I think supports are not your problem.

The bottom of the model does not have steep overhangs, and should print fine.

I think you have a problem with your S3D settings. maybe too much heat?
Maybe too hot bed?

I noticed the model says print with 0.24 layer height. Try it with a standard 0.2mm layer profile.
Also, the contact point on the bed is very small. Try printing with a brim.

Posted : 02/12/2016 11:44 am
Simon
(@simon-16)
Estimable Member
Topic starter answered:
Re: Printing issues

I've printed it with 0.2m resolution/layer, so that should already ok.
I've used the setting posted by Josef here:

http://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/simplify3d-print-settings-august-30-2016--t938.html

What is and how to enable 'brim' ?

The contact point is really small, I know. That's the problem.

About temperatures, the settings used in the Josef's FFF profile are 55°C bed and 215°C extruder.
PLA purchased with the printer.

I'l try with more support and as last try, cutting it in two pieces 😉

Simon

Posted : 02/12/2016 12:07 pm
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