Arcane Game Lore

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3D Modeling – A Big Print

So at work we got a new 3D printer (It’s an Ultimaker 2 Extended or if you want the Amazon page).  I happily volunteered to test it out and put it through its paces.  And I have to say, this is one very nice 3D printer.  However, like all printers, it is not without its share of problems.

As part of testing we wanted to do some “torture tests” and run some large, long prints.  The first of these turned out to be something for one of the library patrons.  He was printing a large nose cone for a model rocket that was just over 3 inches in diameter and 8 inches tall.  Now our current printer can print that but it has to be on its side (build area is 10″ wide by 6″ deep by 6″ tall) which for this particular shape is less than desirable as you get supports running up the side that mar the surface.  That wasn’t working so we decided to try it on the new printer, which can print it straight up since its build area is 8″w x 8″d x 12″ tall.  The print took almost 17 hours at 0.2mm resolution and worked perfectly.  Although it looked like an 80mm artillery shell when it was done and we’re not supposed to print weapons :) .

A Big Ship

So after that it was time to try a 0.1 mm resolution test.  The goal was to print something both wide and tall and with some surface features and details that would require supports and a long print time.  I had just the thing.  I grabbed Jay’s Assault Scout model that I described printing and painting in an earlier post.  Instead of printing it 4″ tall, I scaled the model up to 12″, the full height of the printer.  This made the wing span 10.2″ which is just under the 11.3″ diagonal size of the print area.  This print would fill the bed both horizontally and vertically, a perfect test.

Setting the resolution to 0.1 mm per layer gave me an estimated 42.5 hours to complete the print.  One of the reasons for the long test is that our older printer has a tendency to clog up on longer prints (even at 0.2 mm resolution) and we don’t even print at 0.1 mm resolution on that printer anymore because it clogs even on small prints.  This would be a great test.  I started the print on Friday morning so I could watch it get started and make sure everything seemed to be running okay but then let it run over the weekend.  After a couple of hours it looked like this:

The first 15mm of the printed Assault Scout

Printing at about layer 150

At this point it is just starting to print the back side of the fuselage in the middle.  The back side of the engines are done and the wings are connected to the engines are just starting to connect to the fuselage.

I even grabbed a quick video of the printing.  The quality isn’t that great as I was just holding my phone in my hand. This is real time and it is printing just one of the 3000 layers in the model.  You also get to listen to the sound of the printer, which has been my constant companion for the last few weeks as I’ve been putting it through it’s paces.  This is one of the layers that takes longer to print as there are a lot of features on that level but it gives you an idea of the process.

I snapped this picture just before I left to go home for the weekend:

A bit further on in the print.

Printing layer 195

Here we’ve moved up a bit further in the print and it is just finishing up with the printing of all the details on the back of the fuselage.  At this point all there really is to print is the infill (10%) and the outer surface of the model and each layer will go much faster.   It took about 6 hours to get to this point and we’ve only printed 195 of 3000 layers but they were the most complicated layers in the print.

I almost came in on Saturday and took a look to see how it was going (it would finish sometime late Saturday night/early Sunday morning) but even though I was on campus, I didn’t have time to run over to my office in the library and peek. (I was helping my wife get her night’s observing set up on the campus observatory.)

When I got to work Monday morning, this was the sight I was greeted with:

The fully completed Assault Scout Model still sitting on the printer.

The completed print

What a beautiful sight!  As you can see it pretty much fills the print volume.  When I picked it up off the print bed, I was surprised at how light it was.  (It weighed in at 170 grams or 6 oz).  For some reason, I was expecting a little more weight to it.

The print was almost perfect.  If you look closely at the image, there is a lighter color line running across the print right at the level of the top of the wing where it connects to the engines.  For some reason, about 15 layers here suffered an under extrusion problem (not enough plastic flowing through the nozzle).  That would have happened some time around Saturday morning during the print process.  I’m not sure if it is a problem with the slicing (the code that drives the printer) or a filament issue.  The only way to be sure would be to print another one and see if the exact same thing happens.  The good news is it recovered and to some extent the print quality above that point is actually better than below it.

Other than that one little section of under extrusion, which I’ll need to do something to fill in the small holes before I paint this, the print is amazing.  The surface is really really smooth and the surface details came out nice and clean.  Additionally, because the print was so large, some of the details, especially on the back of the ship, showed up much better than they did on the smaller 4″ model.  Speaking of which, here are the two models side by side:

The smaller painted Assault Scout model next to the newly printed large one. The larger print is 3 times taller and wider than the smaller one.

The smaller painted Assault Scout model next to the newly printed large one.  I haven’t yet removed the printing supports.

I can’t wait to get this big one painted.  I’ll be sure to post pictures when I do but that may not be for a while.  As a Tom Verreault pointed out, this one is almost big enough to be to scale with the character miniatures.  Which of course got me thinking about how to actually print one that is to the right scale.  But that’s a later project.

One last picture.  Here is what the back of the ship looks like with all the supports removed.

A view of the back of the ship showing the full detail of the model

The back of the ship

There is some clean-up still needed as all of the support material didn’t come off cleanly.  So far this has just been cleaned up with the pliers on my Leatherman tool and my fingers.  The little bits of features that you see running upper left to bottom right are residual support material.  Plus the first few layers right about the supports don’t print fully and I’ll want to sand them down for maximum quality.

Thoughts on 3D Printing

If there is anything I’ve learned about 3D printing over the past few weeks while testing out this printer is that it is definitely not yet to the “fire and forget” stage.  There is still a long way to go.  You need to know your printer, how 3D printing works, and be willing to tweak and play with settings and even your models if you want the best possible outcomes.

Every printer is different.  There are things that printed just fine on the older printer that I’ve had to work a bit to get to print on the new one and vice versa.  Another difference is the slicer used to prepare the models for printing.  I’ve noticed that subtle surface features are not as pronounced with this new printer as they were with the old one.  The two use different software to make the printer files and it seems that the older printer’s software would do something that would make surface features more pronounced.  This is something beyond your control and you just have to design for it.

In the end, there is really no substitute for practice and hands-on experience.  Make a model, print it, see what works and what doesn’t, make changes, and do it again.  If you’ve got a single printer you’re working with, you can optimize your prints for that printer.  In a way, that’s what I’ve done as all of my prints have been made for the older printer we have here at the library.  Seeing how this new printer handles those same files has given me some more ideas on what to do for models I make in the future.

The other thing to remember is that the settings that work for one model may not be good at all on another or even on the same model at a different print resolution.  You really need to look at the model, what your goals are for the print and what settings will allow you to print that successfully based on the characteristics of your printer.

3D printing has a bright future ahead of it.  The technology continues to improve and the costs continue to come down.  But right now it is definitely a hobbyist’s area that takes a certain level of dedication and commitment to if you really want to do it right and create and print models of the highest quality.

Have you done any 3D printing?  Any success stories or failures you want to share?  Let us know in the comments below.

 


Categorised as: 3D Modeling/Printing



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