Monthly Archives: February 2016

3D Printing

Last year I finally bought a 3D printer. In retrospect I should have done this a long time ago.
I used to believe that you needed a high-end machine to create usable parts,
and that anything less was a waste of time. There where toys only capable of churning out useless trinkets.

Boy I was wrong. Anybody interested in mechanical engineering or industrial design should get one immediately.

I got a Printrbot metal simple kit. My appreciation for 3D technology is colored by my personal experience with this particular machine, that turned out be an amazing piece of equipment.
Sturdy, reliable, elegant and honest in its design, the simple metal has performed well beyond my expectations.

One of the reasons I was holding back my purchase, was that I was afraid that after a couple of week of tinkering, the machine will be collecting dust on a corner. But to the chagrin of the rest of my family, the Printrbot is constantly churning out parts.

Currently, I’m even considering getting a Ultimaker or a Lulzbot Taz, not to replace my Printrbot but to extend my build size and printing capacity.

Setup

At the same time last year I start evaluating OnShape a cloud based professional CAD solution. I have used Autodesk Fusion 360 on and off for some time, but the chemistry wasn’t there. I do think Fusion is an amazing piece of software and I still use their CAM and rendering features, but modeling on OnShape just “clicked” with me from day one.
My current workflow looks like this:
I’ll do my modeling on OnShape, export the part to STL, slice the part in Simplify3D and sent the G-code to Octoprint.

On a side note, before upgrading your hardware get Simplify3D!

Design

Having a 3D printer at hand allows you to develop your designs skills at a fast pace.
You can iterate over small aspects of your design until you get them right.
Say, two parts need a snap-click assembly. You can isolate the snap-click features and print only the relevant sections, until you get the tolerances and amount of material right. Then you add those sections to your main parts.
You will learn a lot about designing within the constrains of a production method.
In 3D printing, orientation plays a crucial role.
Orientation impacts the level of precision you can achieve on a given surface.
Because parts consists of layers, the forces they can withstand vary depending on the direction applied.
In order to get the ideal orientation for a critical aspect of your design, you will sometimes need to split a part into discrete components.
The filament (type of material) and the chosen extrusion settings can have an impact in tolerances.
For mechanical parts where you need a higher level of precision, you are better of with slower speeds and low heat.

When you get orientation right, the (usually unwelcome) striation,
suddenly became an esthetic asset that reinforce the structural ideas behind your design.

Holding such a piece in your hand with the original digital model still on-screen is remarkably satisfying.
It’s and idea materializing out of thin air, and it feels like magic.
If you already have or want to buy a 3D printer, don’t forget that it’s not about the technology, but about what you can imagine.

Resources

Hardware
I own a Simple metal, but have I played with, and can recommend the Ultimaker and the Taz.

– Printrbot Simple Metal

Assembled Printrbot Simple

For Europeans I can recommend ordering from RoboSavy
https://robosavvy.com/store/assembled-printrbot-simple.html

– Ultimaker 2+
https://ultimaker.com/en/products/ultimaker-2-plus

– Lulzbot Taz 5
https://www.lulzbot.com/store/printers/lulzbot-taz-5

Filament
Don’t be cheap on the filament. You are not going to use that much, and quality shows. Recommended brands are Colorfabb & Monsterfil.

First layer adhesion
I start using blue tape (3M ScotchBlue 2090 Painter’s tape from Amazon or from Adafruit ) with mixed results. Printing larger flat surfaces without warping was a challenge, until I start heating the printer bed with a heat gun.
Because the bed on the Printrbot is solid metal, it could accumulate enough heat to get me a solid foundation. But applying the tape quickly became annoying.

Then I got the Zebra Plate from PRINTinZ! I can not recommend this enough. No preheating, or taping or warping.
The only problem is that sometimes parts can be difficult to pray of the board.
If you can wait you can put the plate on the freezer for some minutes.

One trick for the first layer is to add small pieces of paper under the bed. If the first layer is too squashy you can take them out while the brim is still printing.
It not squashy enough you can remove the center clip. This will give you enough wiggle room to compensate for small z calibration issues.

CAD Software
OnShape
Fusion360
Meshmixer

Slicers
Cura
Simplyfy3D
– Even if you don’t use Simplify3D check their quality guide.
This is a great resource to understand how to improve your prints.

Print servers
Astrobox
Simple UI, to get you started but you’ll be long for more control pretty soon.
Adafruit starter package.

Octoprint
Full feature solution with lots of plugins
Adafruit starter package.

YouTube Channels
There are a lot of 3D printing channels on YouTube. My favourites:
Makers Muse
Thomas Sanladerer
Noah & Pedro Ruiz (from Adafruit)

Web sites and 3D repositories
Pinshape
Thingiverse
YouMagine