Overview

This page is based on a presentation I gave to the Rappahannock Valley Amateur Radio Club in May (or June?) of 2014. There's a huge amount of information out there on the topic, I only just touch on the topic because I have limited time but I try to touch on the topic enough to explain it regardless of the level of understanding you already have. If you wish to view the slides by themselves, you can download a PDF version of my presentation though it will not include any of the explanations that I include on this page. In the future, if I give any more presentations I will make an effort to record them for posting on YouTube to include the audience questions and real-time demos.

Before I get started, I'd like to say my 3D Printer is a Solidoodle 2, it's still going strong (with a few modifications and repairs. Unfortuniately it seems like the Solidoodle company had something happen and announced it formally suspended all it's operations March 28, 2016 which includes both printer production and sale of replacement parts. I learned this when I recently identified an issue with a bent Z-axis rod and was unable to order a replacement. After much research, it turns out most of the parts are much simpler than I realized, I just had to match up the specs of the stepper motor and find a relatively straight rod of the same thread at my local hardware store, then order a flexable coupling to connect them. The new rod is bent slightly too but since it is connected by a flexable adapter to the motor it is free to wobble slightly and eliminate the problem I had with the original rigid motor+rod assembly that was bent. I'm hopeful one day maybe Solidoodle will figure out how to pull itself back together and resume production, it seems like they had something really good going back when I got my printer from them.

Slide 1

Welcome to my presentation on 3D Printing...

Slide 2

What is 3D Printing?

First, 3D Printing is not magic. It is nowhere near instant, frequently prints take multiple hours to run - a very small print takes about 15-20 minutes of pre-heating and another 10-15 minutes of printing, followed by a cool-down period ranging from a few minutes to 10+ minutes to ensure that it doesn't deform as the parts are removed from the printing platform.

It is also not "zero cost" creation of whatever you want. Besides the cost of the raw material there is also the cost of maintaining the equipment, lubericants, replacement parts when they are damaged or wear out, and in the case of ABS that I use also the kapton tape that covers the heated build platform. Then there is the cost of time, which can be quite significant for everything from applying bubble-free kapton tape and lubericating moving parts to waiting for the prints to run. This is vastly increased when parts fail to print correctly for various reasons from delamination to running out of filament.

3D printers are impressive, but they certainly aren't the magical replicators from Sci-Fi.

Slide 3

3D Printing is very useful though. It has a variety of uses from rapid prototyping (easily making changes and testing within hours or days) to prepeated production of identical parts in small quantities.

The optimal use case for 3D Printing is production of simple parts in small quanitites. These parts can then be used as a basis for other things, whether being assembled into a more complex whole or fine-tuend and used to produce a mold for casting on a larger scale. It's also ideal for small batches of parts.

Slide 4

Now let's talk about how 3D Printers work. There are a couple types of 3D Printers, each with different benefits and limitations.

The first and most common type of 3D printers use additive layering where many strands of material are extruded on top of each other. It is comparable to using a hot-glue gun and putting multiple layers of hot-glue to build up a desired thickness and shape. This is what most people think of, and what is typically shown in the news and available to the consumer market. They are relatively inexpensive (available for under $1000) but also produce lower quality parts (typically no more than 0.1mm resolution) and are slower (most useful-sized prints take hours to days).

The second major type of printer is resin-based. It operates by using a laser or projection onto light-sensitive liquid material to harden it at the desired locations. This type of printer is typically much faster (producing useful parts in minutes to hours), and higher resolution but significantly more expensive. As a result, it is uncommon for the consumer market but more useful for commercial and industrial applications.

Slide 5

Above, you can see the sepcifications of my 3D Printer. Below you can see the actual printer that accompanies this slide.

The printer I have is a slightly modified Solidoodle 2. I've added plexiglass panels to partly-enclose the build area (held on by magnets), designed a PVC pipe filament holder above the printer (stock holder was behind it), and a lightweight plastic sign-board enclosure over the top to reduce drafts and dust. In this picture I was also experimenting with using a heating pad to help regulate the build area temperature but since then I have installed modified firmware which does a better job of regulating the bed temperature and no longer need it. I have also added power switches for the main power and interior lights so I can turn it off without hunting for the power cord behind my UPS.

Slide 6

Now that you have an overview of the types of 3D printers and have seen the unit I have, I'd like to move on to where you get parts to print. There are a couple ways of doing this. The first method is to download them from the internet, a couple popular sites are Makerbot's Thingiverse and Sketchup Warehouse. Some of the parts are useful such as cases for electronics, others are for fun such as a "Com-Badge" from Star Trek.

Slide 7

Here are some examples of Amateur Radio related parts other people have designed and posted online for anyone to download.

Slide 8

Here are some examples of Amateur Radio related parts other people have designed and posted online for anyone to download.

Slide 9

Here are some examples of Amateur Radio related parts other people have designed and posted online for anyone to download.

Slide 10

The other method of getting parts to print is to create them yourself using CAD software (I use Sketchup). Many CAD design programs can export to the STL format used by 3D printers, or have conversion utilities available. It's also possible to download files from the internet and then modify them in a CAD program to adapt them to what you need.

Slide 11

Here are a number of examples of things that I've created for myself or others.

Slide 12

And here you can see the CAD drawings of some of these parts.

Slide 13

And here you can see the CAD drawings of some of these parts.

Slide 14

Here's a close-up of a part I designed for one of my friendds and fellow hams. They had a radio which they complained was difficult to quickly re-tune because the VFO knob was awkward to spin. The solution we came up with was to design a cover which fits the shape of the existing VFO knob and adds enough thickness to provide a dimple for the operator's finger to spin the knob easilly.

Slide 15

The goal with this project was to make a switch to turn on some LED lights in a storage unit. The door doesn't fit particularly tight so I needed to construct something that would be reliable but also allow for some "play" in the parts. I started with a micro-switch from RadioShack and a case to hold it with a track for the "pin" to slide in. I then made a matching cover for the box. Next, I constructed an exterior pin that would be depressed by the door closing. To absorb the slop, I used a spring which fit over the roller part of the microswitch. For the inside of the pin, I made a small part which fit the track and held the other end of the spring from popping out of position.

Unfortuniately the online version of this loses part of the iullistration because I can't easily show the slide annimations. At some point I may attempt to re-create this slide as an annimated GIF to help make it easier to understand.

Slide 16

Here you can see the final result of my effort, the switch is screwed onto a 2x4 in the corner. The wire leads down to the battery pack and lights. So far it's been very reliable and effective.

Conclusion

At this point I presented a brief demonstartion of making a simple part in Sketchup on the computer. In lou of that, I can suggest looking up some of the many videos on YouTube of Sketchup 3D Printing tutorial videos.