How to 3D-print a Handle and Trigger for the 3Doodler (and to make it look like a Phaser).

The 3Doodler  is a hand-held 3D printer!  The company is taking pre-orders now for April delivery.  Last summer it was a “crowd-funded” Kickstarter project, and we invested in it.  Our reward for sponsoring this clever invention was to receive our very own pre-production device in January. It is kind of a cross between a hot-glue gun and a 3D printer.

Doodler 1

Unlike a glue-gun that melts a stick of rubbery plastic to glue things together, the 3Doodler can melt a 3mm filament of ABS (a kind of plastic that many things are made of) and extrudes it into a softened web-like thread that can draw up off of the paper in the open air and into almost any shape you can imagine.  While it is intended to be used for making plastic objects by drawing 3-dimensional doodles, we use it primarily to fix plastic objects that have broken or to hack plastic things by adding features to them.  But more about that in a later blog post.

Now we would like to tell you how the team of MacGyvrBot and Skip have found a way to make this great product even better!

Doodler 2

We used Tinkercad to hack-up a model for a Handle and Trigger mechanism, and then we published the design at so that anyone with access to a 3D printer can download the .stl files and make a Phaser Handle for 3Doodler of their own.

or you can just click these links to download the 3 files

Handle ,



This kind of sharing is called open-source hardware design, and the practice allows people to build on each other’s ideas.  You can also use Tinkercad to copy this design at  and modify it with your own ideas.  Progress is faster this way, so open-source design is the best way to get the most out of 3D printing.

Doodler 3

This Phaser Handle makes the 3Doodler look cool (like the Star Trek weapon), but it also makes doodling more comfortable (especially for people with small hands).  The makers of the 3Doodler obviously have plans for making a handle, because they provided a handy mounting bracket with threaded holes for M3 screws.  But we couldn’t wait!

The handle alone is beneficial, but using the trigger with the handle keeps the hand more relaxed during extended doodling.

Doodler 4

The Phaser Handle is attached to the 3Doodler with a pair of M3 x 10mm screws (any head design).  The trigger attaches to the handle with a pair of small flat head screws (such as 6-32 x 3/8 inch or M3 x 6mm) serving as hinge pins.  The screws are available at Lowes and Home Depot.

Doodler 5

The handle is hollow to allow access to a mounting screw (rather than having an infill of plastic in a sparse honeycomb pattern).  If your printer drops a few threads while bridging across the top of the handle, just let it finish the job.  Chances are it will recover before the top layer is reached.  If it fails, you may have to adjust your slicer settings (such as slowing the speed for bridges) and try again.

In our next blog post, we will show you how to use the 3Doodler itself to update the Phaser Handle.   The exercise will be a good demonstration of using the 3Doodler to hack an existing product.

Stay tuned!

from on March 10th, 2014Comments0 Comments

Can 3D-Printing and Computer Aided Design be of value in the Contemporary Urban Elementary School Curriculum?

The answer is a definitive YES!

During the past 4 weeks we tested this hypothesis as follows:

MacGyvrBot, a Personal Manufacturing Robot (also known as a table-top 3D-Printer) and Skip Meetze (both affiliated with INTERLOCK) volunteered to be part of the team teaching 4th, 5th and 6th Graders at School No. 52 in the Rochester City School District.  The 4 weeks of Tech Camp ran 3 mornings per week.  Michael Slade (another volunteer) and Susan Reuter (the teacher) rounded out the instructional team, and 20 students developed their skills at rapid prototyping while having fun learning some principles of physics.

America's Cup Toy Boat

The students each constructed an America’s Cup Toy Boat Kit (an STL file for the design can be downloaded at America’s Cup Toy Boat Kit by MacGyvrBot – Thingiverse) with soda straws and parts made on a Printrbot LC (Printrbot LC (v2) | printrbot).  Then they conducted a “shoebox regatta” where the sailboats were each sailed in a plastic shoebox half full of water.  The boats successfully (1) sailed on a reach (with wind from the side) (2) from one end of the box to the other, (3) without touching the side of the box, and (4) under the power of a student gently blowing through a straw from the side of the box.     This activity taught the students the basic principles of sailing while they developed confidence in their new skills of measuring materials (the straws) and assembling rapid prototypes (the boats) as MacGyvrBot chugged out the plastic parts right before their eyes.

Subsequently the students learned some basic skills in CAD using Tinkercad (Tinkercad – Mind to design in minutes) and Sketchup (SketchUp | 3D for Everyone).

At the end of the camp, students evaluated their experience by (anonymously) rating some of the lessons presented.

Student ratings

The Students’ ratings clearly show that using the 3D Printer and CAD are at the top of the list of things they would like to do again.

MacGyverBot in the classroom

A warning about Tinkercad:

There were special work-around requirements that we encountered for safely using the current version of Tinkercad with young students, and they will be further discussed in a later posting.  Tinkercad is resident on the internet cloud and not on the local computer, so continuous adult supervision is required (with an adult logged into the website) for Tinkercad to be safely used by kids (else the child’s access to sharing on the internet will be unsupervised).  Autodesk, the new owner of Tinkercad, is working on eliminating this requirement.

Parents and teachers, stay tuned… 

More about what we learned from participating in the Tech Camp will be discussed in later postings.  One of the neat things about rapid-prototyping in the classroom is the ease with which teachers, parents and designers can share their designs and ideas with each other.

from on August 2nd, 2013Comments0 Comments

Hackers are not the Bad Guys: Confessions of an Inventaholic.

Transcription of the talk given at BarCamp Rochester on April 20th, 2013, by Skip Meetze.

Hello.  My name is Skip.  I’m an inventaholic.  I am compelled to invent things for reasons that I can not control.  I would like to welcome you to Inventaholics Anonymous.

Over the past 40 years, I have followed a path familiar to many people with my affliction by accumulating as many patents as I could.  But with the help of my new friends at INTERLOCK, I have overcome those tendencies, and I am proud to say that I have moved on to the sober world of hackers and makers.  A world  known as the Open-Source Hardware Movement.

stepcounter 1

First Patent: The Stepcounter

In many ways, being an inventor has scarred my life.   In the early 1970s I squandered all the funds I could beg or borrow (at least I didn’t steal), and I blew it all on my first patent.  The Stepcounter was a research device to measure the activity levels of laboratory animals.  My wife wanted to make the down payment on a house.  Thanks to my addiction, we rented for 25 years before we bought our first house.

Kenneth Brown, the author of a book called Inventors at Work asked my old friend, the late Bob Gundlach an important question during an interview: “Is it better to be an inventor working for a large corporation, or would you rather be working on your own?”  I can relate to Bob’s answer: “Being an inventor on your own is a good way to go broke! Being an inventor in a corporation is a very fortunate happenstance.”

But even within a corporation you run into the Not Invented Here Syndrome.  If you offer a solution to improve a product that is outside of your assigned responsibilities, you will probably be rebuked with something like “No thanks. I’ve got my own ideas and I know what I’m doing.  Go work on your own assignment.”

vue iPad in comfort


I graduated from Xerox a few years ago and in 2010, my friend Ken and I invented a stand for iPads that we called the vue-stand.  It would hold your iPad at a comfortable eye-level.  As a human factors engineer I have spent decades designing easy-to-use products, and I thought that we were onto something.  After we spent thousands of dollars to do a pilot run at manufacturing and did a little test market, I couldn’t help remembering Bob’s words of wisdom.  People didn’t buy the vue for reasons we now understand.  We decided not to keep throwing money at trying to market a dead horse, so I bought out Ken’s interest in our company, and I continue selling off my inventory online without promotion.  That inventory will cut my losses, but it will not cover my investment.

Last summer something happened that changed my life:  A couple of guys from this Hackerspace called INTERLOCK Rochester gave a talk at AppleCIDER, a local Apple Computer Users Group.  They demonstrated a little desktop 3D printer that they had built themselves.  I was blown away.

I knew about Stereolithography and CAD (Computer-aided design).  Xerox engineers had made rapid prototypes using that technology for decades.  But specialist operated those machines, and they had talent and training that I didn’t have.  Furthermore, the machines cost more money than an individual could afford.

Now, people are building these little machines that can even build parts to replicate themselves.  And people are sharing their designs and discoveries for other people to build upon.  The source code for anything built on these little industrial robots can be shared online at a site called

They call the shared technology RepRap for replicating rapid prototyping.  The designs are evolving unbelievably fast because people are sharing with each other!  What a sobering thought!

I don’t plan to get any more patents.  Now I have a reprap machine, and I have joined the people who share ideas in a Hackerspace.

I used to think of hackers as being the bad guys who stole identities and maliciously created computer viruses and things like that.  Now it has come to mean people who take an existing good idea and hack on it to make it better.


iPad on a HandleStand

For instance, I have hacked-up an iPad accessory that I call the HandleStand.  I took a protective iPad case that I bought on Amazon for $8 and hacked it.  I drilled two holes and attached a pair of hinged handles to it with screws.  The case I chose also allows me to attach a Keyboard that protects the front of my iPad.

The handles open up to make a stand that allows the iPad to tilt at any angle.  Great for making videos or calling people on FaceTime with the iPad camera that can be pointed in any direction.  By the way, it also holds the iPad at a comfortable eye level just like the vue-stand.  But it is better for all these reasons.

Where can you buy this HandleStand and how much does it cost?  Sorry, but you can’t buy one.  You can get the source code from Thingiverse however, and if you can get access to a 3D printer you can make your own!  You can even hack it to make a better one!

You don’t have a 3D printer?  Well come on over to INTERLOCK on any Tuesday or Thursday night and we will help you hack one up.

I must admit that getting these little printers to run is a bit tricky sometimes.  They are complex electronic devices that run on an open source micro-controller called Arduino.  The hardware and software are made from the contributions of many-many people, and instructions don’t necessarily keep up with the latest developments. A lot of things can go wrong, and Murphy’s law does apply.

But hackerspaces are springing up all around the world where people help each other with things like that.  So you should join the world of hardware hackers.  Free CAD software has gotten so easy to use now that even I could learn it.

Pretty soon most people will know how to design using CAD just like now most people can make Powerpoint presentations.  Perhaps it won’t be long before most people will have access to a 3D printer.  I built one from a kit for a little over $500.  Or you can get a MakerBot already assembled for $2000.

I no longer spend a lot of money trying to sell inventions, I give them away and save a lot of money.  My designs can no longer be stolen from me.  I’m publishing the source codes on Thingiverse and I am happy that people are downloading them for free.

People tell me that I’m missing an opportunity to make money on my inventions… I don’t care.  I’m an inventaholic.


from on April 21st, 2013Comments0 Comments