Embryo Endurance Prairie Bird : Designed by Rob Peck : Peck-Polymers

free flight rubber powered model airplane

Summer of Free-Flight

My “Summer of Free-Flight” has been a lot of fun! It’s been a learning experience, not always smooth going, but always fun! I’ve built and flown a few really fun balsa wood stick and tissue paper airplanes this summer.  The latest plane added to my fleet of planes is Rob Peck’s classic design, the Prairie Bird.

free flight rubber powered model airplane

Peck Polymers Prairie Bird Airplane

A friend recommended I build the Prairie Bird because of its reputation as a great flyer. He was correct; more on that later. I searched around on the internet and downloaded the plan. The plan was formatted to print nicely on 11″x17″ paper – so I uploaded the file to Staples and had them print me a few on some quite nice card stock. I believe five copies cost me under $3 total. I pinned the plan to my building board, covered it with Saran Wrap and got to work.

free flight rubber powered model airplane
Carved balsa wood exhaust pipes and a front shot of the assembled fuselage.

I really took my time on this project making certain everything was as perfect as could be. The straightforward design of the plane made it easy to construct a straight and square fuselage. I practically glued the cross-braces one at a time and waited for the glue to set before I adding the next one.

Adding tissue paper was a snap because there isn’t too many compound angles and curves to the parts. The tissue on everything except the rudder and stabilizer was shrunk with 50/50 water/alcohol mixture. Following the shrinking I added a three coats of 50/50 SIG Lite-Coat/Thinner. The windshield is made with clear plastic from a salad container. I used plastic Peck wheels, a Peck Nylon Bearing and Peck propeller. The propeller was balanced by gently sanding away material until an even balance was achieved (a lot more sanding than I expected).

free flight rubber powered model airplane
The Prairie Bird over Watsessing Park.

My test flights were a great success. At first I was flying with approximately 300 turns on the motor, eventually increasing to about 600. Many more turns are possible, but I didn’t have a helper or a stooge to help me stretch wind the motor. I didn’t want to press my luck.

free flight rubber powered model airplaneThe Prairie Bird performed wonderfully and was a champion at catching thermals. One of the flights concluded in a tree. Lucky for me it was low enough to the ground that I whacked it loose with a six foot long stick.

The thrill that is achieved from flying these little beauties is beyond words. The careful work and attention is forgotten – and happiness consumes me when they take to the air, and when they land where they can be easily retrieved.

Download Vintage Universal Model Airplane News · 1932 1933 1934 1935

Vintage Model Airplane News Magazine

My recent interest in building old fashioned balsa wood and tissue model airplanes inspired me to visit a local estate sale featuring model building and model train supplies. I immediately focused my attention of a few stacks of magazines of all sorts. Lucky for me I found twelve issues of Universal Model Airplane News spanning from 1932 to 1935.

The magazines are in “less than ideal” condition. Several of the magazines crumbled into pieces during the process of flatbed scanning their contents. Also, these magazines were owned by someone who enjoyed scrap-booking, resulting with square holes of missing information and photos. With that said, plenty of useful information and plans remain in these little gems. Each magazine has regular columns such as: The Aerodynamic Design of the Model Plane (by Charles Hampson Grant), Aviation Advisory Board, Model Kinx (by J. G. Marinac), “Whats” and What Nots” of Model Plane Building (by Howard G. McEntee) and Air Ways – Here and There.

With that said, I am currently scanning these magazines and eventually all twelve will be available for download here. Even if you’re not interested in model airplanes, you should download them and give them a read – for history’s sake!

1932 September Universal Model Airplane News:

Vintage Model Airplane News Magazine
Click to download PDF
  • The Landing Field Goes To Sea
    by Lieut. (j.g.) H. B. Miller
  • Georges Madon of France
    by F. Conde Ott
  • How Well Do You Know Your Airplanes?
    Junkers and the Armored Plane
    by Robert Fencl
  • The Lockheed Orion (Modern 3 View)
    by Stockton Ferris, Jr.
  • The Lockheed Orion To Test Your Skill
    by Robert Morrison
  • Endurance – “And How”
    by Carl Goldberg
  • The Pfalz Scout (War Time 3 View)
    by Stockton Ferris, Jr.
  • Building the Boeing Bomber
    by Howard McEntee

1933 April Universal Model Airplane News:

Vintage Model Airplane News Magazine
Click to download PDF
  • Bail Out!
    by H. Latane Lewis II
  • The Aeronca Collegian (Detail 3 View)
    by Orville H. Kneen
  • Blaze Air Trails With This Howard Pete
    by Stockton Ferris, Jr.
  • Maneuver Contest
  • Foreign Model Plane Activities
  • Modern Fighters of the U. S. Navy and the
    British Army (3 Views)
    by James W Hawkins, Jr.
  • The Voisin L.A.S. (3 View)
    by E. Tabio
  • A miniature F.9 C.2 Fighter
    by Joseph Battaglia
  • Machine Guns For Your Scale Model
    by Joseph F. Morris

1933 May Universal Model Airplane News:

Vintage Model Airplane News Magazine
Click to download PDF
  • The Siemens-Halske D4 Pursuit
    by Willis L. Nye
  • New Wings For Our Airplanes
    by Fletcher Pratt
  • Helpful Hints for the Model Builder
    by Alan D. Booton
  • Fighting Wings
    by Orville H. Kneen
  • Build This World Record Fuselage Model
    by Gordon S. Light
  • Who Developed the Airplane?
    by Alan R. Moulton
  • The Fokker F-10-A
    by Robert L. Anderson
  • Let the Glide Improve Your Flights
    by Gene F. Rose
  • 1933 Official National Championship Model Airplane Meet
  • A Twin Tractor That Amazed Experts
    by Charles H. Grant
  • The New Curtiss-Wright Condor and The Beechcraft (3 View)
    by Stockton Ferris, Jr.
  • Airplane Maneuver Contest

1933 June Universal Model Airplane News:

Vintage Model Airplane News Magazine
Click to download PDF
  • Flying Boats vs. The Atlantic
    by Alexander Klemin
  • The Hall-Springfield Racer
    by Howard F. Schmidt
  • Fighting Wings (Part 4)
    by Orville H. Kneen
  • Building A Flying Stinson “R”
    by C. L. Bristol
  • The New Waco Cabin Plane (3 View)
    by Stockton Ferris, Jr.
  • The Barrel Sprouts Wings
    by Richard Rioux
  • The German L.V.G. – C5 (3 View)
    by E. Tabio
  • The National Model Airplane Championships
  • An All-Weather Twin Pusher
    by Stockton Ferris, Jr.
  • Airplane Maneuver Contest
  • National Aeronautic Association Model Airplane
    Definitions and Competition Rules

1933 November Universal Model Airplane News:

Vintage Model Airplane News Magazine
Click to download PDF
  • Wings of the Navy
    by H. Latane Lewis II
  • The Pfalz Scout D.12
    by Barnett Feinberg
  • The Development of the Fokker Fighters
    by Robert C. Hare
  • Keeping Pace with Model Science
    by Carl Goldberg
  • Build A Flying Scale Model of Wiley Posts’s Lockheed Vega
    by J. D. Bunch
  • Model News from Other Countries
  • New N.A.A. Model Plane Records
  • Helpful Hints for the Model Builder
    by Alan D. Boonton
  • Maneuver Contest Winners
  • The U.S. Army X-B1A (3 View)
    by Willis L. Nye
  • How You Can Build A Solid Scale Douglas Dolphin Amphibian
    by Burton Kemp
  • The I.A.A.P.E. On Parade
  • The British Short “Singapore II”
    by John I. Roe

1934 May Universal Model Airplane News:

Vintage Model Airplane News Magazine
Click to download PDF
  • Sky Fighters of the Rising Sun
    by Fletcher Pratt
  • Fundamentals of Model Airplane Building
    by Edwin T. Hamilton
  • On the Frontiers of Aviation
  • Including Plans to Build Solid Scale Models of:
    – The Lockheed Electra
    The B/J Mail Plane
    by Robert C. Morrison
  • Build the Kawasaki Fighter
    by Elmer Pilzer
  • How the Aeroplane Was Created (Part 5)
    by David Cooper
  • The Eastern States Outdoor Contest
  • How You Can Make Hydrogen
    by Herbert Greenberg
  • N.A.A. Junior Membership News
  • Including Plans for a World’s Record of:
    – Outdoor Fuselage Model

1935 March Universal Model Airplane News:

Vintage Model Airplane News Magazine
Click to download PDF
  • New Developments in Blind Flying
    by H. Latane Lewis II
  • The Development of the Fokker Fighters
    by Robert C. Hare
  • Building the Famous Udet Flamingo
    by William Winter and Walter McBride
  • On the Frontiers of Aviation Including:
    How to Build Scale Models of the G.A.38 Transport
    and the Boeing XF7B-1
    by Robert C. Morrison
  • How to Build a Smoke Screen Model
    by Marshall Mulvany
  • Slipstreams
  • N.A.A. Junior Membership News

Check back soon, there’s more on the way!

2017 Summer Update – I know I haven’t posted in a while!

The summer of 2017 is flying by! Pun intended. I’ve been busy building free-flight rubber powered Peanut Scale airplanes (and some other styles as well). Sadly I haven’t been spending much time flying them – it’s either windy or dark outside when I find time for actually flying! For relaxation and inspiration I took a long weekend road trip to the AMA (Academy of Model Aeronautics) Museum in Muncie, Indiana, the National Museum of the USAF as well as the Dayton Aviation Heritage National Historical Park in Dayton, Ohio. I highly recommend all of these destinations!

The Labor Day 2017 weekend bring the Long’s Park Art Festival  in Lancaster, PA. I don’t present any of my work at the festival, but I always look forward to seeing the various crafts on display. My favorite, without a doubt, is the great stuff Lohr Woodworking Studio showcases! For the past few years they’ve been kind enough to allow me to help pack up their trailer at the end of the show. It’s my once-a-year workout.

Speaking of the awesome folks at Lohr Woodworking, I’ve been invited (okay, I invited myself) to be a teacher’s assistant during the Sold Out Sept 18-23, 2017 Practical Woodworking Course. The kind hearts of Jeff, Larissa, Rob and Eoin provide me a relaxing getaway, to be surrounded by big power tools and reeling minds excited about learning the craft of furniture making. For the most part I catch up on my woodcarving projects quietly in the corner.

The plan was to attend the Barron Field Air Races in Wawayanda, NY Oct 22-23. I was going to try my hand at entering a few of my peanut planes into some friendly Flying Aces Club contests for the very first time. However, on one recent evening as I nodded off to sleep I was thinking “October. October… When is the…?” Instead of racing planes I’ll in Wayne, NJ at the North Jersey Woodcarvers Woodcarving & Art Show Oct 22-23 2017. It’s been a few years since I’ve had a table at the show – and I really miss the gang from the club and the American Woodcarving School.

Attending the show will give me an excuse to complete some of the carvings I started with enthusiasm several years ago. I guess I’ll be putting the planes on hold until November. I have a lot of carving to do if I stand a chance at finishing two or three of those carving projects!

Sorry it’s been a while since I posted on the blog. I have been keeping my status up to date on Instagram if you’re interested. Until next time!

Sterling Models Peanut Scale Monocoupe – Vintage Rubber Powered Free Flight Model Plane

jchismar Sterling Models Kit P-2

Canarsie Courier and Canarsie Canary
The Canarsie Courier (top) and Canary (bottom) From the Don Ross book.

I’ve been busy making good old fashioned balsa stick and tissue rubber powered free flight planes. As I likely mentioned in an earlier post I’ve decided to take some time from woodworking and carving to relax and explore the hobby of flying model planes. My focus is primarily on Peanut Scale fliers, but instead of jumping right in I wanted to do it right and take some time to learn the nuts and bolts of making planes that fly. I’ve worked my way (mostly) through Don Ross’s book on rubber powered planes, with some success with building and flying these airborne works of art.

stick and tissue model airplane
The complete SIG AMA Racer

I assembled and flew a few of the SIG Models beginner planes: AMA Cub, AMA Racer, etc and had fun flying these sticks with wings. These projects helped me gain an understanding of how to trim (adjust) model planes for flight. Because these planes are so light their flight times are long and magical! I moved onto building and flying my own (no longer produced) SIG Uncle Sam plane which flew well until I accidentally locked it in the hot car too long and warped the stabilizer and rudder.

After completing the prior projects I decided I was ready to assemble my first Peanut Scale plane, which is the whole reason why I started on this journey. I was a busy boy online snatching up vintage Peanut Scale kits. For whatever reason Sterling kits (manufactured in Philadelphia, PA) captured my interest. My plan is to complete all six kits, twelve planes in all. I started the process with Kit #2: Monocoupe – Citabria. I laid out the plans for both on my building board and got to work.

stick and tissue rubber powered
Sterling Models Monocoupe in progress

I completed the Monocoupe first. At first I wasn’t interested in decorating the planes, I was simply going to apply white tissue and call it done. As the Monocoupe was taking shape, something clicked in my psyche and suddenly I was interested in applying all the details.  Because of this they project took about twice as long as expected (a few weekends).

I’ve had an opportunity to take the complete Monocoupe out for a few test flights. To my surprise, it flew straight as an arrow. There are a few adjustments I’d like to make to balance the model better and improve the performance of the propeller. However, I think I’m going to hold off on any ambitious changes until I get more experience building and flying these wonderful Peanut Scale marvels.

Canarsie Canary Rubber Powered Free Flight Airplane Part 2

The Canarsie Canary In Flight

The video above is of the Canarsie Canary I built using the plans from the Don Ross book Rubber Powered Model Airplanes. My previous post shared some of the construction of this model. I mentioned the first few flights were encouraging, but subsequent flights continued to get worse. This was because the propeller bracket was slowly tipping downward with each winding of the rubber band. I shimmed the bracket and the plane flies great!

Moving on to the next plane in the book. The Canarsie Courier. My model of this plane still isn’t flying as it should. I’m pretty sure I need to add weight to the nose, even though the weight of the plane is balanced as it should be. In the meantime I will share a little of my experience working through the book Rubber Powered Model Airplanes.

My Introduction to Building Balsa Airplanes

When I recently made the decision to start the hobby of building model airplanes I started with research. Despite how long this pastime has been around I quickly learned there isn’t a thorough Beginner’s Guide available for the novice. There is a wealth of information online but it assumes the reader has building experience and an understanding of the terminology. Because I am most interested in free flight rubber powered airplanes I’ve started with the aptly titled book Rubber Powered Model Airplanes by the late Don Ross.

The book is a fantastic introduction to the hobby and shares a wealth of tips and information for every newcomer. It isn’t, however, without shortcomings. The book instructs the reader to read the text multiple times and to have a complete understand of the plans before building the projects. There are many disparities throughout the text and illustrations which directly contradict each other. According to the author the plans are drawn in various scales to improve the reader’s competency with model plans. However, the plans don’t match.

Canarsie Courier Pylon Don Ross
Canarsie Courier pylon from plans

The plans for this pylon are taken directly from the Canarsie Courier plans. Here the pylon illustration on the right is reduced to match the illustration on the left. It’s not hard to notice the illustrated height is different between the two, also no height measurement is provided in the plans or the text. Another inconsistent example is the length of the  motor stick. The plan stipulates a length of eighteen inches; if the plans are properly enlarged they motor stick is actually drawn to a length of seventeen inches.

I assume the plane will fly, to some degree, regardless of the length chosen by the modeler. However, this is a book for beginners. I’ve already learned enough to know these planes are tricky to build and fly with meticulous effort. It’s easy to become frustrated when inconsistencies such as these are discovered.

Therefore I’m taking a break from working through this book and exploring a few other options on building free flight planes.

Canarsie Canary Rubber Powered Free Flight Airplane Part 1

Don Ross Canarsie Canary Free Flight

The Canarsie Canary

I mentioned in an earlier post at the summer of 2017 is time for me to learn the ins and outs of rubber powered free flight model planes. To do so I’m starting from square one – the fabulous book by Don Ross titled Rubber Powered Model Airplanes. The first project in the book is the Canarsie Canary, a basic balsa wood design. All that is needed is some balsa wood, a propeller with mount and a loop of airplane rubber.

I purchased the balsa wood from my local hobby shop, the propeller and rubber was ordered from SIG, a popular model plane manufacturer. While I waited for the parts to arrive (and they came within a few days) I started building the balsa wood parts. As you can see it’s not a very complicated design, basically a stick with wings, rudder and stabilizer. The most complicated aspect of the build is setting the wing dihedral, bending the wing tips upward – this adds flight stability.

Rubber Powered Canarsie Canary
Setting the Wing Dihedral

I followed the instructions somewhat diligently. Scotch tape is applied on the top of the wing where the bend will occur. The wing is flipped over and lightly scored to allow the wood to bend, but not break. The wing tips must be folded upward 1 1/4″ and the gap is filled with glue. For precision sake the wings were supported on two stacks of plywood scraps (each stack is a piece of 1/2″ and 3/4″ plywood) 1 1/4″ tall. I used tape to hold everything in place while everything set.

When the remaining parts arrived I assembled the entire plane and gave it a test flight. To my surprise it flew straight and smooth. A few hours later I headed to the local park with plenty of room to give the plane a true test. Before the Canarie Canary can take flight two small rectangles of paper are taped on the wing and rudder. This forces the plane into a gentle left turn.

I’ll be honest, the plane had about ten flights, three of them were somewhat graceful and responded as it should. At times there was a breeze, and some of the adjustments of the plane were not ideal. Suddenly some of the advise that is shared in the book became quite clear. So I’ll be trying out a few modifications and returning to the park soon. I’ll report with more information when it comes to fruition.

2017 The Summer of Free Flight Rubber Powered Model Airplanes

Free Flight Rubber Powered Model Plane

Rubber Powered Free Flight Model Airplanes

It’s been a while since I’ve posted to the blog, not because I’ve been a slacker – but because I haven’t completed any noteworthy projects recently. Preparing for the Maker Faire required a lot energy and time. With the event behind me I’m ready to take on my summer. You may be thinking, “So you’re going to complete some of your carvings or other ambitious projects?” The answer is, “No.” I’ve decided it’s time to take a break and relax.

How do I relax? Well, by starting another project! Way back in the day I enjoyed assembling scale models and balsa wood planes. I’ll admit my planes looked nice, but never flew as they should. This summer is a chance to redeem myself and earn my wings. I picked up a few balsa and tissue kits at an estate sale on the cheap. These kits are currently being assembled as practice projects. Maybe they’ll fly – it won’t be the end of the world if they don’t.

Concurrently, I’m working through the great book by the late Don Ross titled Rubber Powered Model Airplanes. You can expect a few posts regarding the projects from the book in the near future. I’m waiting for a few necessary parts to be shipped and I can complete assembly and start to learn the ins and outs of trimming (tuning) model airplanes for free flight.

Free flight?

What’s that? I’ll let my friend Wiki answer that for you:
From Wikipedia, the free encyclopedia

Free Flight is the segment of model aviation involving aircraft with no active external control after launch. Free Flight is the original form of hobby aeromodeling, with the competitive objective being to build and launch a self controlling aircraft that will achieve the longest flight duration, within various class parameters.

That’s right! Airplanes are built and flown with no control once it’s in the air. If built correctly, and the flight conditions cooperate, the plane doesn’t fly away to a distant back yard. It’s recommended to write your contact info on the plane, just in case.

I’ve rambled enough for this post (which is only the tip of the iceberg of ramblings my wife’s been kind enough to endure lately) so for now I’ll leave it at that. Stay tuned for what will surely be entertaining (and possibly educational) updates on my progress.

Walking Wooden Poodle Automata / Karakuri Machine

jchismar Poodle Dog Automata Karakuri

Yesterday was my super-sweet standard poodle Fleur’s thirteenth birthday. To commemorate the occasion I dug in and built an automata in her likeness. Loosely defined, an automata (or Japanese karakuri) is mechanism that imitates the movement of a living creature. This project has been on my to-do list for several years and I thought it was about time I gave it a go.

The mechanism is based on a popular design that’s been around for a while. In the early 2000’s Theo Jansen, either refined or invented the linkage for his very popular wind-powered walking machines. Each part of of Jansen’s mechanism is carefully specified, elegant and mind-boggling in it’s function. Me? Well, I just sort of guesstimated the dimensions and ran with it.

jchismar Poodle Dog Automata Karakuri

I first made templates out of cardboard of each part. Each template was transferred to 1/8″ plywood and cut out using a scroll saw. The holes for the pivots were made with the drill press. I then used 1/8″ wooden dowels to assemble the mechanism.

Assembly was tricky at times because I didn’t have an assembly schematic. I just went with the flow. I made sure the dowels were plenty long to allow me to put the puzzle together on the fly. Once everything was in place the excess was trimmed from each dowel.

All in all I’m pretty impressed with the complete mechanism. This was the first, but certainly not the last machine of this style I build. I already have tweaks I’d like to try to give this girl a little more life. Watch the machine in action in the video below.

How to Design and Make Automata or Whirligig Gears Using the Power of Geometry

“…Chemistry is not an exact science” ~Mario Andrada

jchismar How To Make Wood Gears

In this post I will do my very best to simplify the process of designing and making gears from wood and other materials. The process to build a simple Spur Gear and Pinwheel Gear will be explained.

Thanks to my background in 3d animation I have a rudimentary understanding of geometry and mathematics. I would love to be a math magician but like many people I get lost with anything beyond algebra. Thank goodness for the internet and calculators!

jchismar N-Gon Automata GearAs my math magician friend Charlie reminded me, “To get the teeth to mesh, the spacing BETWEEN the teeth need to be the SAME on all gears.” With this in mind, using the n-gon is ideal to design a gear, the spacing between each vertex is uniform. Simply stated, an n-gon is a polygon with “n” amount of edges. The image to the left is of an eight sided n-gon. The n-gon has two radius measurements: circumcircle (rc)and incircle (ri). If you need a refresher, the radius is the distance from the center to the outer edge of the n-gon, the diameter is the complete distance from side to side (through the center). Vertices are the angular points where each edge meets (the white “edge” arrows point to vertices).

When designing gears we will focus mostly on the circumcircle radius (rc), the vertices are positioned along this radius.  The vertices will become the teeth of our gears.  If the desire is to use a gear to turn another gear uniformly each gear will be identical resulting with a 1:1 ratio. To use a drive gear to rotate a second gear at half speed the second gear needs twice as many teeth as the drive gear, a 2:1 ratio.

Below I have included a calculator to do all the hard stuff for us.

Say you want to make a pair of gears with a 2:1 ratio, the drive gear turning twice for each turn of the second. You also want the drive gear to have a 1″ radius (2″ diameter). You also want the teeth to be separated by 0.5″. This is easily accomplished with the use of the above calculator. The calculator’s default settings are Edge Length (a): 0.5 and Number of Vertices (n): 8 resulting with radius (rc)  of 0.6535. This radius is just over half of what we desire. We can’t change the Edge Length because in this example we want the tooth spacing to be .5″. Instead, increase the Number of vertices to 12. Now radius (rc) is 0.9664 just under the 1″ radius we were looking for. Perfect!

The 2:1 ratio requires the second gear to have twice as many teeth. This doesn’t mean twice the teeth makes the gear twice as large. Let’s see. In the calculator change the Number of Vertices to 16, doubling the amount of the drive gear. Radius (rc) is 1.9162.


This is important! When I started designing gears I was under the impression that to double the ratio, the radius simply needed to be doubled. This is NOT the case (thanks Charlie)! Let’s examine our calculated radius values:

  • 12 vertices Drive Gear (rc): 0.9664
  • 24 vertices Second Gear (rc): 1.9162

That’s double, right? No. It’s not double. By doubling the drive gear radius (rc), 2 x 0.9664 the product is 1.9328, a difference of 0.0166. Doesn’t seem like a huge deal, but a .0166 error can, in fact, impede the smooth operation of the gears. To emphasize this point let’s examine a more extreme 10:1 ratio example.

  • 12 vertices Drive Gear (rc): 0.9664
  • 120 vertices Second Gear (rc): 9.5552

Multiplying the 12 vertices Drive Gear (rc): 0.9664 by 10 (0.9664 x 10) results with a product of  9.664. That’s 0.1088, or a tenth of an inch, larger than calculated (rc) value.


Making Spur Gears

Right about now you’re probably thinking, “Hey John. I thought you were going to show me how to make gears, not bore me to death with math.” Well, you’re in for a treat, let make some gears! We’ll start by making a pair of spur gears: one 1:1 and another 1:2. A spur gear is a gearwheel with teeth projecting parallel to the wheel’s axis, this is the sort of gear everyone is familiar with. For this example we’ll be making wood gears. You’ll need paper, wood, glue, drill (or drill press), saw, an accurate caliper gauge and a quality pencil compass.  If you don’t own these instruments you can find them at any hardware store – or you can be like me and score vintage beauties at flea markets and estate sales. Cheap tools may work, Harbor Freight – cough, cough, but I often find cheap tools more frustrating than productive.

jchismar How to Make Wooden Gears 01
Step 1

Step 1: Layout the Gear

Laying out the gear is the most important task of making your own gears. I own a few sets of old drafting tools I picked up estate sales for a few dollars. The compasses in these sets are fantastic quality and several of them have an adjustment lock. I use several compasses, and once their settings are perfect, I don’t change a thing until every gear is marked on on wood.

First, calibrate the compasses by drawing on paper. To layout the drive gear use a pencil to draw a small dot on paper, this is the center of the first gear. Set your caliper gauge set (rc): 0.9664 (or as close to this value as the gauge allows) match the pencil compass to this value. Place the compass needle on the pencil center mark and draw the circle. Reference your caliper gauge from the center of the circle to ensure the drawn circle is correct.

Set the caliper gauge to the Edge Length (a): 0.5 and adjust a second pencil compass (preferably locking) to match. Using the circle as reference, draw ticks across the circle (rc) at .5 intervals. When you’ve gone all the way around the circumference your last tick should match the first tick exactly. Refer to the Step 1 image to see my terrible first result (red circle). If it’s not perfect, something went amiss in your settings. You’ll need to start again. This requires patience and practice. The width of the pencil line complicates creating accurate marks. You’ll need to get a feel for the process.

Once you’re comfortable laying out the gear, layout the pattern for each gear on the wood you’re using. This also may require a few tries. Working on this example required about two hours to layout eleven gears from start to finish.

jchismar How To Make Wood Gears 02
Steps 2 & 3

Step 2: Cut Out the Gear

Now you’ll need to cut the round gear from the block of wood. Generally I use the band saw or jigsaw for the task. You can use whatever works best for you: hand jigsaw, Dremel, router, etc. Cut to the outside of the radius (rc) line you created with the compass. Try not to remove the line! Once the gear is roughed out, use a disc sander to shape the circle precisely to the line (bottom left Steps 2 &3 image).

Step 3: Drill a Hole

I generally use 1/8″ wire to mount the gear to the project. The wire serves as the shaft for the gear to rotate about. I use an 1/8″ drill bit in my drill press for the task. Drill an appropriate sized hole centered on the depression you make with an awl. This is the middle of the gear.

After the gear is complete I use a small round file to enlarge the hole to make it rotate more easily on the wire shaft. But that’s the last step!

jchismar How To Make Wooden Gears
Step 4:

Step 4: Add the Teeth

This is where personal preference, practice and experience comes into play. For this example I will be using poplar that I’ve planed to .125″ thickness. The strip of .125″ poplar is ripped on the table saw to .75″ width. Individual teeth are crosscut from the strip to a .75″ length. Each tooth is .125″ x .75″ x .75″.

I’ve constructed a miter bar jig for the table saw to hold the gear while cutting a dado for each tooth around the the gear. The dado I cut is .25″ deep and .125″ wide.  With the table saw jig I am able to center the vertex ticks drawn in Step 1 spaced at .5″ around the gear. I center the tick to the blade, cut the dado. The gear is rotated to center the next tick and the next dado is cut. This process continues until each required dado is cut.

I squirt out a puddle of wood glue on a scrap. I dip the point of a wood skewer (the grocery store kind) into the glue and spread glue into a gear dado. Then, using the skewer, add a little glue to the end of a tooth square. It is important to insert the tooth square into the dado so the wood grain is perpendicular to the dado. If the tooth is attached with the grain parallel to the dado you run the risk of the tooth breaking with the grain.

Continue this process until you’ve completed the gear.

Step 5: You’ve Made a Spur Gear!

Congratulations on making your first gear! Repeat these steps for the second gear (keeping in mind the second gear is larger: 24 vertices Second Gear (rc): 1.9162).


Making Pinwheel Gears

Let’s say your project requires the drive shaft to power another element or shaft at a ninety degree angle. Enter the Pinwheel Gear. You’ll need wood, drill (or drill press), saw, an accurate caliper gauge and a quality pencil compass.

jchismar How To Make a Wood Pinwheel Gear
Step 1: Layout the Pinwheel Gear

Step 1: Layout the Gear

The layout for differential gears is the same as spur gears above. Use an awl to mark center. Then draw the circle with radius (rc) using a compass. Use the compass again to draw evenly spaced vertex ticks around the circle. Because we’ll be using nails as the teeth on these gears we’ll need to draw another larger circle outside radius (rc). In this case radius (rc) is 0.9664, I generally add an eighth of an inch (0.125) resulting with a radius of 1.0914.

Step 2: Cut Out the Gear

Cut the gear to the outside of the largest circle. Then sand precisely to the line.

Step 3: Drill a Hole

This is exactly at Step 3 for the spur gears. I drill a 0.125″ hole centered on the awl mark.

jchismar How To Make Wood Pinwheel Gear
Step 4

Step 4: Add the Teeth

I use the drill press to create an appropriately sized pilot hole at each vertex cross tick. The pilot hole should not be completely through the gear, only as deep as the nail will be driven into the wood. Here, I’m using three penny nails. Start the nail in partway then place a scrap of wood against the nail as a depth gauge. Then hammer the nail until you’re hammering the wood scrap. Continue adding nails in this fashion until your pinwheel gear is complete.

Step 5: You’ve Made a Pinwheel Gear!

You’re an expert gear maker now. Let your imagination run wild! I’d love to see the mechanical creations you’ve built.

A Note About Gears

I started the post with a quote that originated from the 2016 Rio Summer Olympics, “…Chemistry is not an exact science…” This was an Olympics official’s response to questions pertaining to why the pool smelled rotten and the water was green. I’m here to say Chemistry is and exact science. What does this have to do with making gears? Well, making gears is an exact science also. This post, however, is the groundwork to understand how to construct gears, not exact science.

Earlier I posted about building a Pegasus whirligig kit. Assembling the kit was a fun distraction, but I honestly didn’t learn much from the task. I’m a tinkerer. I enjoy spending time considering how to make things, and how things work. I find little satisfaction in following a detailed design – robots do that. I like to build the plane while it’s in the air, as they say. It’s fun to start something, and troubleshoot and modify along the way. This is how I gain a full understanding of the project. I often build many test projects before I tackle the actual build.

Creating mechanical machines is challenging. There is a lot of trial and error involved for the novice (myself included). There is more to designing precision gears than I’ve mentioned in the post. I’ll be honest, I don’t understand most of the technical mumbo jumbo, big words like dedendum, addendum, clearance and working depth versus whole depth. If things don’t work – that’s normal. It’s an entertaining learning experience. I personally find as much enjoyment in the flops as in the successes. When the project is complete, the challenge is over – and that can be a bummer.

Making gears using this method will require trial and error. The space between the gear positions will be an issue. The heads of the nails and the lack of a taper on the ends of the spur gear will likely cause these gears to jam. Consider using a metal cutting wheel to cut the heads off the nails – and taper the metal end. Also consider sanding a taper on each tooth before assembling the spur gear.

For those makers that want a detailed, guaranteed plan you can visit http://geargenerator.com/ to design and print precise gears. This post will get you started making functioning gears. Please take what you learned here, build on it and make it your own. There’s more than one way to make a gear.

I am planning a follow up post regarding making wooden gears. There will be more information and project ideas to be found in the follow up post. In the meantime, be creative and have fun.

Mize Mini-Mize Whirligig Automata Pegasus

Mize ME07J Mechanic Series jchismar

As you probably figured by now, I can’t sit still. Yes, I have a zillion started projects in my workshop and plans for more in my mind and hard drive. I may get around to finishing some of these projects but I have such little time! I’m not a humongous fan of 3d printing and laser/cnc cut stuff, but every once in a while I scratch the creative itch and dabble with this sort of thing.

I decided to purchase a mini automata whirligig kit manufactured by Mize, based in South Korea, online for $21.00 including shipping. There wasn’t a whole lot of information about this item in the description, but judging from the single image of the item it looked like it was going to be small. The package arrived from South Korea and I thought it was a thick holiday card, roughly 6″ x 9″ x .75″.

Mize Mini-Mize Pegasus Instructions

I opened the package and looked at the instructions. Yup, as assumed all the instructions are in Korean. Not a problem though because the images tend to explain everything clearly (enough). Curious, however, I photographed the instructions and uploaded them to i2ocr to translate. I don’t think it translated too well. Here’s a few selections from the translation:

  • The city is divided into cities
  • Excessive stress on the stomach can damage it
  • You have to do the complexion
  • I want to be a transit agent, too.
  • Sennepusa Seeking Confession | Do not be sick
  • The lungs are soaring
  • Even if I left you, I would like you to be my best friend

For real. I can’t make this stuff up.

jchismar mize pegasus translated

Lucky for me I work with Heeman, a talented Korean designer. Heeman was kind enough to translate the pertinent information in the image above. Thanks!

jchismar Mini Mize Pegasus

jchismar wood automata gears
A few gears from the project

Above are the three panels of parts that create the project.  Along with the instructions this is everything in the package. Excited, I retrieved my Loctite Go2 Glue, a toothpick and a paper towel. I reviewed the assembly instructions for the first few parts. I carefully removed the necessary parts from the panels by first scoring each sprue (the little piece of material holding the part in pace on the panel) with an Exacto, then carefully nudging the part free.  After test fitting the parts together I squeezed a small puddle of glue on a scrap of paper, applied a small amount of glue to the joints with a toothpick and reassembled.

The image at the top of the post displays the assembled crank box and completed project. This was an enjoyable and easy project to build. It’s important to be patient and clamp the pieces together (when possible) as you wait for the glue to cure between steps. I’ll admit, when I was attaching the pegasus to the gearbox, pretty much the last step, I carelessly broke the propeller off the gearbox. Luckily a dab of super glue came to the rescue and worked flawlessly.

I’d be remiss if I didn’t say the pegasus whirligig is not suitable for prolonged outdoor use. The material is MDF or something similar. I am surprised at how smoothly the mechanics operate because the drive shafts are simply square cut MDF material positioned in round holes. Birthday cake candles are provided in the kit. These are used to lubricate the moving parts. The lubrication the candles provide also works much better than I anticipated. The video clip below is of the complete kit operating outside in relatively gentle gusts of wind. Most likely I will be purchasing more of these Mize kits in the near future.