Saturday, December 10, 2016

EMG-6 "Shop Notes" December 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

December 12, 2016

Ben, One of the new builders, came by the shop today to share a couple of new motors that he is going to be experimenting with. We will post more information about them as he shares it with us.

18 KW spinning a 34x 14 propeller


Thursday, December 1, 2016

Tube Cutting Templates Sport Aviation / Experimenter "Technically Speaking" Article November 2016

Tube Cutting Templates

The classic 4130 chromoly steel welded structure has always been one of the most common building mediums to work with on experimental aircraft. This type of construction lends itself to a multitude of different types of applications and renders one of the highest strength to weight ratio manufacturing techniques, especially when it comes to fuselage assemblies. The welding of steel tube assemblies is a process that can be readily learned by just about anyone. And with current welding technologies like the TIG (tungsten inert gas) welder now coming down in price and becoming readily available to the average builder, precision welded aircraft subassemblies are no longer relegated to the professionals. (Figure: 1) Although this article is not a treatise on welding techniques, it is the primary answer to “How do I become a good welder?”

Becoming a good welder requires that you learn the principles of welding. Our recommendation, especially if you’re brand new to welding, is that you simply engage in a training program. Often a community college class is your most cost-effective method of learning the skills you need. And then, of course, practice is the key to becoming proficient. As you begin the process of welding, one of the first things that you will identify is that it becomes very easy to make beautiful looking welds if everything is set up properly. Good equipment, good environment, clean materials, and, equally as important, a proper fit of the pieces of material which you’re welding together. This has always been one of the most frustrating parts of making a 4130 chromoly steel fuselage assembly. Typically, when we are working off of a set of plans, we are taking a piece of 4130 tubing, cut it to length, and then grinding each end to precisely interface with the adjacent tube. We refer to this as “coping”. This process is usually a lengthy process of trial and error. We place the tube in position, then mark it, and then grind the end of the tube, refit the tube in place, check it, market and duplicate the process all over again until we have a proper fit. The process can be tedious, but if you have patience and a good eye for spatial orientation, with a little bit of practice, you can become pretty good at the process. All this being said, I’ve never met anyone who has welded a steel fuselage frame who has not come across the issue of fitting the tube and ending up with a fairly large gap on accident. If you’ve ever tried to close up that 1/4-inch gap by welding, you know that the end result isn’t going to be all that pretty. Those really pretty welds, that we all admire, are primarily a result of having two pieces of metal properly prepped and with a very nice clean consistent fit against each other. The welding bead flows very seamlessly and consistently because of this close contact. Producing a beautiful weld with these conditions is a no-brainer.

Monday, November 14, 2016

EMG-6 "Shop Notes" November 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

November 12, 2016 

We have just finished up a marathon of 120 hr. Light Sport Repairman maintenance classes. October and November have been totally consumed by teaching. This class was the second half of a split class that that started three months ago and returned in late October to finish up the second half. The split class is normally smaller than the full class. This is held normally once a year to accommodate students that can't take 3 weeks off at a time.

Tuesday, November 1, 2016

Oleo Strut Sport Aviation / Experimenter "Technically Speaking" Article October 2016

Oleo Strut Basics 

An oleo strut is a pneumatic air–oil hydraulic shock absorber. The primary purpose of the oleo strut, as you are probably already aware, is to absorb the landing loads on an aircraft. The force, which the aircraft structure is subject to, can be expressed in Newton’s 2nd law of physics F = M A or Force = Mass X Acceleration.  Acceleration is simply the change in velocity over time. If we can double the time interval for deceleration of the aircraft through the landing gear by lengthening the shock strut, you can see that we can reduce the total force exerted on the structure by half. This is the basis for incorporating the long struts on STOL (Short Takeoff and Landing) aircraft like the Just Aircraft SuperSTOL and the Fieseler Storch. Watching these aircraft performing short field operations, you can see what appears to be near vertical approaches, culminating in a very impressive squat of the aircraft as the long stroke landing gear struts absorb the landing loads.

Although there’s been many variations upon the oleo strut, there is some particular genius in its design. The basic physics incorporated in the operation of the oleo strut is what has made it so popular in so many different designs from the smallest aircraft to the largest. This basic design concept (Figure: 1) is so efficient that even the most modern of aircraft use the same basic principles that adorned aircraft landing gear designed and built as far back as the 1930s.

Figure 2

Let’s look at the basic operation of the oleo strut. (Figure: 2) Inside the strut we likely have a combination of Mill-H-5606 hydraulic fluid and dry air or nitrogen. The primary job of the air located in the upper chamber of the strut is to act as a spring. And the primary job of the hydraulic fluid, which is located in the lower chamber of the strut, is to regulate and transfer the loads from the lower half to the upper half of the strut and subsequently into the airframe. Located in between the upper and lower sections, but attached to the upper portion of the strut, is an orifice (Shown in Green). This orifice restricts the flow of hydraulic fluid from the lower half to the upper half of the strut. This basically lengthens the time interval during the compression stroke created by the landing gears impact with the ground. Many early strut designs simply stopped at this point using a fixed orifice to control the fluid transfer from the lower to the upper half of the strut. Later designs improved upon this concept by incorporating one more component called the metering pin (Shown in Pink) which takes the design to an entirely new level.  This metering pin is attached to the lower portion of the strut and is tapered starting at the top getting wider as it approaches the bottom section of the strut. This metering pin is co-located within the center of the orifice essentially creating a variable sized orifice. When the strut is fully extended, the gap between the orifice and the metering pin is relatively large allowing fluid to flow rapidly. According to Newton’s 2nd law the greatest amount of force imposed onto the landing gear structure will be at the point where we have the highest amount of deceleration (initial impact). As the rate of strut compression decreases, so does the force. This design allows the restriction between the orifice and metering pin to progressively get smaller and smaller essentially maintaining a constant force onto the structure while exponentially decreasing the rate of strut collapse. (Figure: 3) This allows the entire length of the lower section of strut to progressively collapse absorbing the landing loads over the longest time interval possible. It’s really quite a brilliant concept. A properly serviced strut is virtually impossible to bottom out because of this increasing restriction.  Landing forces that could cause the strut to bottom out would likely result in ripping the strut from the aircraft structure. Recognize that it is the fluid and only the fluid that is responsible for the struts’ amazing ability to absorb these landing loads. A strut that has lost its fluid is virtually useless. A strut without fluid is the equivalent of welding the bottom half of the strut to the upper portion strut in the collapsed position. The time interval for deceleration, in this case, drop off dramatically. This, in turn, increases the loads imposed into the structure to also increase proportionally. We often wonder how many of the accidents, where we see a collapsed nose strut, are a direct result of improper servicing or simply loss of fluid.

Monday, October 24, 2016

EMG-6 Webinar Hosted By EAA (Video)

EAA Hosted Webinar: EMG-6 Update October 2016

This is upgraded video of the EMG-6 webinar hosted by EAA. We have edited out some of the trivia and the questions at the end and added a significant amount of video to enhance the webinar.

Wednesday, October 19, 2016

EMG-6 "Shop Notes" October 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

October 21, 2016 AOPA Electric Article

October 20, 2016

Tim sent the Webinar report from yesterday. We want to thank everyone for giving us such a high rating. And even though we only had 173 attendees we feel pretty good about the total attendance. Especially considering we were up against the 3rd presidential debate. Maybe that's why we did have such good attendance. Everyone looking for an escape. We will post the link to the webinar When it becomes available. 

We are getting ready for doing our new VLOG (Video blog). It will be called the  "Hangar 7 Video blog" We will be doing a weekly Video update with everything that is happening not only on the EMG-6 but with the going's on at Rainbow Aviation as well.

Tuesday, October 11, 2016

EMG-6 Electric Motor Glider Webinar Hosted by EAA

Register now and block your calendar to be able to attend the EMG-6 Electric Motor Glider webinar hosted by EAA. The webinar will be on Wednesday, October 19, 2016 at 7 PM to 8:30 PM central daylight time.

Our moderator for the webinar will be Tim Bogenhagen from EAA.

Click Here to Go to the Registration Page
EAA Registration

Saturday, October 1, 2016

Stronger 3-D Printed Parts (Part2) Sport Aviation / Experimenter "Technically Speaking" Article September 2016

3-D Printed Parts (Part 2)


3-D printing with ABS plastic provides tremendous versatility when it comes to post-processing of your part. When we refer to post-processing, we are simply talking about any process that modifies the original part after it comes out of the 3-D printer. Although there are many applications that do not require any post-processing, it is generally the post-processing that converts the part from a simple 3-D printed part into a usable part on your aircraft.

Figure 1:  Close up of Roughness in a 3D Printed Part


Tuesday, September 20, 2016

Solidworks 3D Modeling (Bing Carburetor) Step by Step (Videos)

 Bing Carburetor 3D Modeled In SolidWorks

These videos are a pre-release that are part of a larger series of videos compiling the step-by-step process of modeling all of the components on a Bing carburetor. The introductory video will not be completed until after all of the individual components have been modeled and we can provide a table of contents and a larger explanation along with links to each of of the individual videos.

If you are new to the SOLIDWORKS environment just watching the step-by-step process along with the trials and tribulations associated with trying to reverse engineer each 1 of these components can be helpful.

Each 1 of these videos are basically raw unedited video segments. As such there are a multitude of better ways to attack an approach the modeling of each of the components in this larger assembly. The idea behind the videos is to basically show a newcomer the thought process involved in being able to create each one of these individual components to a fairly high degree of accuracy.

Friday, September 16, 2016

EMG-6 "Shop Notes" September 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

September 16, 2016 Production of Kits Continues

kit production continues. Jason has been putting together the subassembly kits and in this picture here he is assembling the components necessary for the horizontal stabilizer subassembly.

Monday, September 12, 2016

Builder Charlie Becker S/N 15-024 Oshkosh Wisconsin

Builder Charlie Becker S/N 15-024 Oshkosh Wisconsin

September 12, 2016

Charlie gets his landing gear mounted to the fuselage 4130 chromoly steel frame. Charlie is still currently in the lead for the 1st customer built EMG-6. 

This picture is indicative of Charlie's enthusiasm for aviation in general. He has several projects that these currently working on you can see the super cub in the background. Charlie is director of communities for EAA in Oshkosh. And his enthusiasm and love of the sport is very encouraging.

Although we made this page to highlight the most recent progress on Charlie's aircraft and we will continue to update this page as he sends us new photos. You may want to check out Charlie's Facebook page which is a great deal of more information about the EMG-6 project that he's working on.

Friday, September 9, 2016

3D Printed Vortex Generators Part 4 (Video)

In part 4 of 3D printed vortex generators video,  we go through the complete process of designing a vortex generator in SOLIDWORKS, exporting an STL file to the Zortrax software, and then printing and extracting the 3D printed vortex generator.

Wednesday, September 7, 2016

3-D Modeling Software “Home Built meets High-Tech” Sport Aviation / Experimenter "Technically Speaking" Article August 2016

3-D Modeling Software “home built meets high-tech”

In last month’s article we talked about the wide variety of opportunities available with 3-D printing. In this article, we want to talk about the process of creating those 3-D models. Within, literally, years of the initial offering of personal computers that software engineers started creating software for generating mechanical engineering drawings. And just like the computer industry itself, the exponential growth of CAD (computer-aided drafting) programs has blossomed into some of the most amazing collection of capabilities which only years ago were relegated to organizations such as NASA and Boeing. These capabilities have now become available to the average experimental aircraft builder/designer. If your aspirations revolve around being a component or aircraft designer, it is imperative that you recognize and embrace these new CAD technologies. For those holdouts, who do not wish to undergo the difficulty of learning to use a CAD program but still wish to be an aircraft designer, the only advice that we can offer is to lock yourself in the closet until you change your mind. Of course, we jest, but the capabilities of solid modeling software put the designer at such an advantage that the difficulties associated with learning the software are far outweighed by the results and capabilities that can be achieved.

Figure 1:  3D Solid Modeling Software Learning Curve

Friday, September 2, 2016

3D Printed Vortex Generators Part 3 (Video)

3-D printed vortex generators part 3. In this video we step through the installation process and placement of vortex generator using a template and commercial grade double sticky tape.

Monday, August 22, 2016

3D Printed Vortex Generators Part 2 (Video)

3-D printed vortex generators part 2. In this video we step through the installation process and placement of vortex generator version 1-150. We do a comparative analysis from the baseline tests that we conducted in part 1, and provide some analysis of the process. We are using the Quicksilver GT-500 that is currently being used as the tow aircraft for the EMG-6 electric motor glider as the test bed for our 3-D printed vortex generators.

Friday, August 19, 2016

EMG-6 "Shop Notes" August 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

August 29,2016

Jason hard at work making up sub assembly kits. In this picture here Jason has been boxing up elevator Kits.

Thursday, August 18, 2016

3D Printed Vortex Generators Part 1 (Video)

In this video we begin the baseline testing for the 3-D printed vortex generator article. The baseline test was to get a video of the tuft tested wing as a comparative analysis against the additional tests that will be conducted with different 3-D printed vortex generators.

Thursday, August 11, 2016

Icom IC-A6 / IC-A24A Radio Mount (3D Printed)

3-D Printed Handheld Radio Mount

Although originally designed for the a Piper J-3 Cub, hence the color.  This mount can be used on any aircraft including the EMG-6. The radio mount is designed with a split clamp system which allows the installation and positioning on to a 7/8" diameter tube. We can design other size clamps that are interchangeable with different sized tubing if anyone has a specific request. The mounting system requires (4) (3/16" Dia) Cap Head Screws. (4) (3/16") Washers under the head of the cap screw. additionally there is a hex cut out in the clamp that will automatically hold a 3/16" nylon nut. (4) required. Mount can be mounted either horizontal or vertical relationship to the tube.

You can download the STL files if you wish to print your own radio mount. the files are located under 02-90-10-10 ICOM Radio Mount in the builders database.

Link to 3-D printing  STL files.

Tuesday, August 9, 2016

"Stronger 3-D Printed Parts (Part 1)" Sport Aviation / Experimenter "Technically Speaking" Article July 2016

Stronger 3-D Printed Parts (Part 1)

With the extensive proliferation of LPD (Layered Plastic Deposition) 3-D printers, their use in experimental aircraft has begun to grow exponentially. One of the most commonly asked questions, is whether or not we can reliably produce structural components using a 3D printer. The answer is an emphatic yes. Just as with any other process or material, it has its limitations as well as its strengths. Learning to utilize the 3-D printer’s strengths and work within its limitations is the key to its successful utilization.

Because the LPD printers are laying down one layer of plastic at a time the resulting component has a “grain” to it.  And much like wood and other materials the direction of the grain can significantly change the structural characteristics. If you have ever tried to karate chop a board, you know the trick is to strike the board along or parallel with the grain. The amount of force required to break the board across the grain can be 10 times greater than breaking the board with the grain.

Tuesday, July 19, 2016

Sterna Propeller

3 Bladed Sterna Propeller

July 19, 2016   We Receive The 3 Bladed Sterna Propeller

We received one of the propellers that we will be testing on the R and D motor. We have had extensive consultation with Sterna propellers about the propeller that would work the best on the EMG-6 with the 20 hp electric motor. We have selected a propeller blade section that will optimize the performance at a very specific profile. Mainly the ability to operate in a cruise configuration at 45 mph.  We currently have 2 other propellers that are designed for the same motor that we will be testing as well. as we develop data once we begin the flight test program will use this page to accumulate information about this propeller. If the propeller works as expected we plan to offer this as one of the primary propellers for use on the EMG-6. We also plan to become an OEM dealer for the propeller and have them in stock or customers of the EMG-6. We are also working with Sterna for a propeller to be used on the Polini 250 motor as well.

I was first introduced to the Sterna propeller 2 years ago at Air Venture 2014. Sterna propellers are manufactured in China. Their footprint into the US is still somewhat small compared to other manufacturers but they are beginning to gain popularity. If you are at Air Venture, Sterna will have a booth set up and you can talk to them and see some of their other products in one of the big hangers.

EMG-6 "Shop Notes" July 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

July 19, 2016 Display Boards

Before every show we have to work on the advertising, brochures, and display boards to demonstrate some of the different capabilities and construction methods that we use. This year we have added to the display boards a 3-D printed parts board that shows some of the different components that are used both to manufacture the EMG-6 as well as components that are used directly on the aircraft. In addition after the show is over we have to stay a few days extra and do the "Homebuilder Hints" videos for EAA. This year They have requested that we do some videos on both the 3-D printing process as well is the Solid Works software.

Friday, July 15, 2016

EMG-6 Prototype #2 Test Flights Day 2 (Video)

EMG-6 Prototype #2 finishes certification on Thursday, we conduct 12 test flights on Friday, and aircraft is being disassembled on Saturday for the trip to EAA Air Venture 2016 in Oshkosh Wisconsin. This video is a compilation of the flights that occurred on Friday July 15, 2016

Thursday, July 14, 2016

First Test Flight of EMG-6 (Prototype #2) Video

Raw video of the first test flight on Prototype #2.  About 650 foot altitude on the tow. Just at sunset no lift left at all.  Aircraft handled well. Very Smooth, Stable and controllable.

Wednesday, June 29, 2016

EMG-6 "Shop Notes" June 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

June 29, 2016 Aft Fuselage Enclosure

we have finished the lower wing gap seals and are now proceeding to enclose the aft cabin area. The aft fairing will be covered with poly fiber covering just like the rest of the aircraft. The area from the aft fairing and aft fuselage bulkhead to the forward fuselage Bulkhead will be covered with a removable background sailcloth covering. We will be installing a window into this panel.

The 3D Printing Revolution Sport Aviation / Experimenter "Technically Speaking" Article June 2016

The 3D Printing Revolution

We are on the cusp of a new era in experimental aviation like we have never seen before. We often hear doom and gloom from those who have been in the general aviation market and who have seen the downturn in the number of active pilots and airplanes coming off the factory floor. The overused cliché “it’s always darkest just before the dawn” is really apropos in this circumstance. We are here to tell you that the future of aviation looks very bright. There are several paradigm shifting technologies that are changing the world of aviation equivalent to that the Wright brothers first flight, the dawn of the jet age, and Burt Rutan’s contributions to composite aircraft. Some of the most exciting of these new technologies which we have embraced, include, electric propulsion, 3-D solid modeling software, and 3-D printing. Over the next couple of months, we will be writing articles exploring, in-depth, some of these new technologies which are rapidly becoming tangible for the average aircraft builder. In this article, we’re going to take a closer look at the possibilities of using 3-D printing in experimental aircraft.

With today’s proliferation of 3-D solid modeling software available to the average experimental aircraft builder, we are now starting to see the leveraging of this technology into the average builder’s toolbox. We have been using 3-D modeling software for the past 30 years, and “Solidworks” extensively for the last 15 years. We have become so dependent upon it, that we feel it is one of the most valuable tools that we use on a daily basis. With the ability to 3-D model components virtually on your desktop, the cost of design has plummeted dramatically.  It allows us to import the 3-D models into other software and export g-code (computer numerical control (CNC) programming language) for manufacturing of components on different CNC machinery. Seeing this potential, we purchased our first CNC machine some 15 years ago. Since then, we have continued to exploit the advantages of this technology and we now operate 6 different CNC machines. The latest of these “machines” if you can call it that, is a 3-D printer.

Tuesday, June 28, 2016

3D Printing The EMG-6 (Video)

A look at the use of 3-D printing technology to build the EMG-6 Electric Motor Glider. All of the 140+ 3-D printed part files available for free download.

Monday, June 27, 2016

Tube Marking Tools

Tube Marking Tools

For the builders that are building the EMG-6 from plans and the basic kits, There are a lot of holes that need to be drilled in the tubing throughout the build process. As a result we have developed a series of tube marking tools to assist us in the shop for ensuring accuracy during the marking and drilling process. And although we have many of the parts being manufactured with CNC machinery, there are still a significant number of tubes that need to be marked and drilled during the manufacturing and especially assembly process.

We have found these tools to be so useful in the shop that we have decided to make them available to the builders of the EMG-6. This series of tube marking tools that can significantly improve the ease and accuracy of marking round tubing.
These tube marking tools have a multitude of features which can only be created practically through the use of  3-D printing technology.

The tube marking tools are manufactured from 3-D printed ABS plastic, and are color-coded to easily identify each size. From 1/2" up to 2" in 1/8" increments. These are the standard tubing sizes used in the aviation industry.


1.  Color-Coded for Easy Identification
2.  Radial marking guide in 15° increments
3.  "V" marking slots for super precision.
4.   Alignment pin holes for   1/16, 1/8,  3/16, 1/4
5.  Non-marring 1/4-20 nylon thumbscrew for secure positioning.
6.  Center punch holding fixture.
7.  Lanyard attachment hole.
8.  Size markings embossed on housing.
9.  Perimeter marking guide on base.
10.  Manufactured from Non-marring ABS plastic.
11.  Precision marking slots at 90°, 180°, 270°, and 360°
12.  Available in all standard tube sizes from 1/2 inch to 2 inches.

Sunday, June 12, 2016

"Video" EMG-6-250 Local Flights

Carol Carpenter Flies the EMG-6-250. These are the last flights on the EMG-6-250 . The engine and many of the parts were removed to complete Prototype #2 in order to start the Installation of the Polini 250 into the Cabin of Prototype #3. This will be a completely enclosed version similar to Prototype #2 but #2 is currently being fitted with the Electric Power Plant.

Saturday, June 11, 2016

"Video" Cutting Flight Control Gap Seals from Pool Noodles

Cutting Flight Control Gap Seals from Pool Noodles

In this video we go through the process of converting pool noodles into low-cost lightweight, and easy to install  foam gap seals for the EMG-6 electric motor glider.

Let's go through the detailed procedures on how we came up with the final results that we have been using on the EMG-6 electric motor glider. We have cut nearly 30 different dies and guide blocks to come up with the final results that we found that work very well.

Thursday, June 9, 2016

R&D Motor

R&D Motor

 This page is dedicated to  any updates and information regarding the R&D Motor.

 June 9, 2016   Motor Update


 Today we had a meeting with Ed Donovan owner of R&D cable. Ed and his team are developing an electric motor that will be used on the EMG-6 electric motor glider. The design parameters are basically to design a 20 hp continuous operating motor turning at 2500 RPM and producing approximately 65 foot-pounds of torque. We will be spinning a 48 inch diameter propeller. this motor is simply a dummy motor that does not have the winding's and magnets inside but was delivered so that we can use it for the development of the motor mounting system on the EMG 6 as both as a pusher and as a tractor on the to the wing pylon locations. The bolt pattern is the standard two-stroke Rotax engine bolt pattern. the bearing is the same as the front bearing on the Rotax E gearbox. The total motor weight will be in the neighborhood of 25 pounds when completed. There are 6 mounting locations on the rear of the motor housing. During testing at full power  the outer housing gets slightly warm but the winding's and the magnets remain cool even at full power operation. They are still undergoing some operational tests on the motor and perfecting the final design before going into the  mass production phase and developing the tooling for the stamping dies for the winding core. The expectations are that the efficiency of the motor will exceed 95%.. And reliability and durability are  key components in the development of the motor. I would expect that this motor will have a TBO in excess of 10,000 hours. And overhaul cost will be the replacement of 2 bearings. We have been told that we should expect to have a operational motor available for installation before we depart for the Oshkosh airshow.

Tuesday, June 7, 2016

Low-Budget Hydro-forming Sport Aviation / Experimenter "Technically Speaking" Article May 2016

Low-Budget Hydro-forming

We are often looking for methods for creating parts on our experimental aircraft that replicate the professionalism of factory built aircraft. The biggest stumbling block is usually the cost of set up for fancy tooling and machinery. Yet, you might be surprised by what you can accomplish in your own small workshop. In fact, many of the greatest ideas in aviation originated from small workshops like yours.

Saturday, May 21, 2016

EMG-6 "Shop Notes" May 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

May 31, 2016  Prototype #2 Nears Completion

As the month of May comes to a close where getting very close to finishing up all of the small details on the aircraft. We are still awaiting the FAA registration so that we can certificate the aircraft and begin flight testing.

Tuesday, May 10, 2016

Monday, May 2, 2016

"Spark Plugs and The Rotax Engine: Part 3" Sport Aviation / Experimenter "Technically Speaking" Article April 2016

Spark plugs and the Rotax Engine Part 3

In part 1, we discussed the theoretical aspects of the spark plugs. In part 2, we talked about the more practical aspects of installation and maintenance of the spark plugs installed in the Rotax engine. In this, part 3, we are going to take a look at using the spark plug as a troubleshooting tool.

The engine will continuously communicate her condition to you through a multitude of sources. One of the most powerful sources of information about an engine’s internal condition comes from what the spark plugs have to tell you. We call this “reading” the spark plug. (Figure: 1) One advantage of reading the spark plugs is that they don’t often lie. Engine instrumentation can give us a lot of clues about what’s going on inside the combustion chamber, but they are limited, both in the scope and in their accuracy. We see aircraft owners pulling their hair out, modifying the engine, trying to make it operate in a configuration so that the instruments read “normal”, only to find out months later that their instrumentation has been indicating incorrectly all along. By this time, they have modified the engine so far from the stock configuration that the road back to proper operation if often frustrating and expensive.
When we talk about reading the spark plug, we are primarily talking about reading the color of the ceramic insulator that surrounds the center electrode. The automotive industry, and in particular the racing industry, has carried this reading of the spark plugs  to a very fine, nuanced science. And although engine to engine readings vary substantially, we can take away from some general principles that you should be able to apply to your particular engine. It is common that we can get information about all segments of the engine operation from idle to full throttle by looking at selected segments of the spark plug.  Idle operation  can be revealed by looking at the face  of the threaded spark plug body. Midrange, the place where you spend most of your operating time on the engine, shows itself primarily towards the end of the ceramic insulator where the center electrode protrudes. And full throttle operation is more indicative of a ceramic insulator deep inside the area where the ceramic makes contact with the spark plug body. Now I caution you, these principles need to be associated with  a significant understanding of the operating characteristics of your particular engine. Even the visual appearance of a Rotax 582 two-stroke engine versus a Rotax  912 four-stroke engine under normal operating conditions  will have a substantially different appearance.

Friday, April 22, 2016

EMG-6 "Shop Notes" April 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

April 22, 2016 Progress Update

This last week we have accomplished quite a bit of detail work on the aircraft. One of the areas that we've been working on is the 3-D printed fairings. We have now finished and installed temporarily the forward wing strut fairings.

The fairing with primer and initial sanding undergoing a test fit before we continue on with the rest of the finish work.

Thursday, March 31, 2016

"Spark Plugs and The Rotax Engine: Part 2" Sport Aviation / Experimenter "Technically Speaking" Article March 2016

Spark plugs and the Rotax Engine Part 2

In part 1 of this article, we discussed the theoretical aspects of the spark plugs installed in the Rotax engines. In this article, we will take a more in-depth look at the practical aspects and the “how to” of the spark plug in the Rotax engine.

Spark Plug Removal. When removing the spark plugs, during an annual inspection or any time for that matter, keep in mind that there is a lot of information to be had by “reading the spark plugs.” A spark plug rack is a useful way to keep track of the cylinder position of the spark plugs as you remove them. The spark plug rack should be labeled with both the cylinder number as well as top or bottom position. (Figure 1)

Wednesday, March 30, 2016

53-50 Wings to Fuselage Fairing

Builder Guide

53 Fuselage

53-50 Wing to Fuselage Fairing

This is a one-off prototype wing to fuselage fairing that were making. We will update this once we get to the production aircraft.  This will be the premise for the design for the production fairing that utilizes the BRS ballistic parachute system.

Before we begin the prototyping process for this fairing it's important that you have a visual picture in your head of what it's going to look like.

With that in mind we get started with building the center box that we will use to build the fairing from.  Were making this box from 1/4 inch plywood  and the skins from 1/8 inch mahogany door skin.  Both of these pieces of plywood are relatively cheap $12-$15 for a 4 x 8 sheet.

We create bulkheads for the sides of the center box that will carry the profile from the fuselage boom up over the ballistic parachute and transition down to the forward keel. We will need the transition to occur slightly above the keel so that we can use the keel overhead to assist in climbing in and out of the aircraft. 

Wednesday, March 23, 2016

EMG-6 "Shop Notes" March 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

March 29, 2016 Flight Controls

In this picture here we are wet sanding and prepping the ailerons and horizontal stabilizers for the next coat of poly spray silver.

Monday, March 21, 2016

3D Printed Parts

This page will be dedicated to the 3-D printing process for components used on the EMG-6.

Trailing Edge Lift Strut Eye Bolt Fairing

The trailing edge lift strut eye bolt also has a large protrusion with the nut and washer sticking up above the rear spar. This is our fairing that fits over that nut to reduce the drag in this area. This is prototype #1 and was a pretty close fit from the get-go but needed a few modifications.

Monday, March 14, 2016

01-50 Tube Marking (Video)

Another episode of "Building the EMG-6".  In this episode we look at the process of marking tubing. Pretty much every component on the EMG 6 uses tubing for construction. In this video we show you how to accurately and easily mark tubing for these applications.

55-21-20 Horizontal Stab Leading Edge, How it's Made (Video)

Friday, March 11, 2016

55-21-34 Inboard Rib Building the EMG-6 (Video)

This is a 26 minute long video with step-by-step instructions on installing the horizontal stabilizer rib assemblies. This video also contains some good information on how to mark tubing.

Tuesday, March 1, 2016

01-50 Tube Marking Guides

Builders Guide

01-50 Tube Marking Guides

Link to Builders Data Base (Tube Marking Guides)

In order to be able to use the tube marking template on the right side of each of the drawings you need to download the PDF file from the builders database and print them out on your home computer at 100% scale. Before using the template  you should check its physical dimensions with a pair of calipers.

55-21 Horizontal Stabilizer (LD)

Builders Guide

55 Stabilizers

55-21 Horizontal Stabilizer (LD)

Horizontal Stabilizer Main Spar Sub-assembly

We will start the construction of the horizontal stabilizer assembly by beginning with the main spar sub-assemblies. This consists of the main spar to with reinforcing sleeves inserted in 3 locations.

The first part that we have to create is the horizontal stabilizer spar tube.  We will be creating all of the reference marks on the main spar tube. We will start with generating a reference line down the length of the spar.

55 Stabilizers

Builders Guide

55 Stabilizers

55-10 Vertical Stabilizer Assembly

55-20 Horizontal Stabilizer Assembly

Monday, February 29, 2016

EMG-6 "Shop Notes" February 2016

"EMG-6 Shop Notes" is a day-to-day accounting of what's going on in the shop with the EMG-6 Electric Motor Glider.

February 29, 2016

"Spark Plugs and The Rotax Engine: Part 1" Sport Aviation / Experimenter "Technically Speaking" Article February 2016


February 26, 2016

More files added to the builders database for the main landing gear assembly.

"Spark Plugs and The Rotax Engine: Part 1" Sport Aviation / Experimenter "Technically Speaking" Article February 2016

Spark Plugs and The Rotax Engine:  Part 1

We continue to see problems surrounding the use of spark plugs in Rotax engines. Many of the rules which we have used in the past for typical aviation type spark plugs, used on air cooled engines, no longer apply to the automotive type spark plugs used in a Rotax engine. As with most technical subjects, an underlying understanding of the theory and physics involved is essential to our ability to make good judgments about the use and operation of spark plugs. So let’s start with the basics.

The spark plugs used in the Rotax engines are specific to each type of engine. Figure: 1. The most prolific of the Rotax engines is the 912S 100 hp and it uses the DCPR8E. Figure: 2. Using this plug let’s look at the part number designation and what each one of the numbers and letters indicate for the design of the spark plug.


Spark Plug Size: The (DC) in the part number is the thread diameter and pitch. Looking at the NGK part numbering chart, it indicates that this is a 12 mm diameter spark plug with a 1.25 mm pitch on the threads and uses a 16mm wrench on the hex portion of the spark plug.
Reach: The Last Letter in the part number (E) indicates that this plug has a 19 mm thread reach. This is measured from the base of the plug, above the gasket, to the last thread.
Shape: The (P) in the part number indicates this plug has a projected center electrode insulator. The projected center electrode insulator is what you would normally recognize as a typical spark plug and is of course the most common type.
Construction: And the (R) in the part number indicates this is a resistor type spark plug. When a spark jumps the gap on a spark plug, it creates a high frequency burst of energy. This creates radio frequency interference or (RFI) which can generate significant interference with your radios and other electronic equipment. Placing a resistor within the spark plug significantly reduces this RFI. Figure: 3.

Heat Range: The (8) in the part number is an indicator of the heat range. The heat range of the spark plug is designated by the ability of the spark plug to dissipate heat that is absorbed from the combustion chamber. The heat within the insulator nose is transferred into the body of the spark plug and out into the cylinder head which is cooled by air or by water/antifreeze.