Monday, January 16, 2017

EMG-6 "Shop Notes" January 2017

"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.

January 16, 2017

A few modifications that were going to do the ailerons sales include  adding a reinforcement strip on both the inboard and outboard section that will allow us to place a large area head aluminum pop rivet  to hold the ailerons skins in place and properly tensioned. We are going to run the zipper straight out and then tuck it underneath the other side of the skin before riveting in place.

At the outboard section we are going to add some reinforcing material and then add some tabs  that will allow us to Velcro the tip skins together. This should allow us to tension the fabric to an even greater degree  and allow for some slight distortion as a result of the washout at the tip of the aileron.

 January 14, 2017

The aileron sail covers arrived in the afternoon mail.

Because these are simply a trial run on the digital templates, We didn't know what color would show up. In addition the Velcro gap seals for the leading edge of the aileron were not installed.

When we built the aileron  we didn't coordinate with Gary for which side of the aircraft we would start with. There is a slight difference in the  left to right ailerons. The inboard 3 ribs of the aileron has wash-in, and the outboard rib has wash-out. The only difference in the  covering is the positioning of the zipper. The zipper could go either up or down but just for aesthetic purposes we always place the zipper on the lower portion of the aileron so it's not visible. Ironically the sample template that Gary made was the same side as the dummy aileron that we made.

Tuesday, January 10, 2017

Lift Strut Attach Fitting (Video)

53-10-50 Lift Strut Attach Fitting Video

In this video we go through the installation process of the lift strut attach fittings on the fuselage frame.

Monday, January 9, 2017

Seat Support Tubes (Video)

Seat Brace Tube Installation

P/N 53-10-02-106  and P/N 53-10-02-107 Tube installation onto the fuselage frame.

Sunday, January 8, 2017

Ultraflight Batteries Donald Lineback

 "Donald Lineback" Batteries

  Donald Lineback and his latest E-Mail.

 January 7, 2017

  News about what to buy: 

 Before looking at batteries - consider the voltage current demand. Let’s compare voltage to gasoline. One gallon of gas contains 33.7kWh energy according to EPA or 33,700Wh. How big of battery would that be? An NCM Lithium-Ion pack would be 33.7kWh, 172 cells, 635v, 107Ah and weigh 927 pounds. If you factor in the fact that the average car only gets 23% of that energy - the battery pack would still weigh: 213 pounds. So adding a big current demand is not good. Nor is it a good idea to equate the battery pack weight to 5 gallons of fuel in ultralights. ("apples to apples”)

For the number one incentive was to build a highly efficient motor and use less energy. It has been easy for some motor designers to make high kW demanding motors. The problem - airplanes just couldn’t carry enough batteries. Big motors also disqualify themselves to be used with solar and other power supplies like fuel cells. 

What is the best battery and what on the “drawing board?” As for the future - higher energy batteries can be made, but they are only good for 3 or 4 charges and need to be scraped. The batteries that Tesla has been using, sourced from Panasonic, for its Model S electric cars are mostly likely a lithium-ion battery with a cathode that is a combination of a lithium, nickel, cobalt, aluminum oxide. The battery industry calls this an "NCA battery" and they've been around - and made by Panasonic, LG and Samsung - for many years.

Typically, lithium-ion NCA batteries use a combination of 80% nickel, 15% cobalt and 5% aluminum. (The anodes in these traditional lithium-ion batteries is usually a graphite combination, which acts as a host for the lithium ions.) The addition of the aluminum to the NCA battery makes it more stable.
For a home battery grid - Musk said that Tesla will use a lithium-ion battery with a nickel, manganese, cobalt oxide cathode called an NMC (or NCM) battery. Many traditional NMC batteries use one-third equal parts nickel, manganese, and cobalt.

Where do we stand among all the choices? NCM still reigns as king for safety and it works great for cars that handle the slight increase in weight. We have found a new source for the NCA which offers the weight savings needed in aviation. As soon as we have all the numbers - they will be posted on our website. Our new motor has an advantage because with a slower charge time, lower discharge demand and our new Active BMS - the safety went way up. 

Here is some info to help in your calculations:
Note: 1kW = 1000W. To find Ampere hours - Watt hours ÷ Voltage.  
kWh (1000Wh) is unit to measure total energy stored in battery and it can be calculated as battery voltage multiplied by Ah (V*A*h = Wh). In general kWh is unit to measure energy used.
Voltage is similar to water pressure like the height of the dam or water tank.
Current is the flow-rate of water.  
A battery rated for 100 amp hours will provide 5 amps for 20 hours.
If we have a 12 volt battery, we multiply 100 by 12 and determine that the battery will provide 1200 watt hours.
To apply the metric ‘kilo’ prefix, we divide the result by 1000 and determine that the battery can supply the 1.2 KW hours.
In the case of our 1200 Watt Hour conversion, we need to understand that what is really being said is that the battery will provide 60 Watt Hours for 20 Hours.

Sunday, January 1, 2017

Top 10 apps for the aircraft builder. Sport Aviation / Experimenter "Technically Speaking" Article December 2016

Top 10 apps for the aircraft builder

“There’s an app for that.” This overused cliché becomes more and more apropos every day. Even for the aircraft builder, we now have a virtual toolbox in our pocket that has become indispensable. We have reached the point in technology where it is now the norm for an aircraft manufacturer to publish maintenance manuals, parts manuals, and all other documentation, for that matter, in a digital format. If you’ve grown up on paper, the transition to digital can sometimes be difficult, but the rewards are well worth the effort.

#1 The PDF Reader App:(Figure: 1) The Rotax manuals, for example, consists of literally thousands of pages spanning more than a dozen different manuals. The ability to use a search function on a 500-page manual can really speed up the process of locating the information that you’re looking for. In our shop, we have a library of aircraft maintenance manuals accumulated over the last 40 years.

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.