EMG-6 "Shop Notes" June 2017

 

June 28, 2017

It’s time for an update.

We continue  our frenetic pace getting ready for Oshkosh. Most everything that we been working on for the last week has been detail stuff. The only big thing that we are still waiting for is the sailcloth fabric covers. But let’s go over some of the work that we been doing lately.

 

We have finished the installation of the BRS ballistic parachute rocket and the new cover that we 3D printed. The 3D printed plastic cover would easily be broken through with the rocket motor. However we have installed it with 4 nylon 8-32 screws which will also break away if needed.

 

 

The side view shows the installation of the BRS rocket motor mounted behind the fuel tank and radiator transitioning up through the center section of the fuselage boom.

 

Because of the new location of the rocket motor we were required to replace the 4 foot deployment angle and cable assembly with a 6 foot new assembly. This will allow the cable to route more smoothly. The mounting location is the same location that we have decided on from the very beginning.

 

You can see the mirror finish that Austin was able to get on the fuel tank by using Mothers mag polish and lots of elbow grease. It took him almost 4 hours of polishing to finally get the mirrorlike finish that we were looking for. The fuel indicator will be this clear hose that you see here routed along the bottom of the fuel tank and tying in with the upper vent. We have just recently finished the installation of all the fuel lines and have mixed the gasoline for the test run 50 to 1 with Amsoil interceptor oil. Tomorrow we will use a calibrated gauge to fill the tank in one gallon increments. When we get to each gallon fuel level we will position one of these 3D printed fuel line holders precisely at that fuel level giving us a fairly accurate gauge of the amount of fuel that’s in the fuel tank without a complex fuel quantity system. One of the reasons for the mirrorlike finish is it will help to show the fuel level.

 

In this picture here you can see us using the prop balancing tool to balance the propeller. We just recently recondition and refinished the entire propeller. To balance the propeller we simply shoot additional coats of clear polyurethane onto each blade until the prop balances perfectly.

 

Although the picture is fairly blurry because of the slow shutter speed in the dark hangar you can see the bubble level on the buzz master prop balancing tool that we used to ensure that the prop is correctly balanced.

 

We have a built-in hook in the doorjamb to the maintenance office that we use for balancing the propeller. If you’re in need of a prop balancer the buzz master prop balancing system is only about $30. It works great.

 

We use a water-based polyurethane finish for the propeller.

 

Jason has been working on the seat pans for the bottom seat as well as the seatback. We are on headrest version number 3 and still not happy the headrest.

 

The seat pan and the seatback installed in place. Both of these will get a significant amount of lightning holes put into the aluminum. We will wait to place the lightning holes until after the seat cushions have been built and we match the Velcro attachments to the seat pan and back.

 

1 of the final steps in the flight control system installation is the installation of the aft control arm. This control arm allows the controls to be hooked up to the elevators and the elevator and stabilizer be folded without having to disconnect flight controls. We have some small eyebolts that are on backorder that are the last step in the control system hookup.

 

We pulled the prototype sail covering off of both wings and we have started the installation of the jury struts.

 

One piece missing from the 3D printed landing gear fairing installation. These landing gear fairings just simply lock in place. For the missing segment we can simply place the trailing edge segment onto the leading-edge segment, press and the trailing edge will be locked in place. Total weight is very low. It should improve the drag slightly, and it looks cool.

 

June 24, 2017

We have been on a mad dash trying get ready for Oshkosh. As a result the progress blog has not been able to be updated on a regular basis like we would during normal operations. I’ve collected a few pictures from the last couple weeks of work that we can share. We basically have 25 days left until we leave for Oshkosh.  Although the sails from ultralight sails of Canada are being worked on as we speak the schedule to get them installed and then still have time for the test flights for we leave for Oshkosh is getting very close. We are working on some of the basic details of the aircraft at this point. We are waiting until after we fit the sails to the structure to ensure that we do not have any other additional modifications that we need to do the fuselage frame. As soon as the fabric sales have been fit and everything is a go, we will then need to completely disassemble the aircraft, prep and paint the fuselage frame and then do a complete reassembly prior to test flight. We then need to disassemble the aircraft once again to put it into the trailer for transport to Oshkosh. So as you can see, we’ve got a lot to do in a very short period of time. We have been simultaneously trying to fill orders for some of the components and subassembly kits as well as getting together some the parts that we are going to deliver to customers at the air show.

 

In this picture we are machining out some basic welding tabs that are used in different locations on the aircraft.

 

The new nosecone, 3D printed.

 

A bottom view of the nose cone showing the structure that holds the nose cone oriented to the keel. This still allows the nose cone to be removed if necessary.

 

This shows the interface of the nose cone to the keel tube. The instrument panel visor will go on next, and then an aluminum cover will cover all of the instrumentation.

 

Another view of the instrument panel and nosecone.

 

Can the instrument panel with the visor covers Cleco’ed in place. The slip skid indicator is the only instrument left to be placed in the instrument panel.

 

Throttle handle. This throttle handle is CNC machined from 6061 T6 aluminum billet.

 

 

The fuel tank being assembled. The fuel tank is a 5.5 gallons fuel tank that is designed to fit perfectly in the fuselage and act as a air deflector to route air over the radiator system. The fuel tank is a CNC match drilled component that fits together perfectly, we use Pro seal in between each 1 of the joints and then assembled the pieces with aluminum pop rivets that are sealed on the end. We also dip each 1 of the rivets in Pro seal as we assemble.

 

We also install a couple of fittings one for the upper vent and one for the lower fuel outlet to the gas collator. These are CNC machined from 6061 T6 aluminum and are tapped to a 1/8 NPT pipe thread.

 

The upper fitting is used as a vent and the upper end of the fuel quantity indicator.

 

Fuel tank filler neck. We are using a Piper style fuel cap.

 

The top of the fuel tank has an access panel which we can see down into the fuel outlet and the baffled that holds the fuel in the fuel pickup area during turbulence.

 

The seatback aluminum sheet attached tabs welded in place.

 

The throttle assembly. This unique little throttle assembly turned out to be a very versatile installation. We have designed the throttle assembly to be able to be adjustable for any range of throw necessary all the way down to less than .5 inch all the way up to nearly 4 1/2 inches of control cable travel. By lengthening the throttle arm we could get even more throttle cable movement if necessary. We will be hosting an entire page on this throttle assembly how it works and the design.

 

The fuel tank attachment tabs welded in place.

 

The instrument panel visors. These visors are 3D printed and fit perfectly to the new close tolerance instrument panel. This instrument panel will handle up to 6 instruments.

 

A side view of the instrument panel with the instruments install, the instrument panel visor, and the nose cone. An aluminum cover will transition the nose cone to the visor.

 

 

 

Landing gear fairings. These are for locking 3D printed fairings for the landing gear that allow the brake line to transition through the center of the leading-edge fairing up to the fuselage. We will also have a dedicated post for just the landing gear fairings themselves in the near future.

 

Wing Jury struts. We received a large stock of the small streamlined strut material that we use for the jury struts.

 

The aft elevator bell crank control arm. Cooling off after coming out of the powder coating oven. In this picture here you can see a couple of spots around the welds that did not get covered well. Jason had to completely strip them down and read powder coat them.

 

 

June 14, 2017

Progress updates for the EMG-6 #3

 

The landing gear for the EMG-6 #3, the Black Max brakes are installed, the landing gear frame has been powder coated black, and the shock strut has been plated and chromated.

Landing gear installation on the EMG-6 #3.  The installation showing the powder coated landing gear frame, the plated and chromated shock strut. And the installation of the Black Max brakes.

 

EMG-6 #3 landing gear front view. With the aircraft off the ground you can see the camber that is built into the landing gear system. Once the aircraft has the full weight of the aircraft on the landing gear the wheels will be fairly close to parallel with each other.

 

EMG-6 #2 is being disassembled and ready for transport to EAA air venture 2017. We’re getting ready for the air show, in this picture here Austin is removing the wing center section cover in preparation for removal of the wings.

 

EMG-6 #2, we will be removing the BRS ballistic parachute system from this aircraft so that we can use it on prototype #3.

 

The BRS soft pack ballistic parachute system being removed from prototype #2

 

In preparation for the air show we are removing basically every component on the aircraft and either painting, powder coating, plating, or anodizing. This adds a significant amount of labor to the whole project but will make the aircraft look really clean.

 

The landing gear shock strut subassembly after plating and chromateing,

 

We were double checking the fit of the fuselage boom fabric covering. We will be sending this cover to utilize it as a template for the new sail coverings that are being manufactured by ultralight sails of Canada.

 

The fuselage boom fabric covering draped over the fuselage boom. On the original cover it was secured at the center section by Velcro. On the new coverings we will be using a lacing system in place of the Velcro. This should make the coverings be able to be tensioned a little bit better.

 

Rudder control arm part number 32-20-35 being machined from 4130 chromoly steel .090 thickness.

 

32-20-35 rudder control arm machined fittings as they come off of the milling machine. These components still have to go through several other processes. There is a small section that sticks out where the end mill finishes the cut that needs to be trimmed with the disc sander. The parts will then be put into the tumbler for deburring. And then the parts will be put into the welding jig and mated up with the round tube that will be welded to the fitting. After welding the assembly will be put back into the tumbler to clean up the welded joints, and then the parts will be powder coated.

 

32-60-22 weld bushing. This component is coming out of the CNC turret lathe and is 1 of the many steps in the process of making this component. The fitting will be tapped with a 1/8 NPT pipe tap and the fitting will be welded to the fuel tank . This will allow for the installation of fuel outlet fittings, drain fittings, and vents.

 

Part number 32-30-05 landing gear leg. The final installation of this component weighs in at 24.8 ounces.

 

The landing gear shock strut assembly with all of the fittings installed weighs in at 44.0 ounces

 

The complete Black Max tire, wheel, brake assembly, and axle weighing in at 5.62 pounds

 

We are welding up a prototype fuel tank out of 6061 T6 aluminum .040 inch thickness. The labor required to weld this up is unacceptable. Our next step will be to redesign it as a sheet metal component that can be riveted together.

 

June 10, 2017

Well, we started make enough progress on the website that we can continue with our updates on the progress of the EMG-6 prototype 3.  You will still notice several changes happening to the website over the next few days,.  We have lost a lot of links and images  during the transfer process.  Although most of the data is there, there is still a considerable amount of work to do to relink all of the images with the individual pages and blog posts. Most of the website work can only occur on weekends and evenings so that we can reserve the normal part of the day for working on the aircraft and preparing for the Oshkosh air show. Our goal is to significantly upgrade some of the pages to provide more direction for the builders.  So let’s bring you up-to-date with what’s been happening on the aircraft over the last week.

We only have a few items left on the aircraft that are major items to complete.  The fuel system, the landing gear system, and the fabric for the new sailcloth covers. Everything else that we are currently working on is detail stuff, and  finishing the aircraft.

 

 

We received the Black Max wheels and brakes system and have been working on the drawings  and the design for the installation on the aircraft. Were pretty confident that these breaks will now become the standard brake system for the EMG-6 tail dragger configuration. We asked the manufacturer for all of the  solid model 3D drawings for the components,  it didn’t sound like they were very excited about releasing those drawing so we went ahead and  completely 3D modeled all of the components on the aircraft so that we could complete the drawings for the installation and operation  of these new brakes.

 

 

The brake caliper housing will be held in place with a keyway  machined into the axle.. This keyway is the  keystone to the entire installation. When the axle is assembled and the axle nut is tightened the keyway should be just flush with the outer housing of the caliper assembly.

 

 

The axle cannot be installed until after the caliper assembly and the rotor have been preinstalled. The entire package is really well-designed, lightweight, strong, simple, and nearly perfect  size for the weight and size of the aircraft. and as far as brakes go on aircraft in the ultralight industry, The pricing is very reasonable.

 

 

The brake caliper housing has a set screw to hold it in position, positioned directly over the Woodruff key, and although the set screw is not used to carry the load of the wheel pushing inward,  it does help hold the assembly together during the installation process.

 

 

The caliper assembly, rotor, axle and  installation hardware.

 

 

the wheel hub assembly. The wheels and brakes are very similar in size to the Heggar wheels and brakes. However the Black Max brakes have a few design changes. The wheel halves are not exactly the same size as the Heggar wheels but talking to the owner of the company he said that they could be used but require some trimming of the caliper housing in order to provide clearance. The wheel halves, unlike the Heggar wheels are welded at the center. One of the original problems with the Heggar wheels was always the  problem of air leaking through the hubs. This required an O-ring and several other components in order to assemble the wheel halves. This welded wheel assembly should really eliminate a significant amount of air leakage problems that we’ve seen in the past.

 

 

This picture shows the axle and the Woodruff key installed with the hole drilled on the mounting and per the drawings for the EMG-6. In addition the end of the axle has been cut off by approximately 1 inch.  The positioning of the hole is fairly critical as the bolt hole provides the proper distance for the mounting of the landing gear leg.

 

 

You can see in the final installation with the axle positioned properly  that the Woodruff key slot leaves just enough room for a washer to be installed  which will provide the load bearing surface for the Wheel and brake assembly. These are 5 dates axles which are the standard axle size for most ultralight sized aircraft. The wheels and brakes are actually rated for a maximum of 1000 pounds.

 

 

We have been doing some organizing in the shop putting in some new shelving and organizing a lot of the tooling necessary for building the EMG-6.

 

 

1 of our newest processes that we have adopted is  the set up of a  copy-CAD plating system. For all the components that we will be sending out that cannot be powder coated, anodized, or painted  we required some kind of corrosion protection.  This is actually a zinc plating process with a chromate conversion coating applied. Jason has been working for the last week to complete the set up and perfect the process. On parts like this landing gear shock strut component, the parts have to slide together smoothly and move in and out during the landing process the spring will allow movement along these parts. The plating along with lubrication should give a fairly long life to these components.

 

 

More of the parts that Jason has been working on with the plating process.

 

 

Wit’se are even replacing some of the hardware that we are reusing from prototype 1. We want to make the airplane looked pretty before the air show.

 

 

 

Cutting out more welding fixtures, in this case here we had to remake the welding fixture for the control stick in order to be able to provide enough clearance for the hydraulic brake handle that we will be installing on the control stick  as a single master cylinder operating both brakes simultaneously.

 

 

The axles installed onto both landing gear legs ready for the wheel assemblies  to be installed. We won’t install them at this point as we have to powder coat the landing gear legs before installing them back on the aircraft.

 

 

This close-up shows the position of the Woodruff key in relationship to the axle. We are using the axle positioned with the caliper and Woodruff key facing forward. This will give the most amount of strength to the axle during a landing. The mounting bolt hole on the aft side  is what positions the axle in place.

 

 

 

 

 

 

 

 

 

 

June 2, 2017

We begin the month of June at a frenetic pace. This is our last full month of work that were able to do before we start the countdown for the trip to Oshkosh. The schedule appears to be very tight. Prototype number 3 has to undergo a complete series of flight tests and documentation. We have a large number of parts that still have to be built and sent to customers this month. And our top-secret project of the month is a new electric motor for prototype number 2. More information on that if it materializes will be forthcoming.
 

We are currently prepping the Polini 252 get ready to run with the new drive system installed. All of this system is now complete and ready for operational tests. We still have a few other things to complete on the aircraft before we can run the engine. The electrical system and starter system has all been hooked up. The coolant system is now filled and ready to run. Once the aircraft receives its new wheels and brakes we will be able to take it out on the flight line and begin testing.

We have recently contracted with Black Max brakes to be the primary supplier of brake systems for the EMG-6. Although we will have additional options for other types of wheels and brakes on the aircraft we will be focusing prototype number 3 on developing the drawings and installation procedures for the Black Max Brakes.

In order to use the Black Max single lever master cylinder we had to modify the control stick to allow the transition of the plastic hydraulic line to transition through the center of the control stick in order to prevent binding and pinching and possibly damaging the hydraulic line. This also required a modification to the control stick to change the angles so that the brake master cylinder would not hit the instrument panel.

The exit hole for the hydraulic line keeps the installation very clean with minimal bends in the line and an easy transition to the aft portion of the aircraft where the hydraulic line will be teed out to both brakes.

We are currently working on a production run of 10 steerable tail wheel assemblies. In the picture above you can see the main body of the tail wheel housing being machined from solid aluminum billet. 6061 T6. There is a total of 16 different machining operations that take place just for this 1 single part. It has to be reindexed 4 times, so the machining jaws have to be machined to allow reindexing each time that we rotate the part to a new orientation.

Once all of the G code is established the actual process of machining the parts is fairly automated.

The new installation of the Polini 250 inside the fuselage is looking really good. By the time we get the covers onto the fuselage this should be a very low drag profile.

Jason has continued to perfect the wiring system making one bundle that is tucked neatly together and has welded tabs along the fuselage to clamp the wire bundle to.

Worst-case scenario with the control stick all the way forward shows that we still have plenty of clearance from the hydraulic brake lines to the instrument panel.

On the Polini 250 installation we can weld in some additional structure to enhance the seating arrangement. Because of the permanent installation of the motor in the rear seat the ability to be able to utilize that space is no longer an issue. So we have added in an additional tube that will allow us to form a bucket seat. We will probably add a vertical section that will provide a headrest as well.

The demand for parts continues to come in and so we are constantly ordering raw stock material. In the last 2 weeks we’ve ordered over $10,000 worth of raw material to have on hand for manufacturing other components of the aircraft. This box contains 12 foot sections of aluminum tubing to be used in primarily the wings and flight control systems.

This section of aluminum tubing is for manufacturing push pull tubes for the aircraft. All of the push pull tubes except for the long tube that is used for the elevator control system that is inside of the fuselage boom assembly are manufactured from 6061 T6 aluminum .625 ×.035. This will allow us to finish up the control system on the aircraft.

The MS 20219 – 2 pulleys are used in the rudder control system. These pulleys are quite expensive so we have manufactured some lower cost aluminum pulleys that can be CNC machined without bearings in them that we will be testing.

We are constantly ordering new stock of hardware for both shipping to customers as well as using in the shop on a regular basis for building the prototypes. There’s nothing worse than being in the middle of a project and running short on 1 or 2 simple parts.

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Comments 4

  1. You say there are two pulleys in the control system for the rudder. I think there are 4. Correct me if I’m wrong.
    Ed Santucci builder number 27.

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      Author
  2. Really exciting pictures and notes about the EMG-6. Looking forward to seeing more about electric motor and battery selection and mounting. It looks like you are selling Kits, does this mean you’ve made headway with certification? Thank you, Brian!

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      Author

      John,

      We are designing and testing for ASTM Light sport Glider Standards. We dont anticipate offering a LSA version of the Aircraft for some time. (no electric in power in LSA aircraft at this time) So sad, Our country is falling being because of the bureaucratic Swamp. We will be working to offer that option one the rules change. The part 103 is still viable but with the ruling on batteries requiring them to be included in the 245 pound empty weight, Not realistic. Everyone building at this time is relegated to Amateur built.

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