“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.
The right-wing fairing shown being held in place with electrical tape. Actually electrical tape will be used in quite a few areas to help smooth the airflow and hold pieces in place for the final installation the fairing will incorporate the tape at the wing strut junction.
Where now almost completely finished with all of the control system installation. One of the finishing touches that we do to the elevator control horn is to install a 3-D printed and And a 3-D printed 10 that holds the end In place. Just a nice finishing touch
Jason is doing a trial fit on the elevator control stops.
The elevator stop permanently installed after powder coating.
With all of the rear fairing removed from the aircraft we can see all the control system installation. On this aircraft we have decided to eliminate the flapperons and use just ailerons. during the initial flight testing we found them simply not needed. Airplane already can land in very short distances typically 100 feet or less
The fuselage boom shows the transition holes for the pushrod tubes and rudder cables making the direction change using bell cranks around the bearing block attachments shown in blue mounted to the side of the fuselage boom assembly.
The weird design of the aileron bell crank is designed to be of the fit within the rear fairing and have clearance from the other control systems while still providing a substantial amount of differential aileron control.
The elevator control system attachment showing the close quarters between the rudder control horn and the elevator control horn and push rod assembly.
All of the control stick systems have been installed and rigged now. We have mostly been installing and removing powder coating and then reinstalling each one the components after the rigging process has been completed. In this picture here we see the additional idler arms for the rudder pedals. These idler arms are not normally required on the aircraft but because we’ve modified this aircraft for Carol and move the rudder pedals substantially further aft than the drawings call for we were required to modify the rudder control system and incorporate a bend in the pushrod tube in order provide clearance around the control stick assembly.
The rudder pedals also are modified from having the pushrod attachment location at the upper corner of the rudder pedal.. They are now moved downward to provide proper geometry as the pushrod makes its transition over the control stick. once again this is a special modification not required unless the pilot is shorter than 5’4″.
One of the additions to the aircraft that we got quite a few requests for was the installation of shoulder harnesses. So on prototype #2 we installed the shoulder harness system.
The shoulder harnesses attached into the mainframe at the fuselage boom assembly attachment location.
We have finished postprocessing (finish and sanding the 3-D printing part) the handheld radio mount which clips in place onto the forward instrument panel.
The upper horizontal stabilizer fairing being trial fit before finishing for final installation. Shown here with the elevator in the fold-down position showing the proper clearance. The cutouts on the fairing are designed so that the fairing can slide down the length of the strap material over the top of the rivets and Then be repositioned after the bolts have been attached to the horizontal stabilizer.
Front view of the horizontal stabilizer upper fairing
The lower horizontal stabilizer strut fairing shown in position and partially sanded.
April 18, 2016 Progress Update
We have been so busy lately that we have not been keeping up to date with the progress blog. We have some deadlines that we are working towards for the flight test program. And our focus is been primarily on achieving these milestones. We will try to summarize the last 2 weeks worth of work that we’ve been doing to get everyone up to date.
In this picture here we are making up horizontal stabilizer kits.
We’ve continued to keep the 3-D printer operating on a schedule of about 18 hours of printing time per day. Although we are behind on putting all of the 3-D STL files onto the builders database we now have close to 100 components on the aircraft that are 3-D printed. in the picture below we have one of the 3-D printed parts used for the nosecone assembly.
We have been making modifications to the main landing gear shock strut utilizing the streamlined wing strut material with a gas shock strut on the inside, accompanied with a compression die spring.
The front windscreen and nosecone are now going together on the aircraft. Still quite a bit of trimming necessary on the basic nosecone assembly
The front windshield supports transition the windshield from the forward bulkhead into the nosecone. The windshield is designed so that it can be removed from the aircraft and will separate from the nosecone as well as the center section fairing.
The 3-D printed bulkhead for the nosecone provides for a rigid shape of the upper section of the fiberglass Faring
We recently made a trip to pick up more material for the manufacturing process. This is about $6000 worth of material
This is the 1st prototype for the radio mount on the forward instrument panel bulkhead. This partakes about 16 hours to print. Normally it can take even 5 or 6 modifications to any one of the parts to finally develop the final product.
The new landing gear design installed showing the much cleaner profile utilizing the streamlined struts material rather than the ground tube strut.
We are starting to make the transition from the forward bulkhead to the rear bulkhead and interface that with the lower wing skin
This is version number 7 of the vertical stabilizer strut lower fairing.
We have been working on the final installation of the control system. In this picture here we have the elevator control arms modified with streamlined strut material. We have been working on small modifications to be able to reduce the drag on the aircraft and simple things like re-positioning of the control system arms and utilization of streamlined strut material along with 3-D printed fairings. these are making a substantial difference.
We have made a special seat back that will allow me to fly the aircraft in more comfort. You may remember that this particular prototype was designed for Carol who is only about 5’2″ and as a result we have moved the rudder pedals back substantially from the original position to comfortably fit her into the cockpit. The ability to be able to change out seat backs allows for substantial change in pilot position.
April 9, 2016Front Windshield Installation
We have previously installed nosecone and now that we have the BRS ballistic parachute installed for the final time and the wing center section cover basically finished we can now start the interface the front windshield with these 2 components.
We had previously made a template from cardboard and subsequently tried to use a piece of Plexiglas which could not conform to the tight radius of the front windshield and we ended up cracking it at the wing root transition area. So we have switch to .050 thick Lexan material. this material is virtually indestructible and can be cut with pretty much any tool including a pair of tin snips.
For the initial fit we will simply clamp the Lexan in place with clamps.
Next we will use a number 30 drill bit and copper Cleco’s to install the windshield position for the windshield attachment holes in both the wing center section faring as well as the front nosecone.
We have manufactured some U brackets with the 3-D printer to allow us to mount directly to the 4130 frame without adding welded tabs.
April 8, 2016 Inspection Cover Manufacture and Installation
Both the fuselage boom assembly and the wings have multiple locations that provide access for maintenance and inspection. these inspection holes will be getting inspection hole covers and we have now developed a very clean, lightweight inspection cover that prevents the cover from sliding and also prevents the marring of the finished surface.
We have 3-D printed a cover and a cover clamp in this case we are using Zultrat plastic material.
We drill and tap the clamp with a 6-32 Thread and have made the cover to be able to adapt to a socket head screw or a countersunk screw. you can see the beveled edge on the outer profile of the inspection cover that matches the dimple dies that we use in manufacturing the fuselage boom assembly.
The design allows you to back off the screw and slide the 3 Pronged clamp underneath the material and then with a little bit of pressure pulling up word on the inspection cover slowly screw the cover down into position.
With the inspection cover installed it is nearly flush with the fuselage boom profile.
April 7, 2016 BRS Parachute Final Installation
We’ve been working on the final installation in the modifications to the center section for the ballistic parachute installation.
We now have all of the bridal and rocket motor attached to the parachute. All of this bridal assembly is secured within a fiberglass bucket molded into the center section and then wrapped with a Velcro securing pocket. The rocket motor is designed to fire between the 2 wings directly over the fuselage boom assembly and out past the vertical stabilizer and rudder assembly. The mounting and directing of the rocket motor has been very thoroughly thought out. There’s no sense installing one of these systems if you’re not going to plan on it functioning if you ever need it.
The bridal assembly is wrapped and then folded And rubber band together to allow the most efficient extraction from the aircraft. Is then tucked into the bridal wrap which is Velcro together and that is bolted to the fiberglass tub.
We are now modifying the upper center section by removing the aft section of the aluminum top and replacing it with a breakaway plastic material.
Next we will remove the plastic protective covering from the breakaway plastic material and install the plastic into the aluminum center section covered using nylon screws and nuts. The idea being that there needs to be multiple ways for the center section to give way in the event of a parachute deployment.
Next the aluminum fairing has to be cut out to fit around the rocket motor. In this picture all of the center section aluminum pop rivets have been replaced with #6 nylon screws and acorn nuts.
The BRS soft pack container is secured to the frame with Velcro straps on both the fore and aft and of the bag as well as for grommets on either side of the assembly which are zip tied to the wing box.
The breakaway center section is getting modified with a series of holes that will provide for a breakaway section of the plastic during the deployment. The bridal will break along these lines forming a Chute for the parachute to be deployed through.
The design of the pattern is designed to allow both sides to open up and the aft section to tear completely away during the deployment of the parachute.
With the rest of the wing center section covers installed the last few details involves some 3-D printed parts for fairings and structure. The 3-D printed plastic parts are ideal in this case because of their light weight and ability to be designed for optimum parachute extraction.
April 5, 2016 Control System Installation
We have been working from the cockpit area working our way aft installing all of the controls for the prototype #2 aircraft. In this picture here we are fitting the control stick and the aileron torque tube with the universal joint.
The elevator control horn installed on the left side of the control system torque tube. we normally do all of the installation and then disassemble the aircraft to paint, powder coat or anodized the parts before reinstallation.
We have completed the installation and routing of the ballistic parachute cable and handle.
The control cluster on the aft bulkhead. This is the location where all of the controls, rudder, elevator, ailerons all transition vertically into the fuselage boom assembly.
We temporarily flipped the seat around to play with some seat positioning. If you remember from previous postings this aircraft has been set up specifically for Carolyn the rudder pedals have been moved very far aft. That means that for a normal person the seat will have to be modified in order to be comfortable. We will be designing a 2nd seed that simply pops in position with pit pins at the lower hinge section and then the seatbacks will be interchangeable without having to move the rudder pedals.
April 3, 2016 BRS ballistic parachute installation in prototype #2
We have started to steal some of the parts from prototype #1 aircraft to expedite the completion of prototype #2. one of those things that will reduce the cost is using the existing ballistic parachute system from prototype #1.
The harness was specifically manufactured by BRS for the EMG-6 and has for harness attachments on the upper frame of the fuselage. They are designed with a special loop to ensure a smooth transition from the wraparound the 4130 Crome-Molly steel fuselage into the harness.
The harness gets zip tied to the fuselage frame and a very specific routing procedure that allows the harness, rocket, and Chute to depart the aircraft in a very specific pattern without entangling the harness or the Chute.
The next step is to install the rocket motor and the deployment handle which has 4130 steel attachments already welded into the frame.
We continue to print 3-D printed parts for use throughout the airframe we now have identified about 40 specific locations where we will be using the 3-D printed plastic parts.
April 1, 2016 Flight Control Installation.
We are now starting to close in on the completion of prototype #2. Where currently undergoing the installation of all of the new low drag like control systems.
This picture here Jason is installing the horizontal stabilizer attach fittings.
Were using painters tape here to position the horizontal stabilizer for their initial rigging.
The horizontal stabilizer lift struts being prepared for installation.
The horizontal stabilizer lift struts position in place ready for rigging. We will not position them until after the elevator control systems have been hooked up and limit the total amount of travel. The jam nuts on the end fittings hold the streamlined struts in line with the airflow during normal installation.
The rudder control system being adapted for the short rudder pedal installation.