Workshop

11/14/11

The kit was opened and invetoried. Everything ordered is present and in good shape. This plane will be powered with an electric fan jet that will produce around 20 lbs of thrust. While the electric motors are not the usual power source, the technology has evolved to the point that they are a real alternative to the gas turbine we are used to.

A plan was assembled that includes production dates and list of the items needed to finish the plane. This list was sent on and the equipment will be put on order asap. Since we are having many supply problems at present, I may have to start the build before all the parts are in hand. While this is not the perferred way to do planes, it will allow completion of the most planes in the shortest time.

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12/7/11

Work began on the plan without all the parts. This is regrettable but necessary in order to keep the planes flowing through the system.

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I began with the aileron servos. This is a fine kit that was engineered very well, so they have a system for the aileron servos and the linkage. I began with the aileron hatches that were supplied and a pack of hardware to mount the servo to the hatch. first the hatches were identified as left and right and the position of the servos was determined.

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Next the servo mount was constructed and the bolts were glued to the frames as seen below.

The frame was glued and screwed to the hatch and the servo mounted to the frame as seen below. The glue needed time to dry

Next I put the hatch in place and drew a line from the servo arm perpendicular to the hinge line and established the position of the control horn for the aileron.

Above you can see the cuts made in the surface of the aileron for the twin control horns that will connect to the servo.

12/8/11

The control horns were glued in place with Hysol and allowed to dry. The control horns were bolted to the ball link before gluing in place and this ensures the alignment will be correct and the ball link will function properly

The hatches were then screwed in place and the links made and adjusted to work properly. The leads for the aileron servos were not long enough and so extended the leads with solder joints. I avoid extensions wherever I can as the plugs are a source of problems in the future.

The ailerons are live hinged on the top surface and the lower joint needed adjustment so that the aileron would move down without hitting the trailing edge of the wing. I made this adjustment and the ailerons were operating very well.

Next I looked at the stabs and the servos are designed to go in the root of the stab and the arm would run in a slot in the bottom of the stab. The thickness of the stab dictated some small servos to make the setup work.

The former inside the stab was cut out to take the servo and then I set the servo in place for a test fit. I drew the location of the former on the bottom of the stab and cut the slot in the lower surface for the servo arm.

After everything lined up I bolted the servos in place and went on to the control arms. The elevator control arms were installed in the same way as the ailerons and they were set aside to dry.

12/9/11

The elevator control horns were cut and installed and linkages made. The stabs will seldom need to be removed and so I decided to make the tubes solid in one side and to use a bolt through the tube on the right hand bottom surface. This will hold the stabs against the fuse and allow easy removal of the surfaces. I began with a line on the lower surface to indicate the exact center of the stab tube.

next I glued the tubes into the left side with hysol and allowed it to dry.

I turned to the rudder and the first task was to mount the servo upside down in the top of the fuse. This was done with some unique positions.

The push rod was installed and it fit through a hole in the vert stab rear surface. The rod was connected to two control horns much line the ailerons and elevators. These two control horns were positioned through the web in the leading edge of the rudder.

As seen above, the control horns were then glued in position and allowed to dry overnight.

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12/10/11

The session started with the adjustment of the rudder system. I energized the servo for the rudder and set the length of the control rod to center the rudder. I checked the throw and adjusted it to the manufacture's specks. The rudder operation looks good.

Next I fitted the stabs to the plane and energized the two elevator servos. The links were adjusted and the throw checked against the numbers provided by Tomahawk. The surfaces were checked for direction and everything looked good.

2/11/11

The remaining flight surfaces that need work are the flaps. These have internal control horns like the rudder did and the servos are quite a ways inside the wing skins. I began by fitting the servo into the hole in the former in the wings. This is a standard size servo and it was bolted in place with the arm attached and a quick link on the arm. I also energized the servo and set the position of the arm so that it would work inside the wing. The goal was to only mount the servos one time and we will see if that works out.

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12/12/11

I cut the web of the leading edge of the flaps and located the control horn assemblies so that they could be hooked up to the linkage. The assemblies were then glued in place with aeropoxy and allowed to dry for 8 hours.

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The light system was next and the work began with soldering a resister in the wire to each of the landing lights. This allowed the lights to be used with the main batteries in the plane. The landing lights were tested and worked fine

After the flap control horns were dry, I made linkages and hooked up the servo to the horns. This was a slow process as it took many attempts to get the length of the linkage just right so that the flap would be all the way up and would not lock the servo. Both flaps had to be adjusted so that they were identical and worked to the same limits. Below is the flap in the up position.

Above you can see the flap in the full down position. I am not sure this much movement in the flap would ever be used, but the transmitter can adjust the throw as needed. The flaps were then fully operational.

12/13/11

The first item for the day was to secure the stabs to the plane. Since there was a stab tube, the best method of holding the stabs on the tube was to bolt through the tube. The right side of the stab has the tube glued in place, so I set the stabs in position and located the line on the under side of the stab that indicated the position of the tube in the stab.

I drilled and tapped the tube and clearance drilled the stab taking care to keep the hole in the bottom surface only. I then reassembled the stabs and screwed the 4 40 bolt into the stab tube.

Above you see the finished product. The stab is secure on the tube and we can disassemble the stabs if there is a need to service the servos in the root area of the stab. This completes the construction of the stab and the rudder area.

 

The ailerons and flaps are complete so I turned to the alignment of the wings to the fuse. The pins were glued into the root of the wing sections, so I cleared and adjusted the holes in the fuse so that the wings fit correctly to the fuse. As you can see below, the pins were cut to go through the root area of the fuse and provide proper alignment of the wings.

 

CAUTION -- SCIENTIFIC CONTENT BELOW

With the plane fully assembled, it was time to look at the straightness of the airframe and make adjustments. All of the information gained was entered in a book to go with the plane. This information will help in the first flight and will supply great information should the plane ever need repair of any kind. All the data below represents the configuration of the airframe after all adjustments were made.

 

TRAMBLE -- This is the alignment of the wings and stab so that one tip is not ahead of the other. This puts the wings and stab on straight if you look at the plane from directly above. I measured the tramble and the goal is to have no variation from tip to tip.

Wings had tramble of 1/64 of an inch and this is well within the standards.

Stabs were so close that I could not measure any difference in the position of the tips

 

FLATTNESS -- This is the flatness of the wings and stab if you look at the plane from the front. The wings and stab should be straight relative to each other.

The flatness was also very close, indicating a fine job on the construction of the airframe.

 

INCIDENCE -- Incidence is the position of the center section of the wing and the stab. If you look at the plane from the side and draw a line through the root section of the wing, that line should be level with the center section of the stab. This is incidence in the surfaces and for this plane, I assumed the wings were at zero and measured the other points relative the the left wing at the root.

wing incidence was ------Left wing root zero degrees ---left wing tip -.15 degrees

----------------------------------Right wing root was zero -----right wing tip was -.21 degrees

Stab incidence was ----Left stab root +.11 degrees -----left tip was +.01

-------------------------------Right stab root was +.085 degrees ---- Right tip was +.015

 

Summary of the meaning of the data above

1) The wings and stab are on straight

2) The wings have similar incidence with some wash out in the tips. This is done to reduce the chances of tip stall at slow speeds. Tip stall would cause the plane to roll without warning as it was being landed. This is not enough washout to do a lot of good, but it will help.

3) The stab has slight incidence in the positive direction. This will tend to hold the nose down at high speeds and the pilot must be aware that as the speed increases, this plane will go from trimmed flat to a shallow dive.

4) In the first flight we will stall the plane to be sure we know what it will do and the data says it will fall off to the left after a stall. The pilot will need to be aware of this as well.

 

Work will now be on hold for parts

1/20/12

Equipment has arrived and work has restarted on the plane. The retracts were sent to the good folks at Down And Locked to be converted from air to electric. They are now back and they did a fine job on the conversion.

I began with work on the wings. The landing gear bays were cut in an earlier session and so the gear mounts were then tested in the holes provided. This is one of several landing gears that will fit in the wings, and I needed to do some custom fitting to get the gear to fit down on the mounts correctly. The gear was aligned and mounted to the hard mounts.

All the wires and air lines were then run to the root of the wing. This required some custom fitting as there are wires and plugs for the ailerons, flaps and landing gears as well as an air line for the brakes on the main gears.

Next the landing gear was cycled and checked for proper operation. After adjustments, the wing systems all functioned well. As you see above, the brake lines were run up the gear to the wheels and all the wires and lines were run through the wing root

 

1/21/12

The second wing was done in the same way as the first and it was tested to be sure everything operated properly.

 

12/22/12

The nose gear was next to be done and it was inspected and tested to be sure it worked as expected.

The belly of the fuse was then designed for the nose gear to fit. After checking the lines, I cut out the bay for the nose gear.

The gear was then modified to fit in the area I had for the gear and after the re-machining, it was mounted in the plane and aligned to be sure it fit as expected.

Next the nose steering servo was mounted in the plane under the equipment board. The problem with steering designs and retracts is that it has to function 100% of the time the nose gear is down and must never tangle while the gear is retracted into the fuse for flight. We do not have a way to turn off the steering servo, so it will continue to turn with the rudder in flight without causing problems in the nose.

below you see the gear in the up position and the yellow nyrod provides the stiffness to keep the wires out of the way.

I used a pull pull system to connect the servo to the steering gear. This was installed and centered to work with the rudder. When the gear was retracted, the pull pull cables tangled and in some cases it prevented the gear from retracting all the way. I installed some stiffening material to control the cables and all was well.

Above you see the gear down and the steering servo with the wires tight.

The plane was then assembled and checked in all positions to be sure the gear was working properly

 

1/25/12

The present situation with the shop schedule is that we have been waiting for parts on several projects. This Viper is not a very high priority but the parts were in house so the work was done while I waited for parts on the higher priority projects. The intended fly date for the viper is quite a ways off and parts have arrived for the Concorde. Since the Concorde is scheduled to fly in 4 weeks, this plane will be put in hold while I work on the other.

2/4/12

Some time could be spent on Viper so I started by laying out the lower hatch that will allow the motor to be installed and some other work to be done more easily. I set the hatch size to fit within the structure that is inside the fuse.

I cut the hole and marked the hatch for orientation. There was one structural that needed to be removed to clear the area and that was done.

Next I made blocks to be glued into the inside of the wing roots to accept the blind nuts to hold the wings tight to the fuse in flight.

I drilled the holes from the wing root through the blocks and installed the blind nuts.

The plane was then placed in the inverted position and the wings bolted on to be sure of the fit. This seems to be a good system for holding the wings on to the fuse. The drawback is that the gears must be down to get to the bolts so we will have to operate the gear before working with the wing bolts. The customer leaves the planes assembled so this will not be a problem.

In order to bolt the hatch back on the plane, I made corner blocks and installed them with hysol to be sure they would stick to the c/f composite skin of the plane. This hatch is sized so that the motor can be installed in the plane.

The project was returned to storage waiting for the motor and battery.

 

2/28/12

The motor is expected to be here within a week so work can be done to get ready.

I started with the hatch on the bottom of the plane. I mounted the hatch with #6 button head screws. I checked to be sure the fit was good.

 

Next I cut out the vents on the side of the fuse The EDF will require lots of air, so I cut the intakes out full size.

I fit the duct work into the opening and I will glue them in after I meet with the paint guy to be sure we are doing it correctly.

The EDF requires more air than a gas turbine would. The gas version heats the air with fuel and the exhaust is several times the volume of the intakes. With the EDF, there is no expansion of the air and what goes out the back is just what comes in the front. With scale planes, This presents a problem because the intakes are not large enough.

To address the problem, I cut additional vents in the bottom of the fuse under the intakes on each side. These will allow additional air to be pulled in by the EDF.

In order to protect the EDF I put screen material on the inside of the fuse over the slots. The screen will get painted the body color and will look very nice while serving the function of adding air to the EDF

2/29/12

i started on the canopy work. I marked the cut line for the nose area and then taped the canopy frame in place being sure to line everything up. The canopy will have a latch in the rear and will need some locator pins to prevent any motion during flight.

I drilled through the canopy frame and the fuse frame and used a c/f pin for locator. I later made a block for the inside of the canopy frame so that the pin would be supported properly.

I added two pins in the center of the frame and made blocks for them too. The fit of the canopy frame was very nice and we are ready to move on.

3/1/12

Since the EDF will be moving air at a rapid rate,I decided to put all the wires in protective tubing. I made a plate for the wing area and glued the tubing to the plate. I ran all the wires and glued the plate to the inside of the wing root. I then ran the wires to the tail and used tubing to secure them to the side of the fuse.

You can see the screen material over the additional vents.

 

3/2/12

The first and second board were positioned in the plane and the boards were mounted down. The batteries will be on the boards so I added structure to support the weight of the systems.

 

I repainted the inside of the fuse and allowed it all to dry.

 

I began hooking up all the wiring and testing that all the servos work as planned. This takes time to accomplish and is well worth the effort.

 

3/5/12

The color layout of the plane was decided and it will look like the shot below.

I removed both of the red equipment boards and painted then grey to match the inside of the plane. The red would have looked bad with the outside of the plane.

 

The motor is due in the shop today so I began preparations for the installation of the speed control and the EDF.

The EDF requires a thrust tube to develop the power needed to fly the plane. This is a thin light weight material that is formed into a tube and mounted to the back of the EDF frame. I found the best material to use would be some 1/64 ply that is flexible and very light weight. I made calculations on the size of the sheet needed and located the material for use later.

3/8 to 3/11

We decided to finish the plane in automotive paint with clear coat over the color. This makes a very durable finish that will resist fading in the sun.

The motor was mounted inside the fuse and the existing motor mounts had to be rebuilt in order to support the motor.

The equipment board was tested in position and the speed control was mounted and wired up.

The speed control came with detailed instructions and they allowed the main motor to be test run without any problems

Several details were cleared up and the plane was delivered to the paint shop.

 

3/19 to 22

 

The plane is back from paint and looks very nice.

 

The final steps were taken on the plane and all the wiring was done. The canopy was fitted to the fuse and all the systems were checked.

The customer's JR 12x was programmed for the plane. I used flight modes for this plane and all the settings were programmed to the three flight modes. Take off -- cruise -- landing. By throwing the switch the flaps, throws and mixes were all set differently depending on the needs of the plane. I consulted folks that fly the gas version of this plane and used their transmitter settings as a starting place for the plane.

The Center of Gravity was set and the plane was very nose heavy at first. This is likely due to the large batteries for the motor. I changed the location of the equipment batteries from the nose to the wing tube and made other changes to get the CG to the prescribed location.

 

The lateral balance was checked and adjusted to eliminate the heavy wing condition.

 

The nose wheel steering system was set up to stop working when the gear was up so that the linkage will not fail. The retract can be tricky since it is pull pull and as the gear is retracted, the cables are free to wander around and get in trouble. After severa attempts, the gear operates and the retracts all look good

 

Many other final steps were taken and the plane was complete and ready for the taxi test.