Workshop

Feb 16, 2009

With all the work done on the plane, the motor test was the final step. The carb settings were very wrong and that prevented the engine from getting any gas from the tank. After diagnosing the problem, the jets were reset to the spec and the motor came to life with a great roar. Everything was fine with the fuel system and the ignition switch performed perfectly. I am satisfied that the plane is air worthy and Dennis will be by the shop on Saturday to pick up the plane.

The last step is to have some paint damage to one wing repaired at a local paint shop. In the handling of the plane, I dropped the wing and it landed on some hard metal legs to the airplane stand. The top side of one wing was damaged in two places and while I could repair the damage and bondo the surface back to smooth, I wanted a pro to paint the surface. The wing is expected to be done very soon.

Feb 10, 2009

The brass rail was then carefully filed to allow the front screws to hold the track in place. This screw will also act as a stop for the sliding canopy once it is assembled. The length of the track was cut so that the aft end was secured by another screw. In the center of the track,I soldered a tab on and secured it to the fuse.

The track was then cleaned and painted black.

This arrangement will allow the rear canopy to be removed if the need should arise. I think this is a better choice than gluing the canopy to the plane and the track to the canopy.

The inside track was then glued to the movable canopy. This required considerable measuring to be sure the clearance allowed the canopy to slide. The shot below shows the finished canopy with the slider in the closed position.

The shot below shows it open. In most cases this plane was flown with the canopy open and it is safe to do that with this as well. Since you will have to open the canopy to operate the choke and the switches, I would just leave it open.

Feb. 8, 2009

I began the work on the canopy by cutting the black frame into three parts. Front windshield, front seat area and rear seat area were cut and sanded to clean up the cut edges. The clear canopy was then cut to match the frame parts. The windshield parts were glued together so that the air flow will not move the front structure. The rear black and clear parts were mounted on the plane with button head screws and the cut edge was glued between the black frame and the clear canopy.

 

Feb. 5, 2009

I contacted George Hunter and we scheduled the installation of the cockpit rails for tomorrow.

I added the weight to the firewall in the form of lead weights bolted securely to the firewall. This will bring the CG to the specified position and will make the plane flyable for the first try. After the plane flies there might be further adjustments to get it just right.

After the canopy work is done, I will do the engine test and the plane will be ready to fly.

Feb. 2, 2009

The session began with the realization that all the work but the canopy was done and the rails will not change the weight and balance of the plane. I assembled the plane and added the cowl, spinner and prop to complete the setup.

The CG is checked with no fluids in the plane so I put it on the machine and found the CG to be 1.25 inches behind the recommended position of 13" ahead of the trailing edge of the wing at the root. This is not a surprise for this plane and I set about finding the weight needed to bring the CG under control. I planned to put the weight on the firewall so I positioned weights and found that 3 lbs would put the CG on the mark. I will now set about making a 3 lb weight that will fit under the cowl.

The tramble settings of the airframe will be another indicator of the flight characteristics we can expect on the first flight. Checking the wing tramble showed the left wing tip is 1/16" ahead of the right tip and this is such a small error that it will not be a consideration. The tramble on the stab was 1/32" in the same direction and this will also not be a concern to the airplane.

The lateral balance of the plane determines if it will tend to put one wing down at lower speeds. Since we know that this plane will tend to put the right wing down when it stalls ( due to the wash out in that wing) The lateral balance check is key to ensure the plane is balanced from right to left. The gas tank is on the center line so that this measure will not change at flight time. The first check showed The right wing was heavy and it required 1.25 oz in the left wing to make it balance. Uncorrected, this would have ensured the right wing would drop as the plane lost speed and that would have caused the use of the ailerons to correct. This condition has frequently let to other nervous conditions in the pilot. I corrected the problem by adding 1.25 ounces of weight in the left aileron bay and then replaced the hatch and tested the servo.

Feb. 1, 2009

The new receiver arrived and all the wiring was completed. The wires from the fuse to the center section of the wing were bound together and color coded to match the four to be plugged into the center section. At the attachment point for the wings the color code was continued to make assembly easy. All the controls were wired and switches plugged in to give a test of the system and, after some creative problem solving, all the servos were behaving nicely. The switches have yet to be installed in the cockpit pending other work to be done.

I located an automated switch from Ed Cobb at 42%products and it is designed to be used with the G-62 engine. I used the one remaining channel on the receiver to run this switch wired to the ignition system of the motor. It is a filtered relay that will kill the ignition from the channel 8 knob on the transmitter. I hooked it up and confirmed that it did kill the ignition and then mounted it on the firewall with some padding for vibration.

After running the wires and checking the operation one more time, I was very pleased with this improvement to the plane.

The choke was next as I had no real concept how we were going to operate it without impacting the appearance of the plane. The work began by extending the control arm on the choke and attaching a kwick clip to the control horn. The choke could then be operated but the axis is at a sharp angle to the firewall. It seemed that nyrod could be run to the control arm and then run to the cockpit so that the choke could be opened and closed from a position near the switches. In order to investigate this, I drilled a hole at the angle the control horn dictated and used blue nyrod to make a connection to the inside of the fuse. With some adjusting the choke seemed to work quite well.

The next part of the problem was to land the rods in the cockpit and figure a way to make it look like it belonged in the plane.

The floor of the cockpit is very thin fiberglass that could not stand the strain of pushing and pulling on the choke lever and the appearance inside the cockpit were the two factors that had to be addressed for this approach to work.

I used a block that could be epoxied on the inside and a dowel that would protrude into the cockpit. The nyrod was run down the center of the dowel and it was painted green. The nyrod needed support inside the fuse so that was done with a former glued to the inside ring of the fuse.

The block and rod were then glued in place with the support aligned to help the nyrod make the sharp bend to the carb. The blue rod was then trimmed to length and the yellow rod was connected to the quick link and to the pull lever in the cockpit. The lever was made from some 4-40 rod and a nut that was all painted green. The resulting system functioned and looks good with the plane.

Next were the switches that fit in the space to the right of the choke in the photo above. The fiberglass is not strong enough to hold the switches, so I made a back plate from 5 ply and fit it behind the area. The switches were then mounted through the fiberglass and into the plywood. After gluing the plywood in place, this made a secure installation that looks good with the inside of the cockpit

The wiring could then be secured for flight and the rest of the equipment inspected and tightened. All the servos were tightened with locktite along with the center screws on each servo arm. This prevent problems in the air and makes the plane flyable for the first 50 flights with little maintenance.

Below is a shot of the equipment compartment with the work complete.

 

Jan 26, 2008

The session began with the incidence checks on the airframe. The data below is in standard terms ( minus incidence is leading edge down -- plus is leading edge up) All the data is relative to the right wing root which was assigned an arbitrary value of zero. this is done to enable us to see the position of the surfaces in flight.

INCIDENCE DATA

right wing root 0.00 degrees ------------right wing tip -1.5

Left wing root -.3 degrees --------------left wing tip -.8

right stab root -1.8 -----------------------right stab tip -1.8

left stab root -1.8-------------------------Left stab tip -1.8

OBSERVATIONS FOR THE FIRST FLIGHT

1) The stab is at negative incidence and this will make the plane climb at neutral elevator. Be aware that the elevator will be more active in the up direction than the down.

2) The left wing has its leading edge down and therefore the plane will put the left wing down as the speed increases.

3) The wash out in the tips is different by about a full degree. This will make the plane put the right wing down when the wing stalls. It is strongly recommended that the plane be stall tested in the air on the first flight prior to trying to land it the first time. It is hard to predict how much the wing will drop and so it is a good idea to get three mistakes high and slow the plane while using elevator to hold the nose up. the plane will stall and that will tell how much danger there is in the stall. I would test this with the flaps up and with them down to see if there is any difference in the stall performance.

The batteries were then mounted on a tray similar to the gas tank and the tray was glued into the plane. This will allow the batteries to be removed by using the Velcro straps.

Jan 25, 2008

With the decisions made the work began with the fuel system. The deck on the floor of the main compartment will be a fine place for the gas tank but I can only get to the aft part of the tank to strap it down. I solved this be building a tank mount that will hold the tank with a velcro strap on the forward end of the tank and a strap on the aft end will pass through the deck for ease of attaching the tank in the future.

This tray was epoxied to the deck with the tank set as far forward as it will go. With this installed, the tank can be removed by releasing the rear strap and reaching inside the fuse to release the forward strap. The rear brace sill prevent the tank from moving aft in flight.

The installed tank is shown above and below you can see the two gas lines were passed through the firewall and routed to the carb and to the exhaust tube.

On the ground the two tubes can be pulled out of the exhaust tube to show one plugged line for filling the tank and one flagged line that is the vent for the tank. The plugs in the two lines and flag on the vent line will prevent leaking from the tank and notify you not to fly with the vent plugged.

Next, the antenna tube was set from the receiver location on the side of the fuse to the aft section. The tube was glued in place to prevent any vibration in flight. The tube ends near the receiver so that the antenna can be routed easily. I removed the tail wheel assembly to glue the aft end of the tube in place and this made a nice installation.

Jan 23, 2008

I discussed the options for completion of the plane with Dennis Gibbs and we came to several key decisions. The fuel system overboard discharge and fill lines will be hidden in the exhaust port that is not functional. We will change the canopy to a slide system that will allow us to open the canopy over the front seat. This will allow us to put the three switches under the dash where they will be easy to use and not hurt the look of the plane.

These changes will require modification of the plane and some parts that I have begun acquiring. I will also enlist the help of George Hunter who is a noted scale competitor in the Alabama and Georgia area.

Jan 22, 2008

I met with George Hunter to get his concepts on how to hide the services so that the scale appearance of this super bird is preserved. Below are some more shots of this plane, it is a sight to behold.