COMPOSITE-ARF EUROSPORT MODIFICATIONS

Transcription

1 COMPOSITE-ARF EUROSPORT MODIFICATIONS Having supplied these Mod's to many over the months on a oneon-one basis, I thought I would compile a page of all the modifications I have done to the Eurosport for easy review. I will continue to add to this page as I begin to install the armament and tanks to my ES in preparation for it's new paint scheme. Feel free to me if you have any further questions... Enjoy! Todd

2 The center of the tanks are secured using a 2" wide velcro band attached to the fuse as seen here on the left. When the intakes are installed, they will lock the front of the tank in place as the taper of the intake just clears the tank. No further support is necessary.

3 Heat Shield The fuse was getting a bit too warm in the engine compartment during the initial engine runs. I painted the engine / pipe area with BVM heat shield then applied BVM ceramic blanket to the engine bay and pipe area. The blanket is held in place by applying beads of Permatex high temp RTV to the fuse and pressing the blanket in place. There is no heat transmitted to the fuse since I installed the blanket, cheap protection..

4 Intakes I have bee asked numerous times if the intakes are necessary, the answer is NO. While not required, I have had the opportunity to fly this plane both with and without them and can confirm that the intakes do improve the performance quite a bit. Without them there is substantial amount of buffeting within the airframe that you can physically see and feel in flight, not to mention the benefits of FOD protection. In addition, they are much more aesthetically pleasing.tams intakes are a simple two piece design, right and left halves are just trimmed and slid into place. To simplify service and access, I decided to make my intakes removable.

5 Using some aileron stock laminated with 1/16th ply, I made the mounting blocks to support the intake and give me something to screw them to. As you can see here, the blocks are glued to the bottom and sides of the fuse. The intakes are then screwed in place using small BVM flush mount screws. I also place a small bead of "Shoe Goo" to the bottom and side of the intake to bond the forward lip to the fuse. Should I need to remove the intakes I just score the "Goo" with a razor, remove the screws and they slide right out. In order for the intakes to be removable, the upper intake lip plate must be made removable as well. The intake lip plate is hollow, some support inside is required so the skin does not flex as the mounting screws are tightened. A simple solution to this was to drill three holes in the rear of the plate where I injected a puddle of Aeropoxy, enough to form a bead

6 between the top and bottom skin inside. Once the puddle set up, I drilled through the puddle into the fuse to accept 4-40 screws. I then counter sunk the screws by partially drilling into the aeropoxy puddle with a bit the same size as the screw head. Ply reinforcement plates were also fit to the fuse at the attachment points.

7 I have also made the intake "Splitter" removable. Here is what I did... I took some 1/4" balsa and cut it to the rough shape I wanted, I glued 1/4 x 3/8" spruce stick to the back edge. I then shaped the splitter to fit and made sure I left enough clearance to still remove the upper lip center screw. Once I had the splitter shaped I laminated both sides with 1/16th ply so the edge of the ply butted up against the intakes but the 1/4 spruce slid between the intakes. I then glassd the splitter and painted it. The splitter is held in place just like the intakes with BVM flush mount screws.

8 Gear Doors Nose gear door cylinder mounting took some thought. First, the cylinder needed to clear the nose gear. Second, I had to rig it in such a way that I could still have the intakes removable without having to detach the cylinder mount to remove the intakes. After about an hour of head scratching I finally came up with a mount that would work.

9 Just a quick shot here to help understand how I did the nose gear mount. As you can see it is just a simple plate contoured to the intake with a 4/40 bolt that holds the cylinder. To remove the intakes I just remove the nut and slide the cylinder off the bolt.

10 Nose gear in the retracted position... As you can see, the cylinder slips between the strut and the wheel, tight fit ;-)

11 Main gear doors are a fairly simple installation. Just cut the doors on the panel line and hinge with Sonic -Tronics offset hinges. The cylinders are mounted to a 4-40 bolt that passes through the forward engine former. Although I used some balsa to reinforce the gear doors, a better option would have been to reinforce all the gear door areas with carbon cloth before cutting them out, in addition to strengthening them it will also help them retain their shape. Pic Coming Soon! Canards During the early stages of playing with the euro, I managed to break (bend is more like it ) both canards. If I got too hard on my brakes one tended to grab better than the other during their break-in period. A slight tip to one side

12 caused impact of the canard to the ground, since they are hollow they snapped just outward of the torsion rod. An easy fix for this (during the build) would be to laminate a 1/32 ply plate (med CA works fine) to both the top and bottom (internally, use the canard as a template then trim back an additional 1/4" on all sides) of the canard before assembling the torsion shaft and outer rib. This sufficiently reinforces the canard structure so they don't snap should you tip the plane. I was concerned about the canard linkage arrangement, the torsion shaft is 6mm in diameter and instructions call for you to drill a 3mm hole through the shaft and insert a bolt to provide the torsion linkage to the servo. Having less than 1.5mm of material on each side of the bolt to support the torsion of the canard did not seem optimal so I designed a

13 new linkage system with custom machined control horns that clamp the shaft instead. This also allows for easy removal of the canards for transport / service, simply loosen the clamp bolt and the canard slides right off. In addition, I made support blocks with bearings installed to place the shaft load on the bearing instead of the canard tube. The process to build the canards as per the manual is a tedious one at best, here is a much simpler way to assemble them. Install the shaft into the sleeve through the "P" bearing block (seen above) and then slide on the wheel collar (spacer) and control horn (custom made ones), lightly clamp the control horn to the shaft. Slide the root rib onto the shaft holding it against the "Blister" and making it parallel with the side of the fuse while pulling the shaft outward. Using medium CA, tack glue the root rib to the shaft. Once the glue has set remove the shaft with root rib attached. Test fit the shaft/root rib into the canard, mark location where the shaft is located inside the canard on the outside with some masking tape. Balance the canard with lead shot in the very leading edge, drop in lead and tack with thin ca, slide root rib/shaft in place and check. Canard should be balanced on the shaft so, trailing edge should not drop. Once balanced, secure lead with a thinned coat of epoxy. Rough up the canard torsion shaft from the root rib outward with 80 grit. Ok...Now that you have everything prepped you can glue the canards on... Using Aeropoxy, place a generous bead inside the canard top and bottom where the shaft lays (follow masking tape you put on earlier). Also aeropoxy the shaft to the root rib. Slide the shaft into the plane, the slide the canard over the shaft and root rib aligning the canard to the fuse with 1/32 to 1/16 gap front to back. When you have the canard aligned on the shaft perfectly, pinch the canard tightly where the root rib is and gently slide the entire assembly out. Using thin CA tack glue the perimeter of the root rib to the canard.

14 When the glue has set reinstall the canard and double check the fit. When satisfied all is correct, place a small bead of Aeropoxy around the perimeter of the root rib and your done!

15 Here is the final install of the custom canard horns, P-Bearing blocks and linkage. The bearings used for this application were 6mm x 12mm Duratrax that should be available from you local hobby shop. The custom machined horns are now being sold at DreamWorks Model Products

16 Speed Brake I chose to install the speed brake mainly because I wanted easy access to my switches, charge leads, air fills etc... I thought this would be the best location for these items since it would allow me full access without having to remove the canopy. Not to mention the "Coolness" factor the speed brake adds ;-). My biggest concern was how I was going to actuate it since I needed to be able to open and close it manually when the system was powered off. After a bit of research, I found JetcatUSA sells a electronic valve made by JetTronic that vents all the air from the cylinder (not the tank!) when powered down, perfect! To cut out the brake the first thing I did was reinforce the area with carbon cloth. I then proceeded to cut the brake out with a xacto razor saw (backbone removed) using the panel line as a guide. At the pivot tabs I used tapered point dremel bit to score the glass then finished the cut with a #11 xacto blade.

17 Next, I built a box around the opening from 3/32 balsa and a hinge support and bloc from 3/32 ply. The hinge blocks were a bit of fiddley work, I had made three or fou tack gluing them in place to check for correct operation before finding the correct location of the hinge line. Hinge is simply two brass tubes, one inside the other wit small screw to lock side to side movement. Ply rings were made to support the hing on the SB tabs. I also made two formers to strengthen the SB door itself. ~NEW~ I built a Eurosport for a friend and made templates this time for the speed brake assembly. The following will assist you in building the hinge assembly and the corr location... The hinge base is 3/16" ply 6" long and 2" deep (taper ends to match fuse contour). T location of this plate should be 7/8" rear of point A (pic 1) (IE: rear edge of base is 7 back from point A). Hinge block is 2" wide x 1 1/2" deep x 3/16". Rear edge of the hi blocks should be even with rear edge of base. Center of hinge hole is 35mm from re of hinge block and 16mm from top. Location of hinge block on base should be aroun 1/4" from center of hinge base.

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20 When making the top former, you must pull the sides in very slightly so the SB will clear the fuse as it opens. Making the hinge blocks long enough to slot lock into the top former will make the entire assembly rigid. More head scratching when trying to find a good location for the UAT. I like to have a clear view of the header and I wanted a spot that would not require long fuel lines or removing the canopy. Then came this brain storm...rough up the bottle with 80 grit, clean with denatured alcohol and glued in place with a bit of Aeropoxy...

21 Final Shot of the Speed Brake with the floor installed. As you can see, I have access to all the my air fills, fueling, engine lights / data bus, switches and charge jack. I also installed air pressure gauges to monitor the gear and brake systems.

22 Easy-Air BVM Easy-Air system was added to the wings and fuse. This was the first time I have used this system and they work great! Slide the wing on and all my air lines are plugged in... PIC 1

23 PIC 2 Landing Gear Supports I am adding this section by request...although there was some considerable modifications made to the landing gear mounts on my ES, Composite-ARF has since made changes to these mounts in their newer kit to strengthen them. If you have the laminations shown in the picture below, you do not need to perform this step but you should still laminate the root rib with 1/32 ply as shown in pic 2 above. On the older kit (first half of 2003 and earlier) the main landing gear flex plate in the wings was not supported adequately. Upon a slightly harder than normal landing, the ribs that support the flex plate would split, allowing the flex plate and gear to impact the top wing skin usually ending with severe damage to the wing. To fix for this problem is to laminate the root rib and the secondary rib (next rib out towards the tip) with 1/8 or 3/32 ply. The red box in the picture outlines the root area you want to support with the ply stand-off, do the same support to inner support rib as well. I feel it is important to point out here that the landing gear mount is a flex plate and it is designed to flex, absorbing impact loads and is very effective. DO NOT attempt to support the flex plate from the LG mount area to the top skin, you will buckle the top skin on the first landing! Once you have the support

24 plates installed, laminate the root rib from wing tube to wing tube with 1/32 ply. This will strenghten the root rib adequatly. (See pic 2 above) It is also important to inspect all the glue joints on the wings and add some Aeropoxy to any joints that appear thin on glue. I also suggest you make it a routine to inspect the glue joints on the entire airframe periodically as we have found a few that were begining to fail.

25 The new version of the Composite-ARF Eurosport has some changes to the flex plate and ribs to help strengthen them. As you can see above, they have added ply laminations to the flex plate and support ribs at the factory. I will be helping a friend build a new version of the EuroSport and I will post here if we find any further modifications are still necessary. There has been multiple reports of Eurosports disintegrating in midair when they lost the large engine hatch in flight. It appears that when the hatch comes off, air gets into the openings in the wing roots, the added pressure explodes the wings. This happens very quickly, no time to reduce throttle! I believe both airplanes that lost the hatch did not have gear doors which allows for added pressure buildup in the engine bay. Since there are only two small tabs to secure the hatch, I suggest everyone make the following modification to ensure the engine hatch does not depart in flight.

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27 Make a 1/4" ply plate to fit in the wing root (skin to skin) at the opening just behind the rear spar. Drill a hole as seen in the picture and insert and glue a dowel.

28 Make a 1/4 ply 1.5"x 1.5" plate to fit in the hatch and glue at the appropriate location for the dowel to slide into. Take a bottle of testors paint, shake the bottle and then press the cap against the dowel end. Slide the wing on and press the dowel against the hatch to mark the pin location. Drill the hole 1 size larger than the dowel. As the wing slides on the spars, the pin will engage the hatch making it impossible for the hatch to depart in flight. I also suggest you cut some vent slots in the rear former inside the fake nozzles to allow excess air to escape the fuselage. Control Throws for Initial Flights The CG is located at 540mm behind the leading edge of the air intake, no need to shift.

29 Elevons: 45mm up & 30mm down, measured at the trailing edge root. Ailerons: 25mm both ways, measured at trailing edge root. Canard center position: Trailing edge parallel to panel lines on fuse. Initial throw is 15mm up & 10mm down measured at trailing edge root. Don't forget, trailing edge down is up elevator & up is down elevator. Rudder: 35mm measured at the bottom trailing edge % Expo on all control surfaces. Separate nose gear from rudder and keep nose gear on ch 4, low rate should only control nose gear steering as well as trim. You do not need a low rate rudder but you can mix it if you wish.