Maj. Woody's Fei Bao L-39
03-06-2008, 09:43 PM
#126
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RE: Maj. Woody's Fei Bao L-39
While it would be best to glue it in place, it would then be impossible to get at the servos , they are hidden inside the fuselage.
So I assume ( can we assume ...) that FB have given this modification rigorous flight testing to prove its structural integrity. Its a little outside the norm, as we can see , but it may be OK in service. I need Wagner to assure us that this mod wont fail in flight...he is about to land some ARF's with this new setup, and he tells me he will build one shortly, so I may just wait until we know its sound.
I think that with two bolts in the rear it should be OK ...I am not happy that with only one bolt, which creates a triangulated stress scenario that the one bolt mounting point wont become a point of failure in service. Two bolts makes for a considerably improved , (with four mounting points) distribution of the stresses.
The rudder is then bolted on top which adds to the support, but those attachment points are also subject to a lot of stress....maybe we are being just too cautious, but this is a major $$ investment in modelling terms and rudder / stab mounting failure is not something I want to contemplate.
So I assume ( can we assume ...) that FB have given this modification rigorous flight testing to prove its structural integrity. Its a little outside the norm, as we can see , but it may be OK in service. I need Wagner to assure us that this mod wont fail in flight...he is about to land some ARF's with this new setup, and he tells me he will build one shortly, so I may just wait until we know its sound.
I think that with two bolts in the rear it should be OK ...I am not happy that with only one bolt, which creates a triangulated stress scenario that the one bolt mounting point wont become a point of failure in service. Two bolts makes for a considerably improved , (with four mounting points) distribution of the stresses.
The rudder is then bolted on top which adds to the support, but those attachment points are also subject to a lot of stress....maybe we are being just too cautious, but this is a major $$ investment in modelling terms and rudder / stab mounting failure is not something I want to contemplate.
03-08-2008, 11:59 PM
#132
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RE: Maj. Woody's Fei Bao L-39
nice clean install, Dom....I'm taking it all in.... One thing, though....that puky green is sure hard on the eyes! I don't blame you for painting over most of it!!!!!
Any chance you could get a picture with a person next to the L-39 to get an idea of the size??
Any chance you could get a picture with a person next to the L-39 to get an idea of the size??
03-09-2008, 03:17 PM
#135
RE: Maj. Woody's Fei Bao L-39
I added my switches and fill valves to the front tray. The rear tray will house my fuel system, ECU, Receiver and light board. I fuel proofed the rear tray with thin CA before installing the fuel system components. Notice the fuel line routing and vertical fuel filter. I still have to determine the location of the batteries and the air tanks (3) but will first assemble the jet and see where the C.G. is so far.
Dom
Dom
03-11-2008, 06:14 PM
#136
RE: Maj. Woody's Fei Bao L-39
While preparing for the fuel tank installation I noticed that the fuel tank would hit the retracted main wheel tires before seating itself between the bulkheads. I cut a couple of plywood beams and glued them to the bulkheads effectively raising the tank so that it would clear the tires. I had to sand my paint away for a proper glue joint so I then went back and touched it all up. I took the main tank apart so that I could reassemble it my way. The stock setup had a zip tie on the clunk line and nothing to secure the line at the clunk end. The line just pulled off the brass indicating that the zip tie was not doing much. I used my own 5/32" brass tube with a barb soldered to the end. I then substituted the supplied line for genuine Tygon. Finally connecting things with safety wire. I repeated this for the Dubro 16 oz tank that will sit above the main tank. This will give me 90 oz total. Stay tuned for final tank installation pictures along with air tank installations photos. Two air tanks will sit under the main fuel tank positioned side to side.
Dom
Dom
03-12-2008, 01:53 PM
#137
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RE: Maj. Woody's Fei Bao L-39
Nice job!!! Dom!!!
Question - I posted to this thread when it was first started. I have been receiving email notifications every time another post was made, until 02/25. I have received any email notifications, about updates to this thread, since then. I have. however. been still getting email updates to other, older, threads, that I have subscribed to. None of my default settings have been changed.
Anyone know if there is a limit on how often you must reply to a thread before RCU stops sending me email updates?
Question - I posted to this thread when it was first started. I have been receiving email notifications every time another post was made, until 02/25. I have received any email notifications, about updates to this thread, since then. I have. however. been still getting email updates to other, older, threads, that I have subscribed to. None of my default settings have been changed.
Anyone know if there is a limit on how often you must reply to a thread before RCU stops sending me email updates?
03-13-2008, 04:02 PM
#138
RE: Maj. Woody's Fei Bao L-39
Here is my final fuel tank installation. The easy way out would have been to glue strips of wood in place to secure the tanks but removable fuel tanks are a must for me. I like to examine all areas of my jet during periodic maintenance. You can see that the rear of the Dubro tank is held in position with plywood strips and blocks. I had to remove the upper part of the bulkhead in that area in order to fit the tank. The front is also held in with a removable strip that also serves to keep the tank on center. The bottom tank is held in place with one ply strip that is strategically placed to keep the tank from moving forward or up. This keep the tanks in place and a bit of foam on the sides snugs things up even more. You can see the two air tanks that I have linked together with a Y connector. These are for the main gear and doors. I always fit a separate tank for brakes so I needed something small enough to fit under the equipment tray that my fuel system components are on. My UAT placement makes it impossible to fit the standard size tanks there so I got a little creative. I no longer use on board propane so I have a bunch of starter gas tanks lying around. In order to use these for brake tanks I tapped the end for a 3mm nipple then used locktite and goop on the connection. The set up is leak free. I will also connect these with a Y connector and place them under the fuel system equipment tray.
03-19-2008, 09:09 PM
#141
RE: Maj. Woody's Fei Bao L-39
Well my shop remodel is complete and I have resumed building. I made a plywood tray and glued it between the nose gear bulkheads. This is to hold my ECU battery. The battery will be held in place with Velcro and a tie wrap. Note the notches in the tray. This is to keep the tie wrap from sliding around. Next I decided to beef up the nose gear plates. The existing wood is quite hard and is up to the job but I tend to over build things......you never know when you may run off the runway into grass for example. I cut two doublers out of 3/32 aircraft ply and epoxied them to the underside of the existing mount. Finally I installed the nose gear with 6/32 blind nuts and bolts.
Dom
Dom
03-19-2008, 09:34 PM
#142
RE: Maj. Woody's Fei Bao L-39
Rich,
I should be flying this bird soon. I would imaging the weather will be good enough in the next few weeks. I need some video of the flights. Can you take some for me? I have a Sony Handycam if you need a recorder.
Titusville here I come!!
Dom
I should be flying this bird soon. I would imaging the weather will be good enough in the next few weeks. I need some video of the flights. Can you take some for me? I have a Sony Handycam if you need a recorder.
Titusville here I come!!
Dom
03-21-2008, 04:38 PM
#145
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RE: Maj. Woody's Fei Bao L-39
Dom.. I flew mine yesterday, no flutter this time - thanks for the help.
the Elevator is so sensitive !! not too much throw there. and have 30% expo.
any idea why, and do you think moving the CG forward would help.
thanks in advance
the Elevator is so sensitive !! not too much throw there. and have 30% expo.
any idea why, and do you think moving the CG forward would help.
thanks in advance
03-21-2008, 04:59 PM
#146
RE: Maj. Woody's Fei Bao L-39
Congratulations on your flight!!
If your on the tail heavy side your elevator will be sensitive. Where do you have the jet balanced? I will balance mine dead level on the front spar. I should finish and balance mine this weekend. I'll include photos.
Dom
If your on the tail heavy side your elevator will be sensitive. Where do you have the jet balanced? I will balance mine dead level on the front spar. I should finish and balance mine this weekend. I'll include photos.
Dom
03-22-2008, 08:30 PM
#147
RE: Maj. Woody's Fei Bao L-39
I installed my RX packs just behind the Nose Gear Bulkhead with zip ties. I needed to add a couple strips of wood to accommodate the tie wraps. I also used Velcro to prevent any sliding. Next I prepared the nose gear by disassembling, lubing the cylinder and using locktite all screws. Be sure to file flats on all three set screw locations on the strut. I always make a tangle proof system for my pull pull wires on the steering arm. They are made from EZ Connectors that I file a taper on and then solder the backplate in place. If the wires attempt to tangle as the gear retracts, the swivel action of the EZ Connector simply rotates and prevents the tangle. None of the sideways cocked gear that gets hung up with my system.
Dom
Dom
03-22-2008, 08:40 PM
#149
RE: Maj. Woody's Fei Bao L-39
The ECU battery is mounted on the tray I built between the nose gear bulkheads with velcro and tie wraps. Here are the final equipment installation photos. My jet is complete!! It weighs 21 lbs even. It also balanced on the center of the front spar with no weight needed in the nose. My equipment layout resulted in a perfectly level balance at the recommended C.G.
Cycling the gear was a beautiful sight. Watching those doors sequence was just awesome. The UP-2 works great for this. I fired up the P-70 to test the fuel system and all is well............everything functioned perfect. I just have a few minor things to take care of like leak testing the gear, adding my pre-flight checklist and adding my name to the canopy and she will be ready to fly. I hope the weather warms up a bit. I'll try to get some video of the flight. I am very excited to fly this jet!!
Dom
Cycling the gear was a beautiful sight. Watching those doors sequence was just awesome. The UP-2 works great for this. I fired up the P-70 to test the fuel system and all is well............everything functioned perfect. I just have a few minor things to take care of like leak testing the gear, adding my pre-flight checklist and adding my name to the canopy and she will be ready to fly. I hope the weather warms up a bit. I'll try to get some video of the flight. I am very excited to fly this jet!!
Dom
03-22-2008, 08:53 PM
#150
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RE: Maj. Woody's Fei Bao L-39
nice clean installation Daom!.... got that picture of her all assembled??
Any chance you could get a picture with a person next to the L-39 to get an idea of the size??