1/4.5 T-38C Talon scratch build
05-15-2023, 10:43 AM
#302
Things are progressing. The conformal tanks have been pressure tested. There were a few pinholes, so those got filled by mixing up some E20HP hysol and using a gloved finger to press it into the leaking areas. Pressure test two is still needed.
The bypass mount and tailpipe installation was also finished up, that involved molding and laying up the pair of exhaust nozzles.
I also got the equipment mount plate for the nose designed and the test parts cuts. Lots of body work was also done as well a probly half a dozen or more other small tasks.
The bypass mount and tailpipe installation was also finished up, that involved molding and laying up the pair of exhaust nozzles.
I also got the equipment mount plate for the nose designed and the test parts cuts. Lots of body work was also done as well a probly half a dozen or more other small tasks.
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yeahbaby (05-15-2023)
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yeahbaby (05-15-2023)
05-24-2023, 07:01 PM
#309
Today was busy, yet productive. Six different colors and clear were applied and a BUNCH of masking.
Unfortunately the DIY waterslide decal paper i bought for my laser printer was junk. The lettering came off the paper before the paper was ready to come off the carrier. Because of that, the inlet emblems didnt get done, so i need to find someone to do make up those emblems.
Unfortunately the DIY waterslide decal paper i bought for my laser printer was junk. The lettering came off the paper before the paper was ready to come off the carrier. Because of that, the inlet emblems didnt get done, so i need to find someone to do make up those emblems.
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Viper1GJ (05-25-2023)
06-12-2023, 07:11 PM
#314
The fuselage systems are getting finalized and installed. The clear parts were also vacuum formed and are getting glued in.
the fuselage/tail weight is currently sitting at 28lbs 4oz. The only thing missing is some fuel fittings, turbine lipo, steering servo and the nose gear strut setup. Im expecting the finalized weight to be around 35lbs rtf dry, which is right in the original weight range target.
the fuselage/tail weight is currently sitting at 28lbs 4oz. The only thing missing is some fuel fittings, turbine lipo, steering servo and the nose gear strut setup. Im expecting the finalized weight to be around 35lbs rtf dry, which is right in the original weight range target.
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08-08-2023, 05:00 PM
#316
The landing gear parts arrived yesterday and i got them all cerakoted today and partially assembled. I have to go pickup some hardware tomorrow and i’ll have the gear finished.
Degrease soak in acetone
Degreased and degas bake at 300* for an hour
All masked and ready for cerakote
Fresh out of the oven after a 2 hour bake at 250*
Nose wheel assembled
Degrease soak in acetone
Degreased and degas bake at 300* for an hour
All masked and ready for cerakote
Fresh out of the oven after a 2 hour bake at 250*
Nose wheel assembled
08-09-2023, 04:42 PM
#318
T38 update. Landing gear is all assembled and installed in the airplane. I also layed up a third variation of the main gear strut doors… these should fit.
Couple unfortunate things….
First- The retracts worked fine with the manual controller, but once plugged into the Gs200 in the airplane… naddda, no retracts, no brakes and no nosewheel steering… but the gear doors all worked.
Im expecting the worse in that the controller is bad.
Second is that there is a decent amount of fuselage flex at the main engine hatch, so the spine piece i originally planned to incorporate but omitted bc of the tailpipe fiasco, will now have to be implemented.
Third- the springs for the main gear are a weee bit soft, but i already orderes stiffer replacements.
Fourth-it looks like around 4lbs of nose weight will be needed to balance it. Im not sad about this as that leaves me alot of weight to work with for the cockpits.
Total weight RTF minus fuel (including that ballast) is right at 45lbs
Unsupported fuselage gap
Supported fuselage gap
Couple unfortunate things….
First- The retracts worked fine with the manual controller, but once plugged into the Gs200 in the airplane… naddda, no retracts, no brakes and no nosewheel steering… but the gear doors all worked.
Im expecting the worse in that the controller is bad.
Second is that there is a decent amount of fuselage flex at the main engine hatch, so the spine piece i originally planned to incorporate but omitted bc of the tailpipe fiasco, will now have to be implemented.
Third- the springs for the main gear are a weee bit soft, but i already orderes stiffer replacements.
Fourth-it looks like around 4lbs of nose weight will be needed to balance it. Im not sad about this as that leaves me alot of weight to work with for the cockpits.
Total weight RTF minus fuel (including that ballast) is right at 45lbs
Unsupported fuselage gap
Supported fuselage gap
08-17-2023, 01:34 PM
#322
I got the main gear strut doors painted yesterday. That was the last of the painting. Today i got downstairs, got those installed, hooked up and adjusted. I also realizdd i needed to sand a clearance indentation into the main tire doors, just like the fullscale has, so they would close. After that was a few small tasks that i had forgotten about and getting the ballast mount cut and installed. I then got it balanced.
Final RTF with with 2lbs of ballast is 44.5lbs, that is with a CG position giving me a 10% static margin. The last task i need to do is fill it up with fuel and see how the cg reacts as it burns it off, i suspect it’ll be slightly tail heavy at takeoff and nose heavy at landing.
As for the EDF versions, i fully expect those to be 45lbs rtf with lipo’s and not need any ballast weight.
White base coat applied
Doors colored and cleared
Installing scale like band clamps to hold the brake wiring
More brake wiring
All done
Final RTF with with 2lbs of ballast is 44.5lbs, that is with a CG position giving me a 10% static margin. The last task i need to do is fill it up with fuel and see how the cg reacts as it burns it off, i suspect it’ll be slightly tail heavy at takeoff and nose heavy at landing.
As for the EDF versions, i fully expect those to be 45lbs rtf with lipo’s and not need any ballast weight.
White base coat applied
Doors colored and cleared
Installing scale like band clamps to hold the brake wiring
More brake wiring
All done
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Sparhawk (08-21-2023)
08-20-2023, 07:24 PM
#323
Today i got the maiden flight completed on my scratch built composite T-38C Talon. Lots of initial trimming and some nail biting first 20seconds of flight. For the first prototype, its doing fine and only has one small gremlin to work out (left main gear wouldnt retract fully). Admittedly, i yanked it off the ground a bit to early, but with only 600’ of runway, i knew the end was coming soon.
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