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Old Oct 16, 2012, 11:16 PM
Capt. Z
falcon5's Avatar
Tonopah, Nevada
Joined Dec 2004
2,505 Posts
Sounds good ace..a dog fight it is

I may do a thread on the Eurofighter build. I hope to begin construction in a few weeks.

Just want to thank everyone once again for the great time l had on the T-38 build, you all made it so it was like a family building the planes and not just two guys. I will never forget it

Thanks

Andy
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Old Oct 16, 2012, 11:20 PM
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LuvEvolution7's Avatar
St.Catharines, Ontario
Joined Jan 2009
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what's this word "may". come on now, don't be bashful. LOL.
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Old Oct 17, 2012, 08:08 AM
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Crystal River Fl.
Joined Jul 2008
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Cool idea Andy! Yes you NEED to do a build thread! w
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Old Oct 19, 2012, 07:54 PM
DELTAS RULE
corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
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ok, so post mortem on the power system. i knew the turnigy esc was way past smoked, but i wasnt sure about the motors. i hooked them up to the good cc 120, and to my great suprise, both motors ran fine! i ran them on 5s, just to see if they worked. but, i noticed that the fan with the burnt esc ran at a much higher rpm than the other. then i looked inside the motors. the one that turns more rpm has a differnt color windings. not burnt per say, but a differnt color wire. my guess would be that its got a much higher kv, and was improperly marked. that motor looked like some of the resin sealer on the wires, was slightly darkened, like it was getting close to buring the windings. its very possible that its a 1500kv rather than a 1200kv. which would explain why the esc burnt, because the amps would have been sky high. also, might be why i was getting more mah reacharging into one of the sets of packs than the other. pays to do amp check before flying i guess...i would have discovered that before i left my house. lesson learned.

looks like up to a 120mm fans will fit. still lots of considering to do on future power plants.
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Old Oct 19, 2012, 07:57 PM
Capt. Z
falcon5's Avatar
Tonopah, Nevada
Joined Dec 2004
2,505 Posts
Good NTSB investigation wingman..yeah a 1500KV motor would be wicked high on the amps.
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Old Oct 19, 2012, 08:54 PM
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USA, NC, Greensboro
Joined Mar 2002
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Quote:
Originally Posted by falcon5 View Post
Sounds good ace..a dog fight it is

I may do a thread on the Eurofighter build. I hope to begin construction in a few weeks.

Just want to thank everyone once again for the great time l had on the T-38 build, you all made it so it was like a family building the planes and not just two guys. I will never forget it

Thanks

Andy
Andy, I know I sure felt like I was there with you guys the whole way. It was a long road but I know I enjoyed it. I would be dissapointed on days that there was no action on the thread. I hope you do a build thread on the Euro that would be awesome. I am sure we are all waiting for your next build. I know I am.
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Old Oct 19, 2012, 09:00 PM
DELTAS RULE
corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
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you know ive heard of het motors with wrong kv's before. hoped id get lucky i guess. go back and watch the video again. listen to it as it taxis out. you can hear a noticable mismatch in rpm. if its the 1400 or 1500 kv i bet the amps were over 130
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Old Oct 19, 2012, 09:06 PM
DELTAS RULE
corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
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i also remember that after my flight one set of packs had used over 10% more than the other set. if that would have been a full flight i bet it would have been up to a 20% differance.... that equates to a 20~25a differance in power systems...so assuming the low kv side was pulling 105-110a or so i could have been pulling up to 135a on a 120 controller. probably would have been ok if i didnt need to fly wot the whole time
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Old Oct 19, 2012, 09:35 PM
deltas are cool
AIR SALLY's Avatar
Tehachapi ,CA.
Joined Apr 2006
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we need to invest in a clamp on meter...yeah a few more days to prep and test would have been nice .i have a 1200 motor ..so i better ck it too.
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Old Oct 19, 2012, 09:42 PM
DELTAS RULE
corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
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also, after looking at the damage, i think the best/easiest way to go here is to use some thinned epoxy injected into the cracks, then reinforce the areas on the inside with carbon fiber glass and resin. on the fwd fuse, i might just strip off the glass on the nose in front of the canopy and re glass the whole nose section, as i had some unsightly bubles in the glass on top. also, while im having to do all this body work, i might respray most of the fuse, sand out all the runs, and do a much nicer job, and perhaps re spray the half of the wing that was damaged. also, im going to add a battery hatch for sure. not only will that make flying the model WAY easier, it will also be much safer. in its current configuration, its got nice clean undisturbed lines on the turtle deck, but if theres ever a incident like there was on my first maiden attempt, i had to remove the wing to get to the batteries. thats just not safe, on top of that, it could very well have burnt to the ground because i couldnt get the packs disconnected in time. so ill most likely end up with a hatch just like andy's.

on power systems, im thinking twin turbax's would give a solid 32lbs of thrust, using the nose gear opening and ine rmain gear openings as aux air inlets, and not using sealed ducts. 2 turbax's will fit, and on 8000 mah packs, put out jus tunder 6kw a piece, and 18 lbs of thrust in a test stand. i think the model would have great power, and probably have enough to pull off some nice sized loops. i could also run 4" tail pipes which would fill in the tail cones nicely. i dont like not having full ducting, but i dont see any way around it using those pretty, scale inlets. you just cant cheat a 38 inlet, and still look good. im a advocat for full ducting, but sometimes, you just cant do it. this might be one of those times. ill be sad to see those opeings on the bottom with no doors in flight, but it would reduce comlexity of the model as well, because i would have to woryy about gear doors. or, i could keep the gear doors, and do old school jhh style aux inlets with swept up ramps on the bottom side. that might work too, and look less invasive from the ground while its flying. and i know that the turbax 12s setup is extremely proven, having used it myself in my jhh cougar. i know its great at thrust. and i bet two of them with no ducting would sound pretty awesome, and it would be loud enough i could hear it over the turbines at events

on another side note, while i work on getting new power plants, i started a little side project, a 43" long, FJ1 fury plug, i plan to do it reverse style like gramps does, to keep build time low. its a 46" wingspan, and will use a 70mm fan with scale inlet and tail pipe. ive also got 2 other projects for friends i really need to finish before i dig back into the 38. but im already in the planning stage, and i think the outcome will be a much improved model. we already know the airframe/cg/flight controls are proven, and we know its super stable, and has a very light wing laoding for its size, it just needs reliable horse power. i think the 5" fans will take me there, without adding hardly any weight.

ps....i need to try switching my retract lines on the retract valve, i think i may have the up hose on the down spot, and the down hose on the up spot. this would explain why my gear slam down like crazy but hardly go up at all..even though with just a hand pump they go up at only about 50psi. i think andy went through this same issue.
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Old Oct 19, 2012, 11:32 PM
deltas are cool
AIR SALLY's Avatar
Tehachapi ,CA.
Joined Apr 2006
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sounds like a good plan of attack.it deffently need 30lbs of thrust.might gain a pound or two with fan swap/repairs. there might be a bit of weight that could be removed here and there.
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Old Oct 19, 2012, 11:40 PM
DELTAS RULE
corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
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with the 8000 packs, it might have more like 32-33lbs installed....man, it would be a rocket! i figure those poor 90's were only making MAYBE 21-22 lbs of thrust. thats 6-7lbs less than andys, and 10-11 lbs less than turbaxs could make, that would be a 50% increse over the 90's and man, you could probably power way back for cruising, and get damn good flight times i think.
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Old Oct 20, 2012, 12:20 AM
Capt. Z
falcon5's Avatar
Tonopah, Nevada
Joined Dec 2004
2,505 Posts
Man now your getting me all fired up to get mine back in the air

Thanks Reco..It sure was a fun build thread. I recon it aint over yet
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Old Oct 20, 2012, 03:10 PM
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Los Angeles, Ca.
Joined Jun 2010
296 Posts
Fj1...

Quote:
Originally Posted by corsair nut View Post
on another side note, while i work on getting new power plants, i started a little side project, a 43" long, FJ1 fury plug, i plan to do it reverse style like gramps does, to keep build time low. its a 46" wingspan, and will use a 70mm fan with scale inlet and tail pipe.
Greetings Brent,

First let me say how great it was to meet you and all the other "experten" in Vegas. I was both greatly impressed and inspired to keep building ambitious projects! I like your take on rebuilding your T-38 with the upgrades.
You definitely have gotten my interest with the mention of the FJ-1 Fury. Do you mean the straight wing Fury? That one has been on my "future build" list and keeps getting nudged closer to the top. I've been knocking around how I would want to do one and after seeing Andy's fantastic Thunderbird T-33 my thinking has been leaning towards starting with the Lander T-33 and doing a massive conversion. His particular combination of power to weight with that size airframe seems perfect to me. However, if you are working on a smaller straight wing Fury, I'm definitely interested in that possibility as well. What do you see the AUW being? How would you approach the wing? I have ideas on that as well.

Before I ask anymore questions, I'll wait to see if your planning the one I'm jonesing to do!

Again, great to meet you and I'll keep looking out for your various projects.

Cheers,

Scott, aka Sperling
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Old Oct 20, 2012, 03:26 PM
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corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
20,859 Posts
it was great to meet you too, and i loved your sweet modded birds!!!!

yeah, the straight wing fury, ive always wanted to build one. this one is a nice size, but not big. 46" wingspan without tip tanks. im doing a glass fuse, so i could probably make you one for the cost of materials. im going to make my own canopy, and do foam cores for wings, balsa sheeted, and 3/4oz cloth. solid 1/4" balsa stabs. im making the wings thick enough to use cheap hk retracts. power will be 70mm fan in the 850-1200W range. such a cool bird, and ive only seen it modeled 2 times in my entire life! the most recent ive seen was a 40mm edf version, and it looks cool! reparts are that it flies great, and why shouldnt it, its a jet powered P-51 basically. super wide gear track will make for a great ground handler should be able to keep it around 5 lbs, and at that weight, the wing loading will be awesome.

heres a couple shots of my modded T-33, inlets and tail pipe area.
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Last edited by corsair nut; Oct 20, 2012 at 04:08 PM.
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