T-6A Texan II 75-91 ARF build suggestions
#351
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The brown toy truck arrived yesterday and delivered this plane... A bit about me: this is my 32nd plane. My preferences are warbirds and jets. I have a 140 size P40E, a 15lb Yellow Aircraft F/A-18C, and am building an ESM 30lb F7F tigercat. My two favorite planes are the E-Flite Habu 32 and the Hangar 9 P40B (which was recently discontinued...). Came across this one, and when I was trying to decide, I asked my wife: "if you found a $300+ pair of boots offered for $175, would you buy them?" She said "yes!", so I purchased this plane...
Now for the build. All of my planes are electric, and so will this be... I will be using an E-Flite Power 90, 8S 5000mAh (2x 4S) to drive it. Since it is 8S, the non-HV Castle Creations (I'm a loyal customer...) will do. I'm thinking of either an ICE 100 or an ICE 75 (or maybe even an ICE 80HV). Right now, it looks like the ICE 100 (it does an a BEC, although I might do something interesting there... Stay tuned...)
Just opened the box. It looks like full size servos. I'm thinking about the HS-485HB servos. Cheap and working well in other planes of mine...
Also, I will not be using the mechanical retracts. Right now thinking about either the E-Flite 25-46 or the 60-120. Franklyleaning towards the latter. Only if they will fit, so I will open the space now and check. They are only $15 more than the 25-46, but so much sturdier (with a 5mm wire instead of 4mm). I will be replacing the wire with struts, but maybe not immediately.
Any thoughts? Is there another thread for this plane I should be monitoring?
Now for the build. All of my planes are electric, and so will this be... I will be using an E-Flite Power 90, 8S 5000mAh (2x 4S) to drive it. Since it is 8S, the non-HV Castle Creations (I'm a loyal customer...) will do. I'm thinking of either an ICE 100 or an ICE 75 (or maybe even an ICE 80HV). Right now, it looks like the ICE 100 (it does an a BEC, although I might do something interesting there... Stay tuned...)
Just opened the box. It looks like full size servos. I'm thinking about the HS-485HB servos. Cheap and working well in other planes of mine...
Also, I will not be using the mechanical retracts. Right now thinking about either the E-Flite 25-46 or the 60-120. Franklyleaning towards the latter. Only if they will fit, so I will open the space now and check. They are only $15 more than the 25-46, but so much sturdier (with a 5mm wire instead of 4mm). I will be replacing the wire with struts, but maybe not immediately.
Any thoughts? Is there another thread for this plane I should be monitoring?
#352
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YSolomon,
It's been quite a while, but I'm curious how your Texan ii turned out? With all your experience I'm sure it's nice! I just finished mine after reading and re-reading this thread several times to times to pick up all the tips. I modified it with electric power similar to yours, LED's, electric retracts with functional oleos, and scale flaps with internal linkages on the both the inner and outer wing sections. All the little mods took a while but it's finally ready to maiden! Seems like most folks played it safe with the two blade props but I've chosen to go with a scale four-blade set up. I've got both a 16x8 and 15x10 from Zinger and a custom Al spinner from Tru-Turn. With the 4x15x10 it was pulling around 1600 watts at just about 60% throttle with plenty of headroom left on the Castle Ice 100. Didn't want to go any faster since the prop still needs some fine balancing, but after running at what I'm guessing will be "cruise power" for a few minutes in static air the motor and ESC were only slightly warm. It will get a lot more cooling in flight and I'm guessing it won't pull quite as much power either. With this set up I don't expect 100mph speeds like some in this thread, but I'm sure she'll climb like a bat out of.... well, you get the idea. Didn't do much with the cockpit since it's already so heavy with the four additional servos and battery tray. That stuff can come later. Anyway, I'd like to hear about your build if you're willing to post.
Any others with recent builds, maidens, flight experiences on the T6-A?
Cheers,
James
It's been quite a while, but I'm curious how your Texan ii turned out? With all your experience I'm sure it's nice! I just finished mine after reading and re-reading this thread several times to times to pick up all the tips. I modified it with electric power similar to yours, LED's, electric retracts with functional oleos, and scale flaps with internal linkages on the both the inner and outer wing sections. All the little mods took a while but it's finally ready to maiden! Seems like most folks played it safe with the two blade props but I've chosen to go with a scale four-blade set up. I've got both a 16x8 and 15x10 from Zinger and a custom Al spinner from Tru-Turn. With the 4x15x10 it was pulling around 1600 watts at just about 60% throttle with plenty of headroom left on the Castle Ice 100. Didn't want to go any faster since the prop still needs some fine balancing, but after running at what I'm guessing will be "cruise power" for a few minutes in static air the motor and ESC were only slightly warm. It will get a lot more cooling in flight and I'm guessing it won't pull quite as much power either. With this set up I don't expect 100mph speeds like some in this thread, but I'm sure she'll climb like a bat out of.... well, you get the idea. Didn't do much with the cockpit since it's already so heavy with the four additional servos and battery tray. That stuff can come later. Anyway, I'd like to hear about your build if you're willing to post.
Any others with recent builds, maidens, flight experiences on the T6-A?
Cheers,
James
Last edited by justbuyit; 12-01-2013 at 08:38 PM.
#353
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Well, I had a great time with mine. In fact, it was my best flying plane. The reason I went with a two bladed prop was because it is more efficient, and I wanted a speedy plane. That's why I went with the 15x14. On top of that--it had a GREAT sound! I averaged 6 minute flights on it. I started getting aggressive with the plane, and was pulling high speed flat figure eights, at no more than 30 feet above ground. It was a delight!!! You can see where I'm going with this, using past tense and all... It finally crashed... I was pulling a low level full throttle flat figure eight, and as I was rolling from a left turn into a right turn, she just kept on rolling and didn't stop until she hit the ground with full throttle. Man, even the pilots got busted... Since the gear was up at the time, the mains (with the brakes...) were undamaged. That's pretty much the only part of the plane that was undamaged... I still can't figure out what happened, but I'm guessing it was radio failure and the plane just kept on turning. I was very saddened by this crash, as I couldn't explain it, and couldn't see what I did wrong to prevent it from happening again! For a while, I lost my nerve of flying. But nothing like flying two of my jets (a 10lb fiberglassed L39 with a 4kW setup, and a Habu 32) to get me back flying. And then--I bought another T6A... So, sometime this winter I will probably build the second one... I suspect it was flying more than 100mph when it did. But again--my interest was in flying fast, rather than climbing fast...
#354
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Sorry to hear it. What radio system are you using? I watched a friends' Albatros meet the same end - all the controls just went to extreme positions. He sold his DX-8 the next day. I'm still using a DX-7 saving my pennies for Futaba. From what I've read the frequency of blackouts is far lower. Which retracts and brakes did you use?
I'm hoping to get the plane airborne this weekend for its maiden. Wish me luck.
James
I'm hoping to get the plane airborne this weekend for its maiden. Wish me luck.
James
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Had one other question for you... do you remember how much elevator throw you used? This plane is heavy and wing loading will be high so I want to be careful not to stall the wing with too much elevator. I did that on my Howard "Mr Mulligan" with expensive results.
#356
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I used E-Flite 60-120 retracts. Nose strut was robart, main struts were hobby king (the only 75mm long struts...). Brakes are Shulman aviation electro magnetic, powered by the same LiFe receiver battery. Elevator throws were as the manual described. Radio is DX18 with AR9020 receiver.
#357
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A pair of those EM brakes showed up in the classifieds so I'm thinking about picking them up. Did you control yours with a two position switch (I have only aux 2 on a DX-7)? Were they effective/worth it? Any concerns?
#358
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I controlled it with the right lever (RLVR) on the DX18. It is a proportional channel. Those brakes are "somewhat" proportional. By the way, there are cheaper brakes on Park RC Models, and on Hobbyking. I think they are the same make, but they require 12-40V to operate, and I'm not sure those are proportional. I liked the fact that I could use the same LiFe battery voltage to power these ones. This plane lands pretty "hot", it doesn't have flaps. I had perfect touchdowns, but it was still fast on the ground. I ALWAYS used the brakes as I was getting close to the end of the runway, and they worked great. I have no issue with them, and will use them on the second plane. I don't remember how to use the little up/down button left of the AUX2 switch. It might be better...
#359
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HK and Park RC seem like good options if you can power them from the flight battery instead of the rx battery. I may go this route since they're cheaper and I don't have an available proportional channel anyway. Just have to figure out a way to tap into the flight power.... Thanks for the good info!
#361
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Just pulled the trigger on the 2.75" pair from Park. I'm also using the 75mm oleo's from HK which has a 4mm axle so these should slide right in. I also bought a deans tap to pull power from the flight batteries (8S).
#362
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Finally took the Texan to the field today for it's maiden. Nice cold air with a slight breeze right down the center line, and only four other guys at the field. Perfect. (Even though they were flying much bigger and MUCH more expensive IMAC style planes all four of them eventually came over to take a look at Texan - it really shows well at the field.) After I loaded up the first pair of batteries I set the expos on the ailerons and elevator at 35%, checked the linkages and controls, ran down the runway to check and align the steering and rudder, and then set the timer. It powered up and lifted off in a very scale manner with the four-blade humming nicely. It climbed out and turned into the pattern very predictably, but I was surprised that I had to use around 60% throttle in level flight. Then on the downwind leg of the pattern my voltage alarm began beeping. I have it set for 3.7v and all eight cells were fully charged up to 4.2v so this is strange. I expect the voltage to drop with load but I wouldn't expect moderate throttle that it would drop to 3.7 that quickly. I babied the throttle and landed immediately. Pulled the batteries and they were both warm and out of balance. I also noted that the main wheels were slightly misaligned so I straightened them and tightened the set screws. I put the second pair of batteries in and got into the air again. Same thing happened, the alarm went off just after take off. This time I ignored the alarm and flew around the pattern 2-3 times to get the plane trimmed before I came back in. My second landing was horrible. I went long, let it stall before I touched down, and bounced hard. When it settled back down both main wheels shot off the oleos in opposite directions. The plane slid down the runway on the tips of the oleos, scratching them up but only cosmetically. It appears that the set screws on both mains gave way to the hard bounce and twisted badly - then they simply could not handle being dragged sideways so they came apart completely. (Good thing I have those new wheels on order!) I was very relieved to see my Zinger four-blade was unscathed, but as I was turning it to check the tips I realized that the that the motor was scraping badly. After taking the cowl off I could clearly see that at least one magnet had come loose and was scraping up against the back plate of the motor. That stinks, but how lucky was I that the motor didn't seize in the air?!? I've used a Hobby King NTM Prop Drive 50-50 in another plane with great results, but this 50-60 didn't last two flights! I had read about this problem even before I bought the motor, so I did bench test it before I put it on the plane and it seemed OK. Like I said - lucky I still have my plane! As for the flight characteristics I didn't have to much time to evaluate it today. I did keep the airspeed up like so many have warned to avoid stalls, but when it came time to land I can also say my flaps slowed it down nicely. My first approach was steep to make sure I maintained enough speed to avoid any hint of a tip stall. Just a quick flare and it settled very nicely. Second approach was shallower but faster because I carried throttle all the way up to the threshhold. Would have been better if I was a bit slower and more patient on the touch down - have to fly it all the way to the ground, can't let it float. With the few minutes of flight I did get to enjoy I can say this really is a great flying airframe. Can't wait to fix it and get it back up in the air!
The landing from my maiden flight in the first video and the entire second flight in the second video:
http://www.youtube.com/watch?v=Yp7_gWPNmB0
http://www.youtube.com/watch?v=ieCct...X0uNHXFNLX1ImQ
The landing from my maiden flight in the first video and the entire second flight in the second video:
http://www.youtube.com/watch?v=Yp7_gWPNmB0
http://www.youtube.com/watch?v=ieCct...X0uNHXFNLX1ImQ
Last edited by justbuyit; 12-09-2013 at 07:40 PM.
#365
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ysolomon, you might be interested to know there was a hand-written correction on the documentation that came with the wheel brakes I just received. The max input voltage of 40 was crossed out and replaced by a note: "3S-4S." (I've positioned my deans tap to pull power from just one of the two 4S flight batteries.)
On a different note, I swapped out the NTM motor for an e-flite Power110. Initially I'll fly with a few different two-blade props and use the CC data logger to verify that it's behaving like ecalc predicts, but this power system should have plenty of power to drive those electron hungry four-blades.
On a different note, I swapped out the NTM motor for an e-flite Power110. Initially I'll fly with a few different two-blade props and use the CC data logger to verify that it's behaving like ecalc predicts, but this power system should have plenty of power to drive those electron hungry four-blades.
#366
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Good to know. Thanks for letting me know. I was going to drive it off the 8S battery... I think what I will do is have a separate battery for it (I did it initially). I have a couple of small 3S 500mAh batteries... I am going to use a Hyperion motor I have (370kV rated at 2,000W) on 8S.
#368
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I'm not sure about that. The detail around this motor is different depending on where you look... There was some back and forth even on whether it is a 370kv or 314kv motor... I guess all I can do is check...
#370
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Judging from the fiberglass firewall that appears to be the larger ESM version of the Texan II rather than the Seagull Models version being discussed here. That said, I've seen video of that combo before and it's impressive! Cant beat the sound of a real turboprop!
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Add one more T-6A to the trash heap. Reading this thread was a tremendous help when assembling plane... Power 90 on 8s, APC 15x10e, CC Ice 100, CC BEC Pro at 6v, TM1000, AR8000, Eflite 60-120 retracts, Hitech 625/645 servos. Extending battery tray so that LIPO's were all the way back to servo tray yielded COG 3" back from LE at fuse (without adding any additional weight) and plane flew great... until the 2nd flight this morning. Sweeping left hand banked turn at ~85% throttle (CC log later showed 7600 RPM) started OK but then it rolled onto it's back and down it went, full power through a tree on the way to ground. There wasn't much left. Motor + LIPO's are shot, but other electronics tested OK after reassembling at home. This thread taught me to keep the speed up and not over-control this plane and I don't think this was a stall, but I'll probably never be sure. All control surfaces were ripped off and it's impossible to say if the aileron servos coming loose (Gorilla glue had been added to the mounts) or a broken elevator clevis caused this. One thing that puzzles me is this... every time I disconnect the LIPO's after a flight my DX8 alarm goes off because it has lost contact with the TM1000 telemetry. The LIPO's were ejected from the plane this morning when it crashed, but there was NO DX8 ALARM! Anyone have an idea why?
#373
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I've been looking at the pile of trash that used to be my T-6A and have come up with a theory. EVERY control surface (ail, rud, ele) is totally separated from the plane. The CA hinges are not torn, they simply pulled out. I have assembled several ARF's where the CA hinges were not pre-glued, use 8-12 drops of CA per hinge, and have never had a problem until now. When I look at the trailing wing edge where the ailerons attach, there is just a piece of ~3/16" plywood so, although there is ~1/2" of hinge material, most of the hinge is not making contact with anything. And I wonder how well the CA soaks into plywood... not very well I'm guessing. So my theory is that the right aileron partially pulled out during the high-speed left banked turn and, because it was still attached to the servo, that caused the right aileron to point down and stay down. I was able to stop the roll, but by that time the plane was inverted and I was totally confused. Maybe a better pilot could have reacted better and saved it. Anyway, that's my story and I'm sticking to it.
#374
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Did anyone had problems with one or both main retract locked and wont release when choosing to retract , busted one servos trying, any one with a solution would be appreciated .
Roltech
Roltech