Bird Of Time
08-26-2011, 04:12 AM
#2
RE: Bird Of Time
Are you building or fixing an ARF/RTF? I've got my original plans, could copy off a set for you.
Dave
Dave
08-27-2011, 05:06 AM
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RE: Bird Of Time
Dave,
No. I had a crash and lost the fuselage and hor stab and fin. Wings are okay. It was difficult for me to fly the Bird. I'm above a beginner but not a top sailplane pilot. I intend to try again. I noticed E Bay has a Bird up for bid. the bid is up to $57.00. I can't understand how anyone would bid that high on a used kit when a new kit from Tower is $70.00.
Mike
No. I had a crash and lost the fuselage and hor stab and fin. Wings are okay. It was difficult for me to fly the Bird. I'm above a beginner but not a top sailplane pilot. I intend to try again. I noticed E Bay has a Bird up for bid. the bid is up to $57.00. I can't understand how anyone would bid that high on a used kit when a new kit from Tower is $70.00.
Mike
08-28-2011, 04:57 AM
#4
RE: Bird Of Time
Dave,
No. I had a crash and lost the fuselage and hor stab and fin. Wings are okay. It was difficult for me to fly the Bird. I'm above a beginner but not a top sailplane pilot. I intend to try again. I noticed E Bay has a Bird up for bid. the bid is up to $57.00. I can't understand how anyone would bid that high on a used kit when a new kit from Tower is $70.00.
Mike
Hey Mike! Yeah, understood about the bid, but that's how e-bay seems to work these days. If you want, I can copy off my plans and send them to you - including the fuse.
I've heard about the BoT since I first started flying RC (many decades ago) and finally got my own just last year - from Tower. It's the first sailplane I ever put spoilers on and I made them too big (5 wing bays, only 3 needed really) but that wasn't the real issue with the plane. My problems were not enough elevator (down) and not nearly enough rudder for turning - she just isn't responsive enough for me. I increased the elevator travel to twice the plans' recommendations and increased the size of the rudder by 50%. That helped a lot, but if I ever build another I'm going to completely redesign the vert stab/rudder to more of a "full flying" type - like the old Aquila had. On that plane (best sailplane I've ever flown, by the way) the vert stab went just a bit higher than the elevators (also were full-flying) and the rudder finished out the lines. To do the same thing on the BoT I'd have to simply cut a horizontal line above the elevator, make the trailing edge of the fuse/stab vertical instead of the slant she's got, and connect the rudder to the rest of the vert stab, making it all one piece. That added bit of movable rudder would be all she'd need to turn a lot more responsively.
I'd also think about ailerons on the next one.
Anyway, let me know and I can start copying.
Dave
(pics - me and the BoT)
No. I had a crash and lost the fuselage and hor stab and fin. Wings are okay. It was difficult for me to fly the Bird. I'm above a beginner but not a top sailplane pilot. I intend to try again. I noticed E Bay has a Bird up for bid. the bid is up to $57.00. I can't understand how anyone would bid that high on a used kit when a new kit from Tower is $70.00.
Mike
Hey Mike! Yeah, understood about the bid, but that's how e-bay seems to work these days. If you want, I can copy off my plans and send them to you - including the fuse.
I've heard about the BoT since I first started flying RC (many decades ago) and finally got my own just last year - from Tower. It's the first sailplane I ever put spoilers on and I made them too big (5 wing bays, only 3 needed really) but that wasn't the real issue with the plane. My problems were not enough elevator (down) and not nearly enough rudder for turning - she just isn't responsive enough for me. I increased the elevator travel to twice the plans' recommendations and increased the size of the rudder by 50%. That helped a lot, but if I ever build another I'm going to completely redesign the vert stab/rudder to more of a "full flying" type - like the old Aquila had. On that plane (best sailplane I've ever flown, by the way) the vert stab went just a bit higher than the elevators (also were full-flying) and the rudder finished out the lines. To do the same thing on the BoT I'd have to simply cut a horizontal line above the elevator, make the trailing edge of the fuse/stab vertical instead of the slant she's got, and connect the rudder to the rest of the vert stab, making it all one piece. That added bit of movable rudder would be all she'd need to turn a lot more responsively.
I'd also think about ailerons on the next one.
Anyway, let me know and I can start copying.
Dave
(pics - me and the BoT)
08-28-2011, 05:01 AM
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RE: Bird Of Time
ORIGINAL: mdiesu
Dave,
No. I had a crash and lost the fuselage and hor stab and fin. Wings are okay. It was difficult for me to fly the Bird. I'm above a beginner but not a top sailplane pilot. I intend to try again. I noticed E Bay has a Bird up for bid. the bid is up to $57.00. I can't understand how anyone would bid that high on a used kit when a new kit from Tower is $70.00.
Mike
Dave,
No. I had a crash and lost the fuselage and hor stab and fin. Wings are okay. It was difficult for me to fly the Bird. I'm above a beginner but not a top sailplane pilot. I intend to try again. I noticed E Bay has a Bird up for bid. the bid is up to $57.00. I can't understand how anyone would bid that high on a used kit when a new kit from Tower is $70.00.
Mike
08-28-2011, 05:02 AM
#6
RE: Bird Of Time
Oops! Wrong first pic. That's my Spirit-100.
Here's the Bot &Spirit, together - along with my old Aquila (shows the flying rudder decently well but not great).
Here's the Bot &Spirit, together - along with my old Aquila (shows the flying rudder decently well but not great).
08-28-2011, 06:58 AM
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RE: Bird Of Time
Dave,
Thanks for the reply. I do have plans from my first BOT. You mentioned fuse, do you have a fuse or were you making reference to the plans. I do have the original wings and maybe I will attempt to scratch build the fuse, stab and fin. I also had trouble getting enough lift from the elevator. You mention airlerons. Tell me what you did.
Mike
Thanks for the reply. I do have plans from my first BOT. You mentioned fuse, do you have a fuse or were you making reference to the plans. I do have the original wings and maybe I will attempt to scratch build the fuse, stab and fin. I also had trouble getting enough lift from the elevator. You mention airlerons. Tell me what you did.
Mike
08-29-2011, 03:21 AM
#8
RE: Bird Of Time
ORIGINAL: mdiesu
Dave,
Thanks for the reply. I do have plans from my first BOT. You mentioned fuse, do you have a fuse or were you making reference to the plans. I do have the original wings and maybe I will attempt to scratch build the fuse, stab and fin. I also had trouble getting enough lift from the elevator. You mention airlerons. Tell me what you did.
Mike
Dave,
Thanks for the reply. I do have plans from my first BOT. You mentioned fuse, do you have a fuse or were you making reference to the plans. I do have the original wings and maybe I will attempt to scratch build the fuse, stab and fin. I also had trouble getting enough lift from the elevator. You mention airlerons. Tell me what you did.
Mike
Elevator - increasing the elevator travel isn't hard, but it's just a tiny bit touchy to cut-out on the "down" side - on the vertical stabilizer itself.
However, starting with the hardware set-up, all you have to do is move the control rod from the elevator servo to the "L" belcrank in one hole. The original plans (page 14, steps 1-4, especially 3) call for both rods to be connected to the outside of 3 holes (#3 hole & "c" hole in pic below), thus only giving the elevator about 1/2" of travel total. All you do is move the servo-to-belcrank rod from #3 to #2. That nearly doubles the elevator movement.
Now, the "touchy" part of it - cutting the wood on the vertical stabilizer to let the elevator front-rod move more. The bottom of the slot is easy because you're in "skin" wood only - you just make it longer to allow full elevator "up/climb" movement. The top of the slot (elevator "down/dive") is the hard part because you're cutting into the leading edge spar to make that part of the slot longer. To keep from weakening (or cutting totally through) the leading edge spar I epoxied another 1/4" strip of basswood to the front of the spar, thus actually increasing the chord of the vertical stabilizer by 1/4". When I actually cut the top of the slot, the additional cut DID touch the new leading edge, but just barely, so it was a good thing I added the basswood.
The reason I did all this was because of a launch problem that I had originally, on the first few flights. Everything was cut/placed absolutely according to plans (page 13, step 10 especially) but when launching with my high-start, the bird kept climbing back and snapping the launch ring off the tow-hook - no amount of "down" elevator could prevent it. If I moved the tow-hook forward one hole she couldn't climb to the top of the launch, not enough "up" elevator. The 4 two-hook blind-nuts are right next to each other - you can't insert another between them - so I had to look elsewhere to end the launch problems. Only fix I could think of was to increase the elevator travel.
At the same time, I removed the original rudder and built a new one 50% thicker, front-to-back. This helped a lot in turning but I'm still not totally happy with it. Still thinking about ailerons to help in that department, but like I said before - if I build another BoT it would be with the full-flying rudder too.
Ailerons - I haven't done it yet but I've seen it done on u-tube and it apparently works pretty well. Most especially, the one that impresses me the most is a guy down in Brazil (I think, might be Bolivia) that has a BoT with electric motor - he flies way up in the mountains and has lots of videos of his BoT (on-board camera) threading its way through the mountains. He mounted ailerons and they look to be about 3 rib-bays wide, not including the solid wingtips.
Building the ailerons would be easy. All you do is cut off the trailing edge of the outside 3 bays, cut 1/4" from the rear of the ribs and add a 1'4" strip of hard balsa to remount the trailing edge with your hinges. Voila! Ailerons. I'd think a pair of mini-servos would be more than enough to control them. Will probably do just exactly that this winter.
My turning issues are that the rudder simply isn't enough to make that 118" wing move like I want, and there'd probably be the added problem of aileron-drag and adverse yaw - already got enough of that. Best fix I see is to off-set the amount of travel of the ailerons (there's a term but I can't think of it right now) so they go "up" more than "down", thus decreasing lift on one wing more than increasing lift on the other. It's the increasing of lift that increases drag (and adverse yaw), as I understand it.
The last issue I had when building the BoT wasn't even related to the BoT. Every glider/sailplane I've ever built broke the launch hook repeatedly on landings. Seems I have this penchant for finding the only rock in a field when I put the plane down and I keep breaking hooks. To prevent this on the BoT I simply added a bit of a "chin" to the bottom of the nose - just enough to make sure the hook doesn't touch the ground on landings, and it works pretty well. Also made the tail skid wire longer to help clear the rudder more from the ground. This was all decided before I ever glued the first piece of wood together.
BTW, I used Dubro quick-links for the servo-to-belcrank - screw those "Z"-bends. Not that it matters, but I HATE "z"-bends. Actually, I used quick-links everywhere.
Got 3 pics below. First is a graphic showing how I did my elevator, 2nd is the area I'd add ailerons to, 3rd shows the chin pretty well.
Dave
08-29-2011, 07:46 AM
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RE: Bird Of Time
Dave,
Thanks for all the info. When I built my orginal BoT the installation and operation of the stab/elevator gave me nothing but construction and flying problems. This eventually lead to my crashing. Question, what do you think if I would install the stab permanitly to the fin and a push rod to control the elevator? I feel the ailerons are a must and intend to install them. I will have to read you infor agaiin. Also, I power my sailplanes with electric motors. I would like to reach this fellow in Brazil and chat with him. My question is the size and make of the motor he uses.
Mike
Thanks for all the info. When I built my orginal BoT the installation and operation of the stab/elevator gave me nothing but construction and flying problems. This eventually lead to my crashing. Question, what do you think if I would install the stab permanitly to the fin and a push rod to control the elevator? I feel the ailerons are a must and intend to install them. I will have to read you infor agaiin. Also, I power my sailplanes with electric motors. I would like to reach this fellow in Brazil and chat with him. My question is the size and make of the motor he uses.
Mike
08-30-2011, 03:38 AM
#10
RE: Bird Of Time
ORIGINAL: mdiesu
Dave,
Thanks for all the info. When I built my orginal BoT the installation and operation of the stab/elevator gave me nothing but construction and flying problems. This eventually lead to my crashing. Question, what do you think if I would install the stab permanitly to the fin and a push rod to control the elevator? I feel the ailerons are a must and intend to install them. I will have to read you infor agaiin. Also, I power my sailplanes with electric motors. I would like to reach this fellow in Brazil and chat with him. My question is the size and make of the motor he uses.
Mike
Dave,
Thanks for all the info. When I built my orginal BoT the installation and operation of the stab/elevator gave me nothing but construction and flying problems. This eventually lead to my crashing. Question, what do you think if I would install the stab permanitly to the fin and a push rod to control the elevator? I feel the ailerons are a must and intend to install them. I will have to read you infor agaiin. Also, I power my sailplanes with electric motors. I would like to reach this fellow in Brazil and chat with him. My question is the size and make of the motor he uses.
Mike
Naw, I'd definitely keep the stab/elevator as designed. Just gotta get it to work right.
As I stir the gray crap in my noggin I remember another thing I spent a lot of hours thinking about as I was re-doing the horizontal stab - the placement of the drill holes as shown on the plans. That hardwood block that the stab anchors onto - I drilled it in the exact center as the plans show. IF you were to drill it back about 1/4" and lower about 1/4" (also moving the belcrank hole the same amount and direction, back and down) the interferrence problems with the vertical stab leading edge would go away. You'd also have to carve out a bit of that solid vert stab interior but you could increase the throws without re-building that leading edge. Just a thought.
Hey! Found several BoT videos you might be interested in. First is from a guy in Wyoming, shows his electric BoT flying and gives an awful lot of info on how it's powered. This particular one is the best of the bunch for how it was done. Here it is: http://www.youtube.com/watch?v=L8uwc_Z9kmw&feature=related
Also found one of the South American videos - was from Chile. http://www.youtube.com/watch?v=HvmI5v9a-7g
Several others showing BoT's - one's as a slope soarer and you can see what the ailerons do for performance. It's first: http://www.youtube.com/watch?v=KswkuUhZER0
Electric BoTover Arizona - not half-bad music too: http://www.youtube.com/watch?v=Edh1poKpvu0
There are a whole lot more videos out there that I haven't included here. You could watch u-tube with BoT's exclusively until you retired and not see them all. There are also an awful lot of BoT forums right here with some GREAT info on them (many/most of which I'm subscribed to). The Big Wing Build-along is one of the great ones; http://www.rcuniverse.com/forum/m_9347511/anchors_9347511/mpage_1/key_/anchor/tm.htm#9347511 even though the original point of the thread is another, much larger, sailplane. Definitely worth going through.
Good discussion of building a BoT for electric; http://www.rcuniverse.com/forum/m_10397114/anchors_10397114/mpage_1/key_/anchor/tm.htm#10397114
Another BoT with flying problems. Goes a lot into "how to do it"; http://www.rcuniverse.com/forum/m_9674275/anchors_9674275/mpage_1/key_/anchor/tm.htm#9674275
One of the more "entertaining" BoT threads, includes pics about 2/3 down the first page of a "Super-BoT". This plane's BIG!http://www.rcuniverse.com/forum/m_4715082/anchors_4715082/mpage_1/key_/anchor/tm.htm#4715082
Anyway, there's a lot out there, info-wise. Amazing what you can learn via u-tube and right here on RCU.
BTW, early-on you mentioned that "It was difficult for me to fly the Bird. I'm above a beginner but not a top sailplane pilot. I intend to try again." You're definitely not alone!! Note my signature here. I've been flying since I was 7, RC since the early 70's, and I don't consider myself anything more than "able to do it - most of the time". My technical expertise is minimal, at best. I like to build them - sometimes incorporating my own ideas into it, love to fly them, and don't mind repairing them, but to ever think about designing one myself - I know about 1% enough to do it. That's why I clued you into some of these other threads. Some of the guys out there have already forgotten more than I've ever heard of, let alone what I might be able to learn about it. I can show what's worked for me, but it's not necessarily right and it's definitely not all there is.
Should have brought this up before - don't know why I didn't - - why not just start with a new kit and go from there instead of scratching from plans? IMHO, in the long run it would be cheaper, you'd get a better bird and you could incorporate the mods right from the building board. You'd also have the advantage of already having a ready-built wing as a spare (not a bad thing at all). Just a thought.
Dave
08-31-2011, 12:57 AM
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RE: Bird Of Time
Dave,
Thanks for all the info and videos, everything is great and very helpful. However, I think I will continue to install the stab as I originally anticpated. I feel it will make the BOT a little easiser to handle. Only time will tell. Perhaps your right about buying a new kit instead of scratch building the fus. But what else would this 77 year old retire guy do with his time. I also enjoy building and repairing.
Mike
Thanks for all the info and videos, everything is great and very helpful. However, I think I will continue to install the stab as I originally anticpated. I feel it will make the BOT a little easiser to handle. Only time will tell. Perhaps your right about buying a new kit instead of scratch building the fus. But what else would this 77 year old retire guy do with his time. I also enjoy building and repairing.
Mike
08-31-2011, 04:47 AM
#12
RE: Bird Of Time
Ye gads!!!! 77!! (almost makes me feel like I need a diaper change or something).
Sorry, another bad example of my horrible humor.
D
Sorry, another bad example of my horrible humor.
D
08-31-2011, 09:25 AM
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RE: Bird Of Time
A friend of ours is 75. I asked her if she wanted to go on the senior trip at our church. She said no because all the old people 90+ order her sound and make her do everything since she is young.
