anybody look at this month's issue of rc heli? i was curious if anyone has tried using the interesting setup shown by john adams from eflight (developer of the blade & spektrum radio's). the most interesting part to me was the use of 2 gyros, which he claims gives the ultimate tail control for 3D. he uses a g90 at 100% gain for a solid lock, along with the stock 3n1 rate gyro set to 25% to eliminate wag (very interesting!!!). he states that using the 2 gyros works extremely well with the gws DD & a 3020 prop. i'm assuming since there's no separate tail esc listed, he must be running from the rx, to the g90, then to the 3n1, making use of the stock tail esc. right guys?

i don't have a spare 3n1, but i figured i'd post this for anyone who has a 4n1 & a g90. if you guys try it and like it, please let me know so i can get myself a 3n1 and follow along.

btw, among other interesting tidbits from john adams blade:
-wood eflight symmetricals (lighter than cf for faster cyclic)
-10.5" boom (chopped for lower inertia)
-blade grips flipped upside down (LE control for more precise cyclic)
-g90 is mounted up front, on side of 4n1 (help balancing & reduce inertia)
-eflight 4100kV (10T pinion from HPI RS4 car)
-phx 10 esc (fixed heli mode?, with motor hardwired to esc, lol)
-uH Al swash (for more cyclic travel)
-s60 servos (lighter & faster, and don't tell anyone they're digital)
-dx7 radio
-tp3S730

this could be the stuff we've been waiting for on our blades!!! hehe, and it's all been around for a while.

cheers,
-kev

[edit: added blade grip mod & pinion that i left out plus a few why's.]

If he's using 2 Gyros why do they say to disable the onboard gyro, would'nt you go receiver, 3n1, internal gyro full blast, to external gyro to fix wag, to tail.

Anyone tried this? i don't have a CP Pro, just CP

you're right, the manual does say to disable the stock gyro when adding a g90. i figure john adams was tweaking around and recently discovered this. the writer of the rc heli article says he saw john's helis and spoke with him about the modifications during the 2007 las vegas heli fun fly. btw, the article mentions his credentials: technical director of horizon hobby (imho this makes his claims more credible). there's still a chance this trick won't make it in the manual, at least until they include a DD tail upgrade in the manual to go with it.

as far as putting the external gyro (HH/g90) after the 3n1, it doesn't work because the 3n1 outputs to the tail motor, as opposed to a standard servo pwm signal. starting with a 100% gain HH signal, then using the rate gyro to damp it makes sense to me. i figure if you had the hh gyro after the 3n1, you'd still have terrible wag at 100% gain because that's just how hh works with a tail motor.

so i suppose nobody has tried this trick yet? i do have an esky 4n1 that isn't being used right now. i could remove the 3n1, shrink wrap it, then install a DD motor & prop (i have a spare gws DD motor & a 3020 too) to complete the package. the biggest problem i'd have pulling this one off soon is i have a brushless tail on there now; it would take me several hours to complete the work, so i wouldn't be able to comment on anything for at least a few days (work & life are keeping me very busy).

perhaps some of you that are already running a g90 with DD as shown in the eflight blade cp pro manual (with a 3n1), could go ahead and turn those 3 screws and see how it goes (yes, if you already have a g90 with a 3n1, it's that simple to "activate" john adam's "killer tail setup", turn the g90 full cw, turn the 3n1 propo full ccw, turn 3n1 gain 25% CW). i figured by the time i got off work at least a few of you would've figured it out and posted how awesome it works, and how you couldn't believe you were flying with the 3n1 gyro turned off! c'mon now folks, where's the enthusiasm?

here's a quote from the article if you need some help getting motivated: "continuous flips at knee high... backwards circuits at top speed (~40mph) are easy, as the tail happily maintains heading even through backwards loops & rolls. garbage can size funnels, right side up and inverted a foot off the deck..." p109, may 07, RC Heli Magazine.

Truglodite
I am having trouble hooking up my brushless DD using an Align gyro, DX 7 w/ a 6100 rec. When I run it up I don't get a tail responce until almost at full throtle. It is going at the right direction. I'm also not sure I have the wiring set up between the reciever, gyro and ESC. Any help you can offer?
Don

well, it works great, turning down the proportion disable the mix of rudder to throttle, but doesn't disable the gyro itself. it's been talked on every other forum awaile back already. knee-height flips i dunno, but i've done waiste high continuouse stationary rolls before, and moderate backward flight, all is very good. my funnels were far from garbage-can size, but mine does travel quite fast on a large radius, all is good. i did have a blow out when rolling from inverted back, dunno why, i suspect it's a glitch, but was never sure cuz i never had a glitch on the tail rotor, i somehow miraculously managed to save it in a somewhat piroflip, and flew the rest of the pack without blowouts or anything doing light 3D. i'm using the black curvy prop, and he's using the square orange prop. my batt is dying and can't hold voltage well thus not able to maintain headspeed well even with bl motor. so i suspect that the tail will hold even better with consistent headspeed with such a light and powerful batt.

sounds good chopperdudes. i think i'm going to operate on my blade now. looks like i'll have to come up with another small plank to put the extra phoenix 10 and feigao motor in (indoor pylon racer comes to mind), and i'll finally have no good reason holding me back from getting rid of my cp2 once and for all.

oppie, i need more info to give any meaningful help. how is the tail responding? does it appear that the gyro is functioning properly? are you using HH mode or rate? revo mixing? which brushless tail esc are you using?

[edit/update: just cleaned up my workbench from part 1 of the surgery. so far i removed & disassembled 4n1 from my cp2, then shrink wrapped the 3n1. i tore up my cp pro too, removing all the electronics except the servos and main motor. i don't have a spare tail mount and i wanted to shorten the boom before reassembly. it's getting late, i'm going to get a tail mount & finish up tomorrow. hehe, i'm excited i'll have a setup i know can easily do 3D. i was getting tired of dealing with problem after problem with the route i was going.]

Very interesting thread.
Lets keep it going.

I quickly tried this on my brushless pro and all i got was wag.
Although I'm only running a stock tail .

p01rogue, from your results i'd guess that you need the power of DD to work at such high gains. i say that because i know higher gains require quicker response times to keep up without oscillation (wag). the stock tail definately is at a disadvantage to DD when it comes to response time.

another factor that will affect the overall response of the tail is boom length. john cut his boom to 10.5" (measured from rear of frame to cut), then glued on the tail mount & installed the DD motor. the stock boom is about 11 3/8" long from the frame, which does 2 things: 1) it reduces the moment of inertia (rotational mass) about the yaw axis and 2) it reduces the moment arm of the tail motor.

while part 2 works against us by reducing torque, part 1 (lower inertia) is the dominant factor. when the boom is shortened, the reduced inertia has more of an effect on acceleration than does the reduced torque. this can be seen in the basic formula for rotational movement: T=F*r=a*I~a*r^2. inertia (I) is proportional to the square of the radius (r), and torque (T) changes linearly with radius (assuming the motor is much heavier than the boom, which it kind of is). we can exploit the square radius of inertia, so the shorter the boom, the faster the response. the limiting factor of course, is tail rotor to main blade clearance.

fortunately, the more powerful tail rotor setup (gws DD w/ 3020 prop) uses a much smaller prop. so if you have DD, there's more clearance to work with when shortening the boom.

hopefully i'm not confusing anyone. the moral of the story here is tail holding performance on blades is improved with shorter boom lengths. so perhaps you'd get better results if you shorten the boom too, but you need DD to have clearance to do that anyways (it's all or none).

cheers,
-kev

[edit: this post & those equations should also be a hint on how to place components on our helis too. keeping everything as close to the head as possible will end up helping performance in all areas, including cyclic.]

[edit2: btw, i just noticed john is not making use of governor mode on the phx10 esc. very interesting, and i wonder why? maybe he had problems finding a suitable governor gain, or maybe he likes having excess headspeed going in to maneuvers? i haven't had problems using governor mode yet, and i doubt using this tail setup will change that. fyi, john's t/p curves are NORM: 0,85,100/-11,0,11 and IDL-1: 100,92,100/-11,0,11]

thanks for the response.
I'm actually at my limit as to what I'm willing to experiment with as far as the tail goes.
Actually, I'm pretty sick to death of the tail and am
currently in the process of building a t-rex 450se v2.
I love the blade and will keep if tail issues are easily adjusted but if not,
well , who knows?
Damn , I love the new brushless , but hate my tail.

you'll have to find the sweat spot on the stock gyro's gain, i thought at first that it's turn it higher until the tail stop wagging, i was rong, above the sweat spot, it'll wag, below it, it'll wag also.

srry, double post.

chopperdudes, thanks a ton! that was a very important piece of info you gave me about the sweet spot on the rate gyro gain. good to know before i test fly it today. i just finished hours of work, and knowing how the gain is going to work will save me from a ton of frustration.

p01rogue, i feel your frustration with tail experiments. you might already be familiar with the countless hours i've spent tweaking with at least 6 very different tail setups, including 3 brushless DD's, a brushless geared, gws DD, & stock. i really enjoyed the extra right yaw power of the brushless, but they're just too twitchy & laggy for 3D use. lately i've had such a fun time flying my simpler planks lately that i finally gave up on experiments & i am ready to just have fun flying my blade, at least for now.

update on the blade surgery: the building/wiring is done.
the wiring was a tiny bit more complicated than i thought, since i forgot i had to split the throttle signal to arm the 3n1 (been a while since i've done 3n1's ). the 3n1 arming process also required me to reprogram my throttle cut program so it only kills the main (no more full left rudder when i hit the kill switch). my blade looks like a x-mas tree when it's initializing now with all the flashing leds (g90-blue, phx10-red/grn, 3n1-red/grn).

after i got it all wired up & programmed, the bench test went well, with the tail reacting as it should at 100%HH gain & a starting point of ~25% gain on the 3n1. i noted that the tail's response was very hard; ie rotate the heli one way past the center point & the motor is full on, rotate just past the center in the other direction & the tail is off (digital like on/off action). given this, i'm predicting some wag on my first liftoff. the only other major thing i noticed is the battery balances the heli about 2" farther back than before. this was due to my relocating all the components up front. woohoo, no more battery sticking out the nose, & that's a plus for inertia (battery much closer to the rotor axis). only problem i have with it is the rx wires stick out of a cooling hole in the canopy, which i had to widen to aviod chaffing the insulation.

after the first "electrical" bench test, i strapped up the wires, flipped my blade grips, and installed some "old school" eflight sym woodies. the blade easily passed the second "RTF" bench test, so i'm ready to test fly it.

sorry so long, but that's just my style: overly thorough. i'll post pics & update with a flight report describing, to the best of my novice piloting abilities, how all these mods work together.

[edit: if it works as well as i think it will, i'll have to spend some of my free time writing a howto guide for stock pro owners. i'll do it in the name of preventing frustration, including why not to experiment with other tail setups.]

hmmm... i'm not sure i like this setup now. i dunno what my problem is, but ever since i went to this setup, i seemed to be getting sudden loss of tail authority during hard collective manuevers. and the tail will blow out adn start spinning, at first i thought it was a glitch, but it's weird cuz i never had a glitch on the tail. then during a backflip the flight before, it really didn't make it around, it got verticle and the tail started spinning and basically did a very ugly 540 stall turn. then last flight i did the same backflip and it got around, well almost, before the tail start spinning again, managed to save it. then a left roll back to inverted it did the same thing, i miraculously saved it in a somewhat piro flip. i think i'll go back now, to hh and revo setting. i know i'm not suppose to be using revo with hh, and i dunno how all the pro's got it to hold without revo, but i personally can't, and oh right, my tail motor has only seen about 10ish flights on it, so it shouldn't be a problem.

I'm feeling bad about the ccp.
I've been a defender of the blade rep for a while now but am currently building a T-rex v2 as I'm sick to death of the blade tail.
You will not see a nicer brushless ccp than mine often and I'm proud of it but am almost at the point of ditching it.

I mean seriously , is the fun not supposed to be in the flying?
I spend more time dinking around with the tail than actually having fun anymore.
shortcomings are all to a parent to me.

Lately ive had more fun on the cx2 , at least the tail is consistent.
Sorry about the rant , but i feel frustrated that e-flite sells the blade under the premise that the brushless combo will work with the crappy tail motor that actually sticks for about 5 flights before it cannot keep up anymore.

have you by chance upgraded the tail motor? the stock motor does not handle very well, but you probably already know that. What tail system are you using?

chopperdudes, don't tell me that now. i just finished the maiden and discovered the old motor i installed was dead; it was too weak to do anything but hover. i was starting to get excited when zeroed in on the sweet spot & i got the wag to go away. now i'm hoping when i replace the motor i won't start finding random problems like yours when i start to fly it around.

p01rogue, again, i understand your frustration. mrasmm is right, the stock motor lacks the power to work with very high gains. the gws cn12-rxc (aka gws edp50x) DD motor and 3x2 prop is what you need. when you start logging hours on that trex, your blade will be replaced by your new "mother ship". once that nervous fear of crashing is transfered on to the trex, you'll probably find your blade more fun to fly.

it'll be ok for sport flying, just not for mis-timed 3D manuevers. i acutally modified it abit. i kept the hh gyro gain at 100%, and about the sweat spot on teh stock gyro, however, i also dailed in some revo mix and now the tail seem to stay very put during my test flight in my living room. constantly punching up and letting go... i'll have to test fly it to see how it'll work outside. i really dunno how all of the 'pros' got their hh and dd tail to hold SOOOOO good without the use of revo mixing. anyways, you can try it to see if you like it, if all your doing is fff and a loop or two, it shouldn't reveil any problems.

interesting how revo is still doing the magic for you. i'm normally not one to believe in vaporous ideas, but it doesn't matter if i understand why the revo works with HH. i'll give it a shot & see if it changes anything (if it does it'll be our little secret).

if this setup fails me, i'll have to trash hh, stay in rate mode, use my brushless tail again, and get a trex. for what the blade is, the geared brushless rate mode setup has so far been the most fun for me. hopefully my "john adams" edition works as planned.