i've jumped through dozens of loops to find the tail that best suits the cp; from stock, to outrunner, to geared brushless, and i'm still working on it. so far i found that although brushless motors have much more power and last longer, their slow startup time makes them not so dominant over brushed motors when it comes to tail rotors with hh. i'm now getting enough experience with these things to not rule out brushed motors as top performers. that's why i wanted to start this thread: to discuss whatever it takes to get the ultimate performance out of our tails (all the bling aside in this thread).

here's a background on my experiences with various tail mods (all 3S lipo):
i started stock, and went to a brushless main. i found the stock tail was underpowered, end of story. investigating gws dd motors and dual motors, i chose dd for performance and was pleased. after having a few tail motors fail, i decided it was time to go brushless/hh. that's when i found that in rate mode, the dd feigao with 3020 prop was solid, but in hh the tail would slap back when going from hard left to stop (c'mon brushless hh ppl, don't lie, your setup does it too).

disappointed with the results, i started my recent testing of the eflight 250 outrunner. my results proved that small outrunners don't have the quick accelleration from stop required to keep the tail in check.

still on a quest for the perfect tail, i ordered a feigao short can motor to use with the stock gear rotor (chopped 3/16" at the TE and lengthwise to 5" diameter). i found the setup to run very cool and it resisted slap back unlike the other brushless setups. i also noticed the tail seemed on the waggy side during left yaw only. it seemed like an effect related to slap back, and it got worse as gain was increased.

throughout my testing, i have to say the 30mm feigao dd w/ 3020 prop has the most raw holding power and works extremely well in rate mode. i found the geared 22mm feigao with the cut down prop is the best so far with hh.

next up?:
after my improved results going back to gears, tonight i decided to install my long can feigao with the geared setup. this time i'm using a stock tail rotor, chopped to 5 3/4" for clearance. haven't flown it yet, but my 910mAh tp pack is stuffed all the way toward the nose to balance it out.

after that:
i know that there have been a few ppl who have already documented similar experiences with different tail motors, but one thing i noticed about all of the threads i found is that ppl are biasing themselves to what they own (it's human nature, everyone wants to be happy with what they have). all i know is i don't care if my brushless is high tech compared to joe schmoe's brushed tail, if his performs better i want it. the problem is, joe is likely to say his tail performs better because that's what he's flying right now.

now that i have a phx10 (mounted on the boom for accurate timing), a multirole tail mount installed (can rapidly change from dd, geared, stock or 12mm), a phx link, both brushed motors, and both feigao motors on hand (not to mention several stock rotors cut to various sizes as well as a several dd props to choose from), i'm armed and ready to find the truth about the tail motor. the only thing i would need to complete my test matrix would be a brushed motor control so i can retest stock and brushed dd setups with hh.

feel free to post comments on and comparisons of all the tail motors out there (please comment on rate vs hh modes); i'll update this thread with any good setups i run into.

oh yeah, anyone know of a solid brushed esc that works well on tail duty? i'm not necessarily looking for cheap, since i prefer to have more settings to play with. these tail mods are finnicky as you know, the more settings to perfect them the better.

nice post

Thanks for putting all this in one place

Karl

I've found that the added pitch of a 4530 GWS prop does a better job than the 3020. The extra pitch plus the torgue of the bl 12mm produces faster push at lower rpm. your right about the time it takes for a bl motor to spin up. with more pitch it doesn't have to spin as fast to gain authority.

I haven't had any problem with heat due to the fact that a 4100kv tail motor is simply not working all that hard. I don't even use a heat sync which also helps in tail weight.

Setup:
feigao 12mm with GWS DD adaptor and 4530 prop
cc10 esc
gy240

Yes, it will slide an average of 3 inches on hard punch outs and quick drop catches. I think the key is being happy with what you have and learning to fly it the way it is. There are more than enough vids of young kids showing us how it could be if we were simply good enough to actually fly the tail in hard torque moves.

I have a great setup and I don't think I'm being biased either. but I know for sure I spent to much for what I got.

i agree with the idea of getting used to what you have and learning to fly it. after thinking about what i've done the past few months with my heli, i've realized that this is really all about getting hh to work with a high output tail setup.

i've found most high output setups are nice for rate mode, because revo mixing follows with perfect timing. with hh though, a gyro is trying to tell a motor to act some way to make the tail do what it wants it to do, even if the motor isn't up to the task. hh requires somewhat symmetrical force from the tail, but most high output tail motors accellerate/decellerate too assymmetrically for hh gyro's to understand (specifically, brushlesses accellerate too slowly at low rpms).

to understand you must think about internal input vs external forces (stick command vs wind/gyroscopic force). rate mode merely damps out the effect of external forces so the angular speed of the tail matches the input (rate=angular velocity control). ie: if you tell the tail to stop right there, the rate gyro might let the tail slide past a little, then hold it still. hh however, cares less about external forces and does whatever it technically needs to hold the tail in the position where it was told to, even if the motor isn't physically capable of holding it the way the gyro wants it to (hh=positional control). ie if you tell it to stop right there and the motor spools up too slow to stop it on the spot, the hh will say, "ok, we overshot, now we need to hit reverse and back up to that spot". that's what causes the dreaded bounce back, and we're left with slap happy tails in hh mode. it's pretty simple when you think about it for a minute.

i love the way my pro flies in rate mode, except in wind or flying backwards. now that i'm flirting with 3d, i'm concerned that rate mode might leave me hanging in some scenarios. too bad i got off work late today, or i'd be posting another test flight report with that long can geared setup.

btw futura, my long can is a 5300kV, that's probably why i'm overheating with a dd 4030. oh well, i'm going to fly this geared brushless and i'm going to like it.

[edit: i too have spent too much experimenting with my pro; enough to where i'd have half a trex 450se if i saved it all instead. look at me now, ppl would laugh if they saw a 450se in my garage after knowing all the money i've dropped on my pro. oh well, it's all good when we're airborn isn't it. besides, after the hell i've gone through with tail motors, flying a trex for the first time will be like loosing my virginity.]

This is probably an extreme newbie post, but has anyone tried an Axe CP tail motor on the blade yet? I have both a blade cp and an Axe. My Blade Cp motor is almost dead, (full left trim, and hold left yaw during flight) but my AXE Tail motor still works like new. Is there any reason why I shouldn't try this other than the price of the motor?

I was wondering why you didn't test the dual tail motor setup with stock tail motors. It is the cheapest solution, not saying it gives the same performance, but if you are going to build a matrix of solutions it would be good to include it. If you need a Castle Creations 20a brushed esc I think I have one sitting around I would give to you.

PS Works best with a TP1320 so you can get the thing to balance.

How about picking the best setup and then shorten the boom an inch?

ok folks, i just finished my first flight with the long can feigao 5300k on the stock geared tail and boy does it handle. my weather channel page shows 6mph winds, but in front of my house the test conditions were more like 9mph sustained with 17mph gusts. not exactly fun, but it gave me a healthy dose of snappy inputs, and the tail was the most stable brushless hh solution i've ever flown. i got my gain to 85% without any wag compared to 70% with other brushless setups. i found 75% gain was the most flyable (feigao dd w/3020 came the closest, flying best at 60%).

i didn't get to fly as aggressively as i would've liked due to the wind, but i did get to test for bounce back and collective punch. all i can say is this tail has given be back my confidence to let 'er rip.

i'm still going to give my old gws dd a try with hh, and possibly duals as well since i still have two new stock tail motors (making a dual motor mount would be the thing that delays me).

lwatson, i appreciate the offer, but i'm running a phx10 on the tail now and would like to keep the weight down for a close comparison.

i'm not going to post the finer details of any setup until my test matrix is complete, so there's no confusion over what parts to get and what settings to use.

[edit: here are some pics of my current setup]

Does anyone recognize this set up? This is an AXE CP tail rotor assembly on a Blade CP. The bore in the Axe tail rotor mount is 5mm so it is a direct replacement. This motor has a LOT more authority than the stock blade motor and it seems to be very durable. I don't know if it has any benefit over any of the other set ups, but it is one of the cheaper solutions. The Motor is expensive, $24, but the motor mount is only $4.49 and I think you can use the Blade gear, and shaft. The bearings appear to be a tiny bit different so you will have to purchase them as well. Helimax does not sell just the tail bearings, only the complete set. I didn't put the ampmeter on it so I can't tell you if I'm cooking the factory esc or not. I can't imagine that it would be any harder on the controller than a dual motor set up but I have been wrong before.

So, 5300kv and stock gearing and blade. The big pitch stock blade gives pleanty of torque and the gear takes the load off the motor. Very interesting.

thanks for going through this and posting the results.

Truglodite,

How much better would you say the 12 x 30 long can feigao is over the 12 x 22 short can for overall performance.
I just completed the upgrade to the 12 x 22 short can and am very happy with it so far. If there is a substantial improvement going to the 12 x 30 long can feigao, I will go that route.

Thanks for all the great information you share.

Bill

np always happy to share heli stuff with you guys (and gals).

i'd say that the 30mm long can feigao provides a substantial improvement over the 22mm short can. i felt the short can was very waggy during slow left yaw maneuvers, and the long can showed no such behavior. with the short can this wag during slow left would only go away with gains so low they make the hh gyro useless. also, comparing the collective punchout (quickly moving the collective a full +10degrees, then directly to -10degrees, then back and forth several times in a row) the short can yawed roughly 20degrees near the top, and the 30mm stayed locked in. for both motors i used my cf blades and max flyable gain on gyro.

even with my latest setup i still have a barely noticeable bounce back, but it is tolerable and predictable now. i may be able to tune it out with adjustments to the brake/advance/throttle... on my phx10 (thank goodness for castlelink). also, i recommend a 1320mAh with this setup to help balance the tail and have some extra flight time.

like i said, this geared long can 5300kV feigao tail (prop chopped to 5 11/16" for clearance only) has restored my confidence to yank the sticks around. in fact, during my collective punchout testing i was amazed that i was flying a brushless tail with hh that held like it was in rate mode (rate mode usually dominates this test, as long as you get the revo curves right). still, anybody who has tried 3d stuff with in rate mode knows what hh is for, so this setup is a good thing for aerobatics. i was so impressed that i was tempted to try my first low altitude flip. anyways, glad i didn't since i haven't been hotdogging much lately with all this testing so my thumbs are a little twitchy.

[edit: after thinking about what i learned about control systems in ae controls class, my next round of flights i'll focus on adding some braking to stop the bounce back and get closer to symmetrical yaw performance.

given no braking voltage is applied, a brushed motor decellerates faster than brushless. this makes the brushless slower to respond to the gyro in the left direction. also, despite the fact that a brushless takes longer to start accellerating from a stop (and we're talking milliseconds), it's likely the much higher accelleration makes up for the small delay, not to mention how many times the tail won't stop during left yaw. if brushless does overall out accellerate brushes when you take in to account startup time (and i think it would be hard to argue it doesn't), that means a brushless is generally faster to respond than brushes in the right direction. i'm not sure if the brushed tails available have symmetrical performance, but if they exhibit less bounce back than brushless, then asymmetrical brushless performance is the problem that should be focused on. the bounce back problem ppl have with hh brushless can be cured by reducing accelleration and/or increasing decelleration to make the response more symmetrical, which would make the gains match up in both directions, which would make for a nicer performing PID control system.

anyhow, i have a hunch a mild braking action might stop the bounce back altogether.]

I added 30% brake and it made a big difference....almost eliminated the bounce back your refering to

i think i'll try 30% brake. what are your other settings? here's mine:

################################################## #####
# Castle Link Data File
# Created: Tuesday, January 23, 2007
# Do Not Edit This File By Hand
################################################## #####
Brake Ramp: Immediate (*)
Cutoff Voltage: 40
Hex55: 85
Brake Strength: 50
Direction: Reverse
Spool-Up Speed: 8
Throttle Type: Airplane: Auto Calibrating (*)
Current Limiting: Disabled
Brake Delay: No Delay
Motor Start Power: 85.2698412698413
Throttle Response: 9
Motor Timing: Standard Advance (*)
Cutoff Type: Soft Cutoff
PWM Rate: 11khz (*)
Governor Gain: 50

btw, i copied and pasted that. i just learned castlelink saves plain text.[8D]

[edit: i definately like brake strength=30. i also wanted to add that i set the cutoff voltage to 4V so i don't piro in. my main motor esc is set to 9V, so it sputters down in a (barely) controllable way.

First, I have had better results from the older version of phoenix link and esc firmware

Changing to these versions was the first time I got the motor to stop at rest without having to sub trim or change rudder trim/settings at all.

Phoenix Link version 2.12
ESC firmware version 1.22

Cutoff - Auto Lipo
Cutoff type - Soft Direction - Forward
Brake Delay - .6
Brake Strength - custom 30
Throttle type - fixed
Brake Ramp - Immediate
Soft Start - fast
Motor Timing - Standard Advanced
Current Limit - Insensitive
PWM Rate - 11khz

I initialise the tail with full left stick only. No left then right needed.

Flies nice but I think I'll remove any brake delay and see if that helps cut back on the three inch slide the tail does after catching a neg pitch powered decent...it grabs and holds but then swings nose right because the motor is still not slowing down fast enough. This though is an extreme test. It does really well otherwise.

I did not have this kind of result with the newer versions of phoenix link or esc firmware. I've shared this info with others with the same setup and they are also happy with the results.

i just got a nice 17min flight in today with the 910 battery, and changed settings for start power to 89 and the brake power to 30. the tail held solid, and instead of bounce back i got a slight wag that i was easily able to fly around. after the flight my main/tail temps were 115F/85F, so i'm sure the tail has room for more advance (at least during winter). this was my first fun flight in a while. i got some fff in and liked how the tail held exactly where it was pointed coming in and out of the turns. i even got some backwards and sideways flight in. it will take me some practice to get used to the way the phx10 governor responds. during my flight i dropped out fast from a tight turn and bounced the tail off the tailgate of my truck. fortunately there was no damage to either vehicle, but i still need to practice adding collective later than normal in tight turns.

i haven't had any problems with the firm/software yet. so far i like using airplane:auto to calibrate epa's correctly; i'm satisfied with how symmetrical the yaw performance is too. of course this means i have to do a fairly easy startup dance to get both phx10 esc's initialized & calibrated: plug in with throttle hold off, apply full left rudder till beep, hold tail firm, apply full right rudder for 2 or more seconds, turn throttle hold on, place heli on ground, and turn throttle hold off. the heli then spools up smoothly for about 15 seconds and i'm ready to go. when i'm done flying, i simply turn throttle hold on to kill both motors then unplug the battery.

Sorry to keep offering low tech brushed motor observations to this otherwise state of the art thread, but While backing my Blade CP into mother earth at maybe 25mph I accidently broke the Axe tail motor mount that I recently installed and had a good reason to try something else. I went to the LHS to get parts and found the uH cnc dual motor conversion. I bought it, installed it, and flew it. IMO the geared Axe CP tail motor setup blows the dual Motor set up away in the quickness department. It's about 4g lighter than the micro Heli dual unit and quieter also. The only downside I discovered with the Axe conversion is that you lose a little main motor rpm when the tail is working hard.
Truglodite, if you are serious about adding some brushed dual motor data into your excellent fact matrix, I know where there is a barely used dual motor mount available cheap. I'm either going brushed DD or going back to the Axe motor until I get good enough to deserve brushless.

swapping out my phx10 for a brushed esc could cut in to my flying time that i'm enjoying so much now. i would also run the risk of having to go back to my current setup to regain performance. still, i must find it within myself to fork out ~$30 more for a decent esc and spend more time soldering in the near future to arrive at the truth on this matter. i'm content right now, but i'm always curious and i love tinkering. this weekend could see some gws DD with HH action. the competition is pretty stiff right now though. it's going to be tough to beat the speed, power, and symmetry of the geared feigao.

[edit: btw, seeing as how i'll already have the brushed esc on there for gws dd and stock testing, i'm going to need a dual tail mount to include duals. i'd like to use a machined plate style mount; the kind that bolts on to the stock mount. anyone have dimensions i could use to cut my own out of pcb? i could just measure and mark, but i'd like some input before i start, especially from ppl who've made their own dual tail mount.]

I've never done a dual tail motor mount because of the CG issue....took it out of the running straight up. Weight is everything. So sorry can't help you there.

I seriously doubt it will be better than your current setup (geared bl). That sounds promising and worth a serious consideration at least.

For those that care, and are (no expense spared) tied into finding the best motor driven/fixed pitch tail solution.....this is a very cool thread. lot_tobe_learned........

thanks for doing all the hard work.

Just received my Fiegao 12 x 30mm brusheless motors and realized that I mistakenly ordered the 5800kv instead of the 5300kv model.
Has anyone used the 5800kv with the stock geared setup and trimmed blade?

I curently have the 12 x 22 mm 5250kv stock geared setup running with trimmed blade and find the setup great.

Do you think the 5800 kv 12 x 30 is worth a try or should i order the 5300kv?

Any feedback would be appreciated.

Thanks

to anyone,
I have seen somwhere the combination of a ziner diode and resister to bring down the voltage to the tail motor when using higher voltage lippo batteries.The item is sold as a plug and play or hard wired version.I would appreciate any info on this subject.
Thanks, Paul

np and thanks for your support futura. i figured if nobody else is going to do it i might as well. like i said, everything r/c around my house finds a happy home, including the small feigao and park 250 outrunner (saw a losi micro-T running the short can feigao and lipos, thinking about it...).

i haven't tested a 5800kV motor, but if it's not possible to exchange your motor it might be worth giving a shot since my 5300kV is running as cool as it is. 5800kV may give more raw piro power, but i'm sure the torque of the 5300kV is better for response time (which i've found is a high priority). the way feigao's come packaged anyways, you could give it a brief test and exchange it without anyone noticing (hard to prove if mine were slightly used or not when i bought them as new at any rate).

if you decide to give your 5800kV a go, i'd start with a smaller prop than i'm using and maybe also crank the start power and advance down a bit. if you get good results and the motor isn't smoking, you can gradually ramp up the advance/start current/prop size to whatever works best without smoking or glitching.

i don't recommend the zener mod, as it reduces efficiency and performance. the stock n-20 motors are far from capable of reliable operation with 3S lipos. imo, if you're looking for a low budget improvement to your tail whether it's for performance or reliability with 3S packs, i'd go with a gws DD tail. it's well worth the $$$, especially if you stick with the original tail mount (which imo is better than the gws fin anyways). if you're using 3S batteries, just make sure you get the version with an "X" in the part number (helifever has them).

finally, my neighbor and i finally got the chance to film each other flying. my neighbor put the camera down early, so most of the video will be of my warming up & trimming. anyways, within the limits of amateur cameramen, you can see how well the tail holds through punchouts/sideways... as well as how good those sm-22 servos hold altitude... and even a slightly exciting radio glitch that easily could've totalled my precious heli. speed and accelleration were limited because we were flying surrounded by large trees & powerlines near a busy street. next time we'll get out to a park or something. anyways, it'll be at least 5hours before the video is done processing (my fastest PC is a dinosaur: 2.6GHz-P4/512MB-PC800/ATA100-RAID-0)

btw, later during that flight after i tuned in my max pitch (after the cameraman ran for cover), near the bottom of my full collective punchouts i heard a clicking sound. i was sure it was my gears slipping, but both of my meshes were fine and tight after landing. then i thought it must've been the himax's massive torque flexing the frame, which was making the gear mesh change enough during punchouts that the pinion skips a tooth once in a while. after looking closer, i found it was the downward g-force that was pulling the canopy into the gear, making it the canopy click (slight chaffing on the canopy near the gear is evidence of this). now that's some power!!!

here's the video (don't expect much here)

[link=http://www.rcuvideos.com/view_video.php?viewkey=dad881378a6fd4092a6c][/link]<---link to video

i was getting warmed up with this pack, and i need a bigger field (and much more practice[sm=50_50.gif]) to shake it down more. the video also has dropped frames during a hard 35' punchout that i wanted you guys to see (i did a bunch more after my neighbor quit manning the camera. check out how solid those sm-22's hover, and how the tail holds during sideways and reverse flight (i could've held my altitude better for the cameraman).

[edit: every once in a while i get those dropped frames with my digital-8. not sure, but i believe it's happening when i capture from the camera to the pc. it's frustrating.[:@]

ok, fixed the video, re-uploaded, and re-linked it. no more dropped frames.]

Have you given any thought to a tail motor that is tied via Y off of your main throttle and a separate servo for your tail pitch like a trex? I don't think it would add much weight and would give you the speed needed to counter the collective.