Joined: 27 Aug 2011 Posts: 11 Location: Northern Ireland
Posted: Sun Sep 25, 2011 5:25 am Post subject:
Hi all
Have to agree with TREV why people fly the likes of the T-34. My main reasons were cost & confident building.
3 days after buying my T-34 I started upgrading it, this has taught me quite a bit.
2 days after completing my upgrades I ordered a HBFP V2. Still worried about taking above 4 feet, but loving it, but nearly got tail in nailed!
If I had went start to a 450, 3 weeks ago, it would now be on e-bay and this great hobby would have lost a new follower.
TREV can you send me details on the double tilt mod, my bottom blades keep rotating slower every so often, so might as well do another mod while I'm fixing the problem.
RC newbie here and just bought a T-34 series. I was all about ready to send it back as faulty when i googled the problem and found this site. Basically i have no foreward momentum at all. with 100% forwards power and full stick use it hovers, maybe moving foreward at about 0.1m/s.
I guess there must be too much weight at the back as it does tend to tip backwards a bit... all this is as it came from the factory
Although i am an RC newbie i am somewhat of an expert in battery tech (i come from the Electric Vehicle world) so i really have to re-enforce the sentiment that no matter what the mah rating of a battery it will not cause a motor, controller, wireing or chip to burn out. This is all caused by voltage and current.
mah is just the measure of capacity in the battery, the best way i find to explain batteries to a novice is as follows.
think of a battery as a tank of fuel. the mah rating is equivalent to the gallon rating of a tank. Weather you have 1 gallons or 100 gallons the car will still operate the same until it runs out.
Think of the voltage as the width of the pipe passing fuel to the motor. the wider the pipe the more fuel can be passed to the motor.
Lastly think of the C rating as the fuel pump. The bigger the C rating the more fuel can be passed to the motor.
Now the width of the pipe and the size of the pump (Voltage and C rating) are the only things that effect how the motor will run.
As electric motors and chips only take the power that they need to run so are unaffected by C rating (as long as there is sufficient C rating to operate at full potential) that just leaves voltage as the sole factor that would effect if a heli part burned out.
therefore... stick with a 2S lipo battery and take what ever mah rating you can fit in the heli without changing the flying characteristics too much due to balance issues.
Just for note, the heli appears to require 5-6c constant so receiver packs with low C rating wouldnt be good. i would advice 15-20C to give the batteries an easy time.
the stock battery that comes with the heli is very weak and struggles to supply the demend of the helecopter due to voltage sag under load so a battery upgrade should give some improvement in performance as well.
Thanks for the info and the reading guys, already ordered a replacement tail rotor
Joined: 20 Jan 2009 Posts: 566 Location: United Kingdom
Posted: Sat Oct 08, 2011 1:44 am Post subject:
Hi TheRealFury,
Finally a battery explanation I can understand, thank you for that.
You may be a battery expert, but I am a T-34 expert lol.
You say the stock battery is too weak and struggles with the demand placed upon them.
I disagree as stock batters are more the capable of carrying the extra weight of a tail motor assembly plus two oversize tail rotor blades full out across the sky with speed for about five minutes.
What tends to happen with new T-34 pilots, they get there shinny new helicopter, are surprised just how well they fly’s, end up going up to high, turn to fast resulting in blade strike, it may hit a ground or wall the blades, don’t break because of their design, but does damage the blades leading edge, this may be hard to see under the rubber edging, once the edges get damaged will not lift off the same, if it’s not the blade edge it’s the top gear being damaged again if so will not lift.
To improve forward flight without modification the battery needs to be moved forward as much as physically possible.
Finally a battery explanation I can understand, thank you for that.
You may be a battery expert, but I am a T-34 expert lol.
You say the stock battery is too weak and struggles with the demand placed upon them.
I disagree as stock batters are more the capable of carrying the extra weight of a tail motor assembly plus two oversize tail rotor blades full out across the sky with speed for about five minutes.
What tends to happen with new T-34 pilots, they get there shinny new helicopter, are surprised just how well they fly’s, end up going up to high, turn to fast resulting in blade strike, it may hit a ground or wall the blades, don’t break because of their design, but does damage the blades leading edge, this may be hard to see under the rubber edging, once the edges get damaged will not lift off the same, if it’s not the blade edge it’s the top gear being damaged again if so will not lift.
To improve forward flight without modification the battery needs to be moved forward as much as physically possible.
Trev.
Thanks for te reply Trev, Ill try not to wreck the blades too soon then
The stock battery is surely capable of putting out the amps required but the voltage sag is quite heavy which means that you loose overall power output due to lower voltage. a Battery with 15-20C rating and 1000mah or more would give slightly better performance.
If it were not for the 40mph winds here at the minute i would be testing it out with my new Zippy Flightmax 2S 1300mah 15C battery i got from HK.
Still waiting for my new tail rotor to arrive as well so would be going nowhere fast even if there was no wind lol.
One question i do have if anyone cal help me is that there is a flexible arial on the heli that was wrapped around the landing grear of the heli, is this supposed to be spooled up like that or should it be down the tail section somehow?
Reason i ask is that once i go above say 7-10 meters high the motor starts to stutter a bit and control is hit and miss, seems to me like its loosing reception but i have seen youtube vids of poeple flying much higher then i have been able to go, maybe im missing something?
Joined: 20 Jan 2009 Posts: 566 Location: United Kingdom
Posted: Wed Oct 12, 2011 5:38 am Post subject:
Like I said you’re the battery expert and would not disagree with you.
40mph winds are okay if you are only flying one way.
The Arial wire is wrapped around the skids because of the length of the wire, not sure if the wrapping Patten is necessary but does seem to communicate with the receiver better this way.
Losing the signal at height, there are a few possibilities the Arial wire Patten as mentioned, the wire shorting out on the metal frame, the transmitter antenna not fully extended.
I have not touched the anenna cable as yet so its as it was supplied new. Doesnt look like there is any damage to the insulation so should not be shorting to the frame but cant be 100% sure unless i unwrap it and check which i think ill leave for now.
As for the transmitter antenna, i never actually paid attention to if it was fully extended or not to tell the truth so ill have to give it another test when possible and make sure it is. may have just been me not fully extending it
Ok guys as promised here's the update on the Sky King tail rotor mod.
Bugger me it's quick!
Step 9 - Test fly and surprise yourself, how a £3 part & 10 minutes work can make such a difference.
Hope this helps some of you that were thinking of trying.
Thanks for that info
New on here and so glad I found you all
I too was about to return mine because of this lack of forward / backward control.
I had tried re-pitching the tail rotor and messing with CofG to little effect.
I have just this minute ordered a Sky King tail rotor off a very well known auction site for just £3.80 all in and cannot wait to try it out. (I could not find a Dragonfly one in the UK so this will do for now).
Just to say, I bought mine as a very first Heli (I have flown R/C planes for years) and I do intend to slowly progress to a "proper" single rotor 6 channel type job in the future.
Firstly I'd like to say thank you to all the pro's here (looking at you trev), you've done some really cool mods, and ultimately made me buy one of these helicopters. You should get sponsorship or something!
I've been flying mine for a few days, and so far all I've done it slide the battery forwards a bit, heated up and twisted the rear rotor to make it a bit more aggressive and removed the horizontal wing(?) at the back, as that seems to do naff all except get pushed down by the downdraft from the main blades.. Doing those things now gives me some forward motion, but I want more!
On order is the Sky King rotor, as I was unable to source the dragonfly one, and a Turnigy 1300mAh battery. I'm really looking forward to get this thing moving fast.
Anyway, no real reason for posting other than to say thanks, I'm sure I'll be back asking questions soon however!
Oh, I did have one thought, does anyone know how the light on/off button transmits? Does it send two separate pulses, an "on" then a different "off" signal? Just a thought, that if it sends a different signal, could it be modded to run two fans either side to allow you two 'slip' the helicopter sideways? May have to try and figure that one out...
EDIT - I assume I wont have to worry about blade strike until I get it moving better (i.e a twin rear rotot setup)? Also, which set of blades did you strengthen? Cheers.
Interesting, definitely a mod I'll be doing in the future. Although I've yet to experience blade strike, I guess it messes the blades up pretty badly when it does happen. Really helpful video, thanks.
Regarding the battery, It's not a huge upgrade, but hopefully it'll give me just a little bit more flying time without compromising handling, we shall see!
I'll have to read up on the receiver a bit, see what outputs etc it offers, I'm sure it could be put to better use than a few pretty lights.
Shame about the Skyking, I'll give it a go anyway, anythings better than nothing!
I do have a question for you, what is the part number for the dragonfly rear rotor?
Joined: 20 Jan 2009 Posts: 566 Location: United Kingdom
Posted: Mon Oct 17, 2011 4:20 am Post subject:
As demonstrated in the video these blades are unbelievably tough,
They can bend but not snap or break no matter what punishment is placed upon them.
Adding The Double Rotor System will give this helicopter extreme forward flight,
These blades was designed for toughness not speed, consequently when pushed the blades resemble rubber in flight,
Once the blades touch each other the built in safety feature cuts the power to the motor, good if the blades contact your fingers or arm, bad news when flying high, as it just brings this helicopter down, that’s why I have added this simple mod,
The lights are more of a signal rather than a voltage, I also could use this extra channel rather then turning on and off lights.
The tail rotor is a Double Horse SYMA 601, 603, 9093, 9083, 9086 5.75 inches ( 148 mm ) from tip to tip
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