450 Building some Align T-Rexs and get read for questions.

[Cloudancer]

Need some advice. I'm wiring an Align T-Rex 450L Dominator and when I shut off the transmitter (Spektrum DX7) my Main motor spools to the top and I need to disconnect the battery to stop it. An I think it is spinning backward because the tail rotor does not spin. I'm using a Spektrum AR8000 and a 3GX. I disconnected the motor and hung a different one off to the side to be safe.

 

[Smoggie]

If the throttle goes to full power when you turn off the Tx then you have the failsafe set wrong. To fix this you need to re-bind. When binding always make sure that throttle on the Tx is fully closed as it's during the bind process that the failsafe position is learned.

If the motor spins the wrong way then swap over any two of the three wires between ESC and motor.

 

[holtneil]

Hi mate like smoggie said rebind ,but you should never turn off transmitter before the heli , so its transmitter on then heli on , heli off transmitter off

 

[murankar]

I personally leave the throttle at just a tad over mid stick. I am looking for 2-3 degrees of positive pitch while in idle up 1 or 2. Why, so that it doesn't just slam in the ground. If you loose signal and it floats down then you regain signal you could possibly save the heli. If you go full negative then the kit will slam into the ground if you are in idle up 1 or 2. Now more and more people are running a straight linear pitch curve while in normal mode.

Just remembered when doing this set up you will need throttle cut active while setting the pitch to 2-3 degrees positive. This is so that you send a zero throttle signal while in any mode. This will allow the heli to float while not under power.

 

[Smoggie]

I personally leave the throttle at just a tad over mid stick. I am looking for 2-3 degrees of positive pitch while in idle up 1 or 2.

Then if you lose reception and the throttle goes to 50% power the heli will potentially fly away and come down who knows where? Also if you lose signal when on the ground (maybe you inadvertently turn the Tx off) the throttle will go to 50% the heli will spool up and potentially lift off!


Nope... where you put the collective pitch is up to you, but throttle MUST be closed when you set the failsafe, anything else is extremely dangerous. (throttle and collective are not the same thing by the way....)


PS.. sorry, i just noticed the edit about throttle cut, but i still think it's confusing to talk about 'throttle a tad over at mid stick'... I believe what you mean is 'collective a tad over mid stick'.. Throttle must be fully closed. This confusion i think all stems from thinking about the left stick (on mode 2) being 'throttle' it isnt, on a CP heli it's collective.

 

[murankar]

If one decides to do what I have done, activate throttle hold for the zero throttle signal and set collective to just above mid for the 1-2 degrees of positive pitch. Then bind.

 

[Smoggie]

Yes, that's exactly how I do it. Collective at mid stick and use throttle hold to set throttle to closed.

I never worry about if I have any positive pitch as I figure if signal loss was going to happen then it could happen any time, upright, inverted, in a banked turn, you just can't tell. If you lose signal for any length of time you have crashed regardless. The only sure thing IMHO is to cut the power, primarily for safety reasons, but it should also lessen the damage in a crash.

Best thing is not to lose the signal in the first place!

 

[D.O.G.]

Yes, that's exactly how I do it. Collective at mid stick and use throttle hold to set throttle to closed.

I never worry about if I have any positive pitch as I figure if signal loss was going to happen then it could happen any time, upright, inverted, in a banked turn, you just can't tell. If you lose signal for any length of time you have crashed regardless. The only sure thing IMHO is to cut the power, primarily for safety reasons, but it should also lessen the damage in a crash.

Best thing is not to lose the signal in the first place!

Is there anyway to prevent from losing the signal?

 

[murankar]

Yes and no. First off keep the antenna outside the frames, make sure you have line of sight of the aerials from all directions. Keep antenna tip away from the air frame. Range test and just in case a competitor bank for the rx.

 

[Cloudancer]

If the throttle goes to full power when you turn off the Tx then you have the failsafe set wrong. To fix this you need to re-bind. When binding always make sure that throttle on the Tx is fully closed as it's during the bind process that the failsafe position is learned.

If the motor spins the wrong way then swap over any two of the three wires between ESC and motor.

That worked for about 3 minutes. I have had this thing working and suddenly it started doing all kinds of quirky things. Motor works, motor doesn't, motor chatters at low stick, BEC voltage disappears then comes back.
Well to make a short story long. I rebound it. I turned on the TX, I turn on the hele, it binds, no motor at low stick. Swash movements good. Took motor to idle, GREAT. I let it idle for about three minutes and decide to run the motor up. ESC smokes. Now I don't trust the motor. I have another ESC and motor and I'm thinking about changing out motor too. I did hook up a battery to the ESC (without the motor) after I ripped it out of the bird and it still smoked but still had BEC..

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That worked for about 3 minutes. I have had this thing working and suddenly it started doing all kinds of quirky things. Motor works, motor doesn't, motor chatters at low stick, BEC voltage disappears then comes back.
Well to make a short story long. I rebound it. I turned on the TX, I turn on the hele, it binds, no motor at low stick. Swash movements good. Took motor to idle, GREAT. I let it idle for about three minutes and decide to run the motor up. ESC smokes. Now I don't trust the motor. I have another ESC and motor and I'm thinking about changing out motor too. I did hook up a battery to the ESC (without the motor) after I ripped it out of the bird and it still smoked but still had BEC..

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What just happened???

 

[Tony]

Running a motor at a very low rpm is not good for the ESC. It is heating up constantly having to lower the voltage for that amount of time, and all the while the amps are very high to keep it spinning. The lower the voltage, the higher the amperage. IMO, invest in good electronics. Good motor, good ESC, good servos and definitely a good gyro. Motor and ESC are fine being Align. I have not had a single issue with Align electronics other than the 3GX. Ikon and BeastX are awesome gyros.

Get a 35a Align ESC (if using a 450) and the 450MX motor. It will run you about a bill for those two, but you can find them a little cheaper if you look around. I am running this exact setup on my Align Pro V2 and it's awesome.

 

[D.O.G.]

If you would like to go cheaper, try this combo out. It works fine on my Tarot 450DFC. Turnigy 2836 Brushless 450-Size Heli Motor 3700kv and Hobbyking YEP 40A (2~6S) SBEC Brushless Speed Controller Just a different and cheaper way to go.

 

[Smoggie]

+1 on the YEP ESC. They are excellent. Hobbywing ESC's are another good option but you cant beat the YEP for bang for buck.

As for why it smoked.. As Tony said, you shouldn't really leave a motor running for a long time on the bench (as there is no flow of cooling air) but i suspect there might be other issues too. Possibly the gear mesh is tight or a stiff bearing making it hard for the motor to turn, poor connections between the ESC and motor can cause havoc too such as the stuttering that you described. But it could simply be a poor quality ESC

 

[Tony]

The reason why I don't suggest the YEP is because 1. I had a horrible time with it and 2. the footprint compared to similar amperage ESC's is quite a bit larger. I like to tuck my stuff away and you just can't do that with a YEP. Not the 40 in a 450 anyway.

 

[Smoggie]

That's true, the 450 is tight for space and the YEP is quite wide so it won't fit under the battery tray like the Align ESC does, so installation is not as neat. I've used a lot of YEP's and generally had good results. They are so cheap it's not the end of the world if you do occasionally get a duff one!

The Align ESC is ok but doesnt have a good reputation as far as governor is concerned. Only an issue if you wanted to use the governor of course!

 

[Tony]

I completely agree with that. The governor is crap on the Align ESC's. Never used a gov on a 450 though. Maybe I should try one of the newer YEP ESC's and give them another shot... ,

 

[Smoggie]

Dont forget the programming card if you get the YEP, they have quite complex programming options so you really need the card.

 

[Tony]

Yea, I had the card before and wouldn't even think of programming them without it.

 

[Cloudancer]

I must of had a bad ESC. I put the other one I had on and it worked. I think I need to rebind it again as the motor does not spin until mid stick. Also my ESC has no magnet. Is that normal?

 

[Cloudancer]

I must of had a bad ESC. I put the other one I had on and it worked. I think I need to rebind it again as the motor does not spin until mid stick. Also my ESC has no magnet. Is that normal?

Tried to rebind TX with the RX and I still get throttle at mid stick. I have a D7 TX and AR8000 RXs. Also tried three different RXs. Maybe it's a radio setting? I can't bind it with the throttle stick in the cutoff position as the TX just sits there and flashes MIX while beeping.

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Tried to rebind TX with the RX and I still get throttle at mid stick. I have a D7 TX and AR8000 RXs. Also tried three different RXs. Maybe it's a radio setting? I can't bind it with the throttle stick in the cutoff position as the TX just sits there and flashes MIX while beeping.

I did the binding with and without the 3GX installed.

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Tried to rebind TX with the RX and I still get throttle at mid stick. I have a D7 TX and AR8000 RXs. Also tried three different RXs. Maybe it's a radio setting? I can't bind it with the throttle stick in the cutoff position as the TX just sits there and flashes MIX while beeping.

I did the binding with and without the 3GX installed.