Thunder Titan E325 maiden flight

[patrickvdb]

Hello,

I just started with heli's and assembled my first E325. After hours on the Sim, I took all my guts and tried it for his first flight.

I have some stupid questions, maybe you could help me.

1) I have added some training sticks (self made, because not available in store). What length should they ideally be. I made some of wooden sticks with plastic balls, but I think they are to big or to heavy because the heli immediatly starts shifting to one side, even compensating slightly doesn't really fix it.
I'm talking about a flying height of a few cm only....
Should they be larger then the rotor?
So what would be the ideal size for this heli?

2) When I power up in normal mode, sometimes (not always) when just giving positive pitch the power goes down. I checked my throttle and pitch curves and they should be ok.

NORMAL MODE Pitch Curve : 40 - 75 - 100
NORMAL MODE Throtle Curve : 0 45 65 85 100

IDLE 1 MODE Pitch Curve : 20 - 75 - 95
IDLE 1 MODE Throttle Curve: 80 - 70 - 100

It doesn't seem to happen in idle 1 mode (although I didn't test it a lot, to scared...)
It doesn't always happen. Any ideas?

3) Sometimes when I hover a bit (the few times I actually dared to), the heli jumps straight down without any specific input.

4) Does the heli let you know when the battery is to flat (not taken into account the result of crashing :)
What is the best way to be sure you have enough battery left?

5) My transmitter is a Graupner/JR MX-12 which supports PPM and SPCM. I currently have a PPM receiver....Is this OK? or would it be better to switch to a SPCM receiver (I read stuff about less sensitive for interference)

6) I have a Flightpower 2170mAH 3s pack. Any idea how long they should last on the E325 with stock motor?
When the packs are used, should they immediatly be charged for storage? I have a Graupner ULTRAMAT 10 charger and it doesn't allow me to half load or something like that.

Anyway, I guess my maiden flight didn't go to bad since I didn't brake anything on my new baby :noteworthy

Thanks for any help and greetings from rainy Belgium.

BTW: My simulation skills are good, but actually flying the thing is still something else :lol:

Patrick
www.parafun.be (http://www.parafun.be)

[patrickvdb]

Somebody posted an answer here, but it was deleted by someone.
Why?

[cholyoake]

Somebody posted an answer here, but it was deleted by someone.
Why?

could have been because of this:
http://www.helifreak.com/announcement.php?f=59

[j bomb]

I was the one who responded to your post over the weekend, I guess it was one of those that were lost. So, here we go again w/ my best attempts to answer your questions.

I'm not sure about the training gear size, but a little larger than the rotor disk sounds about right. If it is drifting to one side, it could be out of trim but having to tilt it yourself a little to the right to counter the tail rotor's thrust is normal. One thing to check is to make sure that your training gear is secure and not shifting around on the heli and causing it to be unbalanced. If you know a more experienced pilot who lives nearby, it would probably be a good idea to have them check it out for you.

As for your "power dropping", does the motor slow down or does the heli just drop w/ no change in RPM? If it's windy, the changing wind speed will also change the lift produced by the rotor. This is something that you have to compensate for w/ collective input. You mentioned that it worked better in idle-up, this is probably because of the increased headspeed which will make the heli handle the wind better. If your mechanical setup is correct, then your radio settings for pitch should have the 50% position giving 0 deg. pitch. I noticed that both of your pitch curves would have you hovering at center stick if this were the case. In normal mode, this is a matter of personal preference but it is my choice to have the center stick value be 50% so that I'm hovering at 3/4 stick. Many on this forum have also stated this preference and some good reasons why, some of which are: more headspeed and thus more stability, hovering stick position the same in all flight modes, hovering stick position the same as most simulators. The center stick position should always be 0 deg. pitch in idle-up mode so that you can easily give negative pitch, if required, for aerobatics in the same proportion as positive pitch. If you haven't already, I would recommend that you watch Finless Bob's video on pitch and throttle curves. He goes into even more detail regarding how to program them and also gives some recommendations for throttle curve values. Using his throttle curves will give you more headspeed which make your heli more stable.

The easiest way to determine the flight time for your batteries is to make a short flight (3-4 min.) on a fully charged pack and check to see how many mAh go back into it when you recharge. You can then calculate how many mAh were consumed per min. and time your flights accordingly. You should use about 80% of the pack's rated capacity. You can leave the packs discharged until your ready to fly unless they aren't going to be used for a long time. If you won't be flying for more than a few weeks, you should give them a partial charge for storage.

I would highly recommend using a PCM or spread spectrum radio w/ any helicopter. As you said, they are more resistant to interference, and they also have the ability to program failsafe positions for all of the channels, which could help to prevent a dangerous flyaway.

Sorry for the slow response to your questions. I hope this was helpful and have fun w/ your new heli. I have seen a Mini Titan fly and they seem to be a really nice helicopter.

[tailStrike]

I set my timer for 4:30 as a 5 minute flight seems to hit the 80% mark on the nose for a 2100 mAh pack on the stock motor. I was setting my timer for 5, but I now use the 30 secs to get it on the ground as I was over discharging a bit. I know that's not a long time, but that ripper motor is a hog. That'll give you a baseline until you can monitor a few charges to see what you're putting back in as John suggested.

[patrickvdb]

Hello, thanks for the repost.

I have measured the pitch using a pitch gauge and make some adjustments.
It is much better now, I can easily hoover.
However the power still drops sometimes and with a reduction of RPM. It can't be the wind because I tried it inside.
So, the RPM goes down and it's nearly impossible to get the RPM back up while hoovering. Increasing the collective doesn't seam to increase the RPM as it should.
When I then put the heli down and restart hoovering it is OK again.

I think it might have something to do with the Governer mode on the speed controller. Does this seam logical? Should it be on or off and what does it exactly do? I can't really find a good explanation about a governer.
Also with the above pitch and throttle curves I start to hoover still a bit below center stick. So I think my pitch angle isn't exactly correct yet.
Tonight I'll go visit a friend (a 3D ace, so I hope he will get it fixed)

Anyway I've been flying little airplanes for a few months, but the real kick truely is in piloting the heli, it's huge fun learning.
I started in RC models to kill time when I'm at the flying field awaiting good conditions for paragliding and paramotoring but it looks like I'm getting real hooked on these things :lol:

Thanks for the feedback

[j bomb]

Sorry, I can't help you out w/ governor setup as I don't use one. I hope you get it figured out.

[tailStrike]

The governor isn't enabled by default - did you turn it on? I have noticed that the low voltage cutoff on the ESC behaves similarly to what you described. Once the battery voltage gets too low and it starts to reduce throttle, it will not allow you to increase the throttle until you have landed and reduced the throttle to 0 for a bit.

Does this happen after you have been flying for a while? It sounds like you might be leaving it in the air too long or maybe the pack was just drained from the time you spent adjusting the pitch. Also note that you are likely over discharging the pack if you are hitting that cutoff.

[patrickvdb]

Hello,

no it happens even when I'm just started. So I guess its not due to battery drain.
The batteries are also brand-new and I charge them using the normal specs.
They are brandnew flightPower EV-25 V-Power 2170Mah batts, which I charge using a Graupner ULTRAMAT 10 using LiPo 3Cell 2170 settings.
So I guess I'm charging them correctly no ?

Another question regarding charging. I read on the Flighpower site that you can charge these batts not only at 1C but also 2C (didn't seen it specifically for this batt type)
does this mean I can charge the battery at 2170x2 Ma so it charges at half the time or is this just a quick way to set my house on fire?

thanks

[tailStrike]

Hello,

no it happens even when I'm just started. So I guess its not due to battery drain.
The batteries are also brand-new and I charge them using the normal specs.
They are brandnew flightPower EV-25 V-Power 2170Mah batts, which I charge using a Graupner ULTRAMAT 10 using LiPo 3Cell 2170 settings.
So I guess I'm charging them correctly no ?

Another question regarding charging. I read on the Flighpower site that you can charge these batts not only at 1C but also 2C (didn't seen it specifically for this batt type)
does this mean I can charge the battery at 2170x2 Ma so it charges at half the time or is this just a quick way to set my house on fire?

thanks

There should be a separate setting for amperage while charging, so I wouldn't change the capacity of the battery in the charger, but rather charge at 4.2A vs 2.1A. I guess that could differ by charger, but that's how it works on the Tritan. If the charger's peak detection logic uses the capacity somehow, it seems like it would be detrimental to change that value. You might also want to stick to 1C until you have a few cycles through it, and definitely only go 2C if you are using a balancer (as you should be anyways).

Did you enable the governor?