marcelg

Mine came with 2200mah battery, 1350 seems not enough.

RCXPLANES

My Feedback: (1)

George,
I think the TP 3s1p 1350 Gen 2 will fly your helicopter, just not for as long a time period. The Gen 2 stuff is the way to go for sure in the long run. I am using the TP Gen 2 2100 3s1p and think it is very good for the T-REX. It fits right in and gives great power with the Park 400 on a 9 T pinion and I have yet to fly a full charge to voltage cutoff on it yet and flew for 8 min.

Coincidently I have been looking for the TP Gen 2 1350 3s1p locally for my foamy fixed wing 3D stuff and haven't found it yet. The 8C discharge Kokam 1500 are giving me trouble of an unknown origin. I just haven't taken the time to order one of the TPs yet.

Bud

skyhawknut

My Feedback: (3)

errolw98,
I thought the pinion to use with the park 400 was an 8 tooth - have you tried an 8T? why did you go with the 9 T?

dornier

Hi Everyone,

Purchased the Thunder Power 11.1v 1900mAH 10C/15C burst (19A/29A) battery today. Hopefully it will work out great.

My local hobby store didn't have the Hitec HS-50, but had a Hobbico CS-5 High Speed servo. Do you guys think this thing will do the trick with my Futaba GY401? Here's a picture of the specs:
http://home.insightbb.com/~goflying757/Servo.jpg

Thanks for the help everyone!

George

RCXPLANES

My Feedback: (1)

Skyhawknut,
It's funny you say that because that's what I thought when I ordered the pinions from heli hobby but ended up getting the 9, 10 and 11 tooth and being talked out of the 8T. The 9 tooth turns the head at 2430 RPM at full throttle with the wood blades. Is that too much? I think thats what the Align with a 13 T pinion works out to be. Thats measured with my Glo Bee airplane tach but should be pretty accurate. I have no idea when I will ever use the 10 or 11 T. Probably never with this motor on this heli.
Tomorrow I will try and work out the gyro and fly it a bit in a stable mode. The Rate mode seems good now. Just have to work on the HH setup. I'll report on how it goes.

skyhawknut

My Feedback: (3)

Where did you get the 9 tooth? and how hot does your motor get?

RCXPLANES

My Feedback: (1)

I got the 9, 10 and 11 tooth from [link=http://www.helihobby.com]Heli Hobby[/link] but couldn't find them on line so I called. Thats when I was talked out of the 8 T.
I have only flown it once for about 7-8 min outside with a very poorly working gyro before I got some good info on it's setup so there was lots of landing and zero pitch running then. I also got one of Heli Hobby's 20 mm motor heat sinks (the blue $7.99 one) at the same time and have never run it without it on. Other than that I have only hovered for 5 - 10 seconds at a time and landed to adjust the gyro gain. I didn't use my infrared temp gun but had no trouble touching the bottom of the motor as long as I wanted. It was warm but not hot at all. The battery was also warm but not hot. My trrottle curve in flight mode 1 was set at 70% as well so I wasn't at full power either.

While I was trying to set up the gyro at 10:30 pm in my garage. I got the RATE MODE set fine and was playing with the gain on the HH Mode when she drifted a bit. I just touched my large toolbox with a rotor blade. I thought I had it. Things went bad from there. I just got the parts this evening (feathering shaft, boom, horizontal fin mount) and put everything right. I decided to wait till tomorrow to finish the gyro setup, outside this time. I am just not good enough yet to hover in the garage with the gyro just out and have great control. This is my first helicopter. I will have to let you know how warm everything gets with my infrared temp gun after tomorrows activities.

Bud

Lowtech

What would you recommend as far as servos go for the Trex 450x?

cbfsoar15

h-56

*Crash*Johnson*

My Feedback: (7)

Good stuff here

I'd say go with the HS-56, as the 55's use cheap plastic gears. I stripped one out and have no idea how it happened. The 56's use the karbonite something or another and wont strip nearly as easy.

Gonna have to get one of these

RCXPLANES

My Feedback: (1)

I finally got a chance to sort out my gyro and fly this T-REX for a couple of full batteries. Verry cool little heli. I am still not a great heli pilot so I was hovering and doing some FF and Fig 8s. For my skill level I have a bit too much Pitch available and it changes quite fast so I will try a little Expo in the center till I get used to it. It was only about 50 degrees outside. After a full TP 2100 Gen 2 battery flight, the ESC and battery were cool to the touch. The bottom of the motor was a bit warmer but easy to hold the back of my finger on for more than 20 seconds.

I am running the HS-55s but think I could use a faster tail servo for the gyro and want to increase the speed of the Cyclic change so I will move the controle rods out to the long end of the arms. Only two real flights and no problems with the HS-55s except for tail rotor change speed for the gyro. My rates have to be turned down pretty far.

Errol

dornier

I purchased a Hitec HS-50 since it's a faster servo for the tail. This was a recommendation from the company that I purchased the Trex from. I also purchased a hobbico fast mini servo, but will try the HS-50 first. I'll let you know when I finally build this thing. Right now I'm trying to get a hang of a FUN Piccolo. I finally figured out that you can't sit in ground effect for any length of time as I have read. The thing is very unstable until I get to about 3-4 feet off the ground. I just need to figure out how to avoid snapping off the skid strut from the frame after landing.

By the way, the Hitec HS-55 has a speed of .17 versus .09 for the HS-50. The Hobbico CS-5 is capable of .09 at 6volts versus .11 at 4.8volts. The Hitec is at .09 at either 4.8 or 6 volts.

Hope this helps,

George

RCXPLANES

My Feedback: (1)

This really is a fun heli. I am learning just how cool helicopters are. This thing is really fast in Forward Flight. I am glad I have spent as much time as I have on the sim or this thing would have been gone once for sure. I have felt the instability of sitting in the ground effect in hover for too long. The problem is that I have flown the sim for so long at that altitude and never noticed it to that degree.

I have never had a FP Heli so I can't say how well they work or how robust they are. I can say that I am pretty glad I waited for the current generation of CP 3D EP Helicopters. This thing is a blast. The other night I was rookieing out in my garage before I got the Gyro sorted and overcorrecting the pitch. I had the poor heli bouncing off the floor and going to the roof then bouncing off the floor again about three times befor I hit the motor Hold and grabed the thing. Luckily, no harm done at all. Lesson learned and I only fly outside now. I am not sure how you could break the Fun Picollo skids off so easy. It took a pretty major tip over in the ground effect in my yard to break the LF foot. I just drilled a small hole in the skid frame and used some safety wire till I get a bit better at this. In the 4th picture you can see the safety wired LF foot. All of the feet are a bit muddy because we have had a lot of rain recently and the baseball field I use for EP flying is pretty muddy.

Anyway, Here's some pictures of how mine came out.

RCXPLANES

My Feedback: (1)

Here is a few more Pics.

I am wondering if the 9T pinion is a bit strong for this thing. I have heard that too much headspeed can cause some problems with gyro response, cyclic response and other stuff. Any thoughts on the 8T vs the 9T with the Park 400, 4200 kV motor?

I was also wondering about the Blue Bird BMS-371 servos for this thing.

skyhawknut

My Feedback: (3)

Your the only one I've heard of that has flown the park 400. I'm thinking about this combo and was waiting to hear from you on how it went. For what little money it would cost - I would buy the 8 tooth and try it.

How was the pitch response? Did it feel underpowered at all? (in pitch response).

RCXPLANES

My Feedback: (1)

Skykawknut,

I think you are right on the money again so I've ordered the 8T pinion. I am using a flight mode with these curves when I fly.

Throtle:
100, 90, 80, 90, 100
Pitch:
-100, -50, 0, 50, 100

Pitch response is almost too much for me at my ability. It just responds to pitch inputs very agressively. It will lift off at just past 0 pitch and feels like it would just keep going if too much positive pitch were left in. I have yet to aproach full positive pitch. At about 1/3 of zero to full pitch, it lifts off with authority and I must very quickly return to hover pitch around 1/4 travel and steady it at eye level. I don't have any experience with full sized nitro helis so it is hard for me to compare. With a little forward cyclic the thing just starts to haul the mail and seems to respond well to coordinated turns.

If anything it may be too hot for a newbe with the 9T pinion. I haven't been able to try a different throtle curve yet but I have a feeling that a bit less head speed would benefit a pilot with my abilities. I may try to reduce the throttle curve a bit before I put the 8T pinion on. In fact it seems to do everything except cyclic changes quickly. Both cyclic servos are on the inside hole so there is definetly room for speed there. On the sim, a bit quicker cyclic response has saved me more than once. I have yet to do anything but fly upright so I can't comment on the 3D capabilities. When I have gone into negative pitch on a tilted landing, it plants the TREX to the ground with authority. I am certian it will hover equally as well inverted if I could do it.

It's been pretty windy here lately so I have shelved it for a few days.

Bud

FlyinTiger

My Feedback: (45)

Anyone else getting a really warm motor after normal flying (no 3D) for 15 minutes? I can't hold my fingertip on the motor for more than about 3 seconds. The battery and ESC are just warm to the touch, as I would expect.

Setup: Explosive 3D Combo from HeliHobby

Trex 450X with wooden blades
8T Pinion
E-Flite 4200kV Brushless Motor
Phoenix 25 ESC
Deans Connectors from battery to ESC
Thunder Power 3-cell 1320mAH Li-Po
Hitec Eclipse 6 RX
Heli 9303 TX

Pitch curve: -100 -50 0 + 50 + 100
Throttle curve: Normal Mode 0 25 50 60 70 90 100

Hover is at slightly above center stick. Still working on getting an optical tach and an infared heat sensor.

Any advise would be greatly appreciated.

skyhawknut

My Feedback: (3)

errolw98 - is using a 9 tooth pinion and a heatsink and says he can hold his finger on it for 20 secs. A heatsink is mandentory for this heli - I don't think anyone has found the 'perfect' motor for this heli yet. Try a 9 thooth and heatsink - that may put the motor closer to it's efficency range.

As a side note - Helihobby used to include an 8 tooth pinion and now includes a 10 tooth pinion in their combos?? They must not have been getting enough headspeed at too high an amp draw, so they went to the 10T.

dornier

Hi,

Isn't there a cooling fan built into the helicopter for the motor?

George

Erich_F

Yes, there is an integrated fan on the tail drive gear. This is why I positioned my ESC under it, with the HS up.

I'm not sure how much air is blown over the motor, however. It's easy enough to install the Align Heatsink though.

Erich

FlyinTiger

My Feedback: (45)

I was puzzled when HeliHobby included the heat sink in all their combos EXCEPT for the "Explosive 3D Combo." They are still including the 8 tooth pinion with the Explosive 3D Combo so I am wondering if I need to increase the head speed.

What I really need is for someone to give me a head speed that is correct for this heli, then I'll get the motor to turn at the right speed with the correct pinion.

skyhawknut

My Feedback: (3)

Weird - when I looked yesterday they said a 10 T was included. Now it's back to an 8T.

Guys on the other forum like a headspeed around 2400 - 2700.

FlyinTiger

My Feedback: (45)

Thanks Skyhawknut, I'll get that head speed right. The other combos come with different motors and maybe different pinions. My E-Flight 4200 kV motor came with 3 pinions and the heli came with one, along with the aftermarket 8 tooth pinion I ordered, so I should have one that will work.

Now to get an optical tach...

WhirlyGirl

My Feedback: (34)

Yeah, get an optical tach...I bet your WIFE would REALLY, REALLY like one!!!!!!!!!

FlyinTiger

My Feedback: (45)

Okay, I give up, she caught me. My wife is WhirlyGirl and she needs an optical tach so she can set up HER T-Rex correctly. Like anyone would have believed me if I said "My wife has a couple questions about her T-Rex..." They would have thought I was coping out. Well, now you know.