T-Rex 450pro Build

[9sec240]

Scott, that looks awesome!! ROCK solid hover. I saw you wiggle that collective a bit... looks like it is going to be fast like mine!

I like the white walls in the place you are flying. Makes for seeing the heli a bit easier than the Field House was for me.

I noticed your have your timer set for 4 min. What battery are you running?

[dunkonu23]

Thank you so much, Ivan. You've been great helping me get it sorted out. It sure felt great. I really like the helicopter! I bet if you flew mine, it would feel just like yours. About the only thing I changed curve wise was to bump up Idle 1 to 90-85-90 and Normal to 0-50-70-85-90. It's the first time I've had normal and idle so close in the flight zone. It's hard to tell the difference in speed, but it's there.

You know the white walls thing had me really worried before I changed canopies. I think with the stock version 1 canopy, it may have blended just a bit too much. As it is now, except for a couple of angles, it's pretty easy to see.

I'm using some Outrage 2200 20C batteries I had bought for my BH500. They're low on power, but it's cool for what I'm doing right now. Each of the five packs I have are at 30 flights, but they've been sitting for a bit with storage charge on them. That said, I put back about 300mAh less than I thought I would so I could stretch to five minutes if I wanted.

I'm looking at new batteries for when the weather breaks, though. What are you flying in yours?

Scott

[Jerrymac]

Lookin good Scott. Nice stable hover. Seems you must have got it sorted out. You are getting pretty good with the hat cam too, if that is what you were using.


Edit: Just saw your video where the tail blades touched and damaged the tail drive. Sorry to see that Scott. I didn't know the torque tube drives were that fragile. I have mowed lots of grass ( and sometimes dirt ) with the tail blades on my BH450 and never damaged anything. I think I will stick to belt drive on all my helis.
Hope you get it back in the air soon.
BTW, I am still a little baffled by the warm vs cold drifting thing. I think I will ponder this some more. Bill might have an idea though, as it being something with a servo maybe, I dunno.

Have you tried flying any of your other helis in the same cold weather to see if maybe something in the TX is affected by the cold making it drift, and not the 450 Pro?

Jerry

[dunkonu23]

Hey Jerry... Here's what I posted over on RCU....

Hey Jerry,

Yep... I've flown my Gaui/Head Hunter outside. No problems. Because the Gaui flies fine in the cold doesn't really serve as a control, so here is what I did today.

1. I exercised the servos at room temperature without links connected and noted their response.
2. I reconnected links and exercised servos at room temperature and noted there was essentially no difference in response from 1, above.
3. I removed links first from the servos and noted free tightness (actually, I did that during 1, above, but you get the picture) at room temperature.
4. I returned the links to the servos and removed them from the swash and noted tighteness at room temperature.
5. I exercised the swash to head linkages by moving the swash by hand at room temperature and noted tightness.

i repeated this procedure outside at the following time intervals: One minute, three minutes, five minutes, seven minutes,15 minutes, and 30 minutes. Air temp this morning was 18 degrees (we're expecting snow this afternoon).

Results in the cold:

One minute: Servo motion was normal, links felt the same.
Three minutes: Servo motion was normal, links felt a little tighter.
Five minutes: Servo motion was normal, links felt a lot tightermotion was free but tight, swash to head links felt pretty tight.
Seven minutes: Servo motion was normal, links were a little tighter than at five minutes, swash to head links were pretty tight and washout base motion was not smooth.
Fifteen minutes. Same as above.
30 minutes: Servo motion was normal. Links were a bit looser but not as loose as as room temp. They were still tight, but the washout base was free again.

i didn't try to fly at 30 minutes because I still haven't replaced the gear I stripped Tuesday. Gear replacement will happen tomorrow.

Conclusion? Cold bad. Warm good. I'm thinking the washout base may be the cause. Thoughts?

Scott

A few minutes later, I thought about it and decided the washout base can't be the cause. It can be contrubutor, though.

The radio idea is a good one, but today, I did check that. I had the radio outside and I felt nothing abnormal.

Scott

[dunkonu23]

Did you hear my little comment, too? I thought I had edited that out... oh, well.

Yeah.. I was using the hat cam. Tell me I didn't feel odd! It's cool, though... I had a blast flying indoors. I just wish it was closer. I also wish the flying boxes were larger. I'll get better flying in a closed in spot, though. That's probably a good thing. I bought a five session ticket.

Scott

[9sec240]

Scott, I am flying Turnigy 2200 20C batteries in all my 450s. For me, right now, they are just fine. I go 5 min on the Pro with them.

[dunkonu23]

Ivan,

I was looking at batteries last night. Turnigy batteries seem to be the best value for the money. Heck, when you can pay $17.85 for 40C pack that will charge at 5C, it's pretty much a done deal! Their specs regarding size and weight compare very nicely to the Hyperion and Thunder Power packs. But the price? Wow!

I'll be ordering some soon for the spring. In the meantime, my 20C Outrage packs do great!

It's funny, I have a Flightpower 2150 25C pack and it went into LVC immediately after takeoff. I'll try again after I've cycled it a couple of times on the charger.

Scott

[dunkonu23]

Something, other than the binding links was bothering me with the T-Rex 450 pro. I noticed the swash, in negative collective wasn't going down as far as it should. So, today I went through a complete setup but prior I found my pitch range was +11,-5. My links were the correct length because at 50 in and 50 out, the washout arms were level. Had to look elsewhere.

First place, set the swash mixes back to -60, 60, 60. Still not equal pitch, but I can tell you with a little more on the pitch setting, this thing can easily get +-15. I doubt I'll ever be there. Moving on, I looked at servo endpoints.

Sure enough, that's where the problem was. I guess in my haste to fix the binding problem, with each setup I had performed, I was reducing negative throw. So, this time, I set them back 100, 100.

What I did is what I forgot to do earlier. Using the Trueblood 450 pro swashplate leveler, I found the one point that was contacting the leveler at full negative and brought it down until the other two points came into contact with the leveler's arms. That easy.

Same thing for positive pitch only I brought the other two end points up until they contacted the leveler.

Lesson learned: If the servo to swash links are correctly sized, endpoints can be used to restore equal pitch.

Final, accurate settings are: +-11 collective pitch, +- 7 cyclic. With final settings being rendered through the swash mix menu.

Scott

[dunkonu23]

Another front tail drive gear stripped. First flight. I figured I'd warm up on the first pack...well, a minute in, the helicopter was flying even better than last week. Literally 15 seconds in hands off!!

Then it started... piro's, pitch pumps, getting ready to try a flip...one more pitch pump, hit the turf, gear stripped. My bad! No video, though... I was going to start that on the second pack.

I did get to help someone who has a bad tail drift. I found a lot of binding in the pitch slider, so we backed off the screws in the assembly one turn at a time. No more binding. Bummer is, the person had on threadlock and I didn't bring any so that was the end of that for both of us.

Home early... recorded House so...that's my early afternoon.

Scott

[dunkonu23]

Trex 450pro Crash... component failure. Upon retrieving the helicopter, the servos were jumping, the ESC was arming constantly, and the lights on the receiver were blinking.



Scott

[Jerrymac]

Sorry to hear that Scott. It was a little hard to see what happened in the vid, but looked like you lost all control of it, and it just kinda continued on in a straight line till it hit the deck.

Do you know what caused it yet? ESC failure? I had that happen on my BH450, but only the motor quit, I still had servo control to do a half-assed auto to get it down.

How bad was the damage? That sucks as I know the 450 pro was your favorite heli.

[dunkonu23]

May 30, 2010 2:57:03 GMT -5 Jerrymac said:

Sorry to hear that Scott. It was a little hard to see what happened in the vid, but looked like you lost all control of it, and it just kinda continued on in a straight line till it hit the deck.

Do you know what caused it yet? ESC failure? I had that happen on my BH450, but only the motor quit, I still had servo control to do a half-assed auto to get it down.

How bad was the damage? That sucks as I know the 450 pro was your favorite heli.

I stripped it in the wee hours... I found a couple of teeth missing on the main gear, bent boom, bent flybar, broken Jesus bolt, and that's it mechanically. After I pulled the boom, I powered up and found the elevator servo does not want to move. It's very tight. I think that is the cause of the crash. If I do not move the sticks. The lights on the receiver as solid on. Move the sticks, the lights flash and the servos chatter... the aileron servo lags behind, as well. It's also very, very tight compared to the other servos. I've ordered the aileron and pitch servos, so I'll replace those. I've got another ESC in hand and can replace that if necessary, but I'm thinking the servos are just drawing too much.

Anyway, I'm getting a big parts order ready so I don't have to wait around. I need more stick time!

Scott

[Jerrymac]

I remember a while back when Bobbybe over at Freak had a similar problem with his Hurri after installing new Align servos on the cyclic. He posted a vid of it sitting on the bench and moving the sticks around. The servos would all chatter, but I noticed that the led on his gyro would blink too.

I suggested to him that it looked like a power issue to me. What he found was that the bec in the esc would not handle the draw of the new servos. He installed a separate bec and it solved the problem.

I know you have flown your 450 pro many times before with no problems, but maybe the hotter weather is causing an issue with the esc/bec, I dunno, just a thought.

Of course, I don't know what electronics you are using in it, so I may be way off-base here too.

[dunkonu23]

May 30, 2010 14:44:11 GMT -5 Jerrymac said:

I remember a while back when Bobbybe over at Freak had a similar problem with his Hurri after installing new Align servos on the cyclic. He posted a vid of it sitting on the bench and moving the sticks around. The servos would all chatter, but I noticed that the led on his gyro would blink too.

I suggested to him that it looked like a power issue to me. What he found was that the bec in the esc would not handle the draw of the new servos. He installed a separate bec and it solved the problem.

I know you have flown your 450 pro many times before with no problems, but maybe the hotter weather is causing an issue with the esc/bec, I dunno, just a thought.

Of course, I don't know what electronics you are using in it, so I may be way off-base here too.

The weather theory is entirely possible. I want to eliminate the servo that is tight first. I've ordered all the parts I think I will need, including a new ESC. Yep, I ordered an Align ESC. I am using the electronics that came with the 425pro Superior Edition.

Scott