700 My New T-Rex 700X Build

[fran11784]

Now you got me thinking, I will take a closer look. I probably have 25-30 flights on it but I'm no 3D pilot. I wouldn't be happy with 3 turns either. Just a side note, I built the kit version and used Savox servos. Cant be much but maybe a slight difference there...
T

 

[Smoggie]

It's possible that different servos have slightly different output shaft positions. Mine has the standard 'Super Combo' servos.

 

[Heliman450]

Hi guys, I was also concerned about the security of the links having had an issue with my T-Rex 550. Steve helped out with some longer links and I used one of a pair he sent and an original to get the nice fuzzy feeling on it. This time, I decided to go for M3 threaded ends and 6 mm tube as the original just looked a bit feeble on the 700X. I also decided on the PTFE tape as it took 8 turns to get what felt like a good firm grip. I've now got 5 turns each end with zero pitch on the blades but I still feel that longer links would improve the quality of the finished product, maybe because the threaded ends are so long

 

[sgtray]

I have a trex 600 that just got rebuilt but I think my question can be answered here also:
I just got the castle BEC (10amp) and the hobby store gave me a 6.6v 2100mah Lifepo4 battery.
Is this ok? (I've never used a Lifepo before)

 

[Smoggie]

I have a trex 600 that just got rebuilt but I think my question can be answered here also:
I just got the castle BEC (10amp) and the hobby store gave me a 6.6v 2100mah Lifepo4 battery.
Is this ok? (I've never used a Lifepo before)

No, the Castle BEC is intended to be powered off the main flight battery. Is your Trex the 6S or 12S powered version? If it's 12S the Castle BEC Pro might have been the better choice because it can accept 12S input voltage and it's got higher output rating, but the 10A version will work if you tap it into the wiring harness so it's taking power from one battery instead of two, like this:


Alternatively you could skip the BEC and use the 2S LiFe to power the receiver/servos directly. You dont need both the BEC and a 2S LiFe, it's one or the other.

 

[sgtray]

Thanks. And you don't see any problem with just the life running the RX and servos till I get the main battery tap done?

- - - Updated - - -

oh and I'm running a 6s

 

[Smoggie]

Yeah, the LiFe pack will be ok providing that you aren't running older generation servos that have a hard 5V limit. If you are running Align DS610/650 or DS615/655 servos then many people have ran them off a 2S LiFe without issue.

 

[Heliman450]

Hi guys,

I always wondered if I'd get the chance of using this 'smiley'

Just kidding, interesting stuff so I copied it over to my 'Reference' section.

 

[Smoggie]

Hi guys,

I always wondered if I'd get the chance of using this 'smiley'

Good point, sgtray, if you want to start a new thread on your heli build I can move these posts over.

Phil, So when is the maiden planned for the 700X, must be close now? By the way, good that it looks like there was no damage done during the short circuiting between Rx and FBL, that must be a relief!

 

[Heliman450]

Hi Steve,

I'm still waiting on a reply from B.D. before I can complete the setup to my satisfaction. Yesterday, I went through my DC-14 making sure it's setup properly and then I'll go through the Axon once more. Fingers crossed on B.D., they were at an exhibition until today, so I suppose it depends how much backlog Joachim has in his system until he gets round to me.

As it isn't in stock I also ordered up a USB Adapter for my REX7 receivers to update the firmware, which I've never done. It prevents me from accessing some of the data and I noticed the 550 was reporting that I need an update but haven't got round to it yet (my bad )

I hope to maiden on Thursday. Also see the PM I'm about to send you.

 

[sgtray]

Thanks I didn't see a tread for it. sorry. But that was my only question

 

[Heliman450]

Thanks I didn't see a tread for it. sorry. But that was my only question

Hi there sgtray,

No problem, it was an interesting subject. I see you're new to the Forum. You can start a thread yourself by visiting the home page and selecting the basic subject from the list. In your case it's located here: Power Supplies

Good luck with your flying and Forum questions in future.

Bye!

 

[Heliman450]

Hi all, latest update.............

Tomorrow, I'll be running through my Axon setup again after spending a lot of time on the Tx. without it being bound to the heli. I'll need to carry out the binding again as it's a new model now and also repeat the fail-safe setting.

I got a reply from Bavarian Demon but not what I wanted so I may have to pursue that one again, we'll see.

Bye for now!

P.S. Apologies to anyone who thought I should already have got it into the air by now. Please be a bit patient

 

[Heliman450]

Hi all, tomorrow's the big day! I've finally got my rather embarrassing bad sorted out

I had a real mess with my channel assignment in the Jeti DC-14 Tx./Jeti REX7 Rx./Axon software. I'd been putting it off in pursuit of correctly setting up the mechanical side of things and have finally got to a point where I'm prepared to flick the switch and go for lift-off. Last job will be to stick the gyro into its final position and glue a couple of screws. I'm going to leave the canopy off for now and do the reinforcing job Steve carried out on the mounting holes later.

I'll gladly publish the stuff from setting up the Axon but it's probably best in the gyro section.

Wish me luck

 

[Smoggie]

Good luck Phil,

Just double and triple check that both control response and gyro correction are working in the correct direction... I'm sure that getting that wrong is #1 cause of maiden flight crashes (excluding dumb thumbs)

And one more thing

 

[Heliman450]

Hi all!

Well, she has successfully lifted off without drama, hovered around a little and is back at the workshop without needing a rebuild, just a few adjustments and the batteries charging

Oh, the video I hear Steve asking. It's on my laptop now, not so interesting as yours, Steve I have to admit. I'll upload it tomorrow as we're having our annual Xmas bash for the flying club tonight and I've got to do my taxi job and collect she who must be obeyed in about 20mins.

Bye for now!

 

[Smoggie]

That's great news about the maiden flight Phil, how did you find it to fly compared to the 550?

I got four more flights on mine today too, nothing exciting but all flights passed without incident which makes it a good day. I installed a 'Jlog' unit on mine today. This passeds on data from the ESC and back to the Tx via telemetry, so I have more data on the Tx than i know what to do with, rotor RPM, battery amps, battery voltage, battery mAh used, Rx voltage, ESC temperature.. the list goes on! Most of it's probably more novelty value than anything else but the mAh used will be useful as an additional safeguard against over discharging the batteries.

 

[Heliman450]

Hi Steve, I think first flight is a bit too exaggerated, first hover is more of an accurate description. Here goes.............

[video=youtube_share;lc1LsGhOrxI]https://youtu.be/lc1LsGhOrxI[/video]

I noticed that it's a lot heavier than my T-Rex 550 as you can see by the rather hard landing. At least nothing broken

Next job is to change over the connections on my batteries and 550 ESC to the Supra X so that I can get more time in the air. I'll also buy another two pairs of batteries but that can wait until springtime when the weather warms up a bit.

Hopefully, the folk at Soloshot will get their v3 camera on the market soon. In the meantime, I must tackle my home 'to-do' list to keep my good lady smiling.......

 

[Smoggie]

That was flying in my book! looks like maybe she's a little sensitive on the cyclics, you could maybe dial in some (more) exponential on aileron and elevator? FWIW I always start out with 20% expo.

 

[Heliman450]

That was flying in my book! looks like maybe she's a little sensitive on the cyclics, you could maybe dial in some (more) exponential on aileron and elevator? FWIW I always start out with 20% expo.

Hi Steve, I wanted to see how the gyro took over so I hardly made any cyclic input. Just enough to keep it in the frame. After about 1min 30secs it begins to settle down and I didn't need to give much correction at all to keep it steady. I'm sure it will need some more fine tuning before I can move around more. The gyro is programmed for 'Normal/Scale' at the moment and looks good to go. Thanks for telling me about its forthcoming release when I was at the beginning of the project, looks like a good buy.

I'm now using two different gyros and looking forward to making an informed assessment of which is best. Neither have particularly good instructions to help out the less experienced builder but both support guys were very quick off the mark to provide help.