700 T_Rex 700E DFC setup?

[SIXFOOTER]

So I have had this bird hanging on the wall ever since I got it a year ago. Some reason I decided I needed a bigger bid and got a pretty good deal on this thing so I bought it. Had no idea it was this big, holy . SO I was scared of it and hung it on the wall. Now I think I am ready to do something with it. I need a recomend for a FC or Gyro, whatever will make it easier to fly.
Also need a pointer to a setup to go through to make sure it is good to go before trying it.
This will take some time but its a waste just hanging there

Thanks
Danny

 

[Smoggie]

Danny,
If you want it to be easy to fly then go for a flybarless controller with 'auto-level' stabilisation. There are a few choices available:

• Brain2 or iKon2 (same thing with different name)
• Spirit Pro
• BeastX Microbeast Plus
• Spektrum AR7210BX

The microbeast and AR7210BX end up more costly because you have to buy an expensive firmware upgrade to enable the self level functionality. The AR7210BX does have the advantage of a builyt in receiver (if you fly Spektrum), but personally for me it would be the Brain2/iKon2 or the Spirit Pro.


Is the heli complete other than the FBL controller?

 

[SIXFOOTER]

Yea its complete. I need to look into the electrics, it is supposed to run off 2 big batteries

 

[Smoggie]

They fly on two 6S 5000mAh batteries wired in series to make 12S. I'd recommend 40C or higher unless you fly very gently. Depending on how the receiver and servos are powered you may need a seperate receiver battery. What servos does it have fitted and is there a BEC installed?

So it doesnt already have a flybarless controller fitted?

Photos would be good.

 

[SIXFOOTER]

Well I feel really stupid about now. There is an AR7200BX installed on it. Castle Ice 120 ESC, all the servos are Align, 3 DS610 and an align DS650 for the tail. Align RCM-BL700MX MOTOR
Don't know why I didn't remember that Rx in there but it is.
2 battery connections, 1 for the ESC and another one to a BEC? looks like its to power the AR7200BX
I'll get pics up tonight. I have 1 45C 5500 battery I need to put a connector on. Guess I need another one, what to feed the BEC with?

 

[Tony]

Post some pictures of the 'connectors'. That almost sounds like the series connector to get 12s out of it. And just about any BEC will work as long as it can withstand 25 volts. Just connect it to one battery, or better yet, use a separate battery to run the electronics and the two large batteries ONLY to run the motor. Much safer that way and if you kill the ESC or motor, you still have control over your servos to bring it back down.

 

[SIXFOOTER]

OK so I don't know how the guy had the batteries wired before, but as I understand it I need to make a wire harness to tie 2 6s batteries in series, ok, got that.
What battery to run the electronics?
Here is the ESC

BEC?

FC

motor

Servos

 

[Smoggie]

The BEC you have there is actually not a BEC as such (because it doesn't eliminate a battery) but a voltage regulator. It must be powered from it's own 2S LiPo, this is the part: 6A External BEC w/ 5.1V Two-way Step-down voltage reg K10382A - English

I'd strongly recommend that you remove it (they really dont have adequate power rating) and simply use a 2S 'LiFe' (LiFe not LiPo) receiver battery and connect it up without the regulator. Alternatively get a good quality HV BEC such as a Castle BEC Pro or Gryphon Quasar and power from the flight packs.

PS.. some of the connections into the AR7200 look like they aren't plugged in all the way! A lot of people use a blob of hot glue to secure the connections into the FBL to stop them vibrating out.

 

[SIXFOOTER]

Thank You! Eliminating the regulator makes sense, simpler is almost always better. What size 2s you think? I started reading on the AR7200 setup last night, a lot to absorb, will take ma a bit. I think I should be able to go all through the setup without the flight packs correct?
Does anyone have a recipe for this thing to run on a DX8?

 

[Heliman450]

Hi SIXFOOTER,

The arrangement for the power supply looks identical to how it was with my T-Rex 550 when I bought it second hand. I dumped the separate 2 Cell battery when I upgraded to a better ESC (Hobbywing 100A) but had no actual problems with it beforehand. I was just advised to keep it simple by my supplier. I use it now with the switch unit for a separate power supply on the bench without using the flight battery.

I also looked at your pictures, check carefully what's plugged into the different connections. It looks like 'Aux 1 and Aile' aren't plugged in the correct way round. The signal wires should face upwards (same side as the labels). You should be able to see a signal cable (white or orange) on the 'THRO' connection and nothing is plugged into the 'RUDD' connection. During flight, nothing should be plugged into the 'BND/DAT' connection.

Below is a photo of the Blade 450X I just set up for a friend.

Good luck!

Phil

 

[Smoggie]

Thank You! Eliminating the regulator makes sense, simpler is almost always better. What size 2s you think?

Sorry, I missed this reply. I use a 2S 2200mAh on mine which is plenty big enough for at least six flights.

 

[Heliman450]

Hi Danny,

On reflection, I think you should take a step back and think about what you want to achieve. You need to consider the budget that you're prepared to put forward into the project. If it's just a straight forward 'get it into the air' project, then you probably have enough bits and pieces already outside of the batteries to power it of course.

However, the hobby moves so fast and if the bird has been in your possession for a year already plus whatever it's been doing beforehand (it looks a second hand purchase to me), then you're probably best following Steve's advise and buy some new stuff to upgrade what's there. Personally, that's what I'd do as the existing AR7200BX doesn't provide you with the stabilisation features included in the gyros suggested in Steve's earlier thread.

If you decide for a separate power supply to the gyro, then you'll need to cut the red wire from the connection to the ESC and only leave the signal and neutral wires for throttle control.

Give it some thought and come back to get feedback on your ideas for the way forward.

 

[Smoggie]

If you decide for a separate power supply to the gyro, then you'll need to cut the red wire from the connection to the ESC and only leave the signal and neutral wires for throttle control.

That's the case if the ESC has a built in BEC and you are adding a seperate external supply (it avoids the two supplies 'fighting' each other).. However the Trex 700 comes with an ESC that doesnt have a BEC. In this case you must not disconnect the red wire because the ESC relies on taking voltage from the red wire to power the controlling circuitry in the ESC. If you disconnect the red wire on this type of ESC then the ESC wont work.

 

[Heliman450]

Hi Steve,

Thanks for the clarification on the ESC. I was interested to look up some info on the 700 as my farmer friend tells me he also has one and I'm going round to use his receivers to do some checks on his DX6's before turning them into the local hobby shop for a checkup.

I followed the link Castle Creations | Phoenix Ice2 HV Controllers to check out what's involved. Was the pictured ESC the standard supplied one? The manual I was looking at seems to suggest that the ESC was not supplied with the kit. Is this the case?

Cheers.

 

[Smoggie]

Hi Phil,

All the Trex 'Super Combo' kits come with an ESC and basically everything else you need except batteries Rx and Tx.
The standard ESC that came with the Trex 700 DFC a couple of years back was the Castle Ice2 HV 120A. Later versions came with the Castle Edge HV 120A (or 160A). All the Castle HV ESC's are 'OPTO' which means that the low voltage control side of the ESC is 'optically isolated' from the HV side, they have no BEC. The red wire must remain connected and you must run some form of external BEC or Rx battery. They are pretty good ESC's i've used a few over the years though I prefer the Hobbywing these days. I still have an Edge 120HV in my Goblin 630.

 

[hoverinabout]

Thank You! Eliminating the regulator makes sense, simpler is almost always better. What size 2s you think? I started reading on the AR7200 setup last night, a lot to absorb, will take ma a bit. I think I should be able to go all through the setup without the flight packs correct?
Does anyone have a recipe for this thing to run on a DX8?

Old thread I know. However, I wouldnt recommend removing the Rx battery supply. I know this is pretty common in the US but in the UK we tend to fly with a separate Rx battery because it gives you a separate supply for your radio and does not leave you without power if you over extend you flight pack. The Align regulator is fine for 2S lipos, I use one to power the rx in my TRex 600.

I know some people say its another point of failure and another battery to charge, well yes, it is another battery to charge and if you pre flight properly, there's no reason for it to fail. As for forgetting to charge it, if you're charging flight packs, why would you forget the Rx battery? Ive never forgotten it yet. It also gives you the advantange of adding balancing weight that is serving a purpose rather than just being 'dead' weight.

Personally Id never recommend any flying model without a separate Rx power supply. Might beok for small models but not large (700 size) models.

 

[Smoggie]

Each to their own but I've given up using an Rx battery on any of my helis. I now use HV BECs (or ESCs with BECs) on them all and they all draw power from the main flight pack, it's lighter takes up less space and is hassle free, this includes seven 700 and 600 size helis so i can say for sure it works fine on large helis. FWIW there is absolutely zero chance of loss of power to the Rx due to running down the flight pack, it cannot happen. The BEC only needs about 7V supply to work and a 12S battery pack is 50V, the motor would stop and the heli would be on the ground long long before the flight battery got low enough to not be able to supply power to the Rx.

I used to use a 2S LiPo powering the Rx and servos direct (HV servos) on a few of my big helis and it works fine (there is no regulator or BEC necessary with modern HV servos). That's a perfectly good solution but i just find the option of a HV BEC more convenient . A lot of good quality ESC's have BEC's built in these days anyway so why not use it?

Different if you are flying Glow (nitro) power because in that case you dont have a flight battery, so you need an Rx pack.

 

[Heliman450]

Hi guys, I concur with Steve (boring, I know but his advice is sound) and have followed this path since his advice with no problem. My 550 had a flight battery when I bought it second hand but I tossed it when I upgraded the ESC to a 100A Hobbywing. Since this, I've done over 20 hours of flight time with no incident. The heli has just entered a major service stripdown. I'm fitting a new DFC head and overhauling the current one to give me a spare to change-out next time.

Incidently, I left the switch unit in place to give me a power supply for testing purposes on the bench to save having to use a flight battery. It worked fine for a while in this service but when the power supply wire came off in my hand due to a broken joint, I decided to remove it. Good job it didn't detach during a flight.

 

[Dennis H]

These work nice for me RX Battery. Fit right in a 600 or 700. They range anywhere from 1,800 to 3,500mAh's.