Which Transmitter?

[jocatch]

Guys, did you know there is a ton of info out there on everything helicopters? There are so many resources like this forum, RCGroups, RCUniverse, TrexTuning, etc, etc that I am a little bit overwhelm will all the info.

I am putting together a Trex 450XL. I also have the Honey Bee FP2 which I am learning (or should I say crashing) to fly. I am absolutely new to RC and flying and old (over 50). What I am looking for is an inexpensive transmitter for the Trex. I would like to have one with PCM and I plan to use HS55/56 servos and a GY401. I need for it to interface via a cable to some good flight simulator program for the PC. I don't need anything fancy other than that.

I would guess Futabu or HiTec but I need some more input like model numbers and brands. Any suggestions? (The ability to connect to a flight sim is very important).

Thanks.

Joe C

[Rick Rotorhead]

Yes there is an overwhelming library of info on HF alone! Best advice I can give is read all the threads pertaining to your heli and copy the relevent bits into a separate document (eg: in 'Word'). Make Finless's HF Tech Room your first stop.
Read all you can about peoples recurring problems with their Trex's (like disintegrating tails and various wobbles). Copy the issues and solutions into your Word file for later reference. Same advice for your FP machine (I've got a Blade/HB CP clone myself). Doubless you've read the 'Flight Sim' section here in HF - its all good stuff! (I use Reflex XTR myself - its just so realistic). As for Tx choices, you'll see loads of advice, weigh the pro and cons carefully - as everyone says, models come and go, but you'll keep the Tx for a long time, so do spend as much as you can on a really good one - for starters the Futaba 7 CHP will do all you need and more - there is a similar Hitec Tx also - just look up the manufacturers web sites for tech specs, Then also see how model flyers rate them in the forums. I'm afraid you'll also have to cope with the jargon, but its important to know what is mean't and talked about in the various forums - it will come in time - I've had to learn and understand loads of new stuff that I didn't know about from airplane flying days, (like Throttle and pitch curves, Gyro types, battery terminology etc etc). Most of all, don't rush it. Read, understand then make informed decisions, it will save money in the long run.

[jocatch]

Well, not sure if I got ripped off or not but last night I went to a local RC store and picked up a used Futaba 6EX for $150. It came with two 3108 servos and the 156F receiver. The unit was only used once or twice and looks brand new. I say ripped off maybe because it came with only 2 servos and the FM receiver whereas I thought it was PCM. I guess a new receiver would get me PCM. I hope the 3108s are good for the Trex XL. I am also surpirsed that the manual for the 6EX doesn't say how to power up the receiver. It only has a socket listed on the receiver as Ch 6/Battery Power. Hmm. I guess I still need to get more info.

Joe C.

[Bayou Talker]

Does the transmitter say 6EXHP or just 6EXH? If there is no "P" then the transmitter is not a PCM version and will not work with a PCM receiver.

As for price, the non-PCM version goes for $169.99 at Tower Hobbies with receiver, 4 servos, battery, charger, etc. The PCM version goes for $219.99 with all of the above. If you shop around, you might just find a better price than those.

[kgfly]

While you're researching radios, look out for discussion of the new 2.4GHz Spread Spectrum technology - Spektrum DX-6 (and the associated JR6102 conversion).

This offers the best probability of glitch-free operation together with high security against channel conflicts, lock-outs and shoot-downs, plus the advantage of no waiting for your frequency to clear at the flight line.

There are lots of people using DX-6 setups on TRexes with great success. Many have done the 6102 conversion but for a beginner (like me!) I don't see any compelling need to do so.

Good luck,
Kenneth

[jocatch]

The transmitter is a T6EXHP and the receiver is a R156F so it looks like the transmitter can do PCM but not the receiver.

When I set up my RC plane years aog (which I never flew), the receivers always had a seperate plug for power. But these new fangel receivers look like they get their power from a servo which mean I don't have the wiring needed to power it up. I assume once I get an ESC/BEC that this will all makes sense.

Joe C.

[Bayou Talker]

The power lead will come from the ESC and plug into the throttle channel. It will both power the receiver and control the throttle.

[ronaldf]

jocatch,

I'm in the same position as you except I'll be 61 Saturday. I started with a Honeybee CP2. After fighting the HB CP2 for about a month and not advancing very much I started looking for some thing better. I got a T-rex 450XL CDE kit and started building it and gathering the electronics. I ended up with a Futaba 7CHP, FM reciever, Align 430L with a 35x ESC, Hitec 56 servos and a 401 gyro and s9650 for the tail. Today I started hovering the rex. A major improvement over the HB. Much more stable. I'm sorry that I didn't start with the rex in the first place. the HB was a waste of a $200.

[jocatch]

Ronaldf, Thank you! You made my day!!!!

I still don't have my Trex together but I have been flying the Reflex Flight Sim and it seems to be alot easier to hover than the Honey Bee. But I wasn't sure as I have never progressed much with the Honey Bee. When I tried to fly it, I would fly, crash,repair, fly crash, repair, fly, crash, repair. Unfortunately, the repair part sometimes takes a while to get. And after a crash, it is like starting over again as things have change and the HB isn't exactly the same as before. You have given me some good encouragement!

I am using the HS56 for the tail and 3108's for the others as those are what came with the Futaba 6EX. I just ordered the Align 430LF. I still need to get the ESC/BEC and gyro.

Joe C.

[ronaldf]

I very happy that I went with a kit instead of another ARF or RTF. I learned a lot about the mechanics of helis building this bird. To me building is half the fun of this hobby any way. I'm sure that my rex isn't set up perfect, but it is good enough for my talents! I have the finless videos to thank for that.

The 3108 servos are not rated for 6V so make sure you get an ESC with a 4.8V BEC. I had gotten the 3110 servos and couldn't use them because I have the Align 35X ESC and it has a 6V BEC. The 3110s are going into a custom micro. It will be a belt drive, alum frame, metal head, brushless 370 micro monster I hope!

[jocatch]

Well, I have had a slight change in equipment. I am not using the 3108s (I only had 2 to start with) because they are very small and wouldn't mount in the servo openings with modification or jury rigging some kind of mount. So I went out and got 4 HS56HBs and put them in last night. The box for the servos says "At 6.0 volt" yet the specs on the other part of the box gives the specs at 4.8v. Go figure. I believe the receiver will work at either 4.8 or 6. So I'll plan to get an BEC with 5 volt output. Actually, if I can't find an ESC/BEC, I was thinking of making my own 5 volt regulator using an LM7805 or something along those lines. I have made alot of electronic stuff in the past. And you are right, half the fun is in the building. I also build and fly rockets and I go on Ebay all the time to see what kits people are selling. The rockets already put together hardly ever sell because I think people want the fun of building (and custominzing) themselves.

I would like to sell the 3108 but I don't think I would get much for them.

Joe C.

[kgfly]

Joe,

Don't worry about the 6V on the servo box, they'll work fine and probably last longer at the standard 4.8V.

You can make a BEC using a linear reg (there are commercial ones like this) but it will run quite hot and waste some power. Remember you will be regulating down from as much as 12.4V (for 3S) at up to 2A, so you could be dissipating as much as 20W in your reg! If you have the skills and want the challenge, build a switching regulator, but be careful about EMI/EFI as you don't want to upset the rest of the electronics with noise from your regulator.

Kenneth