brunobl

Hi,

I am considering getting into gas-powered helis (looking at the Predator Gasser). Being a total newbie in gas-powered models, I wonder how they compare to glow engines in terms of ease of operation. Are they easier/more difficult to start? When hot? When cold? Are they more/less touchy to tune? Do they all have a pull-start mechanism or is it possible to attach an electric starter (as in glow engines)? Is the ignition system a source of radio interference? Does it need its own battery (yet another batt to keep charged...)?

I currently fly a Raptor 50 and I am considering the change driven by fuel economy. Gasoline is a lot cheaper than glow fuel, but is this the wrong reason for considering the gassers? I am not into aerobatics (maybe a mild stall turn every other flight) so not being 3D-capable, or not having the P/W ratio of a .90 is absolutely not an issue for me (being able to carry a still camera would be great though).

What has been your experience, in general, with gasoline-powered helis? Are they worth it?

Am I in for an unpleasant surprise if I have high expectations for economical gasoline-powered RC heli flying (assuming, of course, no unplanned encounters with terra firma)?

Sorry for so many questions, I am looking for all the info I can get before committing.
All info is most welcome.

DebianDog

Are they easier/more difficult to start?
Easier

When hot? When cold?
Easier. Honestly... if my Condor does not start 3rd or 4th pull I start looking for other problems. I swear this is the procedure that works 99% of the time.
- Push fuel bulb till return line is full of fuel
- FULL choke
- ONE pull and only (1) pull
- Choke off
- Pull and it will start or almost start
- Pull and it starts

Are they more/less touchy to tune?

They are VERY touchy to GET tuned but once tuned (and broken in) you NEVER have to screw with them again... unless you seriouly change elevation. Like my buddy said, "How many times do you retune your weedeater once you have it running right?" Once my engine finally broke in, after about 2 gallons, it has been running like an electric with an endless battery!

Do they all have a pull-start mechanism or is it possible to attach an electric starter (as in glow engines)?
You can run a starter shaft with the smaller 231 motor but not suggested with a 231 moddifed or 260. The pull start is designed to be removed after starting.

Is the ignition system a source of radio interference? No

Does it need its own battery (yet another batt to keep charged...)?
No it runs just EXACTLY like a weedeater. Actually it is a weed-eater motor. It has just been moddified a bit to run in a helicopter.

If you DOUBT a gassers 3D ability watch this video. He runs 2 oz Amsoil to a gallon now that it is broken in.

DebianDog

Oh also here is a video I made when I did have it tuned along with some tuning advice.

Once it finished breaking in I had to lean it out a hair. The "Gasser Master" (Bill Meador) suggested that if I move the high end needle 1/8 of a turn you move the low end needle half as much (or a 1/16). Bill Meador was the first person, I know of, to get a gas helicopter flying right... years and years ago.

Gorgok

Arr. Why not continue that very informative vid? I wanna see how it works with the governor and stuff!

Also, isnt that a low headspeed? Or do that big birds fly with low headspeeds?

brunobl

First.. after seeing that first video, I've got to take back the "not being 3D capable" bit from my post. That was some impressive footage and pretty much settles a gasser's aerobatic capability, despite myths stating otherwise. Thanks for educating me with hard evidence!

Thanks also for your very informative post. It is good to be able to get first-hand information from someone who has hands-on experience. I can only imagine that when the time comes I will come back with more questions (I already have a first one... you mentioned a turn-relation between high and low speed needles... I take it that they would both be turned in the same direction, i.e. enrich both and/or lean both, at the respective rates?

And, the second video is definately a keeper. Should be saved for future reference, has tons of useful information.

Thanks a lot for taking the time to get all those answers and providing the video links. I truly appreciate it.

Oh, and I see that was your own video production/editing. Very well done! You might want to put out some educational DVDs some time, RC hobbysts would certainly bennefit from them!

Best wishes.

DebianDog

That is a Camera ship and is swinging 830mm blades (tons of lift) so you want as low of headspeed as you can get away with. Normal headspeed for a 3D ship is above 1700.

DebianDog

Yes

We are discussing it as it has generated a tad bit of interest.

zorka

My Feedback: (4)

Hi I am considering buolding one of these birds. I flew Trex for months some 3d and moved up to Hyper raptor Titan. Considering a Predator Gasser with the Zenoah engine.
What kind of investment is in one of these nirds with adecuate servos, gyros rx etc. except the radio transmitter?

Thx

DebianDog

$2000 for the heli with blades
+Rx
+Gyro
+Servos
Call it $2500

$3 a gallon for fuel

N11634

I got into a Predator Gasser for around $1700+ or - with the kit and electronics. I already had my own radio. I LOVE IT!!!! EVERYONE at your club will be envious. It gathers an audience every time I fly it. They love the smell of the Coleman fuel I run it it, too. Surprised noone mentioned that. It smell like you're grilling out. and it lots cleaner.

I do wish I'd have gotten the 26 instead of the 23, but I was told the 23 is smoother and I bought it for a camera platform but I'm having a hard time settling down and building the mount for it. It's too fun to fly aerobatics with!

Kit w/G23 - $995
V2 Torpedo Muffler (a must) - $125
Collective Servos - $206 (9252's X 3)
Gyro/tail servo - $189 (401 w/9254)
Carbon Mains & Tail - $100
Receiver - $100
and misc. parts and stuff to finish it.

BarracudaHockey

My Feedback: (11)

Nice looking Raptor.

DebianDog

CONGRATS!

N11634

Thanks, getting tired of painting it every winter, though. Even with clear coat, by the end of the summer it looks like crap and it's time to strip and paint it again. Debating on going with just vynil graphics.

BarracudaHockey

My Feedback: (11)

Yep thats what I did. The hirobo holds paint much better for some reason.

joecarbery

yes you can get an electric starter for a gasser ,,but the problem is ..is the weight of the starter and the weight ..and most importtant is space!!!no where really to mount it once the starter is on..or you could convert a gasser for a hex drive starter would be the way to go....

syclic

My Predator Gasser SE comes with both the removable pull starter on the bottom and the hex start system on the top. So I find I usually use the same Sullivan electric starter with the one-way start wand (CN0427) on it, as I use on My Predator 90.

JohnVH

My Feedback: (38)

I just got my first gas heli, Predator, but, I have flown one as a camera ship in the past, stable bird, affordable parts. Affordable fuel and no mess, no glow ignitor, no big battery and starter to take to the field.. Just a heli, radio and fuel is all you need to have fun. It doesnt have the power to weight of my R50, but thats not what I got it for.

tkn0spdr

My Feedback: (8)

The video posted in the OP is gone. Does anyone have a copy?

Thanks,
David

flyinrog

My Feedback: (1)

The video is still there, I got it,,,watched 17 minutes of it...didnt realize how old this thread was!....Rog

Raptor37

Even though this is an old thread is very interesting .

Raptor are very nice fun flight units . I used to run nitro , then I decided to get in to the gasser monsters .

I started modifying a raptor 30 size running a 37 OS engine , and now I used 89 octane and systetic oil , at 30:1 for better performance .

but I ended up installing a Rxcel ignition and a 1/4-32 plug for it .
the OS carb needs to be replace with the diaphragm type carb like walbro or zyma  and the play until is right .

and belive me  the little monster is alive and it has the performace of a 50 size .

the electronics are a most , and because of the torque it generates , you need a good gyro loke the futaba GY401
and a good radio gear such as the T14sgh.

rotor09

I still fly my 6 year old Century Predator GS with the G231 engine on occasion, as I have always been relatively impressed with its aerobatic/3D capability, specially when compared to the number of previous gasoline powered helis that I had before it.

Today's Century gasoline powered helis are even better. Their new Radikal G20 and G30 series, when matched to some of the current high performance Zenoah modified heli engines really make them come alive. You can see it in this video:

www.youtube.com/watch?v=iJJt6J4eMtk

They are very stable in any wind, yet have the response to perform some awesome 3D....or anything in between.

allan47

what servo you need radikal g20

rotor09

A rather basic analogue servo like the Futaba S9202 would work on the cyclic, but as it is an eCCPM control system, I would suggest a good and dependable digital servo with more torque and center holding power and precision like the S9252