Discussion Long term planning: Getting into gas

[gyro]

This vendor is helping me with some advice on building my first gasser: http://www.3drcforums.com/forumdisplay.php?25-ibcinyourc-com

(I bought my 89 slick RTF)

 

[Enterprise]

unique gasser parts list:

Motor
Throttle servo (HS-5665MH for hitec peeps, I have had bad luck with 5495BH and 5496MH)
Throttle pushrod, golden rod for pull throttles, something solid for pushers, try to avoid metal on metal in the setup for vibration
Standoffs for some motors (DLE includes them, as well as Mintor)
Some way to get to choke (choke servo experiement went very bad for me)
Power source for ignition. I personally use techaero IBECs run off a spare RX channel, others use ignition battery with switch.
RX battery
switch for RX battery, Fromeco Badger is a good choice.
Fuel tank, fourtitude tanks are popular. I use Fiji water bottles with PSP kits with a T fitting for the fill on a 2 line system.
Fuel Dot, some switches have them built in. I like magnetic ones from aztech aeromodels.
Fuel line, viton (black) or tygon (yellow)
2x fuel filter. One for fill, and one for vent. Gas motors are less tolerant to contamination than glow.
Spinner, I like tru-turn annodized.

Optional are canisters or tuned pipes. I have noise issues so I'll be doing canisters in the future.

 

[njswede]

I ran my plans by one of the pilots in my club. He's not into 3D, but he's a very good pilot, flying anything from a glow powered Pulse XT to big gasser Edges and Extras. With his 20-30 years in the hobby, he's definitely a pilot whose opinions I respect.

So what did he tell me?

He basically told me that it wasn't a good idea to go directly from 50"-something electrics to "big" gassers. He said there are way too many pitfalls in going from electric to combustion that I should consider getting a smaller glow model to get used to it.

Personally, I'm not so sure. My glow experience is only from RC trucks, and those little glow buggers are quite temperamental IMHO. Tricky to tune and notoriously prone to overheating. Not to mention that the fuel itself is actually corrosive to metals.... Gas on the other hand... I mean, I know how to tune the 2-stroke engine in my chain-saw or leaf blower. Shouldn't a plane engine work exactly the same? What is the big scary hurdle I need to get over?

So was he right? Should I heed his warnings or just plow ahead?

 

[gyro]

I ran my plans by one of the pilots in my club. He's not into 3D, but he's a very good pilot, flying anything from a glow powered Pulse XT to big gasser Edges and Extras. With his 20-30 years in the hobby, he's definitely a pilot whose opinions I respect.

So what did he tell me?

He basically told me that it wasn't a good idea to go directly from 50"-something electrics to "big" gassers. He said there are way too many pitfalls in going from electric to combustion that I should consider getting a smaller glow model to get used to it.

Personally, I'm not so sure. My glow experience is only from RC trucks, and those little glow buggers are quite temperamental IMHO. Tricky to tune and notoriously prone to overheating. Not to mention that the fuel itself is actually corrosive to metals.... Gas on the other hand... I mean, I know how to tune the 2-stroke engine in my chain-saw or leaf blower. Shouldn't a plane engine work exactly the same? What is the big scary hurdle I need to get over?

So was he right? Should I heed his warnings or just plow ahead?

Strongly disagree.

I'd stay away from glow altogether, not many of those motors can work in a 3D airplane, and from what I know, they're very unreliable compared to a modern gasser. You'd essentially be wasting your time on a plane that won't due what you want. I'd say, stick with the advice of the fellas here who are flying 3d everyday.

For perspective, my first gasser (and only one I currently have flying) is an 89" Slick. 55cc of gasser power... Oh YEAH! I jumped from a 74" Edge and 70" Slick electric... but had so few flights on them, that I might as well have just jumped from the 60" size.

Honestly, the only difference I can see so far, (and I flew my 89" again yesterday) is that the instant power isn't as instant when compared to a small electric, and the planes themselves move a pinch slower in response to stick inputs... but it's all stuff you can learn. If you're intimidated, as I was, spend your first few flights on low rates, and just fly some pattern and precision.

You'll be fine

 

[Enterprise]

My first gasser was a EG 88" Raven. I did have lots of help around me, but the gasser is no more complicated that glow. The easiest to build, tune, and fly plane I have is my 105" Hangar 9 Extra 300 with DA-120. The thing was designed around that motor and it literally just bolted on. Very minimal tuning, and a lot of the vibration proofing is not as critical as it was on my DLE-55 rattler.

The power response is very different in most of the gas engines and it takes a while to learn to hear the engine and understand if it is lean or rich.

Now I am SUPER impressed with the O.S. GT33 and it is very electric like in throttle response for a gasser. It does like to start backwards and a glove is mandatory when starting it IMHO.

 

[gyro]

My first gasser was a EG 88" Raven. I did have lots of help around me, but the gasser is no more complicated that glow. The easiest to build, tune, and fly plane I have is my 105" Hangar 9 Extra 300 with DA-120. The thing was designed around that motor and it literally just bolted on. Very minimal tuning, and a lot of the vibration proofing is not as critical as it was on my DLE-55 rattler.

The power response is very different in most of the gas engines and it takes a while to learn to hear the engine and understand if it is lean or rich.

Now I am SUPER impressed with the O.S. GT33 and it is very electric like in throttle response for a gasser. It does like to start backwards and a glove is mandatory when starting it IMHO.

I've seen those electric starter things, that have some kind of rubber grip that spins the spinner and starts the engine... are those things any good?

-G

 

[djmoose]

This is a great thread. I'm assembling my first 100cc plane. (103 Extra) and got a great deal on a great running DLE 111. I have my Fiji tank which I got from here:

http://www.shop.kavarootusa.com/cat...BA4621412160C849C5.qscstrfrnt06?categoryId=19

I also got my Tech-Aero IBEC and already had 2 Castle BEC Pros so I'll be running something like dual 3S 3000s regulated to 7.4v

Right now I'm learning all about geometry and ganging aileron servos...good stuff! There is a LOT of difference of opinion out there about it and how to actually achive it (if you even need to achieve it) and how to program your servos correctly.

 

[Ohio AV8TOR]

Strongly disagree.

I'd stay away from glow altogether, not many of those motors can work in a 3D airplane, and from what I know, they're very unreliable compared to a modern gasser. You'd essentially be wasting your time on a plane that won't due what you want. I'd say, stick with the advice of the fellas here who are flying 3d everyday.

For perspective, my first gasser (and only one I currently have flying) is an 89" Slick. 55cc of gasser power... Oh YEAH! I jumped from a 74" Edge and 70" Slick electric... but had so few flights on them, that I might as well have just jumped from the 60" size.

Honestly, the only difference I can see so far, (and I flew my 89" again yesterday) is that the instant power isn't as instant when compared to a small electric, and the planes themselves move a pinch slower in response to stick inputs... but it's all stuff you can learn. If you're intimidated, as I was, spend your first few flights on low rates, and just fly some pattern and precision.

You'll be fine

I agree with Gyro to strongly disagree with the above statement. I stepped up from electrics to my first gasser a DA-60 powered 3DHS Extra SHP and it flys so good. When I tell people that it makes me look like a better pilot than I am I don't think they believe me but it is true. The bigger gassers 50cc and up are like flying on the sim with the physics speed dialed down. They just float between stunts.
Some things you should read up on to be reliable and safe. But not really any different than electrics with battery and esc selections. You will need a good ignition cut off like the SYSSA Aero Tech IBEC and you should use 2 batteries that are powered through a smart switching circuit. I went with a wolverine switch.
They are a little more intimidating to fly but that is not because of the gas motor, it is because of the cost. But when I land I still go - wow to myself.

 

[SnowDog]

I also disagree with the statement that you should go from electric to glow powered before you go to gassers...just not true.
I also (mildly) disagree with the statement that most glow engines are not powerful enough for 3D. I have been flying glow engines for many years and they have plenty of power.
The main driver for me converting from glow to gas is one of simple economics - the price of glow fuel is ridiculously expensive. At $16-$20 per gallon compared to $4 per gallon for regular gas, it's a no brainer.

Executive summary: go gas...you won't regret it...and there are plenty of people around here to help you out over the learning curve.

 

[Jwmav528]

My naked Extra is a Phoenix Models Extra 330s that I bought off of tower when I got back into flying after finishing school. I hadn't drank the 3D look aid yet so I powered it with a glow engine and it flew like a glow sport plane. I recently converted it to a DLE 20 and it's a whole different animal. It 3Ds like crazy now and I'm still going easy on it for break in. It's so easy to get it going. I'm running dual A123 packs from Redwing RC through miracle switches and an MPI regulator to get my ignition voltage to 5 volts. It's about the same difficulty as glow initially but easy as an electric there after. And the reward is much greater. Definitely go gas.