P50 gasser

[grwarlock]

So what the hell ever happened to the gasser ?

Well oddly enough it has been being worked on by a skunk worx partner.

A different approach was undertaken to try tho make the conversion as painless as possible.

I actually think his is a better approach and more viable for the masses.

The bird has flown many times still got a kink or two to resolve. Keep your eye's here as this cat will be out of the bag soon also !


Pantera 50 , the most convertible RC heli in the world !


Ken

[forvols]

Still chasing the cooling issue? How is this resolved with other heli's like the Radikal?

[helipainter]

The cooling issues are ironed out the same method as the 4 stroke but we sure would like to find a mechanical fan that we could bolt on and never look back. For some of the older guys that really want something cool will want to keep yer ears peeled. This thing is SWEEEEET! Ya might think the bbc is heli crack, can you say 5 hp on gasoline? Wait till the boys get a load of these things.

The 26cc is seeing 24-28 minute flights on a stock p50 tank. I thought i'd get bored, but that aint the case. Now all my others don't fly long enough. Nothing says wow like watchin Big Bastard fly

Of course in typical Pantera fashion, they can be built from mild to wild and the price reflects such. Right now the focus is back on keeping it cheap/simple enough to influence the masses.

Other helis are using huge diameter fans, with the molded frame, we are somewhat stuck with the diameter we got.

[SabreFlyr]

PLEASE keep us posted (I even got down on one knee as I typed that!). Sounds like a very intriquing application for that spare airframe that's coming my way!

[F6Hawk]

Ok, I am over my divorce BS, getting back into the building of the 50, but I want more... details, please???

[grwarlock]

There coming hang on

[F6Hawk]

Now, Ken, U know that's kinda like telling a crack addict there's free rocks downtown, but telling them to wait while you draw them a map....

[helipainter]

psssst, hey dude, over here.... They look like this






I'll bring some more with me next time, gotta run.

[breezer1]

I've waited soooo looong for my E conversion, I almost dont care anymore. Maybe I'll keep waiting just to see how long this gasser thing takes. It's almost an end in itself just for amusement But, thats what we the unwashed, unblessed, loyal Pantera subjects have to do, wait.
What kind of time frame are we talking about anyway???? Or, should I not ask??
In the mean time, I'm just going to keep flying my P50 and fixing the tank every second flight. At least that gives me something to concentrate on while I'm waiting.

Breezer1

[helipainter]

I understand your frustration. I'm one of the lucky ones with access to a machine shop. Everything i've done (both gas and E) were done by myself on my own dime. I heard that the E-kits are super close to ready to sell.

Anyhow, I've somewhat based my ideas around the zenoah 260puh, but am liking the idea more and more of the 20-23, just to keep the weight down so we can spin a smaller set of blades. Right now my 26 spins 800 mains like there not even there. In fact, it is what it wants. Since JB has withheld blessing his head with blades of this size, we need to step it back, just a hair. I just happen to know somebody who just grabbed something in that size.

Here is some more pics of the build. I've gone FBL strickly to swing the blades i'm using. It is running with no stab controller with very little bad habits. The 710 radix fai are about like a 500, it'll flip in it's own tracks really fast for a 12 lbs heli. The Edge 693 are too small for this thing. more testing to follow.













And this is v2, pretty sure this is the orientation we want to run these, especialy if were gonna work on running a mechanical fan.







I honestly don't know if waiting could possibly curb my appetite for a pair of helis like this for 2k, and they aint slaking in the electronics dept either.



Them are both 700's, both around 3.5-4 hp and are both amazing to fly, one on the right is what your after. I'm working on video of the gasser for us to enjoy this weekend. Stay tuned.

[crash.n.dash05]

im soooooooo droooling over this.... i have been seriously thinking about this conversion.... yeah i might have to drop a few hundred to a grand to make it happen.... in fact im selling all my electrics to put back money for the build.... watching a club member hover his Bergen (sp) i just wana take it and try to fly the crap out of it.... and im just a bit on the lower intermediate level of flying... (comfortably)

[helipainter]

It is a whole different deal from what were used too.

Other than the cost of the Zenoah motors, the build is suprisingly simple. I think Ken just found a good deal on something used, but i haven't quite understood what it is he has. Maybe he'll chime in on what he's going to try out and keep us informed to how it goes.

The conversion is just that plate across the bottom and a collet. Of course you would want to make sure the skids and blades are ready to pull around & land a 11-12lbs heli and ya need some of that yellow gasoline tubing. Oh yea, needs the odin 90 fan for now till somebody stumbles on something





I'd expect this project to be rolling pretty quickly now that a few of these are flying.

[crash.n.dash05]

wow so yall are using the clutch and stuff... i just got to ream/bore out the original clutch to motor mount... the plate and skids are the easy part for me to make if i had dememtions.. i got aluminum plate and a variable speed drill press...

[helipainter]

or you could get a really nice plate fresh off the mill very reasonable

For the hub, i have not tried it, but i believe that the bergen collet for the motor you want is going to be the ticket. then bore the p50 hub to fit the new collet. This is a custom aluminum adapter i made, it is rough, but held great. The os/ys stuff i think was 5 degrees if i remember right. The zenoah was 7.5 i think. Either way i was 3-5 degrees sharper so the stock collet didn't fit. It could have been re-worked, but once the slit is cut, it is tough to deal with on a lathe. The raw hub is too big to just bolt on

As for dimensions, it is your 4 skid bolts with an emphasis on where your center line of the crank sits now, flip it over. It's all in your lap, just gotta decipher it.

There is also the option of running the other brand, crrc motors, but i really feel that it costs more to make this airframe start that motor than i think we can just buy zenoahs. I've got one aftermarket way of doing it, involves $150 worth of clutch parts. Another method not proven yet is to mount a pull starter to them, unfortunately there is nothing off the shelf for it, yet.

[grwarlock]

Steve how to you expect them to get excited if they see no video !!!

Show em some of the testing and R&D you been doing !!!!

Lazy man pfft

Ken

[helipainter]

I had every intention of showing up tonight with as hard core of flying vids i got to offer, but my piston/cylinder was a day late.

This is what big bastard looks like in a simple hover in the driveway.

Good news is she is ready to go again with a new fan setup. It is both mechanical and has the odin as a back up. After my brief encounter with 106 degrees, it made me remember what our problem is.

[ame]http://www.youtube.com/watch?v=yLZZRiHFkP0[/ame]

This is one of the begining videos where i'm setting throttle curves. by 4:50 i got the head running pretty steady and super stable. that is flybared with 710 radix

Then i bought a set of 800, just to see what it did. You can also see how the motor is loosening up and purred under 800's. IMO, the 26cc at this weight range wants the 800 with the 12/85 gearing option. We need 13/84 or even 14/83 then i think we could get the 20-23cc spinning the blades 1800 plus which would really help make smaller main blades work better. I'm matching blades to head speed instead of matching the speed to the blades. That is 1650 when it is running right in the vids.

[ame]http://www.youtube.com/watch?v=GGU9x4G3ir4[/ame]

I'm heading back down to my place next week. Will try cutting us a real video then.

[F6Hawk]

Ok, edumacate me... why is cooling such an issue with gas? My weed eater doesn't have a fan, my chain saw... nope. Is it because the have larger cooling fins?

What is that high pitched whine in the background? Even when you shut the heli down....

[The Dude II]

Ok, edumacate me... why is cooling such an issue with gas?

Take the original design - 2-cycle Methanol/ Nitro/Oil burning & COOLING engine.

#1 - This form of 2-cycle is stripped down as far as weight & heat sinking - just enough for the purpose - see #3

#2 - The Nitro engine has a relatively shorter "combustion" period than gasoline - more of a "pop" vs a "burn" - so more heat is generated/ extracted (AKA WORK in physics) out of a gasser - therefore the higher running temps.

#3 - The gasser engines being shoved between the frames are not heli-specific engines - they're for planes - which means natural forced airflow for cooling as the plane flies at 30-60mph - not sitting under a canopy - hovering - protected from the down-wash of the rotor.

#4 - A large part of the "design" of our 2-cycle Nitro fuel is cooling - large volume of oil comes in, goes through lubes & cools and right out the exhaust onto the model...or into the mosquitoes lungs!!!
Look at a 50:1 mix of gas/oil - that's nearly 1/2-gallon of gasoline for 1 little ounce of oil! - Oil is there for lube - better be large heat-sinks, forced air or a water jacket on that cylinder & head!


#5 Crank RPM. - Go back to #2.
With gasoline we have longer burn time inthe cylinder for each combustion cycle - aka greater IMPULSE (force) over a greater period of time extracting more WORK vs Methanol/Nitro fuel. This longer burn time equates to a slower running engine - but an engine that produces TORQUE for a greater angle of rotation of the crankshaft.
So basically the gasser runs slower than the design called for 2-cycle 9.5cc screamer - which means the cooling fan runs slower!
With a Pantera - @ 8.7:1 - if you're hovering at 1700 Head Speed - the engine/fan are spinning at nearly 15K rpm. A 26cc gasser would surely come apart at that RPM - unless designed for it!!! So the gasser is cruising at some where in the 8K rpm range - that fan is not pushing nearly as much air!

I'm guessing the "scream"/ wine in the video is from the ODIN cooling fan - Compass Models came up with the idea for they're ODIN 90 - ditch the cooling fan on the crank shaft - reserve that bit of HorsePower for the rotor head (yes it does make a difference - my FAI Pantera has flown this way for nearly a year now).
The whole "ECS" (electronic cooling system) as I've coined it is a bit science project (aka complex) - but the fan is reliable and it works - especially for a gasser that needs an assist due to the lower crank rpm.

Those are the "high points" that quickly come to mind.

[F6Hawk]

Thanks, Dude, I understand how nitro cools more than gas.... but my question still stands: Why does a weed eater not require a fan to cool it? Or any other 2-cycle application, for that matter?

[helihole]

Your weedeater and saw are definately fan cooled. The flywheel is also the fan. With out it a unit would quickly seize from overheat.