View Full Version : Creating the Stinger Gasser
flyinfool
02-21-2006, 01:03 PM
Now that I am done with the Stinger 90 and it is about ready to start shipping, I am just starting to get started on the Gohbee Stinger Gasser.
Do not ask how much or when it will be ready, it will be at least a year in the making.
OK disclaimer done.
This will be an ongoing thread of my trials and tribulations as I build this new heli.
The engine that I am planning to use for this conversion (subject to change) is the BME G2300 gas engine.
Using this engine will save about a pound over the Zenoah 231 or 260.
Yes I know that the book has not even started to be written on this engine yet, and there are the questions of cooling come summer.
Toward that end I have of designed a cooling fan to fit the application that will have a much higher efficiency than the stock 90 fan, yet allow me to retain the stock fan shroud (maybe). I am still deciding if I should make this fan out of aluminum, or use brass or steel to get some additional flywheel weight.
The stock Stinger 90 fan and clutch do fit this engine and will be tried first to see how much more if any cooling air will be needed.
The engine is close to fitting inside the frames as is. Close but not quite.
I may only need a thick washer at each standoff both sides to make room.
I will have to make an engine mount since this engine is quite a bit longer than a 90.
The fan shroud will have to be bumped out for clearance over the top of the head.
Some pics of the very beginnings.
The fan is my first ever Solid Works part.
DebianDog
02-21-2006, 01:24 PM
The motor looks interesting although it has a lot less HP than my G26 (or are you talking of a different motor?)
http://www.bmeengine.com/html/point90.htm
BME 2.7@14,000 rpm
vs.
Hanson/Zenoah G-260 25.4 cc Pro Heli Engine - 4.2 HP @ 14,000 rpm
flyinfool
02-21-2006, 01:48 PM
This is not the .90 which would be 15cc this is a 1.4 or 23cc motor
This G2300 should be around 4hp.
I am not sure of the RPM range yet but it should (I'm hoping) be around 13-14,000.
This motor is still under development at BME and is not shown on there website.
DebianDog
02-21-2006, 01:52 PM
20 oz lighter? Should 3D nice then :thumbup:
flyinfool
02-21-2006, 02:52 PM
Thats the plan :D
Ade_Law
02-22-2006, 03:19 AM
why reinvent the wheel when a TT or QUK raptor fan will fit?
Ade
flyinfool
02-22-2006, 12:27 PM
The QUK and TT fan will screw onto the crank but are to short, the crank will hit the clutch by .119 interference
The fan that I have designed will pump a lot more air than the QUK or TT fan and will better fit the dimensions of the engine.
The biggest thing that I really do not want to do is to have to shorten the end of the crankshaft to use a stock fan.
Cooling this engine is my biggest concern.
I have considered both of those fans but they need a special collet to fit properly and are expensive.
The other objective that I need to keep in mind is that Gohbee needs to make and market this as a kit. If I were just making this for my own use then a makeshift adaptation would work fine.
But then making that fan in my basement will be an interesting challenge. :arggg:
DavidH
02-22-2006, 01:13 PM
I have some experience with the Supra Tigre engines. Which is what BME is using for a base unit for the gas conversion.
I personally would use the tried and tested Zenoah engines, the G231 or the G26.
Yes the 2300 may be lighter than a Zenoah. But also realize there is going to have to be a battery pack onboard to run the ignition also. I had a Supra Tigre large engine converted to gas back in the mid 90's. I ran it on gas for about a gallon. Then I converted it back to glow.
David
OzarkCopterBum
02-22-2006, 01:49 PM
Jeff.
You must be the James Brown of helis.
flyinfool
02-22-2006, 02:18 PM
David
I already have the Zenoah G230 and G260 and the ST G2300 available. I plan to try it with the G2300 first but keep the G260 and G230 both on ready alert.
I have no experience with the ST engine so I would be interested to talk to you about your experiences.
The weight savings are just to big to not take a look at.
I am not hellbent on any particular engine at this point.
Cost, performance and reliability are all major factors in the final decision.
I am not afraid to try new things, that's how the hobby grows.
But then I don't want to go to far down a dead end road.
If the ST G2300 turns out to not be workable I will most likely fall back on the G260 at that time.
Why not try a 3w- 28.
www.cactusaviation.com
www.3w-modellmotoren.com
epc2.
flyinfool
02-24-2006, 02:52 PM
The 3W is interesting.
I will need to more research on it to see if can be adapted to a helies requirements.
I'm sure that if you contact Wintrich @ 3w Germany he can help you with it , Over there in Germany 3w sell engines for paragliders too , there's even an ultralight plane powered by two 3w engines .
3w's are awesome and powerful engines I've been using them for a few years now on my Gs 3d planes.
epc2.
PaulH
02-24-2006, 05:09 PM
The biggest problem with using a 3W is that the ignition module is mounted to the back of the engine. This would cause it to stick out of the bottom of the heli, or in the case of a Vario, out the top. Another issue is that there is no pull start. You could use a shaft start in many helis, but again in the Vario, you'd be stuck.
The biggest problem with using a 3W is that the ignition module is mounted to the back of the engine. This would cause it to stick out of the bottom of the heli, or in the case of a Vario, out the top. Another issue is that there is no pull start. You could use a shaft start in many helis, but again in the Vario, you'd be stuck.
You are right about the pull start but you can put the ignition anywhere behind the hub sensor , The 28 is rear induction but that's the carb not the ignition , the ignition is electronic and can be located anywhere.
epc2.
flyinfool
02-25-2006, 12:44 AM
The rear carb is a concern since it would be sucking from less than 1 inch of the ground.
With an aircleaner attached it would olmost be touching the ground, might not be good for a hard landing.
At this early point in the game I am not ruling anything out yet. :idea:
Fflipp204
04-19-2006, 12:27 AM
Have you guys thought about the MVVS engines? I had the 58cc with it first came out and let me tell you .. it is an absolute power house. They also make a 26cc, and 35cc version.
Just food for thought!
I personally am about the order the Stinger 50 :D and upgrade to the bigger toys when experience permits.
PaulH
04-19-2006, 08:14 AM
I believe the MVVS engines are the same as the Evolution engines being retailed by Horizon.
The reviews of the Evolution engines seem to be mixed. The nitro engines work really well for a year or two, then poop out for no obvious reason. After rebuilding they never seem to have the power that they did from the factory.
Evolution gas engines don't seem to have any such problem. Also the fact that the smaller versions (26cc and 35cc) are built with the carb in the same orientation as a nitro engine means they might be fairly easy to mount in a heli.
http://www.horizonhobby.com/Stores/Products.aspx?StoreBrandId=EVO&CatId=EAG
flyinfool
04-19-2006, 09:24 AM
I have seen posts where some people have tried the MVVS 26 in a heli and could not keep it cool.
It has been looked at as possible candidate with a bigger head for proper cooling.
If possible we would like to break the trend of the overweight Zenoah.
Fflipp204
04-19-2006, 10:26 AM
I have seen posts where some people have tried the MVVS 26 in a heli and could not keep it cool.
It has been looked at as possible candidate with a bigger head for proper cooling.
If possible we would like to break the trend of the overweight Zenoah.
Amen to the overweight problem! They were a little underpowered for the 3D moves in the planes .. something I will never go back to. Heli from now on for me.
asong26
09-05-2006, 11:31 PM
I have seen posts where some people have tried the MVVS 26 in a heli and could not keep it cool.
It has been looked at as possible candidate with a bigger head for proper cooling.
If possible we would like to break the trend of the overweight Zenoah.
Hi Jeff,
I have been researching this for some time now. I really like the idea of the purpose built Evolution 26GT2. Have you made any progress of finding the right engine for your new heli project?
Please keep us informed. Also, what about utilizing the tried and true OS and with Davis Diesel head converter on it?
Just a thought.
flyinfool
09-06-2006, 10:47 PM
I really don't like diesels.
Finding a new engine for a niche market is tough.
I still have hopes for the BME/ST G2300.
Fortunately or unfortunately depending on your outlook, the other new BME engines have been so successful that BME has not had any time to work on developing the 2300.
asong26
09-08-2006, 10:05 PM
I really don't like diesels.
Finding a new engine for a niche market is tough.
I still have hopes for the BME/ST G2300.
Fortunately or unfortunately depending on your outlook, the other new BME engines have been so successful that BME has not had any time to work on developing the 2300.
I agree with you. Gasser would be my first choice as well. I was following the read somewhere regarding the BME G2300 conversion. As you said, they are so heads down with the 90, that they didn't have any spare time to work on the 2300.
So the question is, if they do start working on the 2300, what level of power to ratio are we talking about? Would it exceed the best of current 90 nitros? That would be soooo sweet.
flyinfool
09-11-2006, 10:02 AM
I believe that the 2300 will end up around 4 HP and only about 8 to 12 oz heavier than a 90 ship RTF.
With the extra torque and HP it will handle a bigger disc area, so the disk and power loading might be very close to a 90.
At least that is the theory and the plan for now.