Building a Custum Made Speed Plane
 

Hi guys,

After reading some posts here about an all out speed plane i decided to try to doing one.

I'm a mechanical engineer teacher, i'm a Catia V5 specialist and i have full access to CNC mill and lathe and also to high end CFD programm called Fluent.

So my goal is to make a plug for a fuse. And after that simply sell it to everyone that helped here to make that plane for about the price of the material. I dont want to make $$$ with that, just having fun.

To make the fuse available to 'everyone' i want to built it around a powerfull and available engine, but not a DF one. So i think everyone his thinking about a Jett engine and it's ok with me.

So the first question is, wich engine do we want to put in it?? A Jett FIRE engine, but wich one???

Thx for the inputs.

RE: Building a Custume Made Speed Plane
 

What is your target speed for this plane? I would base the design on an engine that is capable of at least 200 mph. I don't know how the calculated speed of a plane in this size range translates to actual speed. Whichever engine is chosen, it has to be rear exhaust for this project to have any seriousness to it. ;)

RE: Building a Custume Made Speed Plane
 

Hi, if you don’t consider a DF engine for this speed project, this “all out speed plane” will not be an “all out speed plane” due to the fundamental lack of rpms.

So the only alternative would be the actual engine line for FAI F3D pylon planes (MB 40, Nelson 40, IR 40) – to be capable of +230 mph in a straight line speed flight.

Here spare parts no problem. I’D say: Take the MB .40 engine to design your speed project around, nutting does compare to that rpm regime of 35K! No alternative here in the world of pure speed. If you don't do it you'll regret it shortly after the first flights.

And also lotta sophisticated Carbon propellers available for these engines – very important

RE: Building a Custume Made Speed Plane
 

well if its going to be around a "40 " size engine then the Jett engineering 60LX FIRE would be the go... a good design based on the pure speed frame ..eg fully cowled engine + pipe and a good wing profile should easily see the 200 MPH as I'm sure you'd get the engine to unload in the air enough

and please nobody mention the 150 - 200 mtr speed trap... I'm not so fussy if it breaks 2 bucks over 80 meters good enough for me ..if the speed is there , it's there

P.S..I found the eagle tree flight recorder not to be overly expensive ...not as trick as the telemetry live feed version... but the fixed version allows you to down load after the flight.. at near $400 bucks difference doesn't seem that far out of reach
would be an interesting tool to have.

RE: Building a Custume Made Speed Plane
 

Jett 60LX FIRE.

I will PM you with some questions!

MJD

RE: Building a Custume Made Speed Plane
 

Guys, we don’t want to compare a sport engine design and rpm output with the most sophisticated engine design todays (integral piston liner, no inner bearing ring, double balanced crank and spinner, monster flow paths,…), don’t we? ;)

“All out speed” is the name of the game, as Glorfindel already pronounced, no time for compromises for a non-sport project like this IMHO. But as I said before, you’ll regret it

RE: Building a Custume Made Speed Plane
 

Hi guys,

So i have to questions:

1- whats the size of the mb 40 compare to the jett 60 fire

2- if we make it for the jett 60, are we still able to put the mb 40 in it??

Yes i want to make an all out speed airframe, but i want the engine to be easily available. No DF engine (even if i fly df jet). What'S the price of the mb engine and avaibility???

RE: Building a Custume Made Speed Plane
 

Glorfindel , your speed plane, equipped with the right engine, should be a real contender in the absolute first R/C speed league worldwide. Not much more to say here. [8D]

I’ll send you a PM with some info.

RE: Building a Custume Made Speed Plane
 

Hey, this is "extreme speed prop planes". Doesn't say it has to be internal combustion engine powered! Make the design adaptable for electric.

Don't forget about E-powered!! Just think, no engine sticking out in the breeze, no tuned pipe to enclose. Think of a sleek, sleek, nose!

I propose the following commercially available stuff, some fine tuning will be needed as more parameters are set:

Speed control: Castle Creation HV110

Batteries: As high a voltage as the ESC can handle, 12S Lipo (approx 50 v.) 3700mah at 30C discharge will be over 100amps. Hey, don't expect these batteries to last long, but it'll get the job done (maybe a couple of times).

Motor: Neu, Kontronix, Aveox, Hacker, lots or motors out there, choose size and Kv as needed for application Most have a max RPM of 50,000 to 60,000!!!

Target power: 5 to 6 Kw (lets say 6 to 8 hp!)

erghh.....do we want a landing gear and all that drag? How about a single wheel with some wing-tip wires?


Now this is for straight line speed, no pylon turning requirements here, just be controllable for huge 1000' split S into the speed trap.

RE: Building a Custume Made Speed Plane
 

I would build it around one of the jetts, personally I like the Jett .50. I have not run a FIRE Jett, but the ones they have by all accounts run great.

The MB .40 or Nelson .40 FAI engines are more powerfull, however they are not nearly as friendly. You will need to run 80/20 fuel (no nitro) so plan on mixing your own, you will need to purchase specialty CF or Wood props at $30+ each, you will most likely blow a $5 plug every couple of flights (if not every), you will most likely need a special glow driver that holds a high current up till take off (and possibly a break away igniter), and not to mention a MB + pipe configuration is about twice as expensive than a Jett .50 (which is not cheap).

If all out speed is what you want, than stick with the headaches of a FAI motor. If you want very fast speed with less need for aspirin, stay with a Jett.

RE: Building a Custume Made Speed Plane
 

I'm with airbike, if all out speed is wanted go electric.

if you want to go glow I'd look at the fai f3d 40's for pure speed.

if some engine power is going to be exchanged for good behaviour go with Daven's idea of a jett (or nelson) ship. perhaps q40. engines, or the fire 50 .

not to figure out how to mold the lipo's to the shape of a fuse so they can be the outside of the fuse.[&:]

RE: Building a Custume Made Speed Plane
 

Oh yeah, don't forget that you can probably cram at least a few Lipo cells into the wing since they are pretty thin.

So what's the calc for pitch speed? something like (Pitch in inches x rpm)/ 1056 = mph?

So a 5 pitch will get you to 200mph at 42K rpm, easily attainable with electric motor.
And a 6 pitch at 44K will get you 250mph pitch speed.

I don't know enough to figure out efficiency factors, prop tips nearing/exceeding speed of sound, form drag, lift drag, etc.....

I'm pretty sure that you'd want an airframe with the lowest drag possible, or a HUMONGUOUS-GIGANTIC amount of thrust:)

Also, the Lipo technology is continuing to move at a rapid pace, energy density is going up, packing more and more power into a smaller and smaller package (hey, isn't that what they call a bomb:D)

RE: Building a Custume Made Speed Plane
 

yes it's true you need an all out engine for pure speed, not a sports engine, but please dont forget , as far as I interpert the starting post of this thread is, was NOT, to go the ducted fan route. This isnt a speed cup contender aiming to bust 250MPH( If it could that would be great..)

sure you can use a MB or Nelson ..but I dont think their all that user friendly..I could be wrong ..never owned either of them

Now that 60 LX is going to launch on the ground at about 19,500, and probably unload to near 22,000 in the air, which will get her going.

as for electric... yes we have many benefits over glow and as we can see , our glow engines are being overtaken in the speed stakes.. and very soon I'm sure they will superseed glow engines...but this forum is in the glow section... I think it should be IC powered...or maybe lets pit one aganst the other ...after all , Glorfindel said he did want to make fuses and sell them..maybe we can go for a Glow Vs electric shoot out!!!

either way this is an interesting project...

out of interest is their anybody out who can start a thread, and provide photos of how you go about modifing a glow engine..you know,how to take an engine apart..how you measure the timing( I do have a degree wheel so I know this part)and how much a certain engine can handel , and to show all the steps.. like where to take metal from when actually porting out an engine..I love to see a thread on this...maybe Bob27s or anyone who's successfully done this????

RE: Building a Custume Made Speed Plane
 

Hi speedy fella!!!


First of all i dont want to make an electric airframe, theire is already some good one and i like glow engine ;)

For the first try i will built it around the Jett 60 fire. I dont think it will be a big deal to fit a mb 40 in it or i will simply make 2 plug, one for the more mainstream jett and one all out, competitive speed cup contender.

Anyway it's probably just the nose that will change a little bit.

Ok now we are set on the engines. Now i will need some help. Since i dont have any of these engine by hand, i will need the exact measurement of the enveloppe of those engines, including header and pipe.

Maybe Bob27s can provide me, an IGES or SAT files of the Jett60LX, since they are BSE they sure have a 3d model of it. Like i said we will do this seriously with serious software so if i dont have exact 3d model of the engines the CFD results will be less accurate.

RE: Building a Custume Made Speed Plane
 

Let me make the following suggestions.......

First, Yes, the MB is the baddest of the bad when it comes to engine. Its the top rated FAI engine. For the most part....... the Nelson engines perform pretty much as well in F3D competition.

On a scale of 0-10 on user friendliness - the MB setup is about a 3. Folks racing them spend MONTHS learning the engine, testing props/making props, matching props to the airframe, and properly setting up the entire package.

Not impossible, but keep this in mind when considering any powerplant of this type. And be ready to expense off a glow plug pretty much each flight.

Then, with the above in mind.....
since you live here in North America, if you want to go the FAI engine route, Id consider the Nelson .40 FAI engine. As with the MB, or any hyper-critical pipe/engine/prop/airframe setup - there is a huge learning curve. The difference here, is that Dave Shadel at Performance Specialties and a number of others here in the states and in Canada can help you and answer questions . The Nelson engine was pleanty competitive in the recent world championships. You give up nothing in performance, and in your situation, you would gain LOADS in logistics and technical support.

As for a "sport" engine option......

The Jett 60LX FIRE configuration is a killer setup. It is not going to turn 35K rpm. Its going to turn 20K or less. But its going to turn that with a commonly available, larger prop. A clipped 8.8x9.25 down at 8" diameter will easily turn 20K on the ground. AND, it will throttle, idle, transition - and it is set up for regular glow plugs. Try and keep the ground rpm down to 20K at peak if possible.

To accomodate and FAI engine, simply account for where the engine inlet and fuel system is going to be located.

One other intermediate option - Dub at one time built a few FAI BSE engines, that was along the lines of a FIRE configuration of the Jett QM40 engine. If using an APC carbon QM40 prop sound appealing, and you just need a venturi (no carb) we might be able to pursue this more.

I do not have a 3D model of the engine at this time. Dub still does his design work old-school of sorts :) However the overall and mounting dimensions for each engine can be found on the jett website in the TECH section.

Bob

RE: Building a Custum Made Speed Plane
 

My vote is for one of the jett small block FIREs. If you build it to accomodate the FIRE .50 I beleive it should also fit the 60LX fire since they are the same engine on the outside if I'm not mistaken. I personally would want a .60LX FIRE on mine. Is that available in a BSE FIRE yet?

RE: Building a Custum Made Speed Plane
 

Okay, I'll bite. Are you talking an "all around" speed plane or some pylon thing. I have an idea on a plane that is near impossible to get but may be easy to design.

RE: Building a Custum Made Speed Plane
 

I'm so sorry to hear electric is out of the question...I was starting to get excited. 200+mph has already been done with a electrified Vendetta. I like the idea of being able to taxi out to the runway, control throttle in flight, and get about 6-8 min of flight time (with throttle control). I'm sure a more aerodynamic electric version would be even faster. Hopefully someone will make one someday, because the technology is here!

Here's the vid of the Vendetta

http://www.flyemfast.com/files/BestVen.wmv

RE: Building a Custum Made Speed Plane
 

Hi dudes,

I dont want to make it electric 'cause theire is already some models outhere.

The plane will be optimised for straight line speed not for turning like pylon plane are.

Now we are set on the Jett fire 60lx, like i said i have to do the engine in 3d (outline) i will need the pipe and header combinason that we will use, any inputs for the combo???

RE: Building a Custum Made Speed Plane
 

Ask Bob or email Dubb and ask about what combo would be absolute fastest straight line speed on the .60LX FIRE. He should be able to point you in the right direction.

RE: Building a Custum Made Speed Plane
 

Sent you a PM

RE: Building a Custum Made Speed Plane
 

if using the 60lx and making molds for the airframe why not make a mold for a custom carbon prop, say 8(ish) x 10 or a 7(ish)x12... a seriously oversquare prop to use the raw grunt of this motor. it'll be stalled to hell at launch but once(if?) it bites, watch out.

RE: Building a Custum Made Speed Plane
 

To be practical, how many 230 mph runs can you expect to get out of a MB or Nelson between trips back to the factory for more parts? If someone could say, "100", then I would say let's do it!
If I could get a set up capable of ONLY 200, but with 10 times the service life of the 230 mph set up, then that would satisfy me. After 200 mph flights begin to get boring, THEN it would be time to bring out the 35,000 rpm engines. That is the way I look at it. It is good to know that the Nelson is right there with the MB.

Good to hear from you again DER STEUERMANN! Things have been kind of dull around here since you left us [:o].

RE: Building a Custum Made Speed Plane
 

You will be unlikely to crack 200 mph with any of the sport Jett engines that are limited to 20K or less. "Seriously over square" propellers lack the efficency to convert the engine power to thrust. In this regard, Steering Man is correct, high rpm is required to use a prop that is closer to square.

While the FAI motors mentioned would be one method to achieve performance beyond 200 in a clean airframe, I think that stateside, an old Formula One nitro motor would do it with ease. Find an open exhaust Nelson, Jett, or Supertigre that was set up for 65% nitro fuel. They should cost quite a bit less, while offering extreme performance with less fuss.

There was a thread on here where some old F1 airplanes were tested that were slightly above 200 in long straight passes (faster than I expected). With a cleaned up, minimal airframe, 230 looks possible.

Engine life even on 65% nitro can be quite long, as long as you shut down before it goes lean. Run lean, the piston/sleeve is gone in just a couple of seconds. 50 to 100 runs is reasonable life. Your biggest expense will still be plugs and fuel, at about $5 to $7 per run.

RE: Building a Custum Made Speed Plane
 

Dont worry guys, if the first airframe(for the jett 60lx) is good i will make one available for the mb40 too. I'm still waiting for dimention of the mb40.