RC DeltaGliderIV project

[the.punk]

I'm looking forward to see it flying.
Realy good job so far.

 

[ijuin]

What precisely does "dead-stick" mean anyway?

 

[Usquanigo]

What precisely does "dead-stick" mean anyway?

Without power.

 

[Donamy]

make your glide steep like the shuttle, flare low and hard.

 

[Talon1]

This is one awesome project!!! I can't wait to see it flying!!! Good Luck!

By the way, what kind of propulsion assembly are you using? The ugly looking single (or dual) propeller(s) mounted where the engine nozzles are supposed to be;or will it have a "jet engine" type assembly where there is an air intake at the front (i.e. the scram intakes) and the propellers are inside the body blowing a jet of air out of the main engine outtake? I hope it's the "jet engine" type; it would look the best! All and all, your doing well so far!
Now more importantly, I would hate for this project to die...

 

[RisingFury]

The jet engines you are referring to are called Electric Ducted Fans - EDFs for short and they don't have anywhere near enough power to provide propulsion for this model.

This is what I'm gonna be using. A 500 kV brushless outrunner with a 4S LiPo battery. It'll be mounted in the back and will spin a 17 inch prop (43 cm).

 

[Usquanigo]

The jet engines you are referring to are called Electric Ducted Fans - EDFs for short and they don't have anywhere near enough power to provide propulsion for this model.

What about something like this?

 

[RisingFury]

I don't exactly have 5000$ to blow on a jet turbine...................

 

[Kaito]

Nice jet engine, Only a couple problems I see:
wood body...hot flames...fireball in the sky.
Weight. That thing looks like it weights a ton
Fuel: where's he gonna put the fuel for all that?

 

[Usquanigo]

I don't exactly have 5000$ to blow on a jet turbine...................

Details, details....

 

[RisingFury]

wood body...hot flames...fireball in the sky.

Not really... All planes with jet engines are built from flammable materials and the jet engine is usually positioned in a way that it won't set your plane on fire. Just go to YouTube and look for "RC jet".

Weight. That thing looks like it weights a ton

Well, they do weigh more then electric motors, but their thrust to weigh is far greater. They can easily compensate for the added weight.

Fuel: where's he gonna put the fuel for all that?

The body of the DeltaGliderIV is HUGE... it has far more volume then most planes. I wouldn't have a problem fitting several liters of fuel in there... the problem is weigh

Besides, these things don't burn through fuel *that* fast. Faster then piston engines, yes, but still, a 1 l tank is enough for a long flight time.

 

[ar81]

Just a boring update:

I've got all the plywood construction wood cut out now and have started gluing it together. I'll have a few pics up in a few days when it's all glued together.

Currently I'm estimating the weight to be some 200g too much.
If the thrust is at 26 N, I should get away with it... if not, I can still put a bigger prop with less pitch on to compensate. 14x5, I guess... but it would create more torque...

If you wanted propellers, putting 2 propellers, one behind the other, rotating in opposite directions may solve torque problem.

 

[NukeET]

Try putting 2 propellers, one behind the other, rotating in opposite directions.

That would mean the props would be co-axial, with an inner and outer drive shaft and a really heavy gearbox to drive those 2 shafts.

 

[Usquanigo]

Weight. That thing looks like it weights a ton
Fuel: where's he gonna put the fuel for all that?

Apparently they either don't weigh as much as they look, or there are smaller versions. Check this out -

:OMG:

 

[RisingFury]

They get smaller too:

This one is tiny.

 

[Talon1]

The jet engines you are referring to are called Electric Ducted Fans - EDFs for short and they don't have anywhere near enough power to provide propulsion for this model.

This is what I'm gonna be using. A 500 kV brushless outrunner with a 4S LiPo battery. It'll be mounted in the back and will spin a 17 inch prop (43 cm).

Aww man!!! I was hoping you'd use the EDF's instead. Oh well, whatever works I suppose...

 

[starbird]

There are EDF systems for aircraft much larger than this. They can put out similar or better performance than the older .80 and .90 glow DF.

The trick is sizing the inlets and exhaust, which needs to be a certain percentage of the fan area. If the inlets are too small, the fan can't put out the thrust. On the DG, you would need a pretty good size cheater hole, and an inlet somewhere to get decent EDF performance.

Turbines are getting smaller, the smallest one I know of is about the size of a can of soda (8oz?). Usually they weight 2-3lbs and put out anywhere from 12-20 lbs thrust. They use a lot of fuel tho. Not sure what the small ones do, but they've been mounted on little foamies.

 

[RisingFury]

Well, the body is already built, besides, the DG design doesn't exactly leave holes in the bodies for air intake...

 

[Jer95]

Wow.. How many pounds of thrust you need? (Make sure the rc dg is less than 20 lbs)

 

[0235]

wow! this is amazing! do you have noting to do in slovenia (no offense) its amazing, and more no offense, i evpected you to be a 40 year old with a thick beard, all the RC plane builders at my school, who teach it (yes there is an RC plane class!) are like that. they are all currently making jet planes, but the school only has one jet!