X-34b boost glider - test 1

[MaxQ]

I had some time and a windless day to do some hand launches of this thing.
When I put this together I was just guessing at the wing size (I upsized it) and the CG location.

I taped 14 grams of lead to the nose to get the glide CG where I thought it needed to be and set all control surfaces to neutral to see what would happen...

The first couple of tosses in the backyard from shoulder height had some stall tendencies and after some fooling around with it, it had a noticeable nose down glide (dorked it in a couple of times) and then some left roll. Throwing these things w/o inducing some bad tendencies takes practice.

I added a little right "elevon/aileron" and it took the left roll out.

Then I put some pronounced up elevon in both of the elevons on the wing and took it to a hill behind my house.

It survived....

I got some flat glides with a slight right turn.
Kept tossing it until the breeze picked up and it rolled upside down on one landing...tearing the monokote on the right wing root.

Before I go to the next phase...I will need to put lead in the internal pop pod and see how far I can get the CG for a vertical launch...

If I can get it to a launch pad I'll see what a vertical launch will do to it.

 

[aerostadt]

It looks cool! I am wondering about the construction. How are the wings, nose, and fuselage made? What does the model look like from underneath. Are the elevons activated when the motor tube is blown out?

 

[MaxQ]

It looks cool! I am wondering about the construction. How are the wings, nose, and fuselage made? What does the model look like from underneath. Are the elevons activated when the motor tube is blown out?

Wings: traditional balsa ribs with balsa leading and trailing edges

Nose...balsa frame with foam blocks glued to it and sanded down

Fuselage: rolled posterboard tube with basswood longerons and foam core slabs, card stock aft end

Elevons are activated when the motor tube is ejected...I'll have to use elastic activated elevons with some wire stops on the wing for a preset elevon angle...motor pod would have wire hold downs to keep elevons unactivated during launch.

 

[MaxQ]

What does the model look like from underneath.

...kinda like this, but I covered it with cardstock.

 

[MaxQ]

The source picture for the effort...

 

[powderburner]

It is hard to make a lightweight model of just about anything, but making one light enough to glide is even more difficult (as I'm sure you found out).
How many versions did you have to go through before this one?

 

[rokitflite]

I like the model AND the critter critic.

 

[MaxQ]

It is hard to make a lightweight model of just about anything, but making one light enough to glide is even more difficult (as I'm sure you found out).
How many versions did you have to go through before this one?

Actually, this is the only version of this I've put together...I have been going lightweight for awhile now...it certainly is cheaper to build and fly.

I have built a lot of RC sailplanes and power planes which helps as far as conceptualizing a build, and several of my scratchbuilt rocketry projects were designed around lightweight airframes made of foamcore, posterboard and balsa wood, which have held up under H motors...

Most of the damage I've seen on my Apollo Little BIG Joe is caused by landings - on fins that stick out below the airframe, or caused by my own careless packing job to transport them in my vehicle...

 

[AstronMike]

making one light enough to glide is even more difficult (as I'm sure you found out).
/QUOTE]

Thats why I have dove head over heels into cardstock/Depron for all larger 18mm and some 24mm powered designs. This ends up with models that weigh close to nothing glide wise, and it certainly shows up in the performance. Even though the designs themselves are not in any way 'performy' types, having them suddenly weigh half or less as much shows up in the sky.

Over on YORF a while back I posted about the Depron version Space Camel I slapped together. Well, its my version thereof, and likened to a cross between that and the Cosmos Mariner, and as large as the latter. That thing not only worked on a Quest C6, but did rather well at that.

This X-34 here looks like a reasonable candidate for a cardstock/Depron version, just do not know how large to make this. MaxQ, could you post the critical length/span/wing planform measurements here, as well as the body diameter?

Cant wait to hear your flight report on yours.

 

[MaxQ]

making one light enough to glide is even more difficult (as I'm sure you found out).
/QUOTE]

Thats why I have dove head over heels into cardstock/Depron for all larger 18mm and some 24mm powered designs. This ends up with models that weigh close to nothing glide wise, and it certainly shows up in the performance. Even though the designs themselves are not in any way 'performy' types, having them suddenly weigh half or less as much shows up in the sky.

Over on YORF a while back I posted about the Depron version Space Camel I slapped together. Well, its my version thereof, and likened to a cross between that and the Cosmos Mariner, and as large as the latter. That thing not only worked on a Quest C6, but did rather well at that.

This X-34 here looks like a reasonable candidate for a cardstock/Depron version, just do not know how large to make this. MaxQ, could you post the critical length/span/wing planform measurements here, as well as the body diameter?

Cant wait to hear your flight report on yours.

Yep...as soon as I get home and pull a scale out.

 

[MaxQ]

"could you post the critical length/span/wing planform measurements here, as well as the body diameter?"

length: 17.5 "

wing span: 14.25 "

body diameter: 3 "

BTW: looking at online resources I realize that the correct reference for this variant is X-37 B

 

[MaxQ]

Vids of the real thing for amusement:
https://www.youtube.com/watch?v=7z37FXs3OCE&feature=list_related&playnext=1&list=PL24F16A89FBFCD29C



https://www.youtube.com/watch?v=5TqXUM8LiCY

https://www.youtube.com/watch?v=uwyZka_1Pn4&feature=channel

https://www.youtube.com/watch?v=5UrZ2E8Plzo&feature=channel

 

[MaxQ]

making one light enough to glide is even more difficult (as I'm sure you found out).
/QUOTE]

Thats why I have dove head over heels into cardstock/Depron for all larger 18mm and some 24mm powered designs. This ends up with models that weigh close to nothing glide wise, and it certainly shows up in the performance. Even though the designs themselves are not in any way 'performy' types, having them suddenly weigh half or less as much shows up in the sky.

Over on YORF a while back I posted about the Depron version Space Camel I slapped together. Well, its my version thereof, and likened to a cross between that and the Cosmos Mariner, and as large as the latter. That thing not only worked on a Quest C6, but did rather well at that.

This X-34 here looks like a reasonable candidate for a cardstock/Depron version, just do not know how large to make this. MaxQ, could you post the critical length/span/wing planform measurements here, as well as the body diameter?

Cant wait to hear your flight report on yours.

Say...do you think I should put some diheral in the wing?

 

[AstronMike]

Say...do you think I should put some diheral in the wing?

Yes, thats what Im going to do when I slap mine together. Not much, but just enough to 'get by'. Since it has such a 'fat body', all located above the main wing, a bit o' dihedral seems best.

 

[powderburner]

You might not need dihedral in the wing, since there is so much already in the tails and they are mounted so high on the aft fuselage.

I would do some flight-testing first, to see if you need any at all.

 

[aerospike]

MaxQ, you need a spar than runs continuously through both wing panels (and fuselage) otherwise your wings are going to be subject to breaking.

 

[MaxQ]

Yes...I should have put a spar in...especially since it survived the first test throws...

Thanks pointing that out.

I'll probably beef this thing up for the next round.

 

[CF-105]

I guess the Cat Scan didn't detect that problem!

Nice job, btw.

 

[RocketT.Coyote]

I want one...and I have a cat.

 

[hornet driver]

I'm on board with powderburner. You probably don't need any dihedral. Those vertical stabs look like they have enough and it looks like the bird does'nt weigh much. Great idea finding a hill to test glide from. I'm in the middle of a boost glider project now with high wing loading and a hill was the ticket for me. I actually have anahedral in mine. Have a bit of true airfoil section on my verts though. That might make a diff.