X-37B-ish R/C rocket glider

[burkefj]

I worked on this yesterday, X-37B inspired, came out nicely, using BT-80 tubing, pnc-80BB cone and 6mm and 3mm depron for surfaces and side plates. I moved the wing back and upsized it for glide and to allow it to function like a delta and have fixed V tail which works better in general than modeling the actual X-37B layout. It goes high and fast, around 800 feet, just below the cloud deck today, fast but nice glide. it's small, 24" long, 2.6" diameter, 18.5" wingspan, about 1 sq foot of wing area, 7.6 oz ready to fly using a 24mm composite Aerotech E-6. It was very roll sensitve, I had to tone down the roll rate to 30%. Looks great in the air and on approach.

 

[tab28682]

Good looking little model!

 

[BABAR]

Nice flyer and great looks.

Curious, why tail buttons on top? To make landing skid smoother?

 

[neil_w]

That's a beauty. I'm continually impressed by how immaculate your (partial) paint jobs are on every model.

How does the presence or absence of a dihedral on the wings affect the performance of the glider?

 

[burkefj]

The main reason is rail button attachment. The wing is mounted on the bottom and it's 6 mm foam so it's almost impossible to attach through that with any robustness especially when you're landing on them, on this model the sides also have the foam plates so I can't attach through that either and the v-tail is in the way.

Nice flyer and great looks.

Curious, why tail buttons on top? To make landing skid smoother?

 

[burkefj]

Thank you, in fact the only paint is on the nose and the bottom of the wing that you can't see the rest of the detail is trim vinyl that I cut by hand but it goes on very nicely. The model is very neutral meaning it doesn't want to maintain any particular orientation it pretty much stays where you put it. I don't particularly need dihedral to fly, it also made the wing stiffer and easier to make and attach and matched the model that inspired it.

That's a beauty. I'm continually impressed by how immaculate your (partial) paint jobs are on every model.

How does the presence or absence of a dihedral on the wings affect the performance of the glider?

 

[BABAR]

The main reason is rail button attachment. The wing is mounted on the bottom and it's 6 mm foam so it's almost impossible to attach through that with any robustness especially when you're landing on them, on this model the sides also have the foam plates so I can't attach through that either and the v-tail is in the way.

Call them Antennas.

 

[Richard Dierking]

Cool to see new rocket gliders and types of lifting bodies. Thank you for sharing your creations!

Sorry for going OT a bit, but has anyone come across a 3D print file for a HL-20/Dream Chaser?

Here's a photo of a HL-10 project I've been working on. But, after this, I would like to make a Dream Chaser about 12" long.

 

[JP Johnston]

I worked on this yesterday, X-37B inspired, came out nicely, using BT-80 tubing, pnc-80BB cone and 6mm and 3mm depron for surfaces and side plates. I moved the wing back and upsized it for glide and to allow it to function like a delta and have fixed V tail which works better in general than modeling the actual X-37B layout. It goes high and fast, around 800 feet, just below the cloud deck today, fast but nice glide. it's small, 24" long, 2.6" diameter, 18.5" wingspan, about 1 sq foot of wing area, 7.6 oz ready to fly using a 24mm composite Aerotech E-6. It was very roll sensitve, I had to tone down the roll rate to 30%. Looks great in the air and on approach.

SHUH-WEET!!!

 

[JP Johnston]

Cool to see new rocket gliders and types of lifting bodies. Thank you for sharing your creations!

Sorry for going OT a bit, but has anyone come across a 3D print file for a HL-20/Dream Chaser?

Here's a photo of a HL-10 project I've been working on. But, after this, I would like to make a Dream Chaser about 12" long.

View attachment 442993

How did you develop the model and drawings? Just Curious...

JP

 

[Richard Dierking]

How did you develop the model and drawings? Just Curious...

JP

Hello JP. It's kind of a 'If you give a mouse a cookie' story, but the stl file was created from a scan of a 1:48 scale model I built.
I had to remove the outboard fins because they were causing too much shadowing during the scan. The fins have to fold in to fit in the aeroshell anyway.

I recently obtained a stl file for Dream Chaser. I fellow from Germany is helping me with the 3D files. So, I'm beginning to get that lifting body lined up to create a working model.

I worked on this yesterday, X-37B inspired, came out nicely, using BT-80 tubing, pnc-80BB cone and 6mm and 3mm depron for surfaces and side plates. I moved the wing back and upsized it for glide and to allow it to function like a delta and have fixed V tail which works better in general than modeling the actual X-37B layout. It goes high and fast, around 800 feet, just below the cloud deck today, fast but nice glide. it's small, 24" long, 2.6" diameter, 18.5" wingspan, about 1 sq foot of wing area, 7.6 oz ready to fly using a 24mm composite Aerotech E-6. It was very roll sensitve, I had to tone down the roll rate to 30%. Looks great in the air and on approach.

Wondering what the velocity is when the X-37B-ish glider is flying. I know adding mass can be challenging but it would be interesting to put something like a FeatherWeight GPS in the glider and create a GoogleEarth track with the data.

 

[burkefj]

Hard to say, if you use a coefficient of lift of one and estimating wing area at around 160 square inches and glide weight at 6.5 Oz one online calculator says stall speed is around 12 mph, so glide is probably somewhere around 15-20 depending on the trim, but I have no frame of reference that sounds get feel to be a little faster than what I think it is, it glides faster than most of my other models except for the x15

Quote:
Wondering what the velocity is when the X-37B-ish glider is flying. I know adding mass can be challenging but it would be interesting to put something like a FeatherWeight GPS in the glider and create a GoogleEarth track with the data.
[/QUOTE]

 

[Richard Dierking]

Hard to say, if you use a coefficient of lift of one and estimating wing area at around 160 square inches and glide weight at 6.5 Oz one online calculator says stall speed is around 12 mph, so glide is probably somewhere around 15-20 depending on the trim, but I have no frame of reference that sounds get feel to be a little faster than what I think it is, it glides faster than most of my other models except for the x15

Please let me know which online calculator you used.
I don't know if my lifting body is even going to glide and if so, what velocity. Keeping in mind that these types of lifting bodies at full scale were really moving and at a high decent rate.
I read last night that on the HL-10 maiden flight, the craft was dropped at 45,000', and landed 189 seconds later at 322 mph. Wow; average descent rate was 14,000 ft/min! Most of my rockets on drogue descend slower. It will be parachute recovery deployed at about 500' AGL, but now I'm wondering if the parachute will hold if the velocity is so high.

 

[burkefj]

I have no idea how this calculator compares to reality, but here you go, https://www.rcplanes.online/calc_stallspeed.htm

I usually just look at wing loading as a relative guide and try to stay in the 5-7 oz/sq foot range for what I do.

Frank

Please let me know which online calculator you used.
I don't know if my lifting body is even going to glide and if so, what velocity. Keeping in mind that these types of lifting bodies at full scale were really moving and at a high decent rate.
I read last night that on the HL-10 maiden flight, the craft was dropped at 45,000', and landed 189 seconds later at 322 mph. Wow; average descent rate was 14,000 ft/min! Most of my rockets on drogue descend slower. It will be parachute recovery deployed at about 500' AGL, but now I'm wondering if the parachute will hold if the velocity is so high.

 

[modeltrains]

Looks great in the air and on approach.

Looks good enough that part of me was a bit shocked when the landing gear didn't appear during that first approach and final after the 1:58 point!