SST Orbital Transport-ish R/C Rocket glider large and small

[burkefj]

I've done many R/C Orbital Transport piggyback gliders as standalone rocket gliders, but wanted to try to do something glidable for the booster as a standalone since I like the general SST ish layout. I wanted to use the D2.3 for a slow and easy boost. The stock wing is too far back and too tiny, so it needed to be upscaled, wingspan increased and moved forward to get a reasonable boost/glide cg. 33.5" long, 20.5" wingspan, sub 6 oz rtf.

I used BT-55 tubing, an 18" and 9" piece with a coupler and a Black Brant nose cone since I had that laying around that gave a sort of X-59 ish style look. I used the general layout but tweaked it to work without nose balast and have as large a wing as possible and stay under 6 oz rtf for the D2.3. This allowed me to use 3mm Stabs slotted into the wing, a 3mm canard slotted fully through the fuse, the wing is 6mm with a single 2.5mm spar. The motor mount is centered via three strips and also at the front going into a notch in the rear of the wing.

I covered the tube with white vinyl , slotted for the wing and canard and installed rail buttons. The vinyl added .25 oz to the overall weight.

The wing was installed and centered and glued in place, then the wing tips were added and sanded round at the edge. I installed the tails and glued them in as well as the canard. The intakes were made of 3mm depron with three profiles and a cover plate and an 18mm motor tube cut in half for the two exhaust nozzles. Two were built.

I cut off the vinyl and glued the two strakes to the fuse and front of the wing and did some glide tests indoors. Required CG was just a little forward than 25% calculated for the wing due to the strakes and canards but this is what I wanted since I knew it was going to favor nose heaviness with the length. I will cut a mid body access hatch for the battery and the nose will be permanently mounted.

I will glue the servos to the wings and use short pushrods to keep weight rearward and route the servo wires into the fuse and forward to the rx, then cover the servos with each engine intake assembly to hide them.

Looks pretty rakish...

 

[burkefj]

Spent an hour on some markings, turned out rather nice.

 

[burkefj]

Finished up today, made a hatch on the bottom for rx which required notching out the wing inside and then sealing the hatch back up with vinyl then cutting a top hatch for battery access, worked well no balast needed. Servos installed and wires routed forward then intakes were notched out to clear the servo arm and wires and glued in place. Nice and clean.

 

[neil_w]

Pretty.

 

[Glasspack]

Very impressive Frank !!!!!

 

[burkefj]

Three test flights today were just beautiful, glide trim was perfect as set and boost trim just needed a few clicks of down. Really graceful in the air, with the long neck it reminded me of a swan or crane, nice almost exact 50 second glide times on all three flights using D2.3 reloads. Had a brief respite of sunny no wind conditions mid "atmospheric river" Oregon is experiencing... No videographer today though.

 

[neil_w]

Curious: how long does it take to put one of these together, from design to decals? These build threads make it look like the whole thing is about 30 minutes. (please don't say it actually takes 30 minutes)

 

[burkefj]

Curious: how long does it take to put one of these together, from design to decals? These build threads make it look like the whole thing is about 30 minutes. (please don't say it actually takes 30 minutes)

Depends, 4-6 hours depending on how much I have to think about things and simulation tweaks for component placement etc to convince myself it will make weight and drawing patterns if needed, this I just drew on the foam, actual assembly including cutting parts 2 hours, half an hour for radio install and an hour or so for decals sometimes more. This went together quick for a new design. Many don't require paint, the foam is a nice white and sands fast, everything assembled with CA. Probably 10 hours on more complex built up or my larger models, once I have the approach figured out I burn through it pretty quickly.

 

[Extrapolatedman]

Love the "engine" shrouds over the servo. That's nice.

 

[Johnly]

Sophie has promised me one for Christmas!

 

[burkefj]

Love the "engine" shrouds over the servo. That's nice.

I knew the engine intakes were inboard and so the elevons had to go outboard of them which set the wingspan, the servos had to be close to the inboard end of the elevon so hiding them in the intakes seemed like a natural plan. Cg also meant I wanted them back further than normal so it worked out.

 

[burkefj]

Flew again today in high wind, flew great, launching downwindand rolling into the wind at burnout, hovering spot landings were no problem. Still 50 second glide times, pretty consistent.

 

[Extrapolatedman]

I've built and flown the StratoDart and Big Orbital Transport Orbiter, both great fun. I own but have not yet built the little BT-60 1.6" Mini Orbital Transport Orbiter. My fantasy is to match that one up with a big flyback booster, per the original concept. Which would make it what, about 2.2" diameter?

 

[burkefj]

I've built and flown the StratoDart and Big Orbital Transport Orbiter, both great fun. I own but have not yet built the little BT-60 1.6" Mini Orbital Transport Orbiter. My fantasy is to match that one up with a big flyback booster, per the original concept. Which would make it what, about 2.2" diameter?

Yes. The issue is the design to make a fly back booster would have to be similar to what I did, englarge the wing/wingspan and wing location for CG for glide back, then you would have to space the tails out more to clear the glider, I left them inboard to clear the elevons and not have to move them forward and reduce stability in yaw, then you would have to do the attachment points on both booster and glider, you would need to rebalance the glider without the motor as I don't think you would want to carry weight of trying to do an airstart to the tiny glider, and have a release mechanism for the glider since you don't have the rapid "stop" of the parachute ejection to release with a simple hook attachment like the original, and then the whole thing would be heavier of course so you would have to see what weight it came out at and what motors you could use, if it required a fast burn motor then the stiffness and attachment would potentially be an issue, and you would have to see how the CG came out for boost and all the offset drag of the added glider, would need to fly it on the way up and down, and have a second pilot of course, probably why I haven't done it yet, or anyone else in this same format(there have been piggyback dual glide back but not as an orbital transport)...but I think you should

 

[burkefj]

Nice windy day flight today.

 

[burkefj]

That worked so well, and I just found one more 29mm phenolic motor tube, I think I will do a 2x upscale to 2.6" for single use H-13 longburn motors..

 

[burkefj]

Sim so far, will update as I go along, I have a lot of margin I think on this one, 67" long, 40" wingspan..Main thing will be the wing weight, I've moved the wing back 2" since the motor is relatively a lot heavier on this one and should help natural CG come out ok. Ordered some 5065 digital metal gear servos and adjustable horns. Anything up to around 34 oz is still ok, if light enough could fly on the G12 single use as well. I've allowed 1.5 oz for glue and am still light. I think I will use two 2.5mm spars top and bottom on a 9mm wing and then laminate a 3mm sheet on the top to hide the spar and give a bit more stiffness.

 

[burkefj]

Coming along, most of the parts kit shown, 9mm Wing with double 2.5mm spars top and bottom with a 3mm laminate over the top to hide the top spar and printing on the foam, came out at 7oz. The table is about 36" by 8' for size reference

 

[aerostadt]

What nose cone are using?

(On a different note I am contemplating revisiting and building a Concorde using BT-80 tube and flying on a G12.)

 

[burkefj]

What nose cone are using?

(On a different note I am contemplating revisiting and building a Concorde using BT-80 tube and flying on a G12.)

Pnc-80K. Like the big clipper but different wing

 

[neil_w]

I really liked the PNC55BB (I think) on the smaller one, but I can imagine that is non-existent at BT80 size.

 

[burkefj]

I really liked the PNC55BB (I think) on the smaller one, but I can imagine that is non-existent at BT80 size.

Yea, conical would be a highpower cone if available and too heavy, this will look more like the OT cone design.

 

[aerostadt]

I am wondering if I should build this new OT-ish glider. It might be easier. I have 3mm depron that I can laminate to make 6 mm. Do you have the Open Rocket simulation? I converted your OR simulation to RocSim-11 that I now have on Windows 11. The RocSim-11 turned out pretty good for me.

 

[burkefj]

I am wondering if I should build this new OT-ish glider. It might be easier. I have 3mm depron that I can laminate to make 6 mm. Do you have the Open Rocket simulation? I converted your OR simulation to RocSim-11 that I now have on Windows 11. The RocSim-11 turned out pretty good for me.

I don't have anything accurate drawn in OR, just rough placeholders, you need a large 9mm sheet and large 3mm sheets, 6mm only used for intakes..I think your concorde sounds neat

 

[burkefj]

Tails decorated before adding them to the wing, intakes built, used 24mm tubes for nozzles, I covered the bottom of the intakes with white vinyl for landing protection and re purposed some decals stickershock printed for a project I did, since print setup cost was high, he printed a bunch of extras, 100 points to Griffindor if you know what they are from..they looked jet engine-y..

 

[burkefj]

More progress

 

[burkefj]

Weight as shown is only 16.2 oz.

 

[burkefj]

17.6 oz w motor mount

 

[burkefj]

I made a magnetic hatch in the bottom for rx and battery access at the cg location to keep wires short.

 

[burkefj]