Combat Wing for FF23

[Pieliker96]

With the experience from last year, I'm planning a new-and-improved version.

Design Changes:
Hand-launching was hard and unreliable so I'm giving it a far bigger motor and ESC to take off vertically as a tailsitter (as originally intended). I'll add a bit more wing area to make up for the extra weight and split each elevon in two parts for redundancy and load distribution - especially with the inboard surfaces being in the propwash for control during takeoff. I'll be moving the control linkages and covers to the bottom side of the wing as it's aerodynamically cleaner and they're less vulnerable - turning to stay towards the center of combat exposes the top side of the wing. The nose will be reinforced even more than it was to help crashworthiness.

The design did great on the defensive last year, not so much on the offensive. I'm going to find a better method of deploying the tow line, and make it longer, to maximize its chance of getting out untangled and snagging another plane. I'm also making provisions for wingtip-mounted streamers, in addition to the diffuse lighting for night flights.

Some parts are ready, some are on the way. Shooting for a better showing this time around!

 

[Jonny Gum]

Sounds well thought out. I'll try to take you down!

 

[Pieliker96]

CAD mostly done, should have some foam cut by next week. Ended up at 50" WS

 

[LitterBug]

I've been watching too much battle bots..... Where is the rotating spinners that chew through whatever you run into? ;-)

 

[JasonK]

no split to your elevons, to have reducent sevos for each side?

 

[Pieliker96]

no split to your elevons, to have reducent sevos for each side?

They are split as inboard/outboard. Inboards are smaller to deal with the increased flow from the propwash during vertical takeoff. Two servos per surface is tedious to do without servo binding/fighting and still doesn't guarantee control in case of a servo failure (which is then twice as likely): a jammed or stuck servo probably can't be sufficiently overpowered by the other. In my 8 years of flying I've only experienced one in-flight servo failure (electrical, it just died), it's not something I'm concerned about. They're metal-geared and will be protected by shrouds so I'm not worried about mechanical failure.

 

[Pieliker96]

Got things mostly finished today. Still need to figure out a battery/camera mounting solution and a good drogue line deploy method but otherwise it's good to go!

 

[RossFPV]

View attachment 237955 View attachment 237956 View attachment 237958

Got things mostly finished today. Still need to figure out a battery/camera mounting solution and a good drogue line deploy method but otherwise it's good to go!

View attachment 237957

That coming together fast! For the battery you could make a little pod on the bottom

 

[Pieliker96]

That coming together fast! For the battery you could make a little pod on the bottom

They should fit in the current hatch design, they just need to be pretty far back for the CG to work. I may also add some skids on the wingtips to make them more durable/larger area

 

[JasonK]

They are split as inboard/outboard. Inboards are smaller to deal with the increased flow from the propwash during vertical takeoff. Two servos per surface is tedious to do without servo binding/fighting and still doesn't guarantee control in case of a servo failure (which is then twice as likely): a jammed or stuck servo probably can't be sufficiently overpowered by the other. In my 8 years of flying I've only experienced one in-flight servo failure (electrical, it just died), it's not something I'm concerned about. They're metal-geared and will be protected by shrouds so I'm not worried about mechanical failure.

got you, sounds like you got it figured out well then.

 

[LitterBug]

My last combat was with a flying spider in 2018.... Will it return?????

 

[Pieliker96]

Better deployment mechanism and drogue, tested dropping it off a balcony and no tangles in the line


Gopro mounted and shielded

Hoping for good weather for a flight this weekend.

 

[RossFPV]

View attachment 238140
Better deployment mechanism and drogue, tested dropping it off a balcony and no tangles in the line

View attachment 238141
Gopro mounted and shielded

Hoping for good weather for a flight this weekend.

Make sure the string isnt attached to the plane very secure or the plane you hook will pull yours down too

 

[Pieliker96]

Make sure the string isnt attached to the plane very secure or the plane you hook will pull yours down too

The parachute it's attached to is just friction-fit in there - pulls out with a decent tug. Should be enough to hold it in during deploy and let go when it snags.

With the camera, it came in at 1700g. Measured thrust is just 1800g, though that was with a pair of dead batteries. I expected some thrust loss with the prop-in-slot setup but not this much. I'm going to charge them back to full, enlarge the slot, and have another go. I'll also test a 10x4.5 and a 9x6 and compare those to ecalc predictions - it doesn't help that the 10x7 I'm using is stalled at zero airspeed. I may have to go bigger diameter and lower pitch to get the takeoff TWR I want with this motor - I can just about squeeze an 11" in there if I need to.

 

[Pieliker96]

Static thrust jumped up to 2400g (TWR ~1.4) with fully charged batts. Should be good enough to give it a shot at vertical takeoff, though I've got an 11x5.5 on order to see if I can get TWR above 1.5.

 

[Pieliker96]

Went for a maiden on the 10x7. Took three attempts to get it off the ground. I had much more authority than I expected, and torque roll was a larger problem than I expected. A higher TWR would definitely help.
Beyond that it handled great in the air. The tow line deployed without a hitch (will be lengthened to ~50ft) and the endurance was acceptable (14 mins, down to 3.5v/cell).

 

[FishbonesAir]

With the experience from last year, ... not so much on the offensive. I'm going to find a better method of deploying the low line, and make it longer, to maximize its chance of getting

With the experience from last year, I'm planning a new-and-improved version.
<hack, slash, chop!>
The design did great on the defensive last year, not so much on the offensive. I'm going to find a better method of deploying the low line, and make it longer, to maximize its chance of getting out untangled and snagging another plane.

I haven't been to FF before, and when I asked "what's allowed" in Combat many Moons ago, I got a reply of "oh, you know, kinda whateve" which basically told me nothing.

So... if I show up with a FT F-22 that has LIDAR to guide Estes-powered, guided missiles, everyone's gonna be okay with this??? My son is autistic, and this was the first thing he thought of when he heard "RC airplane combat". He's doing an internship at CU Boulder with a bunch of other brainiac nerds, so don't count him out of being able to do it for FF2024. But I digress.

Please, tell me more about this "Low line" thing. I am your Humble Student.

 

[Pieliker96]

I haven't been to FF before, and when I asked "what's allowed" in Combat many Moons ago, I got a reply of "oh, you know, kinda whateve" which basically told me nothing.

So... if I show up with a FT F-22 that has LIDAR to guide Estes-powered, guided missiles, everyone's gonna be okay with this??? My son is autistic, and this was the first thing he thought of when he heard "RC airplane combat". He's doing an internship at CU Boulder with a bunch of other brainiac nerds, so don't count him out of being able to do it for FF2024. But I digress.

Please, tell me more about this "Low line" thing. I am your Humble Student. View attachment 238304

Realized a typo, should be "tow line"
Basically it's a bit a string that drags behind the airplane in an attempt to catch any planes that fly into it. It's got a small drogue on the end to give it some stability and to act as a spool so the line doesn't get tangled when it gets deployed in-flight. The other end of the line is attached to a model rocket parachute that's friction-fit into a tube in my plane - when someone gets caught and tangled in the line, the parachute pulls out and down they go. That's the idea anyways.

 

[FishbonesAir]

I haven't been to FF before, and when I asked "what's allowed" in Combat many Moons ago, I got a reply of "oh, you know, kinda whateve" which basically told me nothing.

So... if I show up with FT F-22 that has LIDAR to guide Estes-powered, guided missiles, everyone's gonna be okay with this??? My son is autistic, and this was the first thing he thought of when he heard RC airplane combat. He's doing an internship at CU Boulder with a bunch of other brainiac nerds, so don't count him out of being able to do it for FF2024. But I digress.

Please, tell me more about this "Low line" thing. I am your Humble Student. View attachment 238304

..... when someone gets caught and tangled in the line, the parachute pulls out and down they go. That's the idea anyways.

View attachment 238327 View attachment 238328 View attachment 238329

Okay, I'd had some similar ideas, but wasn't sure if they were allowed, lol. 😁

All my time has been going into my B-25 build for the Doolittle Raid. It's finally getting close to finished (yay!). I literally just fitted the servo into the tail to control the twin rudders.


I may try to build something, but it will likely have to happen on site.
Dave "Capt Fishbones"

PS If you, or anyone you know who is attending has a FT B-25, or something similar like a Guinea, we need more planes and pilots Saturday morning!

 

[Pieliker96]

11x5.5 bumped the static thrust up to 3.2kg, TWR = ~1.9 versus the 1.4 of previous. Should help!