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Weightlifting Competition - Stock C Pack

Duck

Active member
#1
I thought it would be interesting to run a contest for building a plane that can do a 400m circuit (standard running track) with a stock power pod & C-pack and 10x4.5 prop. Winner is the one that can carry the most dead weight, do the circuit and land in one piece. What high lift wings to use? Flying wing or conventional? Pusher or tractor? Hand launch, dolly or wheels?

Does anyone have good examples that might fit the criteria? How much cargo weight could you get into the air?
 

BATTLEAXE

Well-known member
#2
It is an interesting contest, really would bring out the creative side. I am sure anyone who would want to win this one would choose a flying wing, built as light as possible. I would also depend on the weight and where it was carried if those are specifications. And to get everyone together to do the contest, which would be a good FF2020 event. I would be interested in seeing the results for sure. could do one for the A or F pack as well.
 

FoamyDM

Building Fool-Flying Noob
#3
So, @Duck go ahead and do it. I like this design/build challenge.
@BATTLEAXE I agree about size categories.

As a guy who will be doing a 4-plane Build Contest/Challenge again in Feb., and I will try 1 last time in April for the 1-month water plane build challenge. My advice is to get the word out over 2 months out. 1 month hype just isn't enough for a 1 month challenge. you need to give time for folks to see it. Think about if they want to join, and how, then they post.
Most folks don't like to fail... so they need to understand that failing is OK, it's the journey and fun that will make it.
Look at my and Rockyboy's FTFC challenges. The ones that have clear definition go further.

So I will play devils advocate in an effort to get this to become a thing:
  • Which stock Power pack - the radials or the 2218/09s?
  • Does it have to take off from the ground?
  • Is there a weight or size limit?
  • Is it strictly payload? can I put lead shot in a cup and put it at the CG or can I opt for other things Like spare batteries, Water?
  • Also is it AUW, or Payload and how do you measure it? Is the battery considered payload?
  • Is there a battery limit? (mAh or Voltage) Can I use a 4S? what about if I run it on 6S (just to win).
  • What is the scoring system (Rubric)?
Either way I look forward to this kind thing.
 

BATTLEAXE

Well-known member
#4
This contest could gain momentum. It has potential to be fun program. Question is how would it be judged? Do we just trust vids? I know it's just bragging rights but there are lots of possibilities to cheat as well. Is it based on first run out or the best run over a number of tries? Is there mod/fix intermissions?

Might need a board of directors for the rules and judging lol
 

Hondo76251

Well-known member
#5
Just to get things started this will be my first entry...


Did a parachute drop for the kids over the 4th this year,

Payload was 12 paratroopers weighing about 21.6 a piece, total weight 260 grams.

Plane is a modified FT Cruiser with original (Old version) C - pack

Big battery, a few cameras, no idea what Gross weight was.

Hand Launched, belly landed.

My $0.02 would be to keep the rules simple.
-Use C-pack motors (or equiv), any battery any prop.
-Weight judged on Payload.
-Flight time of at least 30sec
 
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Piotrsko

Well-known member
#6
You can set it up like they did back at the EAA maybe 20 years back: number of crew gets handicap factor, speed gets factor, seats available, factor, empty factor, loaded factor. On and on. Multiply factor by category, add the factors together. highest one to fly the circuit complete wins. Made my 120 mph Pacer with 4 seats and a thousand # useful actually competitive against a long EZE and a glassair.

I can't see hand launching a 20 lb foamy with any success.
 

Hondo76251

Well-known member
#7
I can't see hand launching a 20 lb foamy with any success.
I was thinking I could get a couple pounds in the air with the franken-cruiser w/c pack motors but if you're already going for 20lbs I've got some work to do! :eek:

I know it doesn't take much to confuse a Jarhead but I don't think I can wrap my head around all that...

I've done some PHRF sailboat racing, where each boat has a rating. Each model/manufacturer has a rating number based on total data for each boat from all previous races compared to all other boats. The Idea being that the point of the race is to test each crews skill in handling their own boat. The fastest boat doesn't win, the best sailed one does.

If i'm understanding you correctly you're saying that you want this to be a competition of pilot skill alone. To me it seems, at least in this format, that this is more of a build competition. In that spirit I still think that the rules should remain simple. Do whatever it takes to get a C pack to lift as much weight as you can...

I'll throw this out there too: since so many of the coolest FT planes are c pack twins (like my FT Cruiser) I'd vote for allowing twin engines ;)
 

Piotrsko

Well-known member
#8
I was more into handicapping the airplane and that was the only solution that came to my feeble mind. The sailboat handicap is more in line.
I built a 2500 square inch oak and plywood combat wing glider once when I was in cabinet shop so I would survive a mid air with this obnoxious rich guy who liked to crash his stuff into yours. I won that one and dumped his debris out over the ocean. So playing with stuff, it's not inconceivable that I can build something that will fly 20lbs. But it will be big and beyond what a lot of people can do so it's a bit unfair IMHO. 1lb in a simple scout would be impressive. Just saying.
 

Hondo76251

Well-known member
#9
I see what you're getting at. Certainly better to include as many participants as possible.

I think using specific motors is a limiting factor itself (though maybe not enough.)

The new radials produce something like 2 lbs of thrust. Just some rough figures for thought; With twin engines and a power to weight ratio of 1:3 and a wing load (WCL) in the 20's you'd have a plane nearing 15 lbs gross and somewhere around 5' wings. Maybe that is too much plane for a lot of people to pack around where they can fly...

Maybe we can keep it to single c pack or an A pack if you are going with twin engine setup...
 

Duck

Active member
#10
I would only count a single engine setup. I am in the middle of building a dual bronco which I am building exactly for lifting things but it is sort of cheating isn't it?

I would want to keep it simple and easy to participate. You should be able to take a FT plane you already have and produce a respectable number. But building to fit is just fine :)
  1. Only dead weight counts. You should be able to remove it and weigh it without impacting the plane.
  2. Single C-pack. Just call out if you are using the radials or the EMAX.
  3. 1-3S only. Otherwise any battery you want. 200mah? Good luck! You are welcome to tell us all about that 4-6S fun though!
  4. Rather then doing a circuit, I think 120 seconds in the air is just fine.
  5. Launch under your own power or hand launch. No power assisted launches. Walking to the top of a cliff counts as cheating :p I see you guy in the back thinking of cheating with a balloon launch.
 

Hondo76251

Well-known member
#11
With so many cool twin engine planes I'd sure like to see them represented in the contest...

Looking at the specs I dont think running a twin A pack against the single C is any sort of unfair advantage. The 1806 has at most 500 g thrust (if that?) The Radial C is well over 1000 I think, something like 1400 grams.

Another question, do I have to land loaded or can it be released in the air? I think releasing in the air will help the airframe make more repeated attempts without the stress damage from heavy landings...
 

Piotrsko

Well-known member
#12
Well with 3:1 gearing, I can probably get 4lbs thrust on helicopter system I have, set up as prop.
figure at least a 7 ft wing probably 3-4 FULL sheets of FB. So at minimum 1 lb thrust for 4lbs aircraft we get to 16 lb really easily. Napkin crunching says 50 ounces a square ft, .34 a sq inch. Leery of jettisoning 20 lb barbell weight. Probably some odd sytem of FB and string tape. Could be a one shot flight, so, requires rules saying plane must fly again possibly with or without load. I Like the 2 minute minimum flight time requirement.
 
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FoamyDM

Building Fool-Flying Noob
#13
The Old 2218/09 C-pack motor was classed to have up to 3lbs of thrust. a 10x4.7 prop was 2.84 lbs.

Description:
Brand:EMAX
Item No: GT2218/09
Item name: 1100KV outurner brushless motor
Weight: 80g/2.82oz
Stator Dimension: 22mm x 18mm
Shaft diameter: 4 mm
Color:Black
Material: Metal
RPM/V: 1100KV
Number of cells: 2-3S lithium polymer
Cell Count:3S
Max.current: 26A
Max Thrust: 1380g, 3.04ib
Recomended Prop APC: 1047,1138 available
Usage: For RC Quadcopter, Multi-copter, Airplane
 

BATTLEAXE

Well-known member
#14
The Old 2218/09 C-pack motor was classed to have up to 3lbs of thrust. a 10x4.7 prop was 2.84 lbs.

Description:
Brand:EMAX
Item No: GT2218/09
Item name: 1100KV outurner brushless motor
Weight: 80g/2.82oz
Stator Dimension: 22mm x 18mm
Shaft diameter: 4 mm
Color:Black
Material: Metal
RPM/V: 1100KV
Number of cells: 2-3S lithium polymer
Cell Count:3S
Max.current: 26A
Max Thrust: 1380g, 3.04ib
Recomended Prop APC: 1047,1138 available
Usage: For RC Quadcopter, Multi-copter, Airplane
That's the same motor I have and I always wondered what the actual Kv was, it's the only number not on the motor. This opens up some possibilities
 

FoamyDM

Building Fool-Flying Noob
#15
Does the power have to be running the whole time of the flight duration? It has to have the weight up there for that time right?
I'm building the Hydra wing... with a C-pack motor! :p
Nope, I have a better idea. :censored:
 

Duck

Active member
#16
With so many cool twin engine planes I'd sure like to see them represented in the contest...

Looking at the specs I dont think running a twin A pack against the single C is any sort of unfair advantage. The 1806 has at most 500 g thrust (if that?) The Radial C is well over 1000 I think, something like 1400 grams.

Another question, do I have to land loaded or can it be released in the air? I think releasing in the air will help the airframe make more repeated attempts without the stress damage from heavy landings...
I have no problem with dropping it as far as the contest is concerned. Please be careful dropping a heavy weight though. A rubber duck it is not.
 

Arcfyre

Well-known member
#19
I like this idea and wouldn't mind seeing some "official" rules put in place.

The brilliant thing about limiting the competition to a specific model of motor is that it kind of automatically limits everything else. Sure, you could build a flying wing with a 20 ft wingspan and lift 70 pounds, but a C pack will never fly it.

In the interest of simplicity, I would propose that the easiest way to score the contest would just be based off of AUW. The highest AUW that successfully completes 2 full cycles (takeoff and landing) on video wins. Hand launch/belly land count, but the plane would have to by flyable again as proof of structural integrity.
 

Piotrsko

Well-known member
#20
Wait a minute, Pilgrim, I never said 20 ft span or 70 lbs. That takes at least 50 lbs thrust, probably use @SquirrelTail as the pilot. I do see 20lbs AUW as a max lift possibility on a C pack but that's going to be close to dangerous. I also still think that 1 pound AUW simple scout should win this but that probably won't happen.