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Have a motor, need to figure out wingspan.

#1
First post, sorry if I mess something up. I have a 1300 kv, 420 watt motor but can't figure out how to make a plane around it. I know how to build most of the plane I just need to figure out what wingspan to use. I used a calculator on radicontrolinfo to try and find out what the dimensions should be but it spat out ~61 inch wingspan which felt large for my small motor. Can anyone direct me to a resource or just give me a rough estimate of what wingspan to use? thanks in advance!
 

quorneng

Well-known member
#3
BatVan
Is it by any chance a Turnigy L3010B?
The size of the plane depends entirely what you want it to do and how you want it to fly.
As a powered glider it could be quite a bit bigger than 60 inch span.
For a foamy aerobatic the span would be smaller, 42 inch or less.
Some more detail on what sort of plane you want would help.
 

Merv

Well-known member
#4
I have found the weight of the plane to be more useful. Look at the table below and decide how you want to fly. This will give you a target weight of plane, then size the wing to support 12-15 oz/sqft.

• 50 to 70 watts per pound is the minimum level of power, good for park flyers and lightly loaded slow flyers.
•70 to 90 watts per pound is perfect for trainers and slow-flying aircraft.
•90 to 110 watts per pound is good for fast-flying scale models and some sport aerobatic aircraft.
•110 to 130 watts per pound is what you want for advanced aerobatics and high-speed aircraft.
•130 to 150 watts per pound is needed for lightly loaded 3D models and ducted fans.
•150 to 210+ watts per pound gives unlimited performance for any 3D model.
 
#5
Sure, it's my first plane so I'm just trying to make a simple trainer. I tried to attach a picture of the motor. The main goal is just to get a 5+ second flight time so really just a simple easy design would be best. I'm also trying the make it almost entirely out of foam so a shorter wingspan would be ideal. What span would you recommend?
 

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FDS

Well-known member
#6
That would work fine on any of the mini sized FT planes and the Tiny Trainer. Shorter wings will mean a faster plane, not ideal in a trainer. Minis are all sub 800mm wingspan and based on a two part wing.
 

Flitedesign 3d

Well-known member
#8
A simple trainer with that particular motor should have a weight of approximately 1200-1400 grams in my opinion. I recommend a wingspan of 1200-1400mm, if you go too short you'll get a really fast trainer and also the motor tork will affect the plane more making the plane harder to fly.
 

FDS

Well-known member
#9
FT has plenty of designs that will work on. It might fly a Simple series or Ugly Stick, plans for the Das Ugly Stick are on here. That looks like a Park 450 sized motor, I thought it was one of the smaller ones.
You can shim the torque roll out of planes and many small FT designs angle the power pod to account for this.
 

BATTLEAXE

Well-known member
#11
Sure, it's my first plane so I'm just trying to make a simple trainer. I tried to attach a picture of the motor. The main goal is just to get a 5+ second flight time so really just a simple easy design would be best. I'm also trying the make it almost entirely out of foam so a shorter wingspan would be ideal. What span would you recommend?
As a trainer I would suggest the Explorer. It's a pusher prop and has an easily replaceable nose. The pusher prop will save your props because it is behind the wing and fuse, and the replaceable nose will be easy to fix when you crash. The wing is nice and loft and can be changed out if you wreck it or want to upgrade it to a 4 channel.
 

FDS

Well-known member
#15
Your lipo will depend on prop pitch and the physical battery size required to balance your plane. You can use bags of pennies to determine maximum battery weight then decide battery voltage based on prop choice. The only issue with the Explorer is its habit of folding the wing, there’s lots of fixes for that, some better than others.
All the larger FT designs are 4 channel.
 

BATTLEAXE

Well-known member
#16
Ok thanks. I was planning on using alirons, rudder, and elavator; would I just add those on if there not already on?
If I was you I would learn with just ailerons and elevator, rudder will come later. You can turn with the bank and Yank technique where you bank the plane over some with the ailerons and pull back on the elevator slightly to make the turn. remember you have to correct the roll and pitch once the turn is complete to maintain level for the straight run back
 

BATTLEAXE

Well-known member
#17
Your lipo will depend on prop pitch and the physical battery size required to balance your plane. You can use bags of pennies to determine maximum battery weight then decide battery voltage based on prop choice. The only issue with the Explorer is its habit of folding the wing, there’s lots of fixes for that, some better than others.
All the larger FT designs are 4 channel.
A box spar is the fix for it, super simple in the build of the wing. Plus the wing is replaceable so it can easily be rebuilt.