Transcript Slide 1
Deep Thoughts and other Random Political Advise for building your Airplanes Sean Henady Nick Setar Stephen Rees Overview •Safety Concerns •Connections •Mounting components •Building tools •Building Techniques •Plan out your build •Extra Time •Freaking ask questions Safety Concerns Batteries • Li-Po batts very safe when properly handled • Use correct charger on correct settings • Charge at correct rates (C rating) • C_rating*capacity of battery • 2000 mah has a rating of 3C for charge, can be charged at 6 Amps. • Do not Discharge past C discharge ratings • Typically most LiPos are in the 15C-20C range • If you short the battery the discharge rate will be significantly higher than this rating and possible lead to rapidly expanding gas fire Safety Concerns Propeller • Ensure it is properly mounted to the motor • Proper propeller is selected • Balance the propeller • Even these small propellers will cut your finger off, end of story. • If a propeller comes off and hits you in a vital area, face, neck…ect…..the injury can be lethal. • Take your time when testing!!! •NEVER Stand in front of the plane when it is running. NEVER!!!!! Safety Concerns Propeller Connections • Class Standards? • Motor Connections • Speed Controller • Battery • Receiver • Servos Connections Motor Connections • Brushless will have 3 leads • Plug into Speed Controller in any combination. Change any 2 leads to reverse motor direction. • Recommend class standards • 3mm bullet connectors (comes with most small motors) Connections Speed Controllers • One end goes to motor (3 leads) • Other goes to battery (2 leads +,-) !!!! • Your team will need to solder ends from the speed controller to the motor and battery. • Recommend you use the 3mm female on the speed controller to the motor end and Ultra Deans male/Eflight batt male connector on speed controller to battery end • BEC, this will use the battery to power the servos/ receiver. •The throttle lead that plugs into the receiver. Connections Battery • Many different types of batteries, sizes brands ect. • Ultra Deans female/Eflight female end •Less chance to short with this style of connector • Think interchangeability Connections Receiver/Servos • Brand of Receiver will determine which channel (port ) the servo will plug into. • The White/Yellow will be the signal line for the servo. • Red will be POWER • Black/Brown are GROUND Mounting Components • Try to use Velcro for battery, receiver, speed controller •Think ease of maintenance and interchangeability • Standardize use of Velcro! Building Tools • • • • • • • • • • Xacto Knifes Razor Blades Glue Accelerator Foam Wood Small hand saw Band Saw Jig Saw Table Saw (not likely) • • • • • • • • Screwdrivers Needle nose pliers Hot glue gone Solder Iron Solder Band Aids Time Practice Building Tools Glues • Pro Thin CA MUST USE ODERLESS WITH FOAM!! – Joint with no gap – Cures in seconds • Pro CA+ – Surface gluing – Filling small gaps – Cures in 20 – 30 seconds • Pro CA– Use when extra positioning time is needed – Great gap filler – Cures in 1 – 2 minutes Building Tools Glues MUST USE ODERLESS WITH FOAM!! • Epoxy – Longer Cure times – Bit heavier – 5,10, 15 min • Hot Glue – Very easy to use – Don’t get too hot!! • Wood Glue – Sandable, heavy • Gorilla Glue – Sandable, expands, great for wing skins Build Techniques • Servo/Control surface linkage • Hinging • Motor Mount • Hotwire • Wing mounting • Tail mounting • Monokote/Ultracote • Landing gear mounting • CNC Build Techniques Servo/Control surface linkage • Stiff • Straight • Plenty of control throw with no binding • Use as much of the servo travel as possible +/- 60 deg • Z-bend • E-Z Connector Build Techniques Servo/Control surface linkage Build Techniques Hinging • CA Hinge • Thin ‘top’ layer on multilayered foam • Tape(not standard scotch tape, use clear tape) • Monokote/Ultracote • Robart/Pinned • Need to get full deflection our of surface, freely! Build Techniques Motor Mount • Lots of torque and forces acting here! • Pay attention to thrust angles • If anything a 1-2 deg of right thrust…. • Make sure your mount can have washers placed on it to shim motor based on pilots request….will help tremendously in hover. Thrust vector is very important in this regime. • Don’t need to add lots of weight, just be smart in your design. Look at the planes up front. • ‘Distribute’ your loads where possible Build Techniques Hotwire • Practice a few times!!! • Very easy to do, with a few practice runs • Easy to make complicated shapes • Very dependent on type of foam used • Research some YouTube videos of people doing it • Be aware of fumes…… • Highly tapered wings are challenging • Slow at tip, move fast at root…melts wing tip Build Techniques Wing Mounting/Tail Mounting • Try to ensure it can break away, not always a possibility • Rubber bands • Nylon bolts • Aileron servo connections to receiver? • May need to brace tail Build Techniques Landing gear mounting • Nylon bolts highly recommend (shear away) ~1032 range <1/4-20 •Wire, carbon, aluminum stock • All acceptable, try to pick lightest and most shock absorbent • Wheels need to rotate freely • Tailwheels need to be steerable Build Planning • Build your plane on paper while waiting for parts. Develop outline and procedure so when parts arrive you can build fast. (A little critical thought will catch many errors later on!) • Realistically estimate how long it will take you to do something, then multiply that by 3. If it takes you 3 min to plug in 5 servo wires to receiver(about what it takes) triple that • Use this to plan your build process. •Utilize your teams strengths and abilities. Deep Thoughts • Make components interchangeable among groups • Standardize Velcro, and soldered ends • Plan your time • Ask questions • Measure twice cut once!!! • Servo to control surface linkage vital for ‘crisp response’ • Research YouTube and other sites to gain more information • Balsa wing converting video (how to monokote) • Building Tutorial for building EPP RC Plane (ways to build) Questions?