Impossible Duct & Mechanism V2 by 1Smug_Bastard

Last crawled date: 3 years ago

5" Duct / Mechanism for use with Tricopter-Mini or Bicopter tail assembly. Mechanism can tilt upwards of 40 degrees without touching the Servo. 5" Ducts require 6" arms to maintain the proper clearance. Servo users require the Imposible Tail Mechanism Servo Holder "Tall" and Back Support. by Motorpixiegimbals https://www.thingiverse.com/thing:1035497)
Note: Can also be used on a Quadcopter making it a Mega-Whoop.
Original Project (Old Files)https://www.thingiverse.com/thing:3028330
See the following website for more detailshttps://rcexplorer.se/forums/topic/impossible-tail-duct-wip/
V2 Major Changes
Updated the Propellers area of rotation giving it a better "sweet spot".
Added a version with a secondary Aero Lip to utilize the thrust from the Propeller to draw in more air mass. (Experimental & untested)
Fixed several join errors.
Added the identical file above without the secondary Aero Lip.
8-5-2018 Update
Updated screw hole placement.
Created a "simpler" duct without Primary or Secondary Aero Lip.
8-8-2018 Update
Added hex tool access hole to Simple Duct.
9-14-2018 Update
Added Beefier Version of Simple Duct.
Step by Step tips for safety, ease of use and greater efficiency
Note This assumes your print quality is good and you haven't altered the design in some unknowable way. Furthermore 5" Bullnose Tri-blade Propellers should be used as they have the largest surface area to come into contact with the Duct wall.
1) When mounting the Duct, first install the Propeller onto the Motor. (DAL T5044 Props are ideal)
2) Install the Motor wires through the Duct side hole (left or right) before soldering them to an ESC.
3) Mount the Motor on the Duct but leave the screws finger tight. (Don't use lock tight)
4) Shim the props, using pieces of cardboard or thick paper that are exactly 0.5 mm thick (verify with micrometer). Be aware that cardboard does give a little so odds are the Propellers ends up closer to 0.3 or 0.4 mm. If done correctly, the shims shouldn't fall out while the Motor mount is torqued down.
5) Tighten down the Motor screws in a cross pattern to ensure that the Propeller spacing is even.
6) Remove the shims.
7) Spin the Propeller by hand to ensure your clearance is <1 mm from the Duct wall at all points of the Propellers rotation.
8) Power up the Motor and slowly increase it's speed while checking to see if the Propellers are making contact. (Be careful) If they do contact the wall, STOP immediately! Afterwards sand down the portion of the Duct wall or re-shim the Propellers to adjust their position and repeat the test.
9) Verify Propeller spacing before flight by spinning them by hand. It's possible (but rare) for the mounts to shift during transport or a hard landing. Trust me, you don't want the Propellers contacting the Ducts mid flight.
Here's a perfect video on how NOT to setup a duct
www.youtube.com/watch?v=mY8ZPB0Gs2I
Bench Test of "Simple Duct" https://www.youtube.com/watch?v=KYfMw9gPbCE
Test flight
Disclaimer this copter is largely untuned so the wind is making it hard to keep the copter in front of the Camera.https://www.youtube.com/watch?v=rvPskyMfO-w