Dragonfly ~ Power Train - Rotor Brake

Notes: To be moved later.

  1. See if the masts can be extended down below the secondary housing by a couple of inches and a band brake located about the outer surface of both masts. Ref: SynchroLite ~ Control - Power Train - Soft Start Clutch - Band Brake Layout
  2. The rotor brake can be located inside a gearbox. There should be no problem with material coming off wearing brake surfaces since this is done in automatic transmissions. Consider using the backside of one or more of the three non-pinion gears as support or part of the braking mechanism.
  3. The default must be 'Off' and the 'On' be a momentary contact. Or, should both be 'maintain contact'?
  4. May want a shorter braking time for the intermeshing configuration because of the low blade tips. Consider having the braking torque the same as the driving torque. This way the components, which are designed for driving torque, will not be overloaded.
  5. Another potential application for the rotor brake might be that of stopping the rotor in flight if there is an emergency where the pilot w/ parachute must bailout.

The Limit Load Factor for the brake is 2.0. The Safety Load Factor should probably be 1.5.

From rec.aviation.rotorcraft:

In the MD500 series you apply rotor brake below 40% Nr and release it during the last turn, to avoid sudden stoppage. ~ Charlie W.

On the Jet Ranger you can engage it under 38%, at about 6% it makes an unnerving chatter that I never liked. According to people at the factory you're just supposed to fully engage it under 38%, no pussyfooting around. I usually disengage it at low RPM and let it coast to avoid the chatter region, then lightly re-engage it just to stop the blades 90 degrees abeam so I can throw the tiedown over them easily. ~ Bart

In addition, see; DESIGN: Dragonfly ~ Control - Flight - Directional - by Tip Brake ~ Rotor Brake

 Working Papers:

 

DESIGN:

B388

MAKE:

 

BUY:

 

Items:

DESIGN:

 

Name

Item

 

 

 

 

 

 

MAKE:

 

Name

Item

 

 

 

 

 

 

Same Page ~ Different Craft: ~ UniCopter ~ SynchroLite (none)

 

Back to top | Dragonfly Home Page

Last Revised: January 9, 2005