News:



  • June 22, 2025, 02:56:25 PM

Login with username, password and session length

« previous next »
Pages: [1]   Go Down

Author Topic: End of run shutoff  (Read 1580 times)

Offline Paul Allen

  • 2014 Supporters
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 402
End of run shutoff
« on: August 09, 2014, 08:26:35 PM »
Is there anything, other than angling the rear of the tank out, to promote a clean cutoff ?
thanks
Paul
In OZ
Logged

Offline Steve Helmick

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 10265
Re: End of run shutoff
« Reply #1 on: August 10, 2014, 06:49:17 PM »
Try reducing outward yaw first...move your LO's forward or reduce rudder offset if there is some.  H^^ Steve
Logged
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Tim Wescott

  • 25 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12899
Re: End of run shutoff
« Reply #2 on: August 10, 2014, 08:07:13 PM »
Paul, what are your symptoms?

Making sure that your leadouts are in the right spot is a Really Good idea (go by Paul Walker's trim article, if you can find it).  If you're still having trouble after that -- let us know what's happening, and we'll make suggestions.  Some of them may even help your situation.
Logged
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline Chris Wilson

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1710
Re: End of run shutoff
« Reply #3 on: August 10, 2014, 08:42:56 PM »
Smaller diameter fuel tubing?
Logged
MAAA AUS 73427

You have enemies? Good. That means you've stood up for something, sometime in your life.
 Nothing in life is so exhilarating as to be shot at without result.  It's not enough that we do our best; sometimes we have to do what's required

Offline Bill Little

  • 2017
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12668
  • Second in COMMAND
Re: End of run shutoff
« Reply #4 on: August 10, 2014, 09:17:28 PM »
Hi Paul,

I have had muffler pressure cure it completely.

Bill
Logged
Big Bear <><

Aberdeen, NC

James Hylton Motorsports/NASCAR/ARCA

AMA 95351 (got one of my old numbers back! ;D )

Trying to get by

Online Lauri Malila

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1733
Re: End of run shutoff
« Reply #5 on: August 11, 2014, 12:16:51 AM »
I took off muffler pressure and it cured completely:)
-correct tank position
-baffle in tank helps but if all is right, it's not completely necessary.
-good piston/ cylinder fitting that does not loosen up too much when engine goes lean.
-even better; a well made ringed setup.
-Fuel filter volume. Sometimes the transparent Sullivan filter (craptrap?) is too big for low consumption engines. Possible air bubbles won't get out easily. Try something with less volume. And, fuel filter, like anything else in fuel/air system, must not have any leaks.

L
Logged

Offline Dennis Toth

  • 2020 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4403
Re: End of run shutoff
« Reply #6 on: August 25, 2014, 07:02:30 PM »
Paul,
Getting the fuse in proper alignment in yaw is the first step. If you are tight on fuse tank compartment to kick the tank out you can build or have built a tank that has the built in wedge shape where the front is a little narrower than the back. Make sure the uniflow is in the correct position from the end of the pickup tube. Last thing is learn to do the "Command Cut Off Loop". You can do a search on YouTube for Al Rabe Command Cut Off Maneuver. He shows how to bring the ship into a gradual climb then a bit of a tight loop. You need to learn the right point once the engine hits the off the uniflow then do the loop. Be careful, if you try it and it doesn't cut you can try it one more time the next lap. If it still doesn't cut just let it run out and adjust your timing next flight (I almost lose a ship doing this when I tried it to late, I didn't step back as I did the loop and it was going to slow, drifted in, just caught it before it hit the ground).

Best,         DennisT
Logged

Offline Balsa Butcher

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2356
  • High Desert Flier
Re: End of run shutoff
« Reply #7 on: August 26, 2014, 02:21:01 PM »
To add to this: In my experience cut off loops do not work if one is using uniflow with muffler pressure. Nor are will they reliably work if the engine has already gone lean. At a contest when they do work, it looks good, bad when they don't. Often used as a desperation maneuver at around 7 minutes and 30 seconds into the pattern. And don't ever do one up wind...I learned that one the hard way. 8)
Logged
Pete Cunha
Sacramento CA.
AMA 57499

Offline RandySmith

  • Administrator
  • Trade Count: (0)
  • Admiral
  • *****
  • Posts: 13756
  • Welcome to the Stunt Hanger.
    • Aero Products
Re: End of run shutoff
« Reply #8 on: August 26, 2014, 08:28:41 PM »
Quote from: Bill Little on August 10, 2014, 09:17:28 PM
Hi Paul,

I have had muffler pressure cure it completely.

Bill

or pressure can cause it !!!

Randy
Logged

Advertise Here
Pages: [1]   Go Up
« previous next »
Tags: