Re: Long-Ez Speed Brake spring tension

Steve
 

The spring in the pictures look like screen door return springs that are easy to get at Home Depot or Lowes.  I got one from Lowe’s last month that I was going to stretch out and wrap around the exhaust under the carb heat muff.  It broke in three places as I stretched the spring.  I then purchased one from Home Depot that was a different brand.  I was able to stretch the new one without breaking.  I don’t have the packaging anymore but it’s clear that some brands are making very brittle springs.  

Steve Sorenson


On Thursday, May 14, 2020, Terry Schubert <jschuber@...> wrote:
Many people set the landing brake spring tension ungodly high.  STOP that!
 
It is dangerous for the GIB when a spring breaks and hard for the pilot to open during normal operation. 
 
The brake should blow shut above 95 kts to prevent structure damage.  That closing pressure is to be controlled by length of the slot in the floor NOT by adding monster spring tension.  Study the geometry.  The push rod and the linkage should never be near straight or ever over center.
 
If your brake doesn't blow shut by itself at 95 kts then the floor slot is too long - shorten the slot so as to limit forward travel of the push rod.  That lowers the required spring pressure.  The plans spring is PLENTY strong.
 
Spring wire is sensitive to scratches and is more likely to break when scratched by pulling pliers that have slipped off the end of the spring or by folks that have attempted to reform the hook on the end.  An excessively sharp bend  increases the chance of spring failure.
 
 
Terry Schubert
retired Central States Association Newsletter Editor

Please note: message attached

From: "Filipe Rosa" <filiperosa@...>
To: members@canardzone.groups.io
Subject: [Canard Zone] Long-Ez Speed Brake spring tension
Date: Thu, 14 May 2020 12:53:54 -0700

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