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Date: Wed, 15 Jul 2009 19:25:33 -0400
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Subject: Re: [LML] Retractable Step IV-P
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Ed et al:  Re step--rather than fighting the aero forces, I suggest you 
consider controlling them.  I have watched many frustrated LIV drivers 
try, try again and then wire their step closed.  I agree it is the air 
pushing the step closed, so I taped an air "trip, Gurney flap" on the 
underside of the horz portion of the step and that has solved my 
problem.   It is just a bent piece of alum that adds a sharp edge 
pointed down so a vacuum is created that helps the step extend.  The 
trip could also be added to the front edge of the spanwise well into 
which the step retracts--anything to disturb the flow and create a low 
pressure area.
Oh, and another suggestion re: air conditioning--do not pressurize your 
LIV when building. My aft fan is all I need on the gnd and ambient temp 
is plenty when airborne.  You pressurization folks are fighting turbo 
air that gets above 140 F when the system is working hard (check your 
induction temp).  Sorry--I have no self control...
Paul, cool N94PT with O2


-----Original Message-----
From: Janie & Ed Smith <2luv2fly@cox.net>
To: lml@lancaironline.net
Sent: Wed, Jul 15, 2009 9:47 am
Subject: [LML] Retractable Step IV-P


"I've done it alone many times, several times just trying to figure a 
way to make the "retractable" step actually work, before I finally gave 
up and disconnected the cable and just locked it down."=C2=A0
=C2=A0
John,=C2=A0
=C2=A0
T
he retractable step has been quite an "opportunity" for us as well. 
They certainly didn't put their "best man" on the engineering and 
design for the step.=C2=A0
=C2=A0
There are many reasons why the step doesn't work, but the main reason 
ours didn't extend with the gear was because the spring just didn't 
seem to be quite strong enough to overcome the resistance of the 
aerodynamics under the wing. I felt like the air flow under the wing 
was a contributor to the step staying in the retracted position because 
every time we put the airplane on jacks and cycled the gear - 
everything worked perfectly! The step would fall down and only take a 
"nudge" to get it into the locked position. My thoughts were that the 
wind load would push it to the down & locked position, so I 
concentrated on getting the step to make that initial movement to the 
down position.=C2=A0
=C2=A0
I found a company in Norfolk, VA that specializes in custom springs and 
I had them make a spring for me that was about 30% stronger. Right 
away, we noticed an improvement because the step would extend, but only 
at about 100 kts. Anything above that speed resulted in the step being 
on the wrong side of the gear. Eventually, after 4 tries of different 
spring sizes, we now have a step that extend @ 140 kts - just about 
every time. The only down side to all of this is that the custom 
one-of-a-kind springs cost $40. each. Of course, i
n the whole scheme of 
things - that is a small cost for the convenience of having a step. 
Like the A/C that Jeff was talking about - - it sure is nice and Janie 
(better half) likes it, so there "ain't" no problem with the cost!! 
<grin> You know the old story about Mamma being happy!=C2=A0
=C2=A0
Tailwinds,=C2=A0
=C2=A0
Ed Smith=C2=A0
N9JE=C2=A0
Chesapeake, VA=C2=A0
=C2=A0
=C2=A0
=C2=A0
--=C2=A0
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