<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;"><DIV>Thanks. I guess that means I'm actually right about something for a change! Cool! LOL That's why it's good to discuss things. We all learn. Speaking of gear plate failures, I'm actually surprised we don't see more of them. Other than the Prestige, I have yet to see a landing gear setup on a modern Pattern plane that impresses me. Sure they all seem to work but I wonder how much of that is luck combined with brute force / overkill. I'm sure someone can come up with something that's light AND strong enough to handle the loads that are involved. i mean actually sit down and Engineer the thing. Unfortunately I studied computer science, not physics so it's a bit of a stretch for me. Then again I have done a lot of custom work on bikes that don't fall apart so maybe I should experiment a bit...</DIV>
<DIV> </DIV>
<DIV>John Pavlick<BR><BR><BR><BR>--- On <B>Fri, 1/16/09, glmiller3@suddenlink.net <I><glmiller3@suddenlink.net></I></B> wrote:<BR></DIV>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: rgb(16,16,255) 2px solid">From: glmiller3@suddenlink.net <glmiller3@suddenlink.net><BR>Subject: Re: [<SPAN>NSRCA</SPAN>-discussion] BOLLY out of business<BR>To: jpavlick@idseng.com, "General pattern discussion" <nsrca-discussion@lists.nsrca.org><BR>Date: Friday, January 16, 2009, 7:20 PM<BR><BR><PRE>OUCH! I hate it when I'm wrong. You are, of course, correct, John<G>!
For paved surfaces, I find that having some toe in is very helpful in
stabilizing the takeoff roll....It is also hard to get with most current gear
installations....I cant the gear forward on the mounting plate to provide a
little toe in, but this is making putting the wheels farther forward of the CG.
For mounting I've used everything from 2 4X40 botls on each side to Three
8X32's on each side. I don't think I've ever broken a bolt....I
have had a couple of gear plates fail, though. I had a buddy who tried 1/4 X 20
nylon bolts....BAD IDEA<G>.
G
---- John Pavlick <jpavlick@idseng.com> wrote:
=============
Maybe, but how many times have you seen this:
There's a strong crosswind (of course there is - you're at a Pattern
contest!). If the caller simply puts the plane on the runway and you slowly
advance the throttle, the first thing you have to do is apply a good deal of
rudder in an attempt to counteract the crosswind. Unless you're very good,
the plane wags it's tail. One way to deal with this is to have your
caller pinch the fin while you open the throttle. This lets the prop blast help
you make the rudder correction ASAP. Why does this happen?
Tricycle gear is NOT "all" forward of the G.G. Just the nose wheel
is. The mains should be just slightly behind the C.G., otherwise you'd need
a tailwheel. VBG Think about it. What makes the plane rest on all 3 wheels? If
the C.G. was behind the mains, it would rest on the tail like uh, a tail
dragger. :)
John Pavlick
--- On Fri, 1/16/09, glmiller3@suddenlink.net <glmiller3@suddenlink.net>
wrote:
From: glmiller3@suddenlink.net <glmiller3@suddenlink.net>
Subject: Re: [NSRCA-discussion] BOLLY out of business
To: "General pattern discussion"
<nsrca-discussion@lists.nsrca.org>
Date: Friday, January 16, 2009, 5:38 PM
Gray,
I think that this may be a theoretical issue without practical importance.
Modern pattern designs have such a long tail moment, that unless they are
really
nose heavy, there is enough weight on the tail wheel to keep them tracking
until
the vertical fin can take over to prevent "ground loops". In fact,
the closer the main gear is to the CG, the LESS weight there is on the tail
wheel and the greater the tendency to ground loop.....I would think. I'm
not an engineer, but it seems to me that the tricycle gear design is ALL
forward
of the CG and they aren't noted for instability...just the opposite.
I have some pattern ships that won't turn around in a cross wind, but none
that has a problem tracking for takeoff.
G
---- Gray E Fowler <gfowler@raytheon.com> wrote:
=============
John
Yours is the first post with a technical reasoning for sweep, and it makes
sense. I of course have a AeroSlave Symphony with an ES gear and have not
experienced ground issues. I am sure other designs do have issues as you
describe. How common is this problem?
Gray Fowler
Senior Principal Chemical Engineer
Radomes and Specialty Apertures
Technical Staff Composites Engineering
Raytheon
John Pavlick <jpavlick@idseng.com>
Sent by: nsrca-discussion-bounces@lists.nsrca.org
01/16/2009 11:13 AM
Please respond to
jpavlick@idseng.com; Please respond to
General pattern discussion <nsrca-discussion@lists.nsrca.org>
To
General pattern discussion <nsrca-discussion@lists.nsrca.org>
cc
Subject
Re: [NSRCA-discussion] BOLLY out of business
Gray,
My understanding of why we try to move the wheels as close to the C.G as
possible is to increase yaw stability on the ground (decrease the tendency
to ground loop). Tail draggers are inherently unstable because the landing
gear is located in front of the C.G. Since we don't have brakes on modern
Pattern planes, the wheels can be pretty far back without causing much of
a problem. Especially on smooth surfaces. The closer you place the wheels
to the nose of the airplane (further ahead of the C.G.), the more tendency
there is to ground loop. Also, it sometimes makes it hard to get the plane
to rotate if the wheels are too far forward.
If Pattern planes were designed with the gear location further back, we
wouldn't need swept gear.
John Pavlick
--- On Fri, 1/16/09, Gray E Fowler <gfowler@raytheon.com> wrote:
From: Gray E Fowler <gfowler@raytheon.com>
Subject: Re: [NSRCA-discussion] BOLLY out of business
To: "General pattern discussion"
<nsrca-discussion@lists.nsrca.org>
Date: Friday, January 16, 2009, 4:37 PM
Why do you prefer sweep?
Gray Fowler
Senior Principal Chemical Engineer
Radomes and Specialty Apertures
Technical Staff Composites Engineering
Raytheon
Richard Strickland <pamrich47@hotmail.com>
Sent by: nsrca-discussion-bounces@lists.nsrca.org
01/15/2009 05:17 PM
Please respond to
General pattern discussion <nsrca-discussion@lists.nsrca.org>
To
General pattern discussion <nsrca-discussion@lists.nsrca.org>
cc
Subject
Re: [NSRCA-discussion] BOLLY out of business
If I were to complain about anything on Matt's gear (I'm not) I would
prefer a little sweep which would preclude 'a one side fits both"
arrangement. How are most of you guys mounting them--two or three bolts?
I've been using three 4-40s but just bought one and the former owner had
two per side.
RS
To: nsrca-discussion@lists.nsrca.org
From: gfowler@raytheon.com
Date: Thu, 15 Jan 2009 16:56:48 -0600
Subject: Re: [NSRCA-discussion] BOLLY out of business
Anthony
What did you think about the ES gear twist? That is the wheel going toe
in- toe out hitting small bumps. ES had nothing but zero degree fibers.
That is the one design issue I am conteplating at the moment.
Also considering that all new planes are widebody that is what needs to be
addressed..BUT having a 1 continuous gear will be more weight. I am
thinking it is better to split the gear for a weight savings. If we make
two pieces, and either piece can be a left or a right, then a broken gear
is only on one side. Any advantage to that?
Gray Fowler
Senior Principal Chemical Engineer
Radomes and Specialty Apertures
Technical Staff Composites Engineering
Raytheon
Anthony Romano <anthonyr105@hotmail.com>
Sent by: nsrca-discussion-bounces@lists.nsrca.org 01/15/2009 04:18 PM
Please respond to
General pattern discussion <nsrca-discussion@lists.nsrca.org>
To
<nsrca-discussion@lists.nsrca.org>
cc
Subject
Re: [NSRCA-discussion] BOLLY out of business
Graph Tech is not for us. I am sure their stuff is well suited for the
IMAC style planes that they are designed for but too heavy and way too
stiff for our use.
I went through their website and picked a gear based on dimension of the
ES. 2+ ounces heavier and twice as thick with zero flex. Broke the gear
out of my Black Magic many times when hitting small holes in the runway.
Rick donated his ES gear and life has been much better.
Anthony
From: jlachow@hotmail.com
To: nsrca-discussion@lists.nsrca.org
Date: Thu, 15 Jan 2009 15:59:26 -0500
Subject: Re: [NSRCA-discussion] BOLLY out of business
Anyone have any luck with the Graph Tech RC stuff? Only experience was
with some smaller electrics that worked just fine. They have carbon pants
and spinners, as well.
From: tony@radiosouthrc.com
To: nsrca-discussion@lists.nsrca.org
Date: Thu, 15 Jan 2009 15:00:23 -0500
Subject: Re: [NSRCA-discussion] BOLLY out of business
Thanks, Jim. Those are $112.00 I think… about double that of the Bolly….
Not sure how that will go….. but if there are no other choices…
Tony Stillman, President
Radio South, Inc.
139 Altama Connector, Box 322
Brunswick, GA 31525
1-800-962-7802
www.radiosouthrc.com
From: nsrca-discussion-bounces@lists.nsrca.org
[mailto:nsrca-discussion-bounces@lists.nsrca.org] On Behalf Of Woodward,
Jim (US SSA)
Sent: Thursday, January 15, 2009 2:52 PM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] BOLLY out of business
Tony,
Luiz at Net Box Hobby carrys the CA carbon gear.
Thanks,
Jim
From: nsrca-discussion-bounces@lists.nsrca.org
[mailto:nsrca-discussion-bounces@lists.nsrca.org] On Behalf Of Tony
Sent: Thursday, January 15, 2009 2:36 PM
To: 'General pattern discussion'
Subject: [NSRCA-discussion] BOLLY out of business
I just received conformation that BOLLY has gone out of business.
Unfortunately, this is a major supplier of CF landing gear and wheel
pants. I have been awaiting a shipment of several items, and now it does
not look like that will happen. I am working now to determine if there
are any gear/wheel pants available.
The really bad thing is that I am not sure what options we have left,
other than going with a kit/arf manufacturer’s gear. Ed Skorpa dropped
his gear last year…
Tony Stillman, President
Radio South, Inc.
139 Altama Connector, Box 322
Brunswick, GA 31525
1-800-962-7802
www.radiosouthrc.com
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</PRE></BLOCKQUOTE></td></tr></table>