Webra Bragging

[Nik Middleton]

I got around my concerns about firewall thickness.  I used 1/4" Nomex coated
with Carbon fiber.  Stronger that 1/4" ply and lighter than 1/8" with the
extra area for gluing.  Don't think I'll ever go back to ply.

rgds

  -----Original Message-----
  From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On
Behalf Of GW
  Sent: Friday, September 20, 2002 12:06 PM
  To: discussion at nsrca.org
  Subject: Re: Webra Bragging


  Great info Matt.  Thanks!

  I have often thought about using a 1/8" firewall for weight saving
purpose, but most kits call for a 1/4".
  I say I am going to try it each time, but back out at the last minute.
  Might do the 1/8" on the next fiberglass kit with a homemade Hyde-like
mount I have made from the info on Bobs site as well.

  I have always thought the pipes were  louder than mufflers, you seem to
prove otherwise, at least according to Mike and Emory regarding the
"Stealthness" of your plane.    Gotta love that word Stealth.  I plan on
using either the Bolly 480 or ES140XL pipe.   I have not commited ,yet, to
either one.
  Later,
  GW
  Gerald Williams
  Webpage :  www.gwair.com
  Email: gw at gwair.com


    ----- Original Message -----
    From: Rcmaster199 at aol.com
    To: discussion at nsrca.org
    Sent: Thursday, September 19, 2002 7:46 PM
    Subject: Re: Webra Bragging


    Gerald,

    My set-up is straight forward as follows:

    Webra 145R, black head, with the standard Macs header. Both purchased
from Piedmont (Lee Davis)

    OS/Hatori tuned pipe for the OS 140 RX or EFI. 23 1/4" from the exhaust
flange to the first baffle, straight line

    My own soft mount I described in the March K Factor. It is based on the
HYDE mount, is all wood including the beams. Bob Pastorello has some of the
drawings on his web site. I followed his drawings for the absorber portion.
Mine differs in that the beams are glued to the front plate and a box is
built around the case with balsa and lite-ply. A standard HYDE soft mount is
a must if you don't make your own.

    I use a ply wood nose ring of my own design but any standard nose ring
will do the job, as long as it fits

    Model is a ZN-Line kit, Alliance. Their construction technique includes
foam sheeting on the Kevlar for stiffness and sound suppression. This simple
technique is extremely effective. You will find that Lance VanNostrand's and
Grey Fowler's (AeroSlave) offerings have a similar construction. Also, take
a look at the new Temptation offered by Piedmont; Lee Davis describes a
similar sandwich in the shell of their fuselages

    My firewall is 1/8: aircraft ply for the front face plus a 1/8" lite ply
"U" shaped crutch behind the firewall, extending about 4" toward the canopy.
It keeps the fuselage from drumming in this area just behind the engine.

    Fuel I use is a special blend of Cool Power heli and standard fuel, to
15% nitro and 19% thinner oil. I have the details on Ed Hartley's RCPattern
page

    Props are: take your pick, the stealthiest is a 15.5x12 apc 4 blade. The
model is practically inaudible and a little spooky to fly because it's too
quiet. The rest are about the same 17x12, 16x14 std and N, 16.5x13 std, all
apc's. The 16.5x13 was used nearly exclusively during early running. The
engine turns anywhere from 7500 to 8000 r's depending on the prop. It will
run faster but does not have to. Power to burn on the 45 deg up 1 1/2 snap
or the figure 9 with 3/2 rolls.

    Should you decide on a similar set-up, please contribute your findings
to Ed Hartley's page

    Matt Kebabjian




    In a message dated 9/19/2002 7:36:02 AM Eastern Daylight Time,
emorydmd at earthlink.net writes:



      Subj:Re: Webra Bragging
      Date:9/19/2002 7:36:02 AM Eastern Daylight Time
      From:emorydmd at earthlink.net
      Reply-to:discussion at nsrca.org
      To:discussion at nsrca.org
      Sent from the Internet



      Gerald,

      Matt's set-up is probably the most quiet I have ever heard. It makes
almost no noise when it's flying. I had a chance to fly his Alliance and the
Webra is a very strong engine. If my Tigers ever fail me, I think that would
be a good choice.

      Emory.


        ----- Original Message -----
        From: GW
        To: discussion at nsrca.org
        Sent: Wednesday, September 18, 2002 9:32 PM
        Subject: Re: Webra Bragging


        Mike,

        I have very little personal experience with big 2S engines, but I
witnessed yours and Emory Schroters <sp> 2S equipped planes this weekend at
Huntsville , and was truly impressed with the lack of "noise" these planes
made. Truly amazing.

        I believe it is a combination of many things that it took to make
these 2 planes this quiet, not just a good muffler, or just a soft mount, or
any one thing. A combo of all is what seems to be the ticket. Hope to
accomplish this myself with my new T2K soon as well.

        If Matt's is quieter than yours and Emory's, then it must truly be a
extremely quiet setup.









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