Weight savings help!!

[Ihncheol Park]

Thanks to all those who replied directly and through the list.

My RTF weight without fuel is 9 pound.
And OOps, I forgot to say what the power plant is.
It is not a 120 size plane, although I heard several flying with YS120.
It is FAT for it's class with 5 & 1/8 inches width of fuse where the front
of wing goeses on and 4.75" for the back of the wing.
I believe this is wider than Desire 120 and Summit 120.
(I've been saying 4" before.  No idea why I thought it was 4")

The rudder post (13" high) at the bottom is 1 inch thick.
When I compared the fuse with Desire 120, it was almost same height.
Height at the back of the canopy is 9.5 inches.
There are a few pictures of this plane at my homepage.

http://www.geocities.com/beaton90/


It is a BeatOn 90.  67.7" (68") span & length.
YS 91AC, MK type rail mount, Hatori header w/ ES Carbon.
The prototype on a magazine review also had similar powerplant setup and
only weighed 3570g (7.75 pound) with Urethane painting one fuse.
I don't think I can repaint the fuse to loose a lot of weight.

If I build a new wing, I am hoping to save at least 100grams from 1160g.
I still have to weigh the foam core + the balsa + other woods that goes in
the wing.

The retracts w/ 136G(165g) + 7005 servos with extensions (100g) +
centralhobbies axles w/ wheels (22g) = 287g + about 12g for servo screws.
that is about 300g.
I was also suggested for using Bolly carbon gears and pants, but weight
saving is less than 10 grams.

The wing has belly pan supports like skirt and pipe mount.
Will I be able to build a one-piece, covered wing of 837 ~ 850 sq-in under
760g w/ belly pan support and pipe mount?

Thanks,

Ihncheol Park


   -----Original Message-----
  From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On
Behalf Of Rcmaster199 at aol.com
  Sent: Wednesday, February 19, 2003 4:31 PM
  To: discussion at nsrca.org
  Subject: Re: Weight savings help!!


  I thought Icheol said the fuse weighed 2870 grams, RTF. That's not 10
pounds.

  It's more like 6 lbs 5 ozs. The powerplant weighs around 40% that weight,
(YS 120 and its exhaust ). Another 3 ozs for the mount and he has 45% of the
weight, tied up in the powerplant alone.

  Icheol, How much does this beastie weigh RTF anyway? From the individual
weights you indicated it should be a little under 9 pounds. Not too bad for
an 840 sq in wing. Lighter would fly better, But, have you flown it already
at this weight and you don't like it? Wassup?

  Matt Kebabjian



    Subj:Re: Weight savings help!!
    Date:2/19/2003 6:22:43 AM Eastern Standard Time
    From:amad2terry at juno.com
    Reply-to:discussion at nsrca.org
    To:discussion at nsrca.org
    CC:discussion at nsrca.org
    Sent from the Internet



    The problem is in the fuze! At nearly 10 pounds! In the wing you will be
    hard pressed to save more than 2 or 3 ounces. My last 2 retract ships
    were in that ball park for size and the weight was very close to the 2#
    8oz you have. but the fuzelages were under 7#. You are ot going to save
    3# by repainting, unless you used a lead based paint and put it on 1/4
    inch thick!

    I think you are stuck, and the only way out is to build a new fuze.
    Changing spinners will save you about 3/4 of an ounce!

    Terry T

    On Tue, 18 Feb 2003 03:32:32 -0800 "Ihncheol Park"
<PatternFlyer at msn.com>
    writes:
    > Hi, All,
    >
    > I am in the process of trying to reduce weight of my plane
    > including
    > building a new wing with foam core, replacing servos with less
    > weight,
    > smaller battery etc.
    >
    > How much can a wing weigh if it is 837 sq-in 67.7" (68") dual servos
    > and
    > glassed in the center sections top & bottom?
    >
    > My wing right now weighs 1160g (40oz) with 136G, Supra 60 size
    > retracts, 2x
    > 55mm Tettra wheels, Central hobbies axles, 2x 7005 servos with
    > central
    > hobbies pushrod, MK horns, and adjusters. Kinda too heavy?
    >
    > My fuse weighs 2870g RTF.  Really heavy for 68". I am not sure how
    > much I
    > can save from repainting the fuse because I have no data on the
    > weight
    > before priming and/or painting.
    >
    > Does anyone know the weight of 2.5" FAI 120-cut, Lightened back
    > plate TT
    > spinner weight without the screw?
    >
    > I use 2.5" standard 120-cut that weighs 56g w/ screw, 51.03g
    > wo/screw.
    > How much can I save?
    >
    > My battery is Nicad 1700mAh w/ JR connector 140g.
    > This runs 1x 8411, 2x 7005, 1x Hitec 225, 1x 8231, 1x Futaba 136G
    >
    > What other type of battery in smaller or lighter weight can I go
    > with?
    > I use Alpha 4 as primary charger.
    > Thanks,


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