REFLECTOR: Sump Tank Design Change Suggestion

[lawrence epstein]

My kit is 1996!


>From: "Hiroo Umeno" <humeno at microsoft.com>
>Reply-To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
>Subject: Re: REFLECTOR: Sump Tank Design Change Suggestion
>Date: Fri, 4 Aug 2006 11:03:05 -0700
>
>I have the similar arrangements.  What I was talking about was not the
>mounting of the sump tank but the construction method of the tank
>itself.  Perhaps the kit design has changed since 1999?
>
>
>
>Hiroo
>
>
>
>________________________________
>
>From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
>Behalf Of Lawrence J. Epstein,MD
>Sent: Friday, August 04, 2006 10:50 AM
>To: 'Velocity Aircraft Owners and Builders list'
>Subject: Re: REFLECTOR: Sump Tank Design Change Suggestion
>
>
>
>What I have done is make 2 hardpoints on the floor of the fuselage under
>the forward edge of the Sump tank. I then made "legs" using small mixing
>cups as a mold and I am putting a rib on each leg to the sump. I am then
>securing the sump legs to the floor. The tank is then supported @ 4
>points.
>
>
>
>Larry Epstein
>
>
>
>-----Original Message-----
>From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
>Behalf Of Hiroo Umeno
>Sent: Friday, August 04, 2006 1:30 PM
>To: reflector at tvbf.org
>Subject: REFLECTOR: Sump Tank Design Change Suggestion
>
>
>
>After my last "incident" on first engine run related to my shoddy
>craftsmanship on the sump tank, I started thinking...
>
>
>
>Admittedly, it was mostly due to the crappy job I did in joining the
>sump tank tub with the side wall.  However, I am thinking that the
>original design also had some contributing factor to it.  My kit came
>with sump tank that had two parts: the part that looked like a tub and a
>flat sheet of fiberglass plate that was to be the "back wall" that was
>oversized and needed to be trimmed to fit.
>
>
>
>What this forces the builders to do is to lay the tub over the sheet,
>mark the tub outline on the sheet, cut to fit, then lay up the edges to
>join the halves.  This layup is a bit tricky since the plate is rather
>thin and even after sanding the edges off, it remains a fairly sharp
>radius.  To make the matter worse, the tub side wall does not meet the
>plate at 90 degrees making the fiberglass tape wrap the approximately
>100 degree corner as it join the pieces.  It is very easy to get
>delamination or bubbles in the lay up which, as I leaned the hard way,
>is a really bad thing for something that contains fuel.
>
>
>
>My suggestion is to change the sump tank design such that two tub halves
>are mated flat at the center much like how the nose gear pants are
>joined left and right.  This will enable the joining lay up to be done
>on a relatively flat side-wall and make it much less problematic for
>first-time builders like me.
>
>
>
>Hiroo
>


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