REFLECTOR: sump tank.

[Keith Hallsten]

Noel,

I copied a few old posts on this subject below your message.  As to how far
down, I think you make your best judgment, and then live with the results!!
If I recall correctly, the manual has a dimension for the height of the
float switch, which would be a reasonable place to start.  You have stated
the applicable considerations; I don't know that there is a single "correct"
height for the fuel level switch.

Keith
 

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of gattenby at tulsaconnect.com
Sent: Sunday, September 09, 2007 8:25 PM
To: Velocity Aircraft Owners and Builders list
Subject: REFLECTOR: sump tank.


As I drill and tap hardpoints...

I'd like to put one of those solid state "led" type
sensors in the sump tank.  I know that we talked about 
them
on the reflector years ago... but I can't find where I 
saved that info.

What diameter hole do I want,
How far down from the top is purdent.
(too low and it cuts in to the Oh S--- reserve)
(too high and it will false alarm when the fuel return 
gets bubbly)

Noel
_______________________________________________



-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Keith Hallsten
Sent: Sunday, June 11, 2006 11:26 PM
To: 'Velocity Aircraft Owners and Builders list'
Subject: RE: REFLECTOR: optical low fuel sensor

Sure, there are 1/2" NPT, 3/8" NPT and 1/4" NPT units in stock that would be
suitable.  I'm not sure, but I seem to recall that the Velocity-supplied
float switch was 1/2" NPT.  You would want to verify that before ordering.
I believe that the Velocity-supplied float switch was made of polysulfone,
but nylon, Teflon, glass, epoxy, polyethersulphone, isoplast, nickel-plated
steel or stainless steel would all be compatible with gasoline.

The ELS-900 series looks pretty attractive, and fairly reasonable at $54 in
quantity of one.  However, it only comes in 1/4" NPT, so you would need a
suitable bushing to install it.  That is probably a pretty good solution to
a small, rugged level sensor.  You would want to use an LED for the
annunciator, since it is rated only for very low current.

Keith Hallsten


-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of lawrence epstein
Sent: Sunday, June 11, 2006 5:20 PM
To: reflector at tvbf.org
Subject: REFLECTOR: optical low fuel sensor

do you know if any of these is a "plug & play" replacement (size/thread)?

Larry Epstein
173 FGE


>From: "Keith Hallsten" <KeithHallsten at quiknet.com>
>Reply-To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>To: <velocity at davebiz.com>,        "'Velocity Aircraft Owners and Builders 
>list'" <reflector at tvbf.org>
>Subject: RE: REFLECTOR: Control system play (was Newbie question)
>Date: Sun, 11 Jun 2006 17:14:30 -0700
>
>Dave,
>
>Most builders fabricate a threaded boss into which the low fuel switch
>threads.  Then the switch can be removed from the tank without too much
>difficulty for replacement.  I don't know how your builder did it, but I
>hope some means of servicing was provided!
>
>Incidentally, the optical liquid level sensors are more reliable than the
>float type switches, so if the existing switch has failed that is something
>to consider.  See http://www.gemssensors.com/TOCResults.asp?nContentsID=29.
>
>Keith Hallsten
>
>
>-----Original Message-----
>From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
>Behalf Of Dave Philipsen
>Sent: Sunday, June 11, 2006 4:10 PM
>To: Velocity Aircraft Owners and Builders list
>Subject: Re: REFLECTOR: Control system play (was Newbie question)
>
>
>Thanks to all who wrote with suggestions for my problem with play in the
>control system.  I checked it out and the problem seems to be the
>attachment of the stick to the torque tube.  I tightened up the bolt on
>the left side and that seemed to take care of it.  I'll call the factory
>about getting a newer stick with the u-bolt attachment.
>
>Next question:  My fuel sump has a "low-fuel" sensor that closes a
>circuit if the sump is not full.  That circuit turns on a warning lamp
>on the panel.  Well, my warning lamp is on but the sump is full.  Today,
>I disconnected the sensor and the lamp went out which tells me that the
>problem is with the sensor, not the wiring.  Well, the sensor is pretty
>well "glassed-in" to the sump so I imagine I'm going to have to remove
>and drain the sump, drill a new hole on the other side and install a new
>sensor.  But shouldn't the sensor really be a normally-closed sensor
>that opens when the fuel is low?  That way, any failure in the wiring
>between the sensor and the panel would cause the system to flag a
>malfunction.  I'd have to wire in a relay so that the lamp is turned on
>when the circuit opens.
>
>Any suggestions on this or perhaps other ideas on how to sense when the
>sump is not full?
>
>--
>Dave Philipsen
>N171SP