REFLECTOR: Leaking sump float switch

Mon Oct 10 11:57:47 CDT 2005

            Ronnie,

            At least for the GRT EFIS installations (which allows input
data into a calibration table), these sensors with the brain-in-the-head
are far superior to the units that needed to be routed through GRT's
little translation boxes which allegedly can be calibrated, though I
found no evidence of it.  

While I initially wasn't keen on having clear plastic tubes in the
strake showing the actual fuel levels, I came to appreciate them big
time when my fuel indication was unreliable I got it resolved with the
Centroid sensors.  

Chuck

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Ron Brown
Sent: Monday, October 10, 2005 12:32 PM
To: Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: Leaking sump float switch

Chuck,

The sensor head is similar to the Westach I have - sticks up about 3/4"
above the mounting base.  I may just redo the mounting base - i.e..
recess it about 3/4" to a 1" so I can raise the tank up off the floor.

Ronnie
	----- Original Message ----- 
	From: Chuck Jensen <mailto:cjensen at dts9000.com>  
	To: Velocity Aircraft Owners and Builders list
<mailto:reflector at tvbf.org>  
	Sent: Monday, October 10, 2005 9:39 AM
	Subject: RE: REFLECTOR: Leaking sump float switch

	            For continuous readout-any length, any depth,
another solution is the Centroid Skyprobe.  They will manufacture to any
length and the electronic guts are in the head and output 0-5v.  They
plug right into the Grand Rapids, and probably any 0-5v indicator.  A
little pricey at $95/ea, but seem to be fool-proof, which is why they
worked for me. http://www.centroidproducts.com/tableofc.htm

	         Chuck

	-----Original Message-----
	From: reflector-bounces at tvbf.org
[mailto:reflector-bounces at tvbf.org] On Behalf Of Alex Balic
	Sent: Monday, October 10, 2005 12:09 AM
	To: 'Velocity Aircraft Owners and Builders list'
	Subject: RE: REFLECTOR: Leaking sump float switch

	Gems sells a solid state unit that uses light dispersion to tell
if there is fuel at the sensor- you can get normally open or normally
closed types -  no moving parts and it will screw in as a direct
replacement for the float type switches. In my former life as a
manufacturing engineer- we went through several plants  on equipment
re-design replacing float types with the non- contact types- the floats
were leaking and sinking and causing all kinds of problems as a result.

	-----Original Message-----
	From: reflector-bounces at tvbf.org
[mailto:reflector-bounces at tvbf.org] On Behalf Of Jim Sower
	Sent: Sunday, October 09, 2005 2:40 PM
	To: Velocity Aircraft Owners and Builders list
	Subject: Re: REFLECTOR: Leaking sump float switch

	If I had it to do over (which may very well develop) I would
dispense with the float switch (more of that 1920s technology) and
install one of the many solid state sensors available like those used
for the low fuel warning lights on our dash boards.  If I thought it
important to know how far into my sump fuel I am, I might mount several
of these sensors "on a stick" and have them drive ladder lights on the
panel.  
	Arguably cheaper than float switch, certainly safer and more
reliable ... Jim S.

	wurzel at alumni.caltech.edu wrote: 
	So, I started noticing blue dye down the side of (and on the
	floor right underneath) the sump tank.  Turns out fuel is
	leaking either through or around the float switch.  D'oh,
	the one-day annual condition inspection morphs itself
	into a full-on project.

	Unfortunately, my float switch isn't screwed into a hard point
	as seems to be the standard these days.  I'm not sure if
	Rick L rolled his own low fuel sensor, or if Velocity
	used to recommend just glassing the switch directly into
	the side of the tank, but in any event it is, in fact, just
	glassed right into the side and providing a lovely 100LL
	aroma to my cabin.

	So, I'd like to convert this to a threaded installation.

	1) Any ideas on the easiest way to do this?  My current
	thought is to remove the current switch while taking as
	little of the surrounding material off as possible.  Then,
	sand the outside of the sump tank so it's flat in the area
	where the switch was.  Next, coat the hard point and the tank
	with epoxy and press them together... finally put some glass
	over the outside of the hard point as well (making sure not to
	get any in the threads!)

	2) What do I need to know about fuel and epoxy?  Is there a
	particular epoxy I need to use for this application?  Flox?
	Micro?  Do I have to put some kind of sealant on the inside
	after the epoxy has cured to prevent leaks or deterioration?
	I saw some comments in old posts on using a shop vac to draw a
	vacuum and suck the epoxy in around things, and that sounds
	like a good idea as long as I'm using the right epoxy and it
	doesn't dissolve as soon as the fuel hits it.  :-)

	Thanks in advance for the help!

	_______________________________________________
	To change your email address, visit
http://www.tvbf.org/mailman/listinfo/reflector

	Visit the gallery!  www.tvbf.org/gallery
	user:pw = tvbf:jamaicangoose
	Check new archives: www.tvbf.org/pipermail
	Check old archives:
http://www.tvbf.org/archives/velocity/maillist.html

________________________________

	_______________________________________________
	To change your email address, visit
http://www.tvbf.org/mailman/listinfo/reflector

	Visit the gallery!  www.tvbf.org/gallery
	user:pw = tvbf:jamaicangoose
	Check new archives: www.tvbf.org/pipermail
	Check old archives:
http://www.tvbf.org/archives/velocity/maillist.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.tvbf.org/mailman/private/reflector/attachments/20051010/0b122c0b/attachment.html