The fuel level swtich I use is from http://fluidswitch.com/pages/fs11.htm
Seems to do well Joe On Sat, Feb 11, 2012 at 7:49 PM, Jeff Scott <jscott.pla...@gmx.com> wrote: > The plate type of capacitance transducers are known for reading pretty > inaccurately due to the sloshing in the tanks. The feedback I have heard is > that they work just fine on the ground, but as soon as the plane is moving > and bouncing around the fuel gauges become relatively useless. If someone > else has been flying with them and has a different experience, I'd sure > like to hear it. > > I did install capacitance gauges in my KR. I used the transducers from > Westach, which are a 1/4" aluminum tube with a wire suspended in the center > that is used to measure the capacitance. I found the tube type transducers > to be accurate and work quite well in rough air. I have had a history of > the Westach transducers losing the ground where the ground wire is riveted > onto the 1/4" tube with a cheap pop rivet, but addressed that issue by > wrapping and zipping them down tight with some .020 safety wire. I've been > flying with these gauges in my KR for 15 years now. It's worth noting that > the more modern Westach transducers come with the ground wire already > wrapped around the tube at the rivet. > > Craig, my fuel system is set up similar to yours with a 9 gallon header > and two 6 gallon aux tanks that get transferred to the header. Maybe it's > just me, but in 900 hours I have never failed to look at the fuel gauge and > transfer fuel from the wings to the header. In fact, it is rare for me to > ever allow the header to go below 1/2 tank until after the wing tanks are > dry. However, I have forgotten to shut off the tranfer pumps a few times, > so was pumping excess fuel to the header which was sending it overboard. > Don't try to over think it as all the warnings can become a distraction. > You may find yourself responding to warnings that may not necessarily be as > critical as just flying the plane first. The only annunciator I have in my > plane is the traffic proximity warning on my PCAS. That's one that gets my > attention, but after more than one near miss while in cruise flight, I want > it to get my attention. > > Jeff Scott > Los Alamos, NM > > ----- Original Message ----- > From: Craig Williams > Sent: 02/11/12 04:36 PM > To: KRnet > Subject: Re: KR> annunciators box > > Mark You may want to look at Jim Weirs (June 2000 kitplanes) design for a > capacitive fuel gauge. It's what I am going to use. No moving parts and no > need to ever go back in the tank. It also has an alarm for low fuel. That > will be useful for me because I do not plan on having and external fill > capability on the mains, all fuel goes through the aux and transfers to the > mains via a pump. http://www.rst-engr.com/kitplanes/ Although I will have > the low fuel alarm I decided to build the timer circuit to alert me every > hour to transfer fuel. The 0-200 will burn my mains down to half full each > hour. Then I flip on the pump switch and watch the gauge climb back to full > and shut her off. (<2 min) If fuel won't transfer then I have one hour to > fix it or land. Craig www.kr2seafury ________________________________ From: > Mark Langford <m...@n56ml.com> To: KRnet <kr...@mylist.net> Sent: Saturday, > February 11, 2012 2:44 PM Subject: Re: KR> annunciators box The reason I > have a fuel transfer LED (and it's just green and doesn't flash) is purely > for information that the pump really is getting power, and that it shuts > off automatically when it's supposed to, after about three minutes. I agree > that the automatic level switch makes a lot of sense, but I've got two dead > fuel level sensors in two different tanks in my plane, both of which lasted > a mater of weeks before they croaked, so I hope folks choose better than I > did in that regard (Compac Engineering). I'd be tempted to find an > automotive (either factory or aftermarket) level sensor that has the extra > connection for a "low fuel" light, and use that to trigger a warning light, > just like in your car. But I've found in my plane that I never, not once, > ran the main tank out of fuel, for the reasons Matt mentioned....the fuel > gauge in the header tank is something I glance at quite often, and when it > drops to the point that it could hold another couple of gallons, I shoot it > over there. The "fuel transfer" light is just to let me know if the pump is > receiving power or not (and hopefully working). That's not to say that I > didn't know what the gauge looked like when it was dead empty. Part of my > annual inspection is to prop the tail up to flying angle and run the fuel > out, to make sure the gauge is still accurate, and that I know how it looks > just before it gets there. As much as I don't like fuel in the cabin, I > have to admit that the Swift has a fuel system I could like in a KR. It has > an aluminum "header" box that holds about a quart of fuel, right under the > seats. It has a standpipe sticking out the top, into which a cork float > twists a magnet that acts on a gauge that sticks out between the seats > (like a boat fuel tank, I'm told). This aluminum box is plumbed to the two > wing tanks, always receiving fuel from both tanks by gravity, and the fuel > is then pumped from the aluminum box to the carb by a mechanical and/or > electric pump. Gravity means no such thing as fuel left in either tank when > it finally runs dry. This way, only one water/trash drain is needed. It's > remoted to a pull knob at the firewall via cable. The fuel outlet runs > through a large fine screen before it can be sucked out of the header and > to the carb. Another advantage to this system is that replacing the gauge > is easily done in minutes with four screws, from inside the cabin, and > without even draining the fuel! Of course my Swift's gauge has been > operating flawlessly for 65 years One of the many nice things about the EIS > is the programmable fuel remaining. I have mine set to alarm at 2.3 gallons > (more than a half hour at cruise), but then that is based on the assumption > that I've been smart enough to empty the aux wing tanks into the header > tank via fuel transfer. With the Swift system, that issue doesn't exist, > and I'd only need two electric pumps (main and backup), rather than four > (add a pump for each aux tank)... Mark Langford ML at N56ML.com website at > http://www.N56ML.com-------------------------------------------------------- > _______________________________________ Search the KRnet Archives at > http://mylist.net/private/krnet/ to UNsubscribe from KRnet, send a > message to krnet-le...@mylist.net please see other KRnet info at > http://www.krnet.org/info.html _______________________________________ > Search the KRnet Archives at http://mylist.net/private/krnet/ to > UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please > see other KRnet info at http://www.krnet.org/info.html > _______________________________________ > Search the KRnet Archives at http://mylist.net/private/krnet/ > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html > -- Jose Fuentes Founding Father (one of and former Vice Prez) of Capital City.NET User's Group Former Microsoft MVP http://blogs.aspadvice.com/jfuentes
