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CIES fuel sender status ?

Larry DeCamp

Well Known Member
Last I heard there is nothing for an RV. Has anyone bought a standard product and made it work in RV. I respect they don?t have any incentive to suggest a config that might work but RV people are pretty resourceful. They were not comfortable with no indication at lower levels. I use low level ?eyes? to enunciate ?no go? for landing so that is not a show stopper for me.
 
I'm glad I'm not the only person thinking about using the magneto resistant fuel senders. I sent CiES an e-mail today. I doubt I can make it work. I think bending the arm to make it fit will throw off the calibration of the sender. I guess we will see what they have to say.
 
Based on what I have seen with the CiES design and installation, changing the float arm geometry would not be a problem as the sensor and display are calibrated together with fuel after the sensor is installed. Much like I believe Dynon and Garmin do now.

Here is the old thread on the sensors.

http://www.vansairforce.com/community/showthread.php?t=92713&highlight=Cies

I believe that on issue is the problem of measuring the fuel at the top of the tank. It appears that this issue that is solved in other aircraft with the installation of an inboard and outboard sensor in each tank that are tied together electrically. It looks like the extra work and expense involved my be an issue for many builders that have never trusted the fuel level indicating systems in their aircraft anyway.

It's good technology, provides very repeatable and accurate information if installed and calibrated properly.

Here is a whitepaper that appears to describe the problem with measuring the furl in the top of the tank.

http://fuellevel.blogspot.com/2013/01/vans-rv-cies-fuel-level-sensor.html

I would like to hear what you find out from CiES.

-larosta

Yes accurate and reliable fuel level measurements are an interest of mine.
 
Any answer from Cies?

cmadams52 & Larosta,
May I ask you? Do you have any news regarding Cies fuel level senders for RVs? Since years I was looking for a replacement of these Stewart Warner senders ... to be more accurate. I would be happy using them with the G3X efis.
Thanks.
 
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CiES Fuel Sending Unit for RV

I cannot speak directly regarding the state of the CiES fuel sending units for the RV. However, when I do get to that point my aircraft will use their technology.

I cna speak to the companies commitment to the accurate measurement of fuel quantity in GA (and experimental aircraft). Case in point, I fly a European aircraft (Socata TB) that uses a sending unit original out of a French passenger automobile much like the standard set Rochester (et/ al.) resistance sending units here in the US. The problem was that the Socata sending units were a smaller diameter and different bolt pattern that their standard production units. The problem is thst because of the limited number of potential installations for a different design and part number CiES was reluctnt to start a new design to address our needs. We talked to the owner and came up with a solution that would allow CiES to manufacture the new design and obtain an STC for all of the Socata Caribbean series wings. Win-Win. I see that as a company committed to their customers and finding new ways to sustain their business.

Now as far as the sending units for the RV aircraft goes. I believe that you can order a sending unit that will fit any of the current RV aircraft from them today. The issues that I recall reading here are that there is a question regarding the dihedral of the wing and the location of the sending unit on the inside tank bulkhead. I believe that there might be a concern with being able to measure the few gallons in fuel in the volume above the level where the inside sending unit is trave limited when it hits the top surface of the tank. This of course is the currently accepted design and is widely accepted. the accepted design in the case of wings with a dihedral that creates this condition is the install two or more sending units that are connected together to accomplish this (the CiES design does this very well and makes calibration accurate and straightforward). I have wondered how much of a problem this really is and have thought about taking a tape measure out to some of the RV's and actually determining what the tank geometry really is and what the scope of the problem really is. My hypothesis is that the amount of fuel is relatively small and my not warrant a second sending unit in an experimental installation. I will leave that to the RV community, CiES, and the FAA.

The third area is probably the cost of this technology relative to a resistivity float unit that you can purchase for less that $50 just about anywhere. My opinion is that the fundamental technology, reliability, and accuracy is significantly better that that designed in the 1920's and has an active electrical component bathed in fuel inside our tanks. As a instrumentation engineer, that one give me chills. I also recall something here in the forums about the possibility of CiES being willing to manufacture a NON-STC unit for the EXP market at a lower price. I think that if there had been enough customers that were interested to convince that CiES could make market that might still be interested in supplying something for the EXP customers.

Based on my experience I would suggest that you contact them and start a dialog. Perhaps they can come up with an acceptable solution.

I have no relationship with CiES other than being a satisfied customer.

- larosta
 
CIES Fuel Senders

I called them a couple of days ago. They answered the phone after a ring or two and encouraged us to go their website and submit a request for a quote. By submitting the request, with contact information, the engineer would discuss the particular needs of the builder. I expect it will be next week.

The accuracy of these gauges isn't disputed, but the two main problems are the bolt pattern and the cost of the units. The gal I spoke with said they might be able to make a template to fit over out bolt pattern, but please to talk to the engineer.

I'll post here if it works out. I am building an RV14a and already sealed in the stock senders, so would have to undo all that, but let's see if they can accommodate Vans builders.
 
Any updates here?

I called them a couple of days ago. They answered the phone after a ring or two and encouraged us to go their website and submit a request for a quote. By submitting the request, with contact information, the engineer would discuss the particular needs of the builder. I expect it will be next week.

The accuracy of these gauges isn't disputed, but the two main problems are the bolt pattern and the cost of the units. The gal I spoke with said they might be able to make a template to fit over out bolt pattern, but please to talk to the engineer.

I'll post here if it works out. I am building an RV14a and already sealed in the stock senders, so would have to undo all that, but let's see if they can accommodate Vans builders.

Supposedly they have a solution for RV-12 and Dynon. I?m planning to call them about a -14 solution with Garmin.
 
Bolt pattern clocking is their concern.

I talked to the sales manager at OSH and expressed our frustration that they are not responsive to RV?s. She said the clocking of the bolts on the sensor are an issue for plug and play install expectations. She agreed that they can supply a unit that works IF you are OK with the reality that FULL might be indicated until fuel level drops .
So, if you are building and have the option to orient bolt patterns, it sounds very encouraging. If you are locked in to a Vans sensor mounting flange, you need to send them the clocking of the bolts , tank section height and dihedral angle. They will respond (she said ) with the options available.
 
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