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Moller Fuel Gauge

DonFromTX

DonFromTX

Well Known Member
Two questions: A while back someone posted the proper place to cut a hole for the Moller mechanical gauge, for some reason a search won't bring it back up, does anyone know where this information is?
Secondly, has anyone got a signoff as ELSA with the Moller gauge installed? Has anyone contacted Vans to see if we can get this as an "OK" addition? (If nobody has, I will myself)
 
I found the photo with dimensions I was looking for, helped a lot to spell Moeller correctly. Still looking for answer if anyone has made this an "approved by Vans" alteration.
 
Remember, you can always add it after certification.
If done before certification, it will have to be approved by Vans in writing.
 
Check out a post on 04-09-2011 from Winged Frog titled "Sight Glass + Fuel Tank in cockpit = Bad Mix?

I too like the idea of the sight guage in the top and blocking off the window. You can see it as fuel is added and I would be skeptical about the value of the sight glass.

I am also concerned about such a plans deviation and would it effect airworthness as a light sport? Doing later would be a mess but might be necessary because of certification as ELSA.
 
I sealed the window and added the gauge after initial certification. It works great. You can see the level while fueling and while flying. To my knowledge, Van's has NOT approved the gauge and it must be added after certification if building the RV-12 E-LSA.
 
Don, I wonder if I could get you to broaden your question to Vans a bit when you contact them. Could you perhaps ask them what - in general - is their attitude to receiving requests for written approval of minor, non-structural changes? As they see it, is it a workload issue they would prefer to avoid, a record keeping issue, a liability issue...or are they generally receptive to requests such as the one you plan to make? Even if it's just you 'picking up the vibes' when you speak to them, it would be interesting to hear more about this.

Jack
 
Good idea Don

The Moeller gauge seems like such a good modification, and has been done by quite a few builders now with consistently good results, that Vans might be persuaded to approve John Benders plans and installation method. In fact, as the gauge is only about $55, they could easily include it with the kit, or at least as a kit option.

Mine is on order, so I'd be very happy to see a positive response from Vans. It might help the case if you were able to get a list of all the builders who have installed the gauge using JB's plans.
 
Plans

Is there a set of "plans" for this modification or is it just a matter of measuring from both sides of the top skin and centering the hole for the gauge there?
 
Don
Now I can't find the photo with the dimensions on it (I did search, really).
Can you post the link please?
John
Edit - I see it has been done - thanks.
 
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From what I understand the float "swings" to the rear of the tank? Forgive the ignorance as I am currently haven't started building, but is the side mounted sending unit only for the fuel level display on the D180? What is the clearance like between the two of those?
 
Very good question. That is why I was wanting to obtain others experience of the proper location, at this position I cannot see where it would ever conflict the other sending unit.
 
pilottangocharlie said:
From what I understand the float "swings" to the rear of the tank? Forgive the ignorance as I am currently haven't started building, but is the side mounted sending unit only for the fuel level display on the D180? What is the clearance like between the two of those?
Click to expand...

The Moeller float swings left to right.
 
Took this while flying one day - -

RV-12GasGaugeInFlight100_1308.jpg



It reads ok when you turn around to see it. It is upside down while filling, but you get used to it quickly. I actually have found I use it more for filling than in flight, but nice to know it is there to verify how much is left.

John Bender
 
Thanks

Thanks for setting me straight - I'll probably build two tanks when the time comes. One like the plans with the sight glass, etc., and the other will be a bit larger with product #035754-10 mounted and no holes on the side to cover up.

Thanks again to all of the 'pioneers' who have kind of 'proofed' Van's already outstanding RV-12.
 
I was skeptical when John and Marty came up with the idea, but having seen how well it works I removed my site glass, added the fuel gage, and it has been the best mod to date. I was concerned about the gage location being completely under the fuel level when the tank is full. Where the gage is located is on the downside slope of the tank when it is installed. When the tank is full the gage is below the fuel level if that makes sense. I was worried about leaks. That was 130 hours ago, and I have left the tank completely full to the fuel cap!.... and no leaks. :D

While I trust the Dynon to be accurate, there is nothing more reassuring on a cross country trip than turning around and seeing the mechanical gage to verify fuel levels. IMHO, in a single fuel tank airplane it is critical to monitor fuel levels, especially going cross country. ;)
 
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. in a single fuel tank airplane it is critical to monitor fuel levels, especially going cross country

....and time!
 
Moeller fuel gauge - summary

1. The Moeller gauge is a logical and useful modification, now proven by a fair amount of field experience, but must be done after certification which requires dismantling the fuel tank.

2. Calling Van's for a Letter of Authority to do this before certification is not logical. Van's has made many changes to the plans, but has never issued a LOA (why would they want to do that?). We all have to accept that under the ASTM standards and E-LSA definition the plane has to be built per the plans.

3. There was a problem with the original fuel tank sight glass.
Van's issued a revision and kit for it and made a revision to the plans.

4. There is no problem with the new sight glass (by a higher level of field experience than the Moeller gauge).

Do I have this right?

Tony
 
Tony_T said:
2. Calling Van's for a Letter of Authority to do this before certification is not logical. Van's has made many changes to the plans, but has never issued a LOA (why would they want to do that?). We all have to accept that under the ASTM standards and E-LSA definition the plane has to be built per the plans.


Tony
Click to expand...

Hi Tony,

I guess the only reason that Van's would want to issue a LOA is to make money and please their valued customers. If they charge a reasonable fee for an optional kit, just as they do for the lights, then they can have some control on what and how it is done and they can make some money. I think this is why they are in business. As a company culture they have not shown much interest in their customers needs or desires so we can only hope that they will be motivated by money.

Best regards,
Vern
 
I suppose you do have it right, and logical or not, I have petitioned Vans for permission to add the Moeller TO MY CONSTRUCTION ONLY. I cannot see the risk to them, and as I stated to them, I will do it AFTER certification anyway, but it will be easier and more safely installed during tank construction. We will see what they think about my request.
A suggestion was made to me that I leave the tank large hole open "for the inspection", then I can add it after approval without so much hassle.
What we really need is a revolving tank, that could be passed around for inspections, then send it on to the next person and install our modified tank. How about it, anybody got a plans tank laying around to use? (It would not even matter if it leaked or not)

Tony_T said:
1. The Moeller gauge is a logical and useful modification, now proven by a fair amount of field experience, but must be done after certification which requires dismantling the fuel tank.

2. Calling Van's for a Letter of Authority to do this before certification is not logical. Van's has made many changes to the plans, but has never issued a LOA (why would they want to do that?). We all have to accept that under the ASTM standards and E-LSA definition the plane has to be built per the plans.

3. There was a problem with the original fuel tank sight glass.
Van's issued a revision and kit for it and made a revision to the plans.

4. There is no problem with the new sight glass (by a higher level of field experience than the Moeller gauge).

Do I have this right?

Tony
Click to expand...
 
Tony

There is no problem with the new sight glass

Tony,

No, I think the new sight glass is probably fine and being used by most. The first of us of course were spooked because our's broke and had to be replaced with a new piece. Confidence "shattered" (so to speak) most of us just sealed up the sight area. It serves little to no purpose anyway. You have to stand on the other side of the plane and squint to see roughly how much fuel you have. Obviously you cannot watch it as you fill the tank. That said, many have put in the top reading gauge to watch as they fill. My Dynon float reading is pretty much on the mark and I still use a "stick" down the tunnel to check it. I always fill it up (to the cap) before I fly and fly by time and use the Dynon float as back-up.
Those of us with the original plastic all watched it crack and the vision of fuel running into the cabin in flight was not pleasant. Covering up the new one was a natural reaction. I don't know of any actual problems with the new one other than poor installation. The red and blue 12's both use the plastic piece and have more hours than anyone.

Pete
 
Tony_T said:
1. The Moeller gauge is a logical and useful modification, now proven by a fair amount of field experience, but must be done after certification which requires dismantling the fuel tank.

2. Calling Van's for a Letter of Authority to do this before certification is not logical. Van's has made many changes to the plans, but has never issued a LOA (why would they want to do that?). We all have to accept that under the ASTM standards and E-LSA definition the plane has to be built per the plans.

3. There was a problem with the original fuel tank sight glass.
Van's issued a revision and kit for it and made a revision to the plans.

4. There is no problem with the new sight glass (by a higher level of field experience than the Moeller gauge).

Do I have this right?

Tony
Click to expand...

The issue is not that the current sight glass is a problem, but simply that the Moeller gauge is a better and more elegant solution. It reduces the number of holes required in the tank (that has to be good), provides better information and is easier to monitor both when refuelling and in flight.

You could equally argue that Van's shouldn't be bothering with Skyview because the D180 works perfectly well. But they are. I see this in the same vein. The gauge is a better solution, and has been shown to work based on quite a lot of field experience. It should be in Van's interest to at least consider it. Without change we would never have any progress. Overall, the RV-12 is a great design, but that doesn't means that there isn't room for improvement in some areas.

Van's may well choose not to issue a LoA, given that there is nothing to stop a builder installing the gauge after certification, but it's worth asking the question.
 
One of the problems with the sight glass is Auto gas is clear. It is very difficult for me to see the clear fuel through clear glass. I also cannot tell when the tank is near full while filling by looking at the sight glass on the other side of the plane. We fuel by calculating fuel used and when we get to the last calculated gallon while filling a wine cork on a stiff wire dropped into the fuel neck shows us our fuel level( the wire and cork cannot fall into the tank it has a nice bend at the end to prevent this). When the cork floats the wire. A mark on the wire tells us the tank is full with no fuel in the filler neck. We don't want to spill a drop with the issue on the turtle deck window.:)
 
Reading through these posts this morning prompts two responses:

There are four methods already of knowing how much gas is in the tank, to wit: Sight gauge, float sensor, Dynon fuel totalizer, and old fashioned time/flow calculations, which I was taught 50 years ago is more accurate than gauges anyway! So why all this stressing over yet another gauge?

At least one member of this forum has some sort of bone to pick with Van's, and likes to throw little jabs at them from time to time, for example: "As a company culture they have not shown much interest in their customers needs or desires so we can only hope that they will be motivated by money." I am frankly getting tired of this nit picking. If you don't like them, don't buy their products, but stop trying to sully their reputation.

Yes, I am feeling at bit cranky this morning!
 
What confused me as to which way the float swings on the Moeller gauge is the picture looks like the float swings forward and backward when viewing the gauge from the upright position.
 
Although Vans did not grant my petition for authority to install the Moeller before inspection, their solution to me seems to be even better, as it gives me a cover for the Moeller hole if it ever goes on the blitz and I can avoid cutting holes in a finished tank, possible contamination the insides of the tank with trash. . EMail me if you wish to see my original request. Here is their reply:

"Donald, Unfortunately, We're not able to easily grant permission for the
change. I wish it were that simple.

What I might suggest, however, is that you purchase the Moeller sender,
prep the tank for installation...ie: cut the hole, install nutplates, trial fit the
sender etc. Do not final install the unit until after your inspection. Instead,
just fabricate a cover plate to go over the hole and use the gasket supplied
with the Moeller sender to temporarily put the cover plate on. After the
inspection, pull the 5 screws, remove the cover plate, install the sender and
you're good to go."

regards,
 
What about the sight window...

DonFromTX said:
Although Vans did not grant my petition for authority to install the Moeller before inspection, their solution to me seems to be even better, as it gives me a cover for the Moeller hole if it ever goes on the blitz and I can avoid cutting holes in a finished tank, possible contamination the insides of the tank with trash. . EMail me if you wish to see my original request.
Click to expand...

Are you planning to have both the sight window and a Moeller gauge :confused:?

Tony
 
Tony_T said:
Are you planning to have both the sight window and a Moeller gauge :confused:?

Tony
Click to expand...

I don't think Van's will ever abandon the sight gauge. Without doing a lot of research I would suspect something in ASTM standards etc mentions the ability of the pilot to visually see the amount of fuel prior to flight. Since it cannot be easily seen down the curved tunnel, this plastic piece fits the bill. I wouldn't fly without filling mine up first (to where I can see fuel) regardless of how many gauges and floats I had inside the tank.

pete
 
Well, I have not yet decided about the sight glass, but I did not waste any time on the Vans suggestion, just in case they change their mind!
2565qok.jpg
[/IMG]
 
Don,

I think it's pretty considerate of Van's to give you a work-around like this. Seems like a good option for those builders that are still pre-certification and want the Moeller gauge.

John
 
Just curious where you guys are buying your fuel gauge? Who has the best price? IMO it's and excellent idea.
 
Try Amazon, just do a search on Google for "Moeller gauge" and it will pop up. Be sure you get the correct size, it is the 12 inch one that you need. And yes, I am very happy with Vans for their guidance. Cutting those holes in a completed tank was a real worry for me because of contamination.
 
Well, they may not have been able to give formal permission for whatever reason, but that sounds like a pretty good endorsement of the Moeller gauge to me.
 
Now I have one...

I had to open the fuel tank to install the SB11-12-14 Service Bulletin reinforcement brackets so I put in the Moeller Gauge.

So here I am, the Moeller skeptic in this thread, now I have one in my tank.

Actually looking forward to using it, it will make refueling quite a bit easier plus the other benefits discussed before.

Spent a nice couple of days this holiday weekend working in the hangar and got the tank SB done and sealed back up. Now waiting a few days for a pressure test and reinstallation in the plane.
I share this hangar, the owner is on a 5 year travel plan in a 38' 5th wheel trailer.
P1030072-M.jpg

Wings are off due to an annual.

Moeller, reinforcement brackets, sealed back up.
P1030073-M.jpg


Took Scott's advice and used MS35333-38 inside star lock washers on the screws to ensure a good ground for the electric fuel sender. Ohmed it out, no ground wire needed.

Tony
 
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I hope you "fixed" the fuel return fitting in the bottom as well, that bit me in the butt after I had my tank all sealed. I used the little retainer trick, but might still just put in a fitting like the outlet has, or something more secure. Will sure ruin your day if it twists a small bit when tightening up the fitting..
 
Instead of another fuel gauge, I think I will mount a small mirror on the left side of the baggage compartment so I can see the sight gauge as I fill up the tank.
 
Doggone, you take nice pictures Tony. (Hope my "drop" didn't ruin my fuel tank. Not my fault!!)

Mirrors? My friend Jim, across the hangar line (82+ something) has an EZ something or other - a tandem with a rear seat, but fuel gages back there. He has 5 (five - count 'em) cameras - one pointing forward, and at least two pointing back at his back seat fuel gages.

Boy, that's a nice looking hangar.....

Bob B.
N737G
 
Tony_T said:
I had to open the fuel tank to install the SB11-12-14 Service Bulletin reinforcement brackets so I put in the Moeller Gauge.

So here I am, the Moeller skeptic in this thread, now I have one in my tank.

Actually looking forward to using it, it will make refueling quite a bit easier plus the other benefits discussed before.

Spent a nice couple of days this holiday weekend working in the hangar and got the tank SB done and sealed back up. Now waiting a few days for a pressure test and reinstallation in the plane.
I share this hangar, the owner is on a 5 year travel plan in a 38' 5th wheel trailer.
P1030072-M.jpg

Wings are off due to an annual.

Moeller, reinforcement brackets, sealed back up.
P1030073-M.jpg


Took Scott's advice and used MS35333-38 inside star lock washers on the screws to ensure a good ground for the electric fuel sender. Ohmed it out, no ground wire needed.

Tony
Click to expand...

Tony,

Be sure not to over-torque the "break-away" bolts. The heads will pop off as planned...and what's left is not a pretty picture. Don't ask me how I know...lol

Pete
 
Peterk said:
Tony,

Be sure not to over-torque the "break-away" bolts. The heads will pop off as planned...and what's left is not a pretty picture. Don't ask me how I know...lol

Pete
Click to expand...

Good advice, Pete. I am concerned about that. I wonder if this might be a case where running a tap into the platenuts would be appropriate to reduce the torque required. I already ran a regular AN3 bolt in and out a few times to loosen them up a bit. I think I will install the tank with conventional bolts to get everything lined up properly, then replace the conventional bolts one at a time with the frangible bolts.
 
I'm sure you'll be fine. I'm probably the only one that did it or at the only one that fessed up...lol. Or worse yet, only 5 or 6 of us have done the fix! Like you, I put the boat gauge in at the same time so I would at least feel like I did something useful. Then I told John, "you didn't tell me the needle bounces around in the air!"
 
Hey Petie - -

You know it ain't stuck then ! ! ! Several have used my design and have had no complaints ( up to now of course ! ! ! ) HA !

John Bender
382.4 hours
 
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