Fuel Flow High

[airguy]

sorry Chris but you're part of the problem. I understand that that won't penetrate but the guy didn't understand and you just repeated your answer like it was his problem that you weren't going to go any further. I tried to help but he was already triggered by his exchange with you.

EXPERIMENTAL airplanes are meant for learning as much as flying. People with zero experience have been doing this for many many decades and, yes, it's scary to think what goes on out there in the privacy of a hangar but the FAA has created this category for learning and experimentation. Dynon is selling avionics for experimental aircraft so this is the kind of thing you are going to get here. You can either participate and help people to learn the basics (if need be) or you can talk over them and create drama.

Welcome to the club Chris! Those of us who are "part of the problem", as clinically diagnosed by SV_Classic, are definitely on the rise in headcount! Soon we'll be in the majority, no doubt!

 

[airguy]

Chris, I suggest you go right away to Dynon and tell them the grave danger they are creating and to stop selling avionics for non-certified aircraft. Then call Okalhoma City and tell the FAA that they should immediately stop licensing experimental aircraft as the danger is too great.

Go check out Vansairforce.com, there are like five million people there of various levels of understanding and experience, actually helping each other! It's too bad as you have knowledge to offer but your interest isn't really in helping others to learn as much as it is in demonstrating that you simply have knowledge.

The whole point of a forum site like this is to promote learning, it's really simple if you just think about it for a second.

Yep, and there's the non-sequitur argument...

Gee, that wasn't predictable or anything.

 

[chriscalandro]

Not understanding the answer IS his problem. It’s certainly not mine.

If someone not understanding a very simple answer makes me “part of the problem” this is my reaction to how much that bothers me -

 

[SV_Classic]

Chris, it looks more and more like you simply didn't know how to calibrate the return sensor and so had no choice but to be obtuse and not actually helpful. But you keep pretending you knew it all along.

As I've said earlier, the three or four of you that think this forum is your personal property aren't helping Dynon to sell hardware and you're actually just making it harder for them since more people are sending them emails directly for problems that could be addressed by the community were the community actually functional. It's all very bush league and reflects poorly on Dynon.

 

[chriscalandro]

Chris, it looks more and more like you simply didn't know how to calibrate the return sensor and so had no choice but to be obtuse and not actually helpful. But you keep pretending you knew it all along.

As I've said earlier, the three or four of you that think this forum is your personal property aren't helping Dynon to sell hardware and you're actually just making it harder for them since more people are sending them emails directly for problems that could be addressed by the community were the community actually functional. It's all very bush league and reflects poorly on Dynon.

Sounds like you also don’t have any idea what you’re talking about. Especially since they are identical sensors and are calibrated in exactly the same way.

But go on. Tell me how I’m “part of the problem” then respond with this nonsense. I’ll be up a bit longer. I’ve got nothing better to do.

 

[Rhino]

 

[SV_Classic]

Sounds like you also don’t have any idea what you’re talking about. Especially since they are identical sensors and are calibrated in exactly the same way.

But go on. Tell me how I’m “part of the problem” then respond with this nonsense. I’ll be up a bit longer. I’ve got nothing better to do.

they're clearly not. one is calibrated with an initial best guess and then tweaked by flying and manually recording actual fuel consumption and comparing it to calculated. The return can only be calibrated on the ground with a bench or lab approach that isn't published in the manuals. But going back to your exchange with Skippy, you didn't understand the question I guess and weren't willing to go beyond the initial cryptic response as if it was his fault he wasn't deserving of further explanation that you weren't actually capable of providing after all! Why admit you don't know when you can just be rude to strangers? It's actually really funny what a boob you are.

I came here to learn about the avionics that I didn't choose for my plane. I see guys teaming up with RTFM to a guy that needed a helping hand, I was told to RTFM after I quoted the manual, and one scammer after another stealing people's money in the classifieds. As a person that has run forum sites for-profit, @Dynon really needs to invest some time moderating content if they're going to refer their own customers to places like this for education and problem solving.

 

[chriscalandro]

Look, everyone, it's the
View attachment 6388

My comments might have been factually correct but this is the most on point reply to this whole thread.

they're clearly not. one is calibrated with an initial best guess and then tweaked by flying and manually recording actual fuel consumption and comparing it to calculated. The return can only be calibrated on the ground with a bench or lab approach that isn't published in the manuals. But going back to your exchange with Skippy, you didn't understand the question I guess and weren't willing to go beyond the initial cryptic response as if it was his fault he wasn't deserving of further explanation that you weren't actually capable of providing after all! Why admit you don't know when you can just be rude to strangers? It's actually really funny what a boob you are.

I came here to learn about the avionics that I didn't choose for my plane. I see guys teaming up with RTFM to a guy that needed a helping hand and one scammer after another in the classifieds. As a person that has run forum sites for-profit, @Dynon really needs to invest some time moderating content if they're going to refer their own customers to places like this for education and problem solving.

that is not correct at all, show me the 2 different part numbers for these devices. Initial best guess may work for a single red cubes but with 2 that becomes much more difficult.

The red cubes for the feed and return are in fact identical, and both need to be calibrated properly and independently.

Not sure how or why anyone in the world would think or argue anything differently.

You can try to attack my answer all you want, but the fact is - it’s the only correct answer.

In order to have an accurate fuel flow and totalizer, both red cubes (which yes, are identical) must be calibrated properly.

Yes, the same method can be used to calibrate them which was outlined very early in this thread.

 

[Europaul]

Slightly off-topic for the detail, but fundamental to the whole question of fuel flow:

Why does the K factor need to be "tweaked" at all?

If the fuel flow transducer is built to a known spec (dimensions etc), and contains a known volume of fuel... then 'r' revolutions must always produce 'l' litres per hour, Shirley?

Or, rephrased: it holds 'a' millilitres, releases 'b' millilitres for every one revolution of the rotor, turns at 'c' rpm... so it must discharge 'd' litres per hour? [d varies with directly c; everything else is a constant]

I probably haven't phrased this very well (in either attempt!), so I'm happy to have my question corrected, in advance of the answer being provided

TIA,

Paul M
(have 912ULS with feed & return lines and 2 x Red Cubes, so have skin in the game )

 

[chriscalandro]

Slightly off-topic for the detail, but fundamental to the whole question of fuel flow:

Why does the K factor need to be "tweaked" at all?

If the fuel flow transducer is built to a known spec (dimensions etc), and contains a known volume of fuel... then 'r' revolutions must always produce 'l' litres per hour, Shirley?

Or, rephrased: it holds 'a' millilitres, releases 'b' millilitres for every one revolution of the rotor, turns at 'c' rpm... so it must discharge 'd' litres per hour? [d varies with directly c; everything else is a constant]

I probably haven't phrased this very well (in either attempt!), so I'm happy to have my question corrected, in advance of the answer being provided

TIA,

Paul M
(have 912ULS with feed & return lines and 2 x Red Cubes, so have skin in the game )

I’m not sure about all the technical details as to why this may be, but slight differences in not only manufacturing but also installation seem to affect the sensor.

So while the value in the manual may get you close, depending on the items mentioned above, fine tuning is required to get more accurate data.

(per the ei manual)

 

[swatson999]

they're clearly not. one is calibrated with an initial best guess and then tweaked by flying and manually recording actual fuel consumption and comparing it to calculated. The return can only be calibrated on the ground with a bench or lab approach that isn't published in the manuals. But going back to your exchange with

Actually, no, the forward transducer can NOT be adjusted simply by flying, refilling and adjusting the K factor in a system with a return line.

The answer here is to calibrate EACH transducer *independently*, which can't be done that way. They'll both have to be done on the ground, and the way to do that is to disconnect each one in turn, pump a precise amount of fuel through it and record the starting and ending raw data values in the EMS Debug Data page, then adjust the K factor and repeat until the calibrated value shown on that page matches the amount pumped. Repeat for the other cube. Reconnect all hoses and go fly.

It shouldn't actually be very difficult, certainly no more time consuming than flying/refilling/adjusting/repeat numerous times.

I suppose, assuming the return line is *always* returning the exact same amount, using the fly/refill/adjust method would work, but it's not how it should be done.

 

[airguy]

Slightly off-topic for the detail, but fundamental to the whole question of fuel flow:

Why does the K factor need to be "tweaked" at all?

If the fuel flow transducer is built to a known spec (dimensions etc), and contains a known volume of fuel... then 'r' revolutions must always produce 'l' litres per hour, Shirley?

Or, rephrased: it holds 'a' millilitres, releases 'b' millilitres for every one revolution of the rotor, turns at 'c' rpm... so it must discharge 'd' litres per hour? [d varies with directly c; everything else is a constant]

I probably haven't phrased this very well (in either attempt!), so I'm happy to have my question corrected, in advance of the answer being provided

TIA,

Paul M
(have 912ULS with feed & return lines and 2 x Red Cubes, so have skin in the game )

Very slight differences in the quality of the bearing, the surface finish of the turbine wheel, and minor turbulent flow areas that can be influenced by how the body was machined internally can all have an effect on the actual fluid flow versus revolutions of the wheel. The "tweaking" of the K value is done to take these factors into account.

Similarly, when we install a static pressure port on an airplane, there is almost always some amount of error that must be accounted for, even though the static port is identical to others made, the position on the aircraft is identical, the model of the aircraft is identical, etc etc. Minor differences add up to significant deviations.

 

[Europaul]

I’m not sure about all the technical details as to why this may be, but slight differences in not only manufacturing but also installation seem to affect the sensor.

So while the value in the manual may get you close, depending on the items mentioned above, fine tuning is required to get more accurate data.

(per the ei manual)

Thanks - maybe I'm being thick, but looking for a manual here:
[https://iflyei.com/downloads-electronics-international-instruments/]

only shows this:
[https://iflyei.com/wp-content/uploads/EI-FT-60.pdf]

which doesn't cover tuning.

Yes, I know the Dynon manual does, but I wanted to compare EI's documentation... (e.g. is there a recommended number to adjust the K factor to achieve a certain change in fuel flow, (e.g. "to lower fuel flow by 5%, reduce K factor by 2%") or is it just a guess, followed by trial and improvement?)

• Do you have a link to an EI tuning manual at all, please?

TIA

P

 

[chriscalandro]

Thanks - maybe I'm being thick, but looking for a manual here:
[https://iflyei.com/downloads-electronics-international-instruments/]

only shows this:
[https://iflyei.com/wp-content/uploads/EI-FT-60.pdf]

which doesn't cover tuning.

Yes, I know the Dynon manual does, but I wanted to compare EI's documentation... (e.g. is there a recommended number to adjust the K factor to achieve a certain change in fuel flow, (e.g. "to lower fuel flow by 5%, reduce K factor by 2%")).

TIA

P

I can’t remember specifically which manual, Dynon or EI which stated a starting point, but I do remember a note that mentioned the starting point suggested was with 1-2% maybe?

In my experience orientations can have a pretty big influence. Really the only real way is to do the flow test.

 

[chriscalandro]

Actually, no, the forward transducer can NOT be adjusted simply by flying, refilling and adjusting the K factor in a system with a return line.

The answer here is to calibrate EACH transducer *independently*, which can't be done that way. They'll both have to be done on the ground, and the way to do that is to disconnect each one in turn, pump a precise amount of fuel through it and record the starting and ending raw data values in the EMS Debug Data page, then adjust the K factor and repeat until the calibrated value shown on that page matches the amount pumped. Repeat for the other cube. Reconnect all hoses and go fly.

It shouldn't actually be very difficult, certainly no more time consuming than flying/refilling/adjusting/repeat numerous times.

I suppose, assuming the return line is *always* returning the exact same amount, using the fly/refill/adjust method would work, but it's not how it should be done.

Welcome to being “part of the problem”!

We’re a small proud group.

 

[SV_Classic]

My comments might have been factually correct but this is the most on point reply to this whole thread.

that is not correct at all, show me the 2 different part numbers for these devices. Initial best guess may work for a single red cubes but with 2 that becomes much more difficult.

The red cubes for the feed and return are in fact identical, and both need to be calibrated properly and independently.

Not sure how or why anyone in the world would think or argue anything differently.

You can try to attack my answer all you want, but the fact is - it’s the only correct answer.

In order to have an accurate fuel flow and totalizer, both red cubes (which yes, are identical) must be calibrated properly.

Yes, the same method can be used to calibrate them which was outlined very early in this thread.

Repeating the most general thing you can say about it over and over doesn't change that you really didn't help the OP. I don't get being proud that Dynon directs their customers to come here for help and you are openly rude to them, unless maybe you are 16 yrs old.

 

[SV_Classic]

Thanks - maybe I'm being thick, but looking for a manual here:
[https://iflyei.com/downloads-electronics-international-instruments/]

only shows this:
[https://iflyei.com/wp-content/uploads/EI-FT-60.pdf]

which doesn't cover tuning.

Yes, I know the Dynon manual does, but I wanted to compare EI's documentation... (e.g. is there a recommended number to adjust the K factor to achieve a certain change in fuel flow, (e.g. "to lower fuel flow by 5%, reduce K factor by 2%") or is it just a guess, followed by trial and improvement?)

• Do you have a link to an EI tuning manual at all, please?

TIA

P

When I went looking for info at EI's site I only found their brief tech document that wasn't very helpful. It's generally straightforward with a single sensor to tweak the K value over the course of a few flights but the return sensor doesn't lend itself to that procedure which is where all of the problems lie. As Chris said, using the starting value gets you close to an accurate sensor and you could probably leave it at that if you were conservative with your fuel planning/usage but it makes sense to expend the effort to calculate a better K value for your installation.

Manufacturing and installation would be my guesses for the variation from one to the next, probably more the installation and vibration/heat inducing flow through the turbine that isn't as perfect as a long straight run in the lab might allow.

 

[chriscalandro]

Repeating the most general thing you can say about it over and over doesn't change that you really didn't help the OP. I don't get being proud that Dynon directs their customers to come here for help and you are openly rude to them, unless maybe you are 16 yrs old.

You are the problem

 

[SV_Classic]

Keep telling yourself that, maybe it'll make you feel better. I've been getting PM's from people saying thank you for addressing the RTFM problem. If you're bored, go somewhere else but don't be rude to people that are asking for help at the place where the manufacturer sends them.

 

[chriscalandro]

Keep telling yourself that, maybe it'll make you feel better. I've been getting PM's from people saying thank you for addressing the RTFM problem. If you're bored, go somewhere else but don't be rude to people that are asking for help at the place where the manufacturer sends them.

Nobody told him to read the manual. He was provided with the correct answer.

Quit being the problem. You act like a 5 year old hall monitor.