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Red Cube Firewall Bracket Question

R

RhodeIsland9

Member
Ok, a lot of information here on the red cube. Every installation I have seen where it's mounted on the firewall have it mounted to an angle bracket. Why?

The instructions give three mounting orientations.(out up,wire up,5 bolt plate up). In my case I would like to mount it to the firewall with the 5 bolt plate up and secure directly to the firewall.

Just for the record I'm not against making a bracket if that's the preferred method. Just like the simplicity of the direct mount.
 
Red cube

Jared. I put mine on the fire wall with a peice of
angle. The reason being to be able to mount it facing
Up so the bolts are verticle. Seems to me I read in the instructions
It was recommended to be mounted this way.
 
The wires on the FT-60 red cube should be pointing up according to the directions .
 
They must have revised the instructions. My instructions for the FT-60 give three possible mounting positions.

Al, I think my flow direction is different than most carbed installations. I might still come take a look at your setup sometime.
 
Here's a picture of mine mounted on the firewall diagonal stiffener, with four #10 screws: two thru the stiffener and two thru just the firewall to close the gap behind the piece of angle the red cube is mounted on. I did use some red RTV to seal behind the angle mount/firewall.

The angle mount mounted on the firewall:
http://www.aclog.com/rv-9a/images/Firewall%20Forward/7f0dcb1f3a83fb90b46dbed16a9c7f9621569_0709001420.jpg

The Red Cube mounted:
http://www.aclog.com/rv-9a/images/Firewall%20Forward/fbe91939de59beecfe4314fa411f351731546_0713001309.jpg

I know of one other builder that used an approx. 9" long piece of 1/4" angle on his firewall to mount his Red Cube. Needless to say, it ain't going anywhere. And you know who you are! :eek:
 
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I spoke to the manufacturer about mounting. They advised against firewall/solid mounting. Their suggestion was to let it float between two hoses.

Larry
 
lr172 said:
I spoke to the manufacturer about mounting. They advised against firewall/solid mounting. Their suggestion was to let it float between two hoses.

Larry
Click to expand...

This what they told me too. It has jewel bearings for the pelton wheel.
 
mikehoover said:
Here's a picture of mine mounted on the firewall diagonal stiffener, with four #10 screws: two thru the stiffener and two thru just the firewall to close the gap behind the piece of angle the red cube is mounted on. I did use some red RTV to seal behind the angle mount
Click to expand...

Where in your fuel line between the firewall and carb idoes it connect?

Mine is angle mounted on the lower right side of the firewall between the electric fuel pump and the engina driven fuel pump. It fluctuates about 2 to 3 gph until the fuel level in the tanks is about 1/2 full then fluctuates 1 to 2 gph. Overall, the fuel needed to fill the tank is within .2 gallons of the fuel used. It just doesn't maintain a steady reading.
 
Jared----we've plumb the FT60's in just about every imaginable location, and then some. Firewalls, engines, tunnels, near the flow divider, wires out the side. I cant remember anyone having any issues. Some of the guys at Team AeroDynamix have theirs mounted very near the flow divider, in a vertical position, with the wires coming out the side, pointing aft. Even with all the aerobatics they do, I havent heard of any issues.

I would make a bracket for mounting though. Just my .01 cent worth.
Tom
 
alcladrv said:
Where in your fuel line between the firewall and carb idoes it connect?

Mine is angle mounted on the lower right side of the firewall between the electric fuel pump and the engina driven fuel pump. It fluctuates about 2 to 3 gph until the fuel level in the tanks is about 1/2 full then fluctuates 1 to 2 gph. Overall, the fuel needed to fill the tank is within .2 gallons of the fuel used. It just doesn't maintain a steady reading.
Click to expand...

No issues so far with my install. I am within 0.3 gallons reliably. The fuel line from the Red Cube to the carb is tie wrapped to the engine mount with a standoff about 2-3" long to dampen vibrations.Here is a picture of how mine is plumbed:
http://www.aclog.com/rv-9a/images/Firewall%20Forward/238a451c83f6efdf1963a48008f604e111987_0721001346.jpg
I think the manufacture has you install so it so that fuel will tend to puddle in the Red Cube versus drain out, i.e., lowest location: "the fuel line on the outlet port should not drop down after exiting the transducer...can trap bubbles in the transducer causing jumpy readings."
 
okykl.jpg
 
lr172 said:
I spoke to the manufacturer about mounting. They advised against firewall/solid mounting. Their suggestion was to let it float between two hoses.
Larry
Click to expand...

BillL said:
This what they told me too. It has jewel bearings for the pelton wheel.
Click to expand...

Then what are the two 1/4" machined holes for? The company needs to make up its mind. Its either for hard mounting or its not and that FACT (if it is) need to be blatantly spelled out in the accompanying paperwork. I find the presence of those two holes completely misleading especially if you have to call the factory to get the secret handshake.
 
lr172 said:
I spoke to the manufacturer about mounting. They advised against firewall/solid mounting. Their suggestion was to let it float between two hoses.

Larry
Click to expand...

BillL said:
This what they told me too. It has jewel bearings for the pelton wheel.
Click to expand...

When did they tell you this? I talked with them in 2011 when we were finishing up the RV-3, and was told that while they at one time had problems with vibration getting the bearings, they had changed the design and were fine with mounting it to the engine, to something solid, floating - wherever - vibration was no longer a consideration. We mounted ours toa bracket in front of the sump, and it has been absolutely perfect for over 400 hours now.

To the OP's question - one reason to make a bracket is to allow clearance to make connections. Think in terms of removal and replacement and initial installation of all your equipment - make it easy to work on!
 
Ironflight said:
When did they tell you this? I talked with them in 2011 when we were finishing up the RV-3, and was told that while they at one time had problems with vibration getting the bearings, they had changed the design and were fine with mounting it to the engine, to something solid, floating - wherever - vibration was no longer a consideration. We mounted ours toa bracket in front of the sump, and it has been absolutely perfect for over 400 hours now.

To the OP's question - one reason to make a bracket is to allow clearance to make connections. Think in terms of removal and replacement and initial installation of all your equipment - make it easy to work on!
Click to expand...

Last Spring. I am struggling to recall the rationale provided, but it wasn't bearings. They made it clear that they wanted it to float and not be rigidly attached. They may have different techs providing different guidance or some are more strongly clinging to issues had in the past. They made it very clear that no harm would come to unit by hanging from the hoses. It made logical sense to me and I decided to mount that way. Seems that the general experience is that the units are robust enough to handle a hard mount.

Larry
 
lr172 said:
I spoke to the manufacturer about mounting. They advised against firewall/solid mounting. Their suggestion was to let it float between two hoses.
Click to expand...
Wow, we've come full circle then. I can recall when I was looking to install mine that the manufacturer wasn't recommending that it be mounted in-line, and many people here on VAF were uncomfortable about having that weight hang off the aeroquip fittings.

Mine is mounted to an angle bracket that is Adel-clamped to the crossbar between the two gearleg mounts (tailwheel RV-6).

rzbill said:
Then what are the two 1/4" machined holes for?
Click to expand...
Even if it *does* need to be rigidly mounted, what are the 1/4" holes for? You could probably pick up the entire engine on two 1/4" bolts. Overkill, perhaps? Maybe it's just easier to find a 1/4" x 2" long bolt than it is a 1/8" x 2" long bolt?
 
Red Cube floating

I just replaced my red cube Ft-60 at 168 hrs. It floats at the rear of my IO 360 after the mech. Fuel pump and before the fuel servo . It became intermittent and unreliable , so I bought one at AC Spruce . I know that the engine on shut down produces very high G's about 30 I have been told . It could be that the failure was caused by mounting it floating on fte fuel line and shakened to death ???? I still have it mounted this way as I never considered the mounting could have been the cause of it failing with only 168 hrs of use until following along on this thread. Something to think about ? :confused:
 
Red Cube Installation Clarification

Emailed Electronics International who builds the FT-60 cube about mounting preference. Daniel from Tech Support wrote me back to say that the cube can be hard mounted using the mounting holes or can float between the fuel hoses. Must be mounted downstream of All fuel pumps. If hard mounted you must use flex hoses in and out of the cube. Mounting should be on the same vibration plane which is to say a hard mount on the engine as opposed to the firewall is recommended.
This is the definitive answer to the question and not my opinion. The older fuel flow transducers prior to the cube were made of a pot metal material and were not strong enough to be hard mounted without cracking. I think this is where the free floating mounting came from originally. The cube was specifically designed for hard mount which is why it has mounting holes in the aluminum case.
Thought I would pass this along....
Brad
 
So I am getting ready to have a condition inspection done on my (bought, not built) RV7. It's only about two years old, but I have been getting obviously bogus readings on the Fuel Flow. I had the cowling off the other day and took a close look at the Red Cube.

It's mounted on the lower right firewall, more or less attached to the gascolator and then to the hose that goes to the engine fuel pump. I don't see any bracket holding it to the firewall. What I do see however is that the wire comes out of the cube facing straight ahead, and some insulation on the white wire is coming off, exposing the inside wires. This wire is barely touching the engine mount.

358nhox.jpg

Picture is taken looking down and aft towards the red cube, gascolator on left.

Not sure what to do at this point but I want to have some recommendations for my IA when he starts work on the condition inspection...

Any ideas?
Thanks
 
edneff said:
So I am getting ready to have a condition inspection done on my (bought, not built) RV7. It's only about two years old, but I have been getting obviously bogus readings on the Fuel Flow. I had the cowling off the other day and took a close look at the Red Cube.

It's mounted on the lower right firewall, more or less attached to the gascolator and then to the hose that goes to the engine fuel pump. I don't see any bracket holding it to the firewall. What I do see however is that the wire comes out of the cube facing straight ahead, and some insulation on the white wire is coming off, exposing the inside wires. This wire is barely touching the engine mount.

358nhox.jpg

Picture is taken looking down and aft towards the red cube, gascolator on left.

Not sure what to do at this point but I want to have some recommendations for my IA when he starts work on the condition inspection...

Any ideas?
Thanks
Click to expand...

You have three issues. I know that EI wants the wire facing up. They are not adamant about it, but I suspect it helps to eliminate problems. They did seem adamant about it not being at a high point. They want something higher than the cube on the exit side. Otherwise any air bubbles will foul the readings. In my case, I mounted on the firewall but cube was higher than the carb. I put a loop in the hose between the cube and the carb with the high point of the loop above the cube. Last, they are adamant that the cube sit between the mechanical pump and the carb/servo. Yours appears be be before it, though can't tell from the picture.

sLarry
 
lr172 said:
You have three issues. I know that EI wants the wire facing up. They are not adamant about it, but I suspect it helps to eliminate problems. They did seem adamant about it not being at a high point. They want something higher than the cube on the exit side. ... Last, they are adamant that the cube sit between the mechanical pump and the carb/servo. Yours appears be be before it, though can't tell from the picture.
Click to expand...

Thanks, sLarry. Without looking at the installation, I am pretty sure the cube is below the carb, it's at the very bottom of the firewall. In any case, it's definitely not higher. And right now, it's set up between the gascolator and the engine driven fuel pump, so I guess I need to figure out how to change the location to AFTER the pump.

Where are most folks installing the red cube in this type of situation? If I relocate the cube is it likely to start giving realistic readings, or will I have other issues that might be due to the white wire insulation gap?

thanks again.
 
edneff said:
Thanks, sLarry. Without looking at the installation, I am pretty sure the cube is below the carb, it's at the very bottom of the firewall.
Click to expand...

I think you may need to look closer. I have a 6A model in my garage and just looked again. The bolt on the nose gear leg is higher than the carb fuel inlet and your picture shows the cube above that bolt.

Either way, I would do some re-routing before replacing your cube to get accurate readings.
 
lr172 said:
I think you may need to look closer. I have a 6A model in my garage and just looked again. The bolt on the nose gear leg is higher than the carb fuel inlet and your picture shows the cube above that bolt.

Either way, I would do some re-routing before replacing your cube to get accurate readings.
Click to expand...

That's not the nose gear leg bolt, this is a tailwheel airplane... The location is the lower right corner of the firewall/engine mount.
 
Got this from E.I. tech support today, I am planning to check my G3X setup tomorrow. Interestingly, he said nothing about the orientation of the wire coming out of the cube.

"For the installation side, the transducer needs to be downstream of the fuel pump and have soft fuel hose in and out of the transducer. I do not believe that your installation location has anything to do with the issue you are seeing.

I have heard of this issue many times specific to the G3X. After speaking with a Garmin rep I am confident that the issue is a K-factoring issue in their instrument. Our transducers K-factor is 68,000. I believe that when the Garmin is programmed for that, the fuel reading will be too high. Recently the calls about this have been declining so I believe that Garmin may have made a change to their system (this is just an assumption based upon tech support calls).

I would first check to see that the K-factor is set to 68,000 in the G3X. If it is then I would recommend contacting Garmin and checking to see if they have a firmware update that fixes this issue. "
 
What about hoses?

I'm about to put in an order for a Red Cube transducer. Could someone please share the sizes and lengths of hoses needed to install it on my RV-8 with an IO-360?
Thanks
 
-4 downstream from the servo. Lengths??? where are you going to put it? That will determine the 2 hose lengths. There isnt a "'SPECIFIC LOCATION" . That would be too easy.
Tom
 
Red Cube?downstream

Thanks Tom. I was looking at putting it between the pump and servo, but I soon saw that those hoses are BIG?hence my question about SIZES and lengths. Putting it between the servo and spider looks like it eliminates any need for reducers/adapters, so that's what I'll do. I'll get back with you about hoses after I look at exact location, per your suggestion.
Do you have any pro/con advise about allowing the cube to float, vs. mounted on FW?
Thanks
 
Has this been decided?

I just spent the last hour reading about 50 posts - all with a different opinion on where and how to mount the Red Cube. What is confusing is the different locations for FI and carbs. I have a carb and there are more locations discussed for carb engines than FI

Im about ready to throw it away and just use a stick to know my fuel use!
 
I was in the same quandary at that stage. Then I happened upon a builder's website (it may have been Randy Lervold's) that showed the Cube in a place that would work perfectly for me. I put it there - between two hoses in the line between the servo and spider - and it has worked great ever since.
I recommend you put it in a place you can access readily ... Red Cubes fail every now and then. My first one had defective threads and had to be replaced at 12hrs flying time.
 
Thanks Terry. I spoke with Tom and he said to mount it and then tell him what length hose I need and he will make them for me. I told him to quit milking his knee - near death experience and get back to work!
 
Here's where I put my Red Cube on my -8.

IMG_6960_zps2vutu1er.jpg

Awaiting new hose from Tom to run between Cube and spider.
Warning: untested. Still building.
 
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AAflyer said:
IMG_6960_zps2vutu1er.jpg

Awaiting new hose from Tom to run between Cube and spider.
Warning: untested. Still building.
Click to expand...

Your chosen location is going to be the high point of the installation. Just what EI's installation guidelines say to avoid.
 
As the op I thought I would share where the cube ended up.

Tom made a short hose with a 45 on one end to go to the servo (rear outlet), keeping the cube as low as possible.


 
Perfect!

Jared, Thanks for the picture. That is exactly what I am going to do. Im even going to paint it white as a tribute to you! Ha!
 
Actually, it's still uphill to the spider from there, per my installation instructions. I Googled for more info, and it looks like there are "old" Red Cubes, and "New & Improved" Red Cubes. I found a 25+ page set of installation instructions on line that I think pertain to the older model. My Red Cube came with a 2 page install sheet, that says: "…the fuel line on the outlet port should not drop down after exiting the transducer."
Pretty sure I complied with that, but will double check…especially in a level flight attitude.
There was no mention of bubble-trapping loops in my installation, but I DID see references to that in what I think was the "old" manual.

Thanks for keeping me honest. Love the feedback on this site.
 
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