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Red Cube Install - Take Two

CJ in EP

Active Member
So, if you hadn’t noticed, I took a shot at a new method for mounting the red cube in my -9A with a Lycoming YIO-320-D1A with an AvStar fuel injection servo under the heading “Red Cube Install, A new look at an old challenge”, and putting it mildly, it was torn to shreds:

20190703_172304-M.jpg


1.) “Adding a bunch of hose length above the engine will result in heating a bunch more fuel while parked. Engine starts after a quick turnaround could be more challenging.” (Scott McDaniels)
2.) “You now have a loop at the highest point for vapor to accumulate.” (Bob Japundza)
3.) “Just wanted to pass on another concern about penetrating the baffle with a hard line at that location. Unless well braced, that spot can be the source of significant vibration, especially if an oil cooler is hanging off the baffles.” (j-red)
4.) “This is evidence enough that there is a lot of vibration induced on this area of the baffling. Putting a hard line between the solidly mounted transducer and the baffle (which has tons of in- service evidence to be always influenced by some level of vibration) is not a good idea.” (Scott McDaniels)
5.) “I'm with Scott regarding the excessive hose length and the hard line.” and “Bob's note regarding the loop is valid. Great place to store lots of vapor.” (Dan Horton)
6.) “Clamping anything much heavier than ignition wires or spider lines to the push rod tubes is generally to be avoided. I’m not predicting anything catastrophic here, but the combined mass of the red cube, the steel bracket, and the attached lines is fairly substantial, and one end of this whole assembly appears to be supported by mid-span clamps on the tubes. The tubes are thin aluminum not intended to be structural elements, and are supported at each end by nothing more than a soft plastic washer jammed into bosses on the engine case and cylinder heads.” (Otis Holt)

I was, and remain grateful for the thoughtful feedback provided by everyone above. Thank you.

It also seems that the engine as purchased through Van’s and configured by Lycoming was somewhat out of the ordinary. It’s my fault for not questioning and fixing this right off, but like I said in my previous post, the engine install skills are my biggest weakness in this build, and I didn’t know enough to question what I received:

- The fuel distributor was mounted between the #2 and #4 cylinders, when it seems that the more common location for this is between the #1 and #3 cylinders. (BTW, all the IO-320 or IO-360 engines on display at the Lycoming booth at KOSH this year had the divider between #1 and #3).
- It also seems that the “IN” port of the distributor is normally positioned perpendicular to the centerline, where mine as positioned at a 45 degree angle to the centerline toward the aft.

This was the first thing I fixed, and it was surprisingly easy to do:

20190802_200311-M.jpg


So, where to next? There were a couple of commenters that pointed out EI’s General Placement Recommendations, but it seems that they were referring to old instructions. Thanks to Ed Fleming for posting the link to the updated information, which can be found here: https://buy-ei.com/wp-content/uploads/FT-60-Info-Rev-F.pdf.

From this document I’ve clipped the following:

If the aircraft has a fuel pump(s), the flow transducer MUST be installed downstream of the last fuel pump. Installing the transducer upstream of the fuel pump(s) can cause vapor lock and jumpy/inaccurate readings.

The Red Cube FT-60 has 1/4" NPT ports. Apply thread sealant to fittings, assemble and torque fittings to 8-10 ft. Lbs., DO NOT EXCEED a torque of 12 ft. Lbs. The Red Cube FT-60 should NOT be installed with the wires pointing DOWN (the best situation is with wires pointing UP). Also, the fuel line on the outlet port should not drop down after exiting the transducer. Both of these configurations can trap bubbles in the transducer causing jumpy readings. The inlet port, outlet port and flow direction are marked on the top of the Red Cube FT-60.

In summary, it MUST be installed downstream of the last fuel pump, do not over torque the fittings, and do not install with the wires pointed down.

Also, thanks to Tom Swearengen for his persistence in seeking out the folks at EI during Oshkosh which he summarized in a previous post as, “I was able to talk to EI at Oshkosh. Actually quite pleasant, and some useful information. Idea is for the transducer to not accumulate any air that may change the flow indications. They did not have any issues with the way we have been installing them at the flow dividers.”

What Tom refers to as “the way we’ve been mounting them” is through the use of a stainless-steel elbow fitting with a male NPT on one end, and a female -4 AN fitting on the other which Tom supplies.

However, a well thought out way to secure the red cube to the engine (so it’s not just left hanging from Tom’s fitting did not exist, and that’s where Dan Horton comes in.

My first attempt at this bracket is shown in the next two pictures. Made from .063? 4130 steel, and again bent on my super cheap HF 18? sheet metal break. Please note that the ?-20 bolt shown holding the divider bracket (Lycoming P/N 75009) and my new bracket gets attached to the existing boss on the engine.

20190807_193622-M.jpg


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Upon his review, Dan had the following comments, ?The bracket is a great idea, but not really well executed.

Main issue is its asymmetry...it is one-sided. Assume a vertical load vector due to crankshaft reaction. Part of the load is reacted to the fitting and part to the bracket. Trouble is, the result is a twist, because the bracket is not symmetric to the mass. Not good for the parts, and it tries to unscrew the bolt. The cure is easy enough; a nested bracket for the opposite side (see sketch attached) or a U-shaped bracket (same as sketch, but one piece).
The sketch which Dan makes reference to above is as follows:

Tom%27s%20Nested%20Bracket-M.jpg


I asked Dan his thoughts about reducing the size of the bracket to aid in fore to aft airflow through the area and he felt this was a non-factor. I also asked about a much smaller bracket only utilizing the lower hole, and he offered the following advice and picture, ?Definitely need two bolts on the cube end of the bracket. The second bolt point effectively makes it a truss. Weak without it.?

Dan%20Horton%20Bracket%20Truss%20Photo-M.jpg


Based on this information I built upon my existing bracket and added a second piece to the aft side of the red cube and here?s where I ended up:

20190810_095738-M.jpg


20190810_095754-M.jpg


20190810_095708-M.jpg


In seeking out Dan?s final approval, he offered the following, ?The attached illustrates why I think it a reasonable plan. I believe the fitting is more than adequate to serve as a tension member.
The side-view truss existed in the prior version, but as noted, it was asymmetric, and that would have subjected both the fitting and the bracket to combined bending and torsion.
If you want to build the Mother of Brackets, simply add a flat plate, sandwiched between the divider body and its bracket. The outboard ends of the plate would be welded to the top edges of your side brackets. The plate would serve as the tension member rather than the fitting. No, I don?t think it is necessary.?

Dan also supplied the following drawing:

Bracket%20Mechanics-XL.jpg


So here?s where this ends, a mounting solution for the red cube which:

1. Does not violate any of EI?s installation recommendations
2. Secures the red cube to the engine using a mechanically sound bracket which can be easily made in any builder?s garage shop with minimal tools
3. Can be completed using parts available from Tom Swearengen / TS Flightlines

A couple of final comments:

? For the folks out there with a careful eye, you might notice things like the use of nylon lock nuts, non-spec. hardware, a loose fitting, no paint on the 4130 steel, or the absence of a propeller. Please don?t feel it necessary to point out the painfully obvious, I assure you all that these things will be remedied before my first flight.

? If you don?t like this solution, please step up and offer an alternative. I know this invitation has already been offered, and unfortunately there hasn?t been a response.

? All credit for the engineering of this goes to Dan Horton, who was incredibly generous with his time and knowledge in helping out a complete stranger.

? Tom Swearengen has been a great guy to partner with for the hardware and hoses for this solution. He?s been exceedingly patient with a total rookie, is nearly always available to answer a question, fulfills his orders in a very timely manner, and I?d bet he hasn?t charged me nearly enough for all the parts he?s sent me.
 
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Chris - wow, you are making great progress!!

You are also taking the correct approach - don't consider anything final and unchangeable. The mount you have looks great.

One thing to consider... the specs on the Red Cube say its upper temperature is 125C, which is 257F. While the cylinders can easily be in the 350F+ range at shutdown, I don't know what temperature the Cube might achieve during the cool down. Perhaps some sort of silicone rubber insulation sheet could be attached to or wrapped around some of it (McMaster aviation has it...).
 
I violated one of the install guidelines and mounted it in the cockpit, between the boost pump and the mechanical pump. But it has long straight runs of tubing on both the inlet and outlet sides, with a smooth large radius bend in the tube far upstream. No elbows. I find that fuel flow indication when the boost pump is on is erroneous. Common finding, but the lesser of evils in my mind at the time.

I like your install, except for the elbow immediately upon exit of the cube. This turn in the flow so close to the cube may cause an error in the fuel flow calibration. As long as it is consistent, you can calibrate it out by tweaking the K value. If the influence varies at different fuel flows, it is going to be an issue.

Have others installed this way with an elbow right at the outlet?
 
This is a great improvement from the last one, thanks for sticking with it, we all benefit from your efforts.

Is Tom or someone making the brackets? Or might you post some dimensions? I have the afp spider bracket which doesn?t look like yours but is likely an easy replacement. Who makes your spider bracket?
 
I like it. Very easy to get to if work is necessary.

Only suggestion is to slot the holes so there's no tension placed on the fittings when the fittings are tightened. Once the fittings are tight...the bolts can be tightened.
 
Hot, high vibration.
I prefer to hang the cube from the fuel hose in a cooler location.
 
Hot, high vibration.
I prefer to hang the cube from the fuel hose in a cooler location.

Walt, Ralph, lots of good ways to skin a cat. Care to illustrate the where and how?

My own is currently below the cylinders, hard mounted to the case. I have an AFP purge valve at the divider, so the bracket used by Chris would be inapplicable. Given the purge valve mounting, hanging the cube in the vertical hose without support would be inappropriate.

All design is compromise.
 
I violated one of the install guidelines and mounted it in the cockpit, between the boost pump and the mechanical pump. But it has long straight runs of tubing on both the inlet and outlet sides, with a smooth large radius bend in the tube far upstream. No elbows. I find that fuel flow indication when the boost pump is on is erroneous. Common finding, but the lesser of evils in my mind at the time.

I like your install, except for the elbow immediately upon exit of the cube. This turn in the flow so close to the cube may cause an error in the fuel flow calibration. As long as it is consistent, you can calibrate it out by tweaking the K value. If the influence varies at different fuel flows, it is going to be an issue.

Have others installed this way with an elbow right at the outlet?

Plus 1 for both points. I had my Red cube also in the exact same place, between the mechanical and electric pump and had very consistent and accurate fuel reading. Each tank refill was within .2-.3G
One concern I have with this setup is that elbow fitting right at the outlet of the CUBE. Heat might be another factor.

FWIW, in my 14, the CUBE is mounted in the standard VANS recommended location, before the fuel servo and I am getting a pretty accurate reading, within .5G at each fill up but it is hard to exactly know as I don't fill up the tank to the neck, I leave some room for expansion.
 
Have others installed this way with an elbow right at the outlet?

Yes it works fine with the elbow. In fact I know of two that are always a few tenths of a gallon repeatedly on fillup.

No reliability issues here. I know several that have been installed this way, none have failed that I'm aware of.

Easy peasy to inspect at this location.

No potential hidden leaks if its wrapped in firesleeve.

No exposure to radiant heat from exhaust pipes.

Fewer fittings as potential sources of leaks.

No weight of the cube in the middle of a line that acts as a pendulum.

Install yours how you want to but this one gets my vote.
 
Newbie question

OK, first I have to confess that I am a lowly FlowScan transducer owner. After reading this thread and doing some investigation, I believe the purchase of a red cube is warranted.

What is the real name of the red cube?

Who makes it and who sells it for the best price???

Perspiring minds want to know!

Charlie
 
For what its worth--

The flow divider install location of the FT60 was my idea. Several years ago, we had clients that wanted to install the transducer between the servo and the flow divider. EVERY one of them was different, 2 hoses of different lengths and configurations. Measuring the short hose was a problem---I have a BUNCH of short firesleeved hoses to prove it.
So after scrapping several hoses, I set out to come up with a generally universal location for the transducer that would work for the majority of clients. Not for everyone, but for most. During that time we tried---unsuccessfully-- to get EI to tell use their location recommendations. So we set out to test this idea. 2 airshow seasons with members of an well known show team with good results in 3 variations.
WE have a bunch of these flying around the world with no issues. The one part that did need some help was making a securing bracket that would work for that application. Dan Horton did a great job of this. Again, not for everyone, but better than it was.

To answer 1 question, Yes we are planning to make the bracket and include it in the install kit. This works IF the flow divider has the inlet port 90* to the case center line. Whether its a Bendix, Precision, Avstar,or AFP divider, it still works. If the divider has the inlet port 45* to the case, then no joy, BUT a short connecting hose can be done and utilize the same bracket. The flow divider bracket in Chris' pics is a Lycoming 75009, the most common one. In research , I found 3, all different. 2 are somewhat expensive.

Rest assured that this is NOT the only solution to the location issue of the FT60. Walt has a valid point about heat and such, but from clients flying with this, it seems this isnt a factor. (Boy I'd love to get a thermocouple in there and measure real world temps.) Texas heat anyone?

Because of the ops install, we asked Dan to come up with a bracket solution. Credit where credit is due---thats Dans bracket as fabricated by Chris. Thanks Dan for the consult and ideas!

Tom
 
If the divider has the inlet port 45* to the case, then no joy, BUT a short connecting hose can be done and utilize the same bracket.

Replacing the steel elbow and nipple? No you can't; in this example the fittings are structural. To re-route the inlet to the flow divider, you'll need the plate I mentioned, re Mother of Brackets.

Walt has a valid point about heat and such, but from clients flying with this, it seems this isnt a factor. (Boy I'd love to get a thermocouple in there and measure real world temps.)

I have a movable thermistor on a wire in the engine compartment. Right now it's up in the accessory case mag area. Next time I have the cowl off I'll move it to a spot under the purge valve, same location as this red cube.

Prediction: Near the divider will be much cooler than any lower cowl location when in flight, and not worse when parked hot.

That said, I've run mine 875 hours in the lower cowl, on the firewall, at higher air temperatures than the fleet average. Spec sheet says the limit is 125C; none will see air temps that high. The major screwup is an installation which allows radiant heating from an exhaust pipe.
 
I moved my Floscan to this location a few years ago. It was previously mounted on the fwd side of the firewall. It has always been between the servo and the flow divider. The lower hose comes from the servo, and the hose going right curves up to the flow divider. This picture was mid-install. There is an adel clamp pair holding it to the intake tube, and there is a firesleeve wrap around the whole thing. It is essentially suspended by the flex hoses. It is not as close to the motor mount as it seems.

N8mMsPFSLqu61Tikclz_oiUJU1hxDW12RqCQ2g5-HRlzVmVeCeQRyG4vU5uWRgz2qYLIHUQhniZUDTTIjLOxDQEUBlFuBZiLbcc36RrvUmHws0BoxEi2cW8KM4dviVBucDqdt7V6Az_5Aikb27ZGMhieAMectRQjYYdsmUh2lpOyltZ35fzxVzbambrPY8BGwHFC5psxFDWdAnHOWO8VjDE-I3IfHG9CPhJ4fHRradouhohMaFOc07X-sTHn6OJ0uZC4iaUw_jyIk30OnoCcZRJUrBbeFAQj1JWvlCB7vO2LNdFOBBf8I2yF7iLOB69-olb1yUu7HD-Zqig97B2sa-ZENpQQ6FLWUlMKBibfydCMyMk838Q0IsfIGmO-k9k5axlIyQGQoSoc-6kHKUyd7sPG4G9tLnXQa2O-LdlZ58UvegGB5SryK33YQ-xEUq5Ri3YNjWuhLc8KT_IgWgN2JMjj_cUOSDdm4pz8-f0WOuoHyJq7XqWb9szHJ5Gb678xkSMIbUidIqCJ6sqIzUyaeBJXoeFk02gefwt9DXItTyExTwQskQBN_K2G3PdlgzjEFfy-yqCmPDMU0dt2hDJu93Z_QRo2nP0ZKLh1NmMC7N1cPJFdVAyiGvoBp29qFYb-imb52UbjSAN8cMoBi9ci1KiPq4sVQWXQjdlAZcr107_suMcco7ut9RB1x2Nq5FqYPL-vMoEZouFFSdDl8pk8wlGn2g=w733-h977-no
 
Spec sheet says the limit is 125C; none will see air temps that high. The major screwup is an installation which allows radiant heating from an exhaust pipe.

Well if we go with a very moderate 300F CHT at shutdown the cube will see 149C. Will it be cooler in flight, certainly.
125C = 250F so I think you'd be pretty safe that temps won't get much higher than that behind the baffling. I'm sure Dan has a number for that?
 
OK, first I have to confess that I am a lowly FlowScan transducer owner. After reading this thread and doing some investigation, I believe the purchase of a red cube is warranted.

What is the real name of the red cube?

Who makes it and who sells it for the best price???

Perspiring minds want to know!

Charlie

Flowscan works fine and is slightly smaller. To replace with a red cube later shouldn't be too tough. The fitting to fitting length is the same.

Ed Holyoke
 
2h9mhF1

I've been struggling with placement on my setup. It's an IO320 B1A with an early AFP FM100 (the one with the purge valve that comes directly off the divider and orients downward between cylinders 1 and 3). I originally had a floscan on the firewall between the electric and mechanical pumps that would "react" whenever I turned on the electric pump. During last annual, I had my FM100 inspected and overhauled per manufacturer recommendations and ditched the floscan for the FT60. Everyone I spoke with suggested placement between the servo and divider. I placed it beneath the inter cylinder baffle, oriented near vertical with the wires facing forward. Tom and I have spent waaaaay too much time (thanks Tom, for not charging by the hour) discussing this. I had accuracy issues noting fuel flow would be fine at full power such as in takeoff but, once in cruise and I configure for LOP, I would notice the flow would start off accurate at 6.7gph and 147 kts 30 degrees LOP and, after a few minutes, would drift down to 4.8 gph and stay there. (No changes in any engine parameters, or speed. This was analyzed by the Savvy guys for anything I missed). I would go through the process of richening then leaning again to LOP and, in most instances, it would stay there for the remainder of the flight, reading an accurate 6.7 gph. So, I took off the cube and had EI check it....... perfect was the result. Re-installed and no change. I am open to ideas here. I thought about mounting it to the firewall but that's a long run by hose and subject to heating the fuel unnecessarily. There has to be a reason for the drift lower that I haven't thought of and I'm betting someone here can help. Thanks,
David
Tried pasting my picture but couldn't make it work. https://flic.kr/p/2h9mhF1
 
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David, have you tried some insulation?

Abnormal behavior initially after climb, vs generally normal after some time period in cruise. Kinda suggests something cooled down a bit. The photos don't show proximity to exhaust pipes.
 
David, have you tried some insulation on the metallic parts? Maybe some fiberfrax covered in aluminum foil tape?

Abnormal behavior initially after climb, vs generally normal after some time period in cruise. Kinda suggests something cooled down a bit. The photos don't show proximity to exhaust pipes.
 
Great Job Team!!

It is great to see collaboration of a common design emerging for builders to use and remove some of the experimental risk of a build while adding durability and reliability to our birds. Congrats to all who contributed!!!

Prediction: Near the divider will be much cooler than any lower cowl location when in flight, and not worse when parked hot.

Having lots of temperature data recorded, I will have to agree with Dan. Although the heads are higher it seems the case, barrels are the dominant driver of the under cowl, under plenum temperatures. I don't have the southern absolute temps but the shut downs seem to follow case and oil temps less than the heads, in my data.

.. . . So we set out to test this idea. 2 airshow seasons with members of an well known show team with good results in 3 variations.
WE have a bunch of these flying around the world with no issues. The one part that did need some help was making a securing bracket that would work for that application. Dan Horton did a great job of this. Again, not for everyone, but better than it was. . . .

Tom

Tom, we have heat/temps, internal flow and fluids, fundamental structural of the mounts, and lastly vibration of the cube. Vibration of the small displacement high kind would be the one of concern since it is rigidly attached to the case. It is a fundamental question for anything that gets bolted directly to any engine.

So - was one of the configurations you tested in the field this mount structure? If so that would eliminate that as a potential issue.

There have been many rigidly attached to the lower structure and they seem to be working quite well. The only thing we could do better is measure the vibration of the cube and it's mounts.
 
Dan,
I thought about the temperature aspect for the same reason you did while EI was doing their testing. I'll order some insulating material from ACS and report what happens. I really appreciate the brain trust!
David
 
Bill---this mounting bracket was not tested, as it wasnt even conceived then.
The fitting concept was tested, with excellent results.

Tom
 
I violated one of the install guidelines and mounted it in the cockpit, between the boost pump and the mechanical pump. But it has long straight runs of tubing on both the inlet and outlet sides, with a smooth large radius bend in the tube far upstream. No elbows. I find that fuel flow indication when the boost pump is on is erroneous. Common finding, but the lesser of evils in my mind at the time.

I like your install, except for the elbow immediately upon exit of the cube. This turn in the flow so close to the cube may cause an error in the fuel flow calibration. As long as it is consistent, you can calibrate it out by tweaking the K value. If the influence varies at different fuel flows, it is going to be an issue.

Have others installed this way with an elbow right at the outlet?
just posting as an additional data point. I also mounted my red cube on the cockpit side of the firewall. In fact, due to the ECI constant flow fuel injection I have on the IO340, I have two red cubes inside the cockpit. The outflow cube, going to the engine is mounted as Steve mentioned, after the boost pump and before the mechanical pump. The return fuel line has a second cube on the cockpit side of the firewall as the fuel returns to the fuel selector.

Steve, I do have an elbow after the cube as the line exits the cube and goes through the firewall. My fuel flow readings have been exceptionally accurate. I have 9 years and about 650 hours with dead on accurate readings that are within .01-.02 gph when calculating my fuel burn at fill up. The potential problems with heat and vibration in the engine compartment were the underlying reasons I chose this location. It has worked very well for my airplane.
 
This is a great improvement from the last one, thanks for sticking with it, we all benefit from your efforts.

Is Tom or someone making the brackets? Or might you post some dimensions? I have the afp spider bracket which doesn?t look like yours but is likely an easy replacement. Who makes your spider bracket?
I would second the request for some dimensional information on the final bracket.
 
Red Cube Install

Gotta say after reading as much as I can about the FT-60 installation, I am as conflicted as ever. There is almost as much conflicting information as what is out there with COVID-19?! To summarize:

From the instructions that came with the red cube:

MUST be installed downstream of the last fuel pump. (Their emphasis...)
Best to have Wires Pointing Up, but NOT pointing down.
Fuel line should not drop down after FT-60
Must be suspended between flexible hoses, and hoses must be supported within 6 inches.

From GRT install:
Do NOT mount on engine due to vibration.
Mount away from heat.
Should be mounted on a straight section of fuel line (6" either side), and another source says 5" before and 2" after must be straight.

...and yet, several people seem to have success ignoring these rules? In fact, mine was mounted right above the exhaust (With a heat shield), on a bracket mounted to the case, with wires sideways, and lasted 480 hours.

Thread Sealant Advice (another can of worms?!!):
Don't ever use teflon tape (seems universal!)
Use Fuel Lube....and DON'T EVER use Fuel Lube! (again, seems consistent except one source)
Use Sealube
Use Permatex 2/3 (but fuel acts as a solvent to these sealants?!)
Use Proseal
Use Loctite 567

Just thought a summary might help someone out and keeping them from having to read for two days...This is not advice, as I have no clue...just a summary as to what is out there...
 
Jeff----I'll bite (not really). To summarize---WE attempted to come up with a fairly universal location for the transducer. Some mounted low and near the servo (fuel controller) required 2 hoses, a short one to the inlet and a longer one to the flow divider. Almost always the short hose created issues in its length, and getting it EXACTLY right. In some cases, we sent the actual hose and hose ends to the client and had him to the actual mockup, including cutting the hose to fit, then we'd do the final assembly and pressure tests. Have any idea what a PITA that is? Thus---the single hose (not single bullet) theory.

We had tested a version of this in the days when we sponsored a well known RV Airshow Team. So we refined it slightly to use at the flow divider, like Chris' install now. It was going to be easier to find the different sump and servo combinations and figure a hose length for that, than doing individual length hoses for installs. This is NOT perfect, as alot of folks on here have stated. BUT, several saw some merit and offered some help. We sought ( me personally for 8 years) to get a location recommendation from EI, but in their defense, it was 'experimental' and was somewhat out of their hands, and they wouldn't or couldn't give a recommendation. I was able to get them at OSH a couple of years ago to state a positive comment about this particular type of install.

So---Steve and I have been working (slowly) on a bracket. Actually 2 different brackets. Slow, well because sometimes life and death gets in the way, and other projects seemed to take center stage. 2 brackets, 1 for the AFP flow divider and bracket, and 1 for the Lycoming 75009 bracket and Bendix/Precision/Avstar flow divider. The AFP was easier---thanks Don!--The Lycoming was much harder. It offsets the divider Aft towards the accessory case which complicates the bracket design. WE had decided early on to make this bracket from bar stock on the CNC Mill, and not angle bent sheet. That would have been easoer, but I dont know how repeatable it would have been without some sort of CNC metal brake. And, we already had the mill's.

So, Solidworks, 3D printer and a few revisions stemming from not using the mockup engine I have but a real live IO360. Little things--like clearing the cylinder flange nuts, little extra radius here and there to where we almost have it where we want it. On both versions. Each will capture the transducer, and will bolt to the case using a aft center bolt that screws into the mounting boss on the case. This will support the transducer and work with the fittings to anchor it.

This has NOT been tested, but is a working theory using Dan's original idea for Chris' bracket.

WE'll see.

Tom
 
Another example

Inspired by this thread and with great support from Tom, I moved my red cube to this position too. It has about 6 hours on it so far and is working fine. I used a different approach for the bracket that might be simpler to fabricate. It uses a longer bolt and spacer to bridge the gap between the bracket and the engine case.

yChubzIh.jpg


fwmetzNh.jpg
 
Larry---ours is a similar idea---but will actually nest against the Lycoming bracket. WE turned the transducer the opposite way-with the wires facing forward. This moves the transducer body inboard towards the case.

Tom
 
Red Cube Bracket

Getting ready to mount red cube to divider on flying RV-7A.

So is consensus when mounting to divider with steel fittings, that an additional bracket is needed ?

Ordered adapters and new shorter hose from TS Flightlines this week.
Thanks for help/guidance Tom
 
Tom and I are very excited to announce the release of our new FT-60 Fuel Flow Transducer Brackets. We have been working on this project for quite awhile and have aimed to make it simple to install as well as to provide a uniform mounting location with a minimum of hose plumbing changes required for the installation.

http://aircraftspecialty.com/rv-7.html

We also put in a very detailed measurement section in the install guide as a new hose from the servo to the transducer will be required.

http://www.aircraftspecialty.com/PDF Documents/FT-60 Transducer Mount.pdf

Happy building!!!!!

Steve
 
Ooooh! This looks interesting. Can you post some pictures zoomed out a little bit? Also, the video? on the website isn't loading, it complains about a flash plugin version.

Are the holes in the sides for bolts? They seem larger than the holes in the transducer itself and in the pics look like they don't quite line up?
 
Ooooh! This looks interesting. Can you post some pictures zoomed out a little bit? Also, the video? on the website isn't loading, it complains about a flash plugin version.

Are the holes in the sides for bolts? They seem larger than the holes in the transducer itself and in the pics look like they don't quite line up?

We don't have any pictures at the moment that show more of a distanced shot. We will see if we can get some as more of these start to get installed.

The flash error is the photo gallery of a few images. Without flash installed, those won't show. However, the install manual has quite a few pictures of the brackets and the installation. The photo gallery doesn't have anything in it noteworthy that isn't in the PDF manual.

Regarding the holes in the sides for the bolts....those are intentionally larger than the holes in the transducer. You have a lot of variables at play in this installation. One of the big ones is the exact amount that the NPT fittings are screwed in. 1/8 turn one way or another would easily yield a situation where the horizontal distance between the transducer and the mount holes would not work. So, those holes are oversized to allow for that variance.

The same thing with the alignment..what you are seeing there is before the hole from the bracket to the case is tightened. That hole is slotted slightly long and wide to allow for up/down and left/right movement of the bracket before securing. That allows you to get everything all lined up and then tighten the assemblies down to clamp the transducer in place.

Steve
 
Awesome! Thanks for working on this!

Any reports from others running AFP and this bracket? I'm hoping this red cube setup will cause the idle stumble to go away?
 
Awesome! Thanks for working on this!

Any reports from others running AFP and this bracket? I'm hoping this red cube setup will cause the idle stumble to go away?

The bracket is brand new, but we have been running this Transducer location setup for quite awhile. Some builders were fabricating their own brackets, while others were utilizing just the fittings to hang the transducer in that location.

We will get more pictures over the next few weeks as we begin to send these out.

Take care,
Steve
 
All---Last in a series of comments on this---for right now. I personally have a year in this project since we helped Chris with his install and got thinking about a bracket. Before that, MANY installs worldwide with zero issues that we know of.
Let me say that this bracket is a TIGHT FIT. Especially for the Lycoming 75009 divider mount. This may not be the perfect solution, but one that may bridge the gap. Chris' bent metal version is great for a one-off deal, but we were going to have issues making one of those repeatable for everyone. Let me say here that we might have been able to make a slightly different mounting plate to be used in conjunction with the 75009 bracket to make this easier. Hindsight is fabulous.
The Lycoming 75009, places the flow divider offset aft towards the accessory case .250 inches from center as measured from the inlet. So a slightly different mounting plate riveted to the original mount that moves the divider forward the .250 inches and aligns the inlet with the case center bolt boss between the cylinders, like the AFP version, would be great. BUT, potential disassembly, moving and possibly damaging the injector lines, and more complexity made us try and come up with a compromise solution. WE wanted a strong bracket, so 6061T6 CNC milled to fit both the transducer and the divider bracket, and bolted to the case was conceived. Looks alittle wierd, but actually pretty lightweight. Red anodised.
Yes we did make the side holes slightly oversize to allow some movement during assembly to compensate for different engine tollerances. The whole project was tough to do, especially at a long distance, and the setbacks of my personal loss moved the timeline back several months. I did the concept, Steve took those ideas and did the drawings and then 3D printed the early prototypes. 3D printers are great! Steve sent me several versions of each style to play with, cut up and modifiy until we closed in on something that resembles what you see here.
So---in working with the Lycoming mount version, we found that there was no way to access the center aft bolt to mount the bracket to the case. Well gee, that was the whole point to begin with. So after thinking about it and saying several inapropriate words, we came up with the forward facing slot, so a wrench could access the bolt. It works, is tight, but works. I've installed this on my mockup engine case a BUNCH, but it still takes a while, so TAKE YOUR TIME. Loosen things up so all the components can move around alittle.
I found that when connecting the 90* outlet fitting of the transducer to the flowdivider straight fitting, a slight amount of downward pressure seems to work well. Seems the metal Lycoming bracket will flex slightly.

The development of this isnt stopping here. I'm sure that we'll hear about it from you guys, take your input, and quite possibly comeup with something else. Such is the experimental aviation life. I'd like to make a single bracket that fits both version applications, but several other components would have to be developed to make that happen. In fact-I'm already thinking about it. But we have to start somewhere---and here we are.

Tom
 
Wow, you guys really out did yourselves and the result looks fantastic. Any new thoughts for those of us that have the AFP FM100 (the one with the purge valve)? I still struggle with my setup but haven't come up with anything that seems better. Tom, I know we've gone over this a few times.
David
 
Hi Dave--actually am thinking about it. Amongst about 200 other things!!!!
LOL----I told you I'd come up with something, and I will.
Tom
 
It is perfect Tom. Thanks for coming up with a good solution. 9 of every 10 other components all require modification. Even from big name makers of stuff that frankly we should not have to modify. Some of them should be ashamed quite honestly. I have thrown away hundreds of dollars of **** parts of other plane components. So the fact that you two thoughtfully built in flexibility is absolutely a leap ahead of 90% of everything else. To say that we have to use a bit of finesse when installing your solution should be done with pride and confidence in craftsmanship. Well done, and thanks. Just weather the critiques with a smile. You’ve done good here.
 
I'm pretty excited about this. In particular, any AFP owners that currently get the idle stumble and install the red cube in this location/bracket please report back if it solves the problem! :)
 
This works well for me on my -10. Hoses from TS.
 

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Red Cube mounting

While I can see that mounting the FT 60 to a modified fuel divider bracket in the upper spine of the engine has some merit in terms of convenience, maintainability and minimum length of hoses, I cant help but think it is really bad from heat, vibration and stress between the fuel divider and the FT 60. Two component masses connected by the bracket and the fuel elbow ( two different spring rates) in a very high vibration environment. My concerns may be overrated and it may not result in stress cracks either at the fuel divider or the red cube but if it does it will almost certainly involve a pressurized fuel leak and an almost certain engine fire. Having had an exhaust stack separate on a 180 king cub while towing a glider and a resultant engine fire I can confirm that it was no fun. Luckily the fire went out after engine shutdown and all the oil around the engine burned off. Would have been another story with a fibreglass cowling.
With that experience in mind I chose to mount the FT 60 on the firewall back to back with the brake hose bracket. Two piece angle bracket supporting the FT 60, hoses by TS Flightlines, secured to the firewall at 6 inches from the red cube. Brackets have slots in both sets of holes to make assembly easier and stress free. Out of the heat, vibration and in the correct plane for level with the fuel servo.
KT
 

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looks good

... Two piece angle bracket supporting the FT 60, hoses by TS Flightlines, secured to the firewall at 6 inches from the red cube. Brackets have slots in both sets of holes to make assembly easier and stress free. Out of the heat, vibration and in the correct plane for level with the fuel servo.
KT
Keith, sure looks like a good installation from what I see. Only tradeoff is the extra length of the hoses, but otherwise very solid.
 
Straight

I'm pretty sure you're supposed to have straight runs of tubing for a certain distance, several inches if I recall, on both sides of the cube. I could be wrong but it's pretty typical to have that requirement for flow meters.
 
Red Cube Mounting

I'm pretty sure you're supposed to have straight runs of tubing for a certain distance, several inches if I recall, on both sides of the cube. I could be wrong but it's pretty typical to have that requirement for flow meters.

I think it depends on the technology used in the flowmeter and if flow straighteners are incorporated in the design. Here is the installation instructions from Electronics International.
“Electrical Interface:
The Red Cube FT-60 interfaces with the FP-5(L) and most other fuel flow instruments. The input (red power lead) will operate from 8 to 30 Volts. Typical supply current is 14 mA over the entire operating range. Power to the FT-60 should be regulated and supplied by the instrument interfacing with the FT-60.
The FT-60 incorporates an open collector output (white lead). The output can operate from 0 to 30 Volts. Saturation voltage at a given sink current is 0.25 Volts (typical) at 4 mA and 0.7 Volts (max) at 10 mA. The output should be limited to 15 mA max. Recommended pull-up current is 1 mA. The output incorporates a two-stage comparator that keeps the output waveform square, even at low flow rates.
Mechanical Interface:
If the aircraft has a fuel pump(s), the flow transducer MUST be installed downstream of the last fuel pump.
Installing the transducer upstream of the fuel pump(s) can cause vapor lock and jumpy/inaccurate readings.
The Red Cube FT-60 has 1/4" NPT ports. Apply thread sealant to fittings, assemble and torque fittings to
8-10 ft. Lbs., DO NOT EXCEED a torque of 12 ft. Lbs. The Red Cube FT-60 should NOT be installed with the wires pointing DOWN (the best situation is with wires pointing UP). Also, the fuel line on the outlet port should not drop down after exiting the transducer. Both of these configurations can trap bubbles in the transducer causing jumpy readings. The inlet port, outlet port and flow direction are marked on the top of the Red Cube FT-60.”
There is no mention of angle fittings not being acceptable on the inlet side from the mechanical fuel pump.
The requirement for level ouflow is probably to avoid bubbles and vapor lock.
KT
 
FT 60

wires up. HUM-----UHHH what if you are flying inverted, where are the wires?
Tom

I guess it depends on how much time you spend inverted. I would guess (but it is just a guess) that the bearing for the flow rotor is designed to take the load of the sensor (hall effect?) in the vertical direction in the plane of the electrical cable. So mounting it in any other direction will reduce the bearing life or missalign the sensor if there is float in the flow rotor shaft. I am just following the instructions provided by the manufacturer. Your milage may be different if you mount it on its side or upside down.
Of course if you mount it with the cable horizontally then you should get the same result shiney side up or dirty side up.
KT
 
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Keith, I wasnt trying to be confrontational. We've plumbed the cubes in just about every orientation you could think of---and probably a few you didnt.
What started out as a plumbing exercise for a well known airshow team, has manifested into this monster of varying opinions, installations, and results.

We've seen from installations that the cube is very robust, thus can take quite a bit of punishment, versus the old FloScan unit . YES, with the FloScan, you really did need to install it with +-2 inches of straight flow, and the wires vertical for it to read correctly. Yes, those of us that tried to vary from that always seems to go back to the baseline. So when we started plumbing the cubes, we followed EI's recommendation.

Then along came some customers that wanted something different--imagine that! After looking at the cube, the ports and internal orifice have a dept of .500 inches. Combine that with your favorite AN adapter (straight, 45* or 90*) and you'll get from 1.5 to 1.75 inches from the orifice to the flare, or the centerline on a AN822 fitting. HUM---thats pretty close to what EI "recommends". (Let me say here--again---that for years we tried to get EI to give use a "recommended" install for IO360s and IO540s, with out success. We were dealing in the experimental world, and all bets were off.) So we tried 3 various types of installs on several different planes ( the airshow team) so we could test the results.

2 airshow seasons, lots of flight hours, various attitudes, and no failures, crazy readings, runs drips or errors. So it was concluded (by me) that maybe the orientation really didnt matter as much as it was thought or we just didnt give it enough time to fail. I surmised that the airshow team with all of their planes were flying a combined lifetime of usage to most normal planes.

Since then ( 8 years) we've found that there isnt really a bad install, but some seem to be better or more convienent than others. Per the recommendation of a well known fuel systems guru, we found that the best performing location was between the servo and the flow divider. NOT to say that a firewall, aft baffle, aft engine mount, or between the mechanical pump and the servo dont work because they obviously do. But in finding a universal location that works for most all the 4 cyl Lycomings, the servo/flow divider installs seemed more appealing.

As for full disclosure---I DO have a friend and client in California that moved his from the firewall to the servo/FD version and has had some strange flow readings, not all the time, that quite frankly didnt make any sense to me----and several others either. I havent heard from him in a while, so not sure of the progress.

WE are working in the experimental world, and we try things and believe the results, not the theory.

Tom
 
There is no mention of angle fittings not being acceptable on the inlet side from the mechanical fuel pump.
The requirement for level ouflow is probably to avoid bubbles and vapor lock.
KT

The instructions that came with my cube actually gave the Mil Spec part numbers for straight, 45, and 90 degree fittings.
My instructions also allowed up to a 2" drop per foot on the fuel line from the cube to the carb.
 
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