FuelSystem
Lower Tank Closeup
03/16/14 23:07 Filed in: All
I dried out the lower tanks and closed up the access hatches. Of course I discovered that there was an interference between the retention ring then the inner part of the nipple fitting inside the tank on the left side where things are pretty tight. Fishing the ring in the tank without dropping it is bad enough, but then fishing it back out is a double pain.
Once sealed, the tanks were pressurized with an extremely sophisticated, NASA inspired pneumatic pressure source. Then all the joints and interfaces were brushed with soapy water to check for bubbles. No bubbles.
With this last set of tasks on the lower tanks, they are ready to install. They can't be final installed, though, until the main transmission is installed. That is now the focus. It has already been fitted once and aligned, so all that's left is to reinstall the plumbing and some final surface prep with Evershield.
Surprisingly those balloons were pretty good. They stayed inflated for 6 days with only the slightest shrinkage. Usually party balloons self-deflate after a day or two.
Lower Tank Final Prep
03/16/14 01:10 Filed in: All
I blew all the crap out of the lower tanks and gave them a good rinse. I did not want to do the final rinse with gasoline as BJ suggests since all my work is inside my shop and it would get stunk up. That left the problem of drying them out after a rinse. Turns out that a little muffin fan blowing in the large hole and venting out through the upper hose nipple was enough airflow that after a couple of hours they were bone dry inside. Excellent. Next up a pressure test.
Top Tank Final Mount
03/15/14 00:47 Filed in: All
Mounted the top tank for the final time.
Double nuts, Loctite, and Torque Seal.
Double nuts, Loctite, and Torque Seal.
Cracked Manifold Bracket
04/30/12 14:05 Filed in: All
One flaw I noticed was that the bracket on which the fuel distribution manifold is mounted is cracked. You can just see the crack in the bent angle of the bracket. I will have to have this rewelded before the engine goes in. It really wasn’t evident until the manifold was removed, so I can’t really get down on Eagle for this. I will truck the engine over to my airplane mechanics to be repaired before starting re-assembly.
Aux Tank Mounting
12/01/11 23:32 Filed in: All
I set to work fabricating the hold-down straps for the aux tank. I didn’t like the way BJ called for the strap to be simply bent and bolted to the back of the seat. Seemed like there would be a stress point right at the bolt, so I riveted on a couple of pieces of angle to better handle the 90 degree force turn.
The curve of the seatback also caused the straps to not sit flat, so I glued on some foam strips, poured in some flox, ground and sanded them flat and perpendicular, then glassed over the foam.
The close up shows a tiny little void in the glass in the lower right, but this is non structural, so we won’t panic. I am learning fiberglass and my results are getting better, but I won’t be building a Long-EZ yet.
I whipped up these little brackets to allow for snugging down the straps and taking up any excess slack in the straps themselves. Not much weight and it should be easier to make sure we’re tight and not moving around at all.
Using BJs method would be lighter, but you’d have to have the strap length absolutely perfect to have them reach the correct tension right as they bottom out. Probably not possible with the flexing of the tank.
One down. One to go. I need more of this jumbo shrink tubing and to paint them up on completion.
12/31/11 This is the fuel pump mount pad. The welds that mount the tabs to the frame extend up a little. Instead of grinding them down (weakening the joint and breaking the powdercoat) I just made this 0.050 shim in the shape fo the fuel pump base. It’s as thick as the welds and everything sits flat now.
Done for now. The tanks have been preliminarily fit, the hoses have been cut, and everything looks good. I have a fuel flow gauge and sender on order. When they get here I will seal it all up and do a leak check and be done with fuel until final assembly.
One note: I did elect to forego the Westberg sender and gauge since it seemed like a pretty expensive way to only measure the lower tank. I saw a video on the web of one builder who ran a sight gauge in the cockpit along the back interior edge of the seat pan. Pretty primitive, but an effective way to see the real level from the top to the bottom. I am thinking this is the way I’ll go as a gauge of last resort. The fuel flow meter will be primary with the visual sight level as backup.
Detail Fuel System Work
11/20/11 23:30 Filed in: All
More fuel system detailed work. I fitted the tanks to the frame and drilled the appropriate mounting holes. This is not too demanding of a task, just a lot of little fitting and futzing. Of course the shape of the frame and the shape of the tanks is not super precise in the fashion in which they fit together, but it’s pretty close. I think the fuel system is a +/- 1/8” kind of precision as opposed to a 5mil kind of operation. EXCEPT the fittings. To be leak free these should be snug and tight fitting.
There are a lot of bits and pieces in many, many bags. I will admit that I did not inventory the fuel system when I took delivery of the kit, but everything seems to be there. So far the only thing I have been missing in the entire kit thus far has been one thin washer back in the mixer assembly.
The top tank is fitted out and drilled. I corked and checked for leaks with water. I plan on pre-assembling the entire fuel system in the ship and leak testing it in its entirety, then remove it all and then setting it aside until final assembly.
Fitting the lower tanks and drilling the spreader plates. I actually fished the little fittings through during the drilling op as they held the tanks more securely than just bolts pushed into position.
Plus, you’re doing this drilling upside down on your back, which is a little awkward.
Fittings all installed in the lower tanks and the holes enlarged. I went ahead and drilled both cover plates. I do not plan on using the Westberg gauge and sender as I plan on using a fuel totalizer. In all the planes I have flown or owned I never use the fuel gauge. Time and total fuel actually used as reported by a totalizer has been far more accurate and reliable.
My Glasair gauges are useless as there is only a small band of gauge movement where they are actually in motion somewhere in the middle of the overall capacity. The totalizer is far more accurate.
Of course the thing you lose is the remote possibility of a catastrophic leak being detected in time to set it down before all fuel has leaked out. I’m willing to accept that.
The aux tank is pretty easy. The only trick is that the upper opening (the large one) is not exactly a uniform cylinder. It took a bunch of sanding and trimming for the fitting to be persuaded in and to fit the O-ring securely.
The only issue that bothers me is that in order to screw in the brass fittings I will probably have to clamp the external threads to hold the fittings steady, which is bound to bugger the threads. That will prevent the inserts from ever being removed.
12/1/11 - I set to work fabricating the hold-down straps for the aux tank. I didn’t like the way BJ called for the strap to be simply bent and bolted to the back of the seat. Seemed like there would be a stress point right at the bolt, so I riveted on a couple of pieces of angle to better handle the 90 degree force turn.
The curve of the seatback also caused the straps to not sit flat, so I glued on some foam strips, poured in some flox, ground and sanded them flat and perpendicular, then glassed over the foam.
The close up shows a tiny little void in the glass in the lower right, but this is non structural, so we won’t panic. I am learning fiberglass and my results are getting better, but I won’t be building a Long-EZ yet.
I whipped up these little brackets to allow for snugging down the straps and taking up any excess slack in the straps themselves. Not much weight and it should be easier to make sure we’re tight and not moving around at all.
Using BJs method would be lighter, but you’d have to have the strap length absolutely perfect to have them reach the correct tension right as they bottom out. Probably not possible with the flexing of the tank.
One down. One to go. I need more of this jumbo shrink tubing and to paint them up on completion.
12/31/11 This is the fuel pump mount pad. The welds that mount the tabs to the frame extend up a little. Instead of grinding them down (weakening the joint and breaking the powdercoat) I just made this 0.050 shim in the shape fo the fuel pump base. It’s as thick as the welds and everything sits flat now.
Done for now. The tanks have been preliminarily fit, the hoses have been cut, and everything looks good. I have a fuel flow gauge and sender on order. When they get here I will seal it all up and do a leak check and be done with fuel until final assembly.
One note: I did elect to forego the Westberg sender and gauge since it seemed like a pretty expensive way to only measure the lower tank. I saw a video on the web of one builder who ran a sight gauge in the cockpit along the back interior edge of the seat pan. Pretty primitive, but an effective way to see the real level from the top to the bottom. I am thinking this is the way I’ll go as a gauge of last resort. The fuel flow meter will be primary with the visual sight level as backup.
There are a lot of bits and pieces in many, many bags. I will admit that I did not inventory the fuel system when I took delivery of the kit, but everything seems to be there. So far the only thing I have been missing in the entire kit thus far has been one thin washer back in the mixer assembly.
The top tank is fitted out and drilled. I corked and checked for leaks with water. I plan on pre-assembling the entire fuel system in the ship and leak testing it in its entirety, then remove it all and then setting it aside until final assembly.
Fitting the lower tanks and drilling the spreader plates. I actually fished the little fittings through during the drilling op as they held the tanks more securely than just bolts pushed into position.
Plus, you’re doing this drilling upside down on your back, which is a little awkward.
Fittings all installed in the lower tanks and the holes enlarged. I went ahead and drilled both cover plates. I do not plan on using the Westberg gauge and sender as I plan on using a fuel totalizer. In all the planes I have flown or owned I never use the fuel gauge. Time and total fuel actually used as reported by a totalizer has been far more accurate and reliable.
My Glasair gauges are useless as there is only a small band of gauge movement where they are actually in motion somewhere in the middle of the overall capacity. The totalizer is far more accurate.
Of course the thing you lose is the remote possibility of a catastrophic leak being detected in time to set it down before all fuel has leaked out. I’m willing to accept that.
The aux tank is pretty easy. The only trick is that the upper opening (the large one) is not exactly a uniform cylinder. It took a bunch of sanding and trimming for the fitting to be persuaded in and to fit the O-ring securely.
The only issue that bothers me is that in order to screw in the brass fittings I will probably have to clamp the external threads to hold the fittings steady, which is bound to bugger the threads. That will prevent the inserts from ever being removed.
12/1/11 - I set to work fabricating the hold-down straps for the aux tank. I didn’t like the way BJ called for the strap to be simply bent and bolted to the back of the seat. Seemed like there would be a stress point right at the bolt, so I riveted on a couple of pieces of angle to better handle the 90 degree force turn.
The curve of the seatback also caused the straps to not sit flat, so I glued on some foam strips, poured in some flox, ground and sanded them flat and perpendicular, then glassed over the foam.
The close up shows a tiny little void in the glass in the lower right, but this is non structural, so we won’t panic. I am learning fiberglass and my results are getting better, but I won’t be building a Long-EZ yet.
I whipped up these little brackets to allow for snugging down the straps and taking up any excess slack in the straps themselves. Not much weight and it should be easier to make sure we’re tight and not moving around at all.
Using BJs method would be lighter, but you’d have to have the strap length absolutely perfect to have them reach the correct tension right as they bottom out. Probably not possible with the flexing of the tank.
One down. One to go. I need more of this jumbo shrink tubing and to paint them up on completion.
12/31/11 This is the fuel pump mount pad. The welds that mount the tabs to the frame extend up a little. Instead of grinding them down (weakening the joint and breaking the powdercoat) I just made this 0.050 shim in the shape fo the fuel pump base. It’s as thick as the welds and everything sits flat now.
Done for now. The tanks have been preliminarily fit, the hoses have been cut, and everything looks good. I have a fuel flow gauge and sender on order. When they get here I will seal it all up and do a leak check and be done with fuel until final assembly.
One note: I did elect to forego the Westberg sender and gauge since it seemed like a pretty expensive way to only measure the lower tank. I saw a video on the web of one builder who ran a sight gauge in the cockpit along the back interior edge of the seat pan. Pretty primitive, but an effective way to see the real level from the top to the bottom. I am thinking this is the way I’ll go as a gauge of last resort. The fuel flow meter will be primary with the visual sight level as backup.
Initial Fuel System Work
10/10/11 23:07 Filed in: All
The fuel system on a Helicycle is relatively complex compared to “normal” aircraft. There are a couple of reasons for this. First, the turbine is very thirsty and needs large capacity. Second, the fuel must be centered on or near the CG since this is a light, single-place machine.
Consequently, there are four different tanks and the associated plumbing and interconnect. Management is easy, though. Since everything gravity feeds to the lowest point where the pickup resides, there is no switching or pilot involvement required other than making sure you don’t run out.
The first thing BJ has you do is to file a bit off the cap threads to allow it to screw in snugly, but smoothly. Easy and quick.
Next is to file the gasket area flush for a good seal. The tank is relatively thin, so don’t be ham handed with the sanding.
A lot of guys seem to modify the gas cap area to allow for better Jet-A fueling options. Maybe I will too, but not until the machine is built to the plans first. Gotta finish, then modify.
Next is fitting the air vent street elbow. There was no way mine was going to fit, so the next time I was at Harbor Freight I picked up a 1/4” NPT tap ($6 for a set of three- amazing).
Just tap enough to get it started (maybe one turn), otherwise it’ll probably be too much. The threaded area is pretty thin overall.
Quick Clamps with the jaws reversed so that they “separate” instead of “clamp” seem to work well to shove the tank back up against the frame tubes in preparation for drilling the mounting holes.
BJ has the tank base plates just tie-wrapped on. Even my dad thought that looked chinzy, so I may end up doing something beefier before final installation.
The machined tank mount bolt plugs were a little snug for the nuts. They had to be cleaned up with a 5/16-24 die, then the holes for the “fishing wire” drilled into the end portion. Another ad for the mill/drill. Quick and easy to center the holes. And of course a picture of me for the FAA.