Today's Message Index:
----------------------
1. 04:50 AM - Re: Alternative fuel tank mounting? (hagargs)
2. 08:03 AM - Mod 78 News - Good and Bad (djaflyact)
3. 09:12 AM - Re: Mod 78 News - Good and Bad (Alan Twigg)
4. 09:47 AM - Re: Mod 78 News - Good and Bad (rparigor@suffolk.lib.ny.us)
5. 11:16 AM - Re: Mod 78 News - Good and Bad (Andrew Sarangan)
6. 12:06 PM - Re: Alternative fuel tank mounting? (Andrew Sarangan)
7. 12:17 PM - Lines of text too long for monitor (jonathanmilbank)
8. 02:45 PM - Re: Alternative fuel tank mounting? (Karl Heindl)
9. 02:59 PM - Re: Alternative fuel tank mounting? (spcialeffects)
10. 03:26 PM - Re: Mod 78 News - Good and Bad (Bud Yerly)
11. 04:03 PM - Re: Alternative fuel tank mounting? (Bud Yerly)
12. 04:10 PM - Re: Mod 78 News - Good and Bad (djaflyact)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Alternative fuel tank mounting? |
Andrew;
If I were to do it over again I would form several brackets or pockets of formed
fiberglass to hold the tank in place but not be bonded to the tank. Look at
the corners of the tank by the tunnel. Brackets formed there would be very stiff
because of the 90 degree angle. Forming a contour along the module at the
radiused edge of the tank would give lateral support. I also thought that bonding
some aluminum angle to the module where the top of the tank's ledge would
rest on would be good to inhibit forward and back rocking movements. That foam
as a compliant surface is right on the mark where anything touches the tank.
All edges of any brackets should be radiused away from the tank so that the edge
is pointed away from the tank,
Steve Hagar
A143 Mesa AZ
-----Original Message-----
>From: Andrew Sarangan <asarangan@gmail.com>
>Sent: Dec 5, 2013 11:01 PM
>To: Europa List <europa-list@matronics.com>
>Subject: Europa-List: Alternative fuel tank mounting?
>
>I am hoping someone can comment on an alternative tank mounting
>strategy. A picture of what I am thinking is attached.
>
>To avoid any potential stresses developing due to tank expansion, I am
>thinking of horizontally bracing the fuel tank against the baggage
>bay wall using two fiberglass straps all the way around the tank - one
>strap below the tank ledge and the other just above the outlet bosses.
>These straps are for simply maintaining the fore/aft and lateral
>position of the tank. Vertically, the tank will simply sit on the
>fuselage floor. The tank bottom is nearly flush with the baggage bay
>floor, so it should sit nice and even on the fuselage. With this
>setup, I have satisfactory clearance between the spars, pitch tube and
>the tank outlets. I plan to add a thin neoprene pad around the tank
>bottom to make sure there are no hard points of contact between the
>tank and the fuselage. The neoprene is oil resistant, non-absorbent
>and has fire resistance.
>
>Since this is such an irreversible step, I want to make sure I am
>thinking this through correctly. Probably the larger questions are,
>will the fuselage floor be able to take the entire tank load? Is there
>any issue with letting the top portion of the tank (the ledge)
>floating with no vertical support?
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Mod 78 News - Good and Bad |
Well, I found the problem with interference with my right wing fit. I had forgotten
(until I pulled the left wing out again) that I had a swelling fuel tank
problem early on in the flying of the airplane. The brackets that hold the tank
back worked great - in the area of the bracket, but in between the tank swelled
until it rubbed on the aileron cross link between the CS08 arms. My solution
at the time was to move one end of the cross link forward of the CS08. That
allowed it to clear the tank, but that is now the reason I cannot get the right
wing to fit. It has to go back to the original position.
I've got two choices: The cross link rubs the fuel tank or the I fly with only
one wing.
Since there is no reasonable choice there, I think there are also now 2 possibilities:
I move the fuel tank wall back or I bend the cross link bar to clear the
swollen tank.
Right now, I only see the arcing of the cross link as the answer. If it is not
straight, it will not be as strong in compression. I doubt the loads are very
high, but there is the issue of jammed controls and the ability to provide force
in a situation like that.
Would I make a contestant arc in the tube?
Would I make a joggle in each end so that most of the rod is straight?
Would I replace it with steel?
Would I fill it with something like epoxy to make it stronger?
Can the tank wall be pushed back? I can only imagine coating it with fiberglass
or carbon cloth and some sort of hydraulic press holding it while it cures (I
doubt this is possible).
Has anyone experienced this issue with the fuel tank?
Of course, the temperatures here have dropped to 0F at night, which is making progress
more difficult. I am getting close, however.
Thanks,
Dave
A227
Mini U2
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=414977#414977
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Mod 78 News - Good and Bad |
Dave, mine is a new build and all is very tight back there with the
modified Spar. I am fettling the right wing top surface at the moment but
can see I will need to shave some material off the Aileron self connect, I
believe I need to anyway to facilitate the main pin.
I have a borescope kit and will try to get pictures.
regards
Alan Twigg
Motorglider Mono
Kit 463 and getting closer.
On Fri, Dec 6, 2013 at 4:03 PM, djaflyact <djaflyact@gmail.com> wrote:
>
> Well, I found the problem with interference with my right wing fit. I had
> forgotten (until I pulled the left wing out again) that I had a swelling
> fuel tank problem early on in the flying of the airplane. The brackets that
> hold the tank back worked great - in the area of the bracket, but in
> between the tank swelled until it rubbed on the aileron cross link between
> the CS08 arms. My solution at the time was to move one end of the cross
> link forward of the CS08. That allowed it to clear the tank, but that is
> now the reason I cannot get the right wing to fit. It has to go back to the
> original position.
>
> I've got two choices: The cross link rubs the fuel tank or the I fly with
> only one wing.
>
> Since there is no reasonable choice there, I think there are also now 2
> possibilities: I move the fuel tank wall back or I bend the cross link bar
> to clear the swollen tank.
>
> Right now, I only see the arcing of the cross link as the answer. If it is
> not straight, it will not be as strong in compression. I doubt the loads
> are very high, but there is the issue of jammed controls and the ability to
> provide force in a situation like that.
>
> Would I make a contestant arc in the tube?
> Would I make a joggle in each end so that most of the rod is straight?
> Would I replace it with steel?
> Would I fill it with something like epoxy to make it stronger?
> Can the tank wall be pushed back? I can only imagine coating it with
> fiberglass or carbon cloth and some sort of hydraulic press holding it
> while it cures (I doubt this is possible).
>
> Has anyone experienced this issue with the fuel tank?
>
> Of course, the temperatures here have dropped to 0F at night, which is
> making progress more difficult. I am getting close, however.
>
>
> Thanks,
>
> Dave
> A227
> Mini U2
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=414977#414977
>
>
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Mod 78 News - Good and Bad |
Hi Dave
Can you just fly with one aileron? I saw a drunk farmers fly like that in
both a Piper and Aeronca!
Bending aluminium is EZ, but since you have the ball end it will allow
your kink to rock up and down. You may get away with it? Don't try
bending in a vise, chance of kinking is far greater than if you drill a
hole in a thick piece of wood, like work table or your basement stairs,
of course a proper bender is best. Filling with sand can also help
prevent kinking.
As far as rigidity and keeping things light, thin wall and large OD for a
given weight gives you the most bang for your buck. In your case a
smaller OD and thicker wall will give you a little more clearance with a
slight weight penalty. 4130 is stronger than aluminium, you should even
be able to go smaller in OD and if you weld it it can get away without
heat treating, again with a slight weight penalty.
If your bow idea is not going to work, you could offset your mounting
stud on the end of your tube to move forward the front edge of the
smaller ID tube as far as you can, this would keep your tube
straight.
I'm not at my aeroplane, but off the cuff a small OD very thick wall,
perhaps even a solid piece of 4130 (see McMaster Carr too for 4130 in
addition to ACS and Wicks) and a welded on piece of 4130 that is tapped
to give you needed offset, then install in it a threaded stud (tack the
far end to keep it from rotating) if you are close you could weld the
stud directly to the 4130 and space the ball end slightly aft.
I would first rig wings without the pushrod to make sure you can rig.
Then screw a piece of metal in place of the pushrod and determine what
clearance you have to your spars. Soft aluminium rectangular bar from the
hardware store comes to mind.
I am doing battle with making sure I can get my flaps to work post 78. I
had my son (going to CMU for mechanical engineering) grind some numbers
for me as far as the side force exerted when you put a bend in a tube. I
used a 4 foot example with the bend occurring at the middle 2 foot point
with a 100lb parallel force exerted on the two ends. May give you an
idea:
http://www.europaowners.org/main.php?g2_itemId=394508
Ron Parigoris
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Mod 78 News - Good and Bad |
I am not building mod78, but it sounds to me like a joggle may be
better than an arc. Instead of bending, you could weld the joints or
use elbow fittings. In any case, I would go with a thick wall tube. I
got some of these for linking my autopilot servos.
http://www.aircraftspruce.com/catalog/mepages/alumtube_6061t6.php
In any case, I can't envision any scenario where the aileron forces
are so strong as to bend a metal tube, unless your passenger is
fighting you at the controls :-)
Speaking of tank swelling, if your tank is currently dry, you may want
to take extra precautions when filling. Most tank failures have
occurred exactly in these instances. One option might be to fill it
slowly, over several days to allow the tank to slowly expand, before
putting much weight on its supports.
On Fri, Dec 6, 2013 at 11:03 AM, djaflyact <djaflyact@gmail.com> wrote:
>
> Well, I found the problem with interference with my right wing fit. I had forgotten
(until I pulled the left wing out again) that I had a swelling fuel tank
problem early on in the flying of the airplane. The brackets that hold the tank
back worked great - in the area of the bracket, but in between the tank swelled
until it rubbed on the aileron cross link between the CS08 arms. My solution
at the time was to move one end of the cross link forward of the CS08. That
allowed it to clear the tank, but that is now the reason I cannot get the right
wing to fit. It has to go back to the original position.
>
> I've got two choices: The cross link rubs the fuel tank or the I fly with only
one wing.
>
> Since there is no reasonable choice there, I think there are also now 2 possibilities:
I move the fuel tank wall back or I bend the cross link bar to clear
the swollen tank.
>
> Right now, I only see the arcing of the cross link as the answer. If it is not
straight, it will not be as strong in compression. I doubt the loads are very
high, but there is the issue of jammed controls and the ability to provide force
in a situation like that.
>
> Would I make a contestant arc in the tube?
> Would I make a joggle in each end so that most of the rod is straight?
> Would I replace it with steel?
> Would I fill it with something like epoxy to make it stronger?
> Can the tank wall be pushed back? I can only imagine coating it with fiberglass
or carbon cloth and some sort of hydraulic press holding it while it cures
(I doubt this is possible).
>
> Has anyone experienced this issue with the fuel tank?
>
> Of course, the temperatures here have dropped to 0F at night, which is making
progress more difficult. I am getting close, however.
>
>
> Thanks,
>
> Dave
> A227
> Mini U2
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=414977#414977
>
>
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Alternative fuel tank mounting? |
Karl
Thank you for the comment. This was my concern too. However, after
staring at the canoe floor, I am not so sure if there is really any
difference. Even with the standard installation, the majority of the
load is borne by on the baggage bay wall, which is eventually bonded
to the fuselage floor anyway. The floor where the baggage bay bonds
and the floor directly beneath the tank are on the same piece of
reinforced foam. So in terms of load, I can't see any difference
whether the tank is directly sitting on the canoe floor or if it is
supported by the baggage bay which is subsequently supported by the
canoe floor.
Also, I am also having a hard time understanding why the top ledge of
the tank requires a separate support. My measurement says there is
only about 2 gallons of fuel here, so 12 lbs is hardly worth bonding
with 6 plies of glass for its entire length.
If anyone has any insights into this, I'd love to hear.
Thank you!
On Fri, Dec 6, 2013 at 1:42 AM, Karl Heindl <kheindl@msn.com> wrote:
> Hi Andrew,
>
> I think you are going out on a limb with this idea. A full tank is a very
> heavy load and the fuselage floor is not designed to take this, or the
> designers would have placed it on the floor.
> The load should be taken up entirely by the cockpit module.
>
> Karl
>
>
>> From: asarangan@gmail.com
>> Date: Fri, 6 Dec 2013 01:01:29 -0500
>> Subject: Europa-List: Alternative fuel tank mounting?
>> To: europa-list@matronics.com
>
>>
>> I am hoping someone can comment on an alternative tank mounting
>> strategy. A picture of what I am thinking is attached.
>>
>> To avoid any potential stresses developing due to tank expansion, I am
>
>> thinking of horizontally bracing the fuel tank against the baggage
>> bay wall using two fiberglass straps all the way around the tank - one
>> strap below the tank ledge and the other just above the outlet bosses.
>> These straps are for simply maintaining the fore/aft and lateral
>> position of the tank. Vertically, the tank will simply sit on the
>> fuselage floor. The tank bottom is nearly flush with the baggage bay
>> floor, so it should sit nice and even on the fuselage. With this
>> setup, I have satisfactory clearance between the spars, pitch tube and
>> the tank outlets. I plan to add a thin neoprene pad around the tank
>> bottom to make sure there are no hard points of contact between the
>> tank and the fuselage. The neoprene is oil resistant, non-absorbent
>> and has fire resistance.
>>
>> Since this is such an irreversible step, I want to make sure I am
>> thinking this through correctly. Probably the larger questions are,
>> will the fuselage floor be able to take the entire tank load? Is there
>> any issue with letting the top portion of the tank (the ledge)
>> floating with no vertical support?
>
>
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Lines of text too long for monitor |
It happens mostly on this website for me, but occasionally on others, that I need
to use the slider at the screen bottom to read each line from one end to the
other.
I'm a computer "numpty/numbskull/dimwit" and don't understand much, but I'm able
to use Control + or Control - or the screen zoom as competently as the next
man. Obviously when I "shrinkerize" the text sufficiently to make each line fit,
then the text is too minute to read.
So what's the story? Is there an incompatibility between the format used by the
website and/or contributors to each thread, versus whatever system is employed
at my end to read the stuff?
Is there a quick and easy and cheap fix?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=415003#415003
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Alternative fuel tank mounting? |
You are right=2C but with the cockpit module and baggage bay assembly the l
oad is spread out over a much greater area. If the tank sits on the floor t
he actual contact area is probably quite small. Just think of the weight=2C
and if you make a hard landing=2Cthe weight is double. Maybe there is a wa
y to re-enforce the floor=2C but I would find a qualified engineer to do so
me calculations=2C preferably someone from Europa/Swift.
karl
> From: asarangan@gmail.com
> Date: Fri=2C 6 Dec 2013 15:05:23 -0500
> Subject: Re: Europa-List: Alternative fuel tank mounting?
> To: europa-list@matronics.com
>
>
> Karl
>
> Thank you for the comment. This was my concern too. However=2C after
> staring at the canoe floor=2C I am not so sure if there is really any
> difference. Even with the standard installation=2C the majority of the
> load is borne by on the baggage bay wall=2C which is eventually bonded
> to the fuselage floor anyway. The floor where the baggage bay bonds
> and the floor directly beneath the tank are on the same piece of
> reinforced foam. So in terms of load=2C I can't see any difference
> whether the tank is directly sitting on the canoe floor or if it is
> supported by the baggage bay which is subsequently supported by the
> canoe floor.
>
> Also=2C I am also having a hard time understanding why the top ledge of
> the tank requires a separate support. My measurement says there is
> only about 2 gallons of fuel here=2C so 12 lbs is hardly worth bonding
> with 6 plies of glass for its entire length.
>
> If anyone has any insights into this=2C I'd love to hear.
>
> Thank you!
>
>
>
>
>
> On Fri=2C Dec 6=2C 2013 at 1:42 AM=2C Karl Heindl <kheindl@msn.com> wrote
:
> > Hi Andrew=2C
> >
> > I think you are going out on a limb with this idea. A full tank is a ve
ry
> > heavy load and the fuselage floor is not designed to take this=2C or th
e
> > designers would have placed it on the floor.
> > The load should be taken up entirely by the cockpit module.
> >
> > Karl
> >
> >
> >
> >> From: asarangan@gmail.com
> >> Date: Fri=2C 6 Dec 2013 01:01:29 -0500
> >> Subject: Europa-List: Alternative fuel tank mounting?
> >> To: europa-list@matronics.com
> >
> >>
> >> I am hoping someone can comment on an alternative tank mounting
> >> strategy. A picture of what I am thinking is attached.
> >>
> >> To avoid any potential stresses developing due to tank expansion=2C I
am
> >
> >> thinking of horizontally bracing the fuel tank against the baggage
> >> bay wall using two fiberglass straps all the way around the tank - one
> >> strap below the tank ledge and the other just above the outlet bosses.
> >> These straps are for simply maintaining the fore/aft and lateral
> >> position of the tank. Vertically=2C the tank will simply sit on the
> >> fuselage floor. The tank bottom is nearly flush with the baggage bay
> >> floor=2C so it should sit nice and even on the fuselage. With this
> >> setup=2C I have satisfactory clearance between the spars=2C pitch tube
and
> >> the tank outlets. I plan to add a thin neoprene pad around the tank
> >> bottom to make sure there are no hard points of contact between the
> >> tank and the fuselage. The neoprene is oil resistant=2C non-absorbent
> >> and has fire resistance.
> >>
> >> Since this is such an irreversible step=2C I want to make sure I am
> >> thinking this through correctly. Probably the larger questions are=2C
> >> will the fuselage floor be able to take the entire tank load? Is there
> >> any issue with letting the top portion of the tank (the ledge)
> >> floating with no vertical support?
> >
> >
>
===========
===========
===========
===========
>
>
>
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Alternative fuel tank mounting? |
So this is the stage that im at in my build and have been putting off bonding in
the tank as so many have been reported to have split recently. Bud yearly has
produced a solution fix using 1/8' cork but the three main things i have put
to the top of my list to stop my tank from having problems later on are.. firstly
before bonding in the tank fill with fuel and leave in for as long as possible
so that the tank expands and trust me mine grew on the back wall were the
fuel comes in from the cobra by about 1/2'. Secondly bond the tank into the
module when it is in this expanded state but dont bond the glass to the tank.
Put some sort of release agent on the tank so that when the tank shrinks back
to its original size the glass would have already set at the tanks maximum size
and this then leaves the "room" for the expansion and contraction of the tank
later on, and finally once the plane is up and flying dont leave the tank dry
keep it at least half full. When i bond in my tank which im hoping to do next
week i also want to make a cradle of it to sit in like another builder has done
on the europa owners site. his photo is attached. Just my two pence worth
but may be some use. Regards Frank
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=415015#415015
Attachments:
http://forums.matronics.com//files/311131313_189.jpg
http://forums.matronics.com//files/3113_126.jpg
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Mod 78 News - Good and Bad |
Dave,
I have not experienced your problem with the cross link rod rubbing the
tank. Most probably your tank was installed a bit forward but it
probably did swell as you indicate.
In 13 cockpit module builds I have always had 1/2 inch clearance and
never had a tank rub even after 5 years of flying. Years ago I noticed
a plane that came in with a rubbing rod but the tank was put in a bit
askew and the aft bulkhead was pulled in 1/2 inch.
If the tank did not break its bond with the back wall or saddle then it
is really bowing quite a bit. Armed with that bit of information and
not wanting to replace the tank, can you build another tank bracket to
ease the bulge back in the saddle area?
It is a nasty hole to work in for sure, and the modded spars really hog
the room.
What I am thinking is a flat aluminum plate of stiff 6061T6 aluminimum
1/8 by say 3 inches and make a U shape around the spars and pushing up
against the tank bulge.
Not being able to see your aircraft, this is a wild assed guess.
I had no problem clearing the bolt heads by countersinking and using AN
509 416R20 screws to replace the AN 4 bolts. Countersinking was done
with a speacial tool we made. 30 minute job.
That said, it will be a game of inches for you for sure.
Borescope and time will tell what's happening I'm afraid.
Regards,
Bud Yerly
----- Original Message -----
From: djaflyact<mailto:djaflyact@gmail.com>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Friday, December 06, 2013 11:03 AM
Subject: Europa-List: Mod 78 News - Good and Bad
<djaflyact@gmail.com<mailto:djaflyact@gmail.com>>
Well, I found the problem with interference with my right wing fit. I
had forgotten (until I pulled the left wing out again) that I had a
swelling fuel tank problem early on in the flying of the airplane. The
brackets that hold the tank back worked great - in the area of the
bracket, but in between the tank swelled until it rubbed on the aileron
cross link between the CS08 arms. My solution at the time was to move
one end of the cross link forward of the CS08. That allowed it to clear
the tank, but that is now the reason I cannot get the right wing to fit.
It has to go back to the original position.
I've got two choices: The cross link rubs the fuel tank or the I fly
with only one wing.
Since there is no reasonable choice there, I think there are also now
2 possibilities: I move the fuel tank wall back or I bend the cross link
bar to clear the swollen tank.
Right now, I only see the arcing of the cross link as the answer. If
it is not straight, it will not be as strong in compression. I doubt the
loads are very high, but there is the issue of jammed controls and the
ability to provide force in a situation like that.
Would I make a contestant arc in the tube?
Would I make a joggle in each end so that most of the rod is straight?
Would I replace it with steel?
Would I fill it with something like epoxy to make it stronger?
Can the tank wall be pushed back? I can only imagine coating it with
fiberglass or carbon cloth and some sort of hydraulic press holding it
while it cures (I doubt this is possible).
Has anyone experienced this issue with the fuel tank?
Of course, the temperatures here have dropped to 0F at night, which is
making progress more difficult. I am getting close, however.
Thanks,
Dave
A227
Mini U2
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=414977#414977<http://forums
.matronics.com/viewtopic.php?p=414977#414977>
www.aeroelectric.com<http://www.aeroelectric.com/>
www.buildersbooks.com<http://www.buildersbooks.com/>
www.homebuilthelp.com<http://www.homebuilthelp.com/>
www.mypilotstore.com<http://www.mypilotstore.com/>
http://www.matronics.com/contribution<http://www.matronics.com/contributi
on>
http://www.matronics.com/Navigator?Europa-List<http://www.matronics.com/N
avigator?Europa-List>
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Alternative fuel tank mounting? |
Fred,
We all learned the hard way that the tank really bonds well to the
glass. Your advise is sound.
The point that the floor is not strong enough to hold the whole tank is
important!
The method I use has a shelf that glasses the tank aft support to the
floor and the back wall.
I do not glass the saddle but only up the sides a bit to assist in side
to side motion.
The front of the tank must be supported also, but not solely by a wedge
of foam or filler, it must be a glass beam.
Typically the tank will set 1/2 to 3/4 inch off the floor. That area is
filled in most cases with expand cell, smoothed and then glassed over to
provide a beam support.
Of course the forward ledge is a good support for the top of the tank as
is.
As you all know I use a thin cork or similar (one of my clients used
felt) to allow the tank to move as it expands and contracts with fuel to
try to prevent stress risers.
Also it is imperative that the tank be wedged in with the forward tank
supports, as well as foam on the sides, front and top to keep it firmly
in place.
Should one have followed the assembly manual (as one would think we
should) and the tank sag becomes apparent, I have filled the area
between the tank and the floor with foam to spread the load out a bit.
It is only a band-aide and not a cure. Someone asked if the forward
wedge could be glassed to the tank, and I don't believe that is sound as
it would become another stress riser now on the forward side.
Bottom line, Do not just let the tank rest on the floor.
Andrew,
The wrap around the tank only holds it from fore and aft movement as you
said but foam will do that also. Something has to hold that 120 lbs of
fuel and tank at 6+ gs. The glass aft bulkhead and T in the front will
do it, but not without a sag on that front edge. I thought about a
floor pan under the tank and a uni strap diagonally from the top rear
bulkhead to the pan to hold the front of the tank early on, but a simple
glassed beam on the floor is all that should be necessary. Make your
forward T on the bench and let it cure (make a mold) then Redux to the
front. On the aft saddle and bulkhead, put a layer of thin release
plastic on the tank ( I put cork on the tank also) and make your bracket
tapes per the book. Put the cockpit module in (I have the advantage of
a ceiling hoist so it is easy for me to say) and check the position and
mark the tank outline. Remove the tank and make a aft bulkhead to belly
support as well as a line under the front of the tank about 2 inches
wide of expand cell or similar and cover with release plastic. (You
noticed the flexibility of the module, so a strap of glass to hold the
bulkheads vertical is fairly smart.) Set the module in place and allow
the expand cell to cure. Pull the module again (repetitive isn't it)
and check, fill voids and smooth in preparation for 2 layers of glass
over the expand cell or filler. Set the module in again and once
assured it is all comfy, you are ready for bonding. In the 5 years 12AY
has had its tank, it has been left full of fuel, empty, and every sort
of load between and the support I have has left the tank still looking
like new, no sags in the floor or belly and has served me well. My tank
is the new style tank which is a bit thicker, reinforced and holds just
a bit more fuel somehow. The top is nice and flat for a change. Older
tanks are thinner and do bulge as many have commented on.
Just my two cents.
Regards,
Bud Yerly
----- Original Message -----
From: Fred Klein<mailto:fklein@orcasonline.com>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Friday, December 06, 2013 2:02 AM
Subject: Re: Europa-List: Alternative fuel tank mounting?
On Dec 5, 2013, at 10:36 PM, Andrew Sarangan wrote:
No, the straps will not be bonded to the tank, just to the baggage
bay
wall. The side of the strap facing the tank will have a neoprene
pad,
so there will be some 'give' to accommodate small expansions.
Andrew...if I had it to do over again, I would attempt to ensure that
the underside (including the "ledge") is fully supported yet free to
expand and contract...I would install all the tapes to the CM which are
called for, but I would provide a cushioned bond-break between the tape
and the tank. In my attached build-photo, the FG tape was regrettably
bonded to the tank.
Fred
www.aeroelectric.com<http://www.aeroelectric.com/>
www.buildersbooks.com<http://www.buildersbooks.com/>
www.homebuilthelp.com<http://www.homebuilthelp.com/>
www.mypilotstore.com<http://www.mypilotstore.com/>
http://www.matronics.com/contribution<http://www.matronics.com/contributi
on>
http://www.matronics.com/Navigator?Europa-List<http://www.matronics.com/N
avigator?Europa-List>
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Mod 78 News - Good and Bad |
Looking at it closer today, I discovered I had the offset brackets installed upside
down. The support for the tank wall was not high enough. In addition, the
CS08 brackets were farther than 3 inches from the seat back. I swear they were
correct when I built it.
I was able to slightly modify the shape if CS08 (bend!) and now have the correct
3 inches. The rod can be straight and the only difficulty is now the swollen
tank on one side preventing the offset bracket from fitting.
I'm planning to encourage the tank face to back up a bit while I slip the standoff
bracket in place. I will warm it slightly as it is freezing right now. Maybe
apply pressure over a period of time.
As insurance, I'll also replace the bolts that hold the rod ends at the top of
CS08 with flush structural screws. I'm thinking that if the CS08 arm ever hits
the spar, it would be better to hit a smooth surface , rather than bolt heads.
Thanks everyone for the input. This story keeps developing.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=415022#415022
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|