S-H canopy seating

[[email protected]]

I'm not sure if my V2C canopy's final fit is correct, and whether this
can be adjusted.

The canopy frame sits very slightly higher than the neighboring fuse
when closed and locked, by 1 - 1.5 mm. I don't know whether this is
within factory tolerance, and if it's not, if there's an adjustment for
it, such as a way to lower the locking pin receivers on the fuselage.

Advance thanks

~ted/2NO

[John Galloway]

How hot/cold is it where you are?

My D2cT canopy which fitted perfectly in the summer
is currently standing a little proud at the front and
back in the Scottish winter. The canopy will contract
lengthwise in the cold proportionately more along the
midline than at the lower canopy sides thus pulling
the front and rear canopy rails more vertical (as viewed
from the side) and raising them at the top. I expect
mine to be fine when the weather warms up.

I would simply stick an overlapping piece of mylar
on the canopy frame to smooth the gap meantime.

John Galloway


At 20:48 28 January 2006, wrote:
>I'm not sure if my V2C canopy's final fit is correct,
>and whether this
>can be adjusted.
>
>The canopy frame sits very slightly higher than the
>neighboring fuse
>when closed and locked, by 1 - 1.5 mm. I don't know
>whether this is
>within factory tolerance, and if it's not, if there's
>an adjustment for
>it, such as a way to lower the locking pin receivers
>on the fuselage.
>
>Advance thanks
>
>~ted/2NO
>
>

[Andy]

Agree with John that there is a big difference in fit with temperature,
and you are seeing extremes. My 28 canopy was binding and hard to open
after baking on the ground in the Arizona sun. I relieved it just just
enough to stop binding but after cold soaking at 9k on a winter flight
there is a large gap front and rear. It also seems to fit high when
cold but flush when warm.

I'd suggest you don't change anything unless the problem is there both
hot and cold.

(temp ranges in Arizona +115 F on ground in summer to well below
freezing at altitude in winter).

Andy

[[email protected]]

Wow. This morning -- when it was nice and nippy -- I pulled the fuse
into the garage and the front and back ends of the canopy frame were
curled up a good 2mm above the fuse. Over the next six hours, when the
temp rose from 40 to 70 degrees thanks to a heater in the garage, that
space got noticably smaller.

Seems like it might be a waste of time trying to seal it, if you can
get it to shut tight at just one temperate range!

~ted/2NO

[Eric Greenwell]

wrote:
> Wow. This morning -- when it was nice and nippy -- I pulled the fuse
> into the garage and the front and back ends of the canopy frame were
> curled up a good 2mm above the fuse. Over the next six hours, when the
> temp rose from 40 to 70 degrees thanks to a heater in the garage, that
> space got noticably smaller.
>
> Seems like it might be a waste of time trying to seal it, if you can
> get it to shut tight at just one temperate range!

I don't notice this kind of variation on my ASH 26 E canopy fit. It does
have a heavy canopy frame and very rigid cockpit sill. Perhaps the frame
and sill are made from the same material so they shrink and expand at
the same rate, and the frame is strong enough to overpower the plexiglass.


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Udo Rumpf]

"Eric Greenwell" > wrote in message
...
> wrote:
>> Wow. This morning -- when it was nice and nippy -- I pulled the fuse
>> into the garage and the front and back ends of the canopy frame were
>> curled up a good 2mm above the fuse. Over the next six hours, when the
>> temp rose from 40 to 70 degrees thanks to a heater in the garage, that
>> space got noticably smaller.
>>
>> Seems like it might be a waste of time trying to seal it, if you can
>> get it to shut tight at just one temperate range!
>
> I don't notice this kind of variation on my ASH 26 E canopy fit. It does
> have a heavy canopy frame and very rigid cockpit sill. Perhaps the frame
> and sill are made from the same material so they shrink and expand at the
> same rate, and the frame is strong enough to overpower the plexiglass.
>
>
> --
> Change "netto" to "net" to email me directly
>
> Eric Greenwell
> Washington State
> USA

The last canopy frame I made was from solid Carbon fibre. The average cross
section was 1" sq.. The fit was noticeable better over a larger temperature
range as against a frame made from fibre glass . The perfect fit is only
reached at one
temperature. I made the compromise at a shop temperature
of 72 degree and allow .010" of clearance at either. It work well.
Udo

[John Galloway]

At 22:00 29 January 2006, wrote:
>Wow. This morning -- when it was nice and nippy --
>I pulled the fuse
>into the garage and the front and back ends of the
>canopy frame were
>curled up a good 2mm above the fuse. Over the next
>six hours, when the
>temp rose from 40 to 70 degrees thanks to a heater
>in the garage, that
>space got noticably smaller.
>
>Seems like it might be a waste of time trying to seal
>it, if you can
>get it to shut tight at just one temperate range!
>
>~ted/2NO


Your canopy seems to be doing the same as mine in the
cold i.e. the ends of the canopy rims rise relative
to the fuselage as the canopy perspex contracts lengthwise
and the fron and rear canopy rims become more vertical.


But two later thoughts:

What happens to SH canopies fitted with metal fence
rails - do they shrink more than perspex and make the
problem worse, or do they support the canpy frame longitudinally
and keep the fit more stable?

Also, I wonder whether circumferential contraction
of the fuselage in the cold may contribute to the poor
fit?

Anyone got a recent SH canopy with rails?

John Galloway