[NSRCA-discussion] Hatch Latch

[Verne Koester]

Jim,

As I said, I used the Graupner 8066 on quite a few planes without a problem.
Not that it matters, but about 4 years ago, I put one in a Genesis
(electric) and the canopy blew off on the first flight. Fortunately, I was
able to find it and it wasn't damaged. I double checked everything and saw
that the latch was fully engaging into the bulkhead so I flew again. The
canopy blew off again, this time with pretty heavy damage to the canopy and
the LE of the stab it hit on the way down. I used tape for awhile and
finally removed the hatch latch and replaced it with a 4-40 screw. Starting
with my next plane, I've been using the red hatch latch because of the extra
spring stiffness and didn't change anything else about my canopy mounting
method and I haven't had any problems. My personal opinion is that the weak
spring tension on the 8066 will allow it to get pushed into the retracted
under just the right vibration and/or airframe torque conditions.

 

I had the 8066 in an electric Partner that I flew all season the year before
the Genesis and the rest of the canopy mounting method was identical. In
fact, the previous 5 or 6 planes prior to that had no problems with the 8066
latch. My guess is that if you've flown your plane with that latch and had
no problems, you probably won't. I just wouldn't pick that latch for
anything I build in the future now that I know. If my comments have you
nervous, you can just put a piece of tape over the slot so the pin can't
move and then remove the tape after your flight. I did that for awhile with
the Genesis and then replaced the latch with the 4-40 screw after I got
tired of doing the tape thing. With a little care and time, you could
probably remove the Graupner latch and replace it with the red one. Winter's
a lot better time than at the start of the competition season.

 

Verne

 

From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of J N Hiller
Sent: Sunday, January 10, 2010 3:10 PM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] Hatch Latch

 

Right the spring seams weaker that it should be. I like it because I install
it through a bulkhead. Now you have me worried. Maybe I should just go back
to making my own.

Jim

 

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Verne Koester
Sent: Sunday, January 10, 2010 12:00 PM
To: 'General pattern discussion'
Subject: Re: [NSRCA-discussion] Hatch Latch

 

I used to use the 8066 until I had a canopy that kept coming off in flight.
The spring tension is too low and under the right vibration, airframe
torque, or whatever, the latch will disengage because of the low spring
tension. I replaced the 8066 with the red one and have been using them ever
since. I used the 8066 on a number of planes before that happened without a
problem. I prefer not to chance it now that I know.

 

Verne

 

From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of J N Hiller
Sent: Saturday, January 09, 2010 8:05 PM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] Hatch Latch

 

I've like the Graupner # GR8066. I get mine from the local hobby shop but
Hobby Lobby has them. 

http://search.hobby-lobby.com/psearch/svc/search.php?uid=1
<http://search.hobby-lobby.com/psearch/svc/search.php?uid=1&q=latch>
&q=latch

Attached is a drawing I made.

Jim Hiller

 

 

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Ron Hansen
Sent: Saturday, January 09, 2010 12:08 PM
To: nsrca-discussion at lists.nsrca.org
Subject: [NSRCA-discussion] Hatch Latch

 

Can anyone recommend a spring loaded hatch latch that will work on a 1/8"
thich fuse side to hold on my canopy?

 

Thanks

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