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PostPosted: Mon May 09, 2005 11:54 am
by Shannon
Actually these plates are not as "monsterous" as what was supplied in the JPX engine install wing upgrade kit (see pic). There are several ways one could do this.

PostPosted: Mon May 09, 2005 11:57 am
by Shannon
JPX engine install upgrade kit. Reinforcement plates and " Mount Pads".

PostPosted: Wed May 11, 2005 6:03 am
by lazflyn
Perfect Shannon. It is all clear now.

The final (hopefully) questions: Are the G412 and F423, 6061 T-6? What guage?



PostPosted: Wed May 11, 2005 11:23 am
by Shannon
Hi Mark,

I do not have the exact specs and diemensions for the materials that were shipped with the JPX install wing upgrade kits (motor mounts, box section, ect). I also do not have the exact thicknesses for 412's and 423 mount pads. What I'd do is get with George as he has installed a factory type set-up. My mounts (plates) however were custom fitted for a doubled D-cell skin wing so they are a little different than what you will need with standard skin.


PostPosted: Mon Jun 20, 2005 2:11 am
by JPXman
just an update: my lazair is ready for test flight finally, after almost 4 years of trial, error, rebuild, recover, podification and modification. we did a weight and balance today, a true one too.

we took a come-along and a 150lb fish scale and set out to weigh the airplane. We came up with the following numbers:

- aircraft weight with:
-no engines, EC, parachute, instrument pod, battery, gallon of gas
= 270 pounds!

- weight of one JPX assembly with nacelle, prop, exhaust
= 48 pounds! (same config yields 80 lbs static thrust on test stand)

for an empty weight of 365 pounds!

so, she's not a light bird, but she's got the elite modifications so it should be fine. Then, I climbed in with my limber weight of 270 pounds and 6'7" frame and we hung it at 15" aft of leading edge and the tail came up before the mains - good news!

then we hung it from 12" aft of the leading edge and the mains came up first - perfect.

So, the CofG with me and the plane and a gallon of gas is somewhere between 12 and 15" just like the book says it should. even though i am way over "quoted" gross weight, i take comfort knowing i'm at least balanced ;)

test flight soon when i have more days off. thanks for all the help myles!

PostPosted: Mon Jun 20, 2005 5:54 pm
by Guest
Tyler re-check the total weight figure, 365lbs empty seems a tad high ??? Shouldn't your plane weigh about 260-270 with the engines but without the full fairing ???

PostPosted: Mon Jun 20, 2005 6:34 pm
by JPXman
nope that's the right number. it makes sense when you break it all down:

- EC = 25 pounds
- instrument pod - 8 pounds
- parachute - 30 pounds
- battery and wiring - 5 pounds
- jpx assemblys weigh at least 15 pounds more than a rotax, adding 30 pounds

so right there that's over 100 pounds of extras. i have a lt of extra aluminum in my frame to to beef it up for my large girth and bigger engines too. so it all adds up. but boy does it look sweet ;) now we have to see if it flies...

PostPosted: Tue Jun 21, 2005 7:34 am
by Guest
Lazair SS EC with electric start KFM's was listed at 343lbs.

PostPosted: Tue Jun 21, 2005 4:10 pm
by JPXman
well i feel a lot better about my bird knowing that, thanks guest!

I'm only above that number by my parachute when you consider the JPX's are probably slightly lighter than the KFMs. yeehaw!


PostPosted: Fri Jul 01, 2005 11:19 pm
by Guest
KFM's were 62lbs each.