Texas Parasol

Ok Fred. I guess I may owe you an apology for being a wee but
suspicious of your motives.

The one thing a man can never defend himself from is the mongrels
snapping at his heals.

But you kinda skipped over _MY_ questions:

What are YOU building?
What have you BUILT?

I'd still like to know.


Ok,

Did you happen to notice the date on the rant you referenced up-thread?
This referenced stuff from five years ago.

Intentional or not, you are perpetuating an old and very tired vendetta.


Regardless of all the noise you have heard here, (and will continue to
hear) there really aren't any serious corrections to be made.


MISSION:

The airplane is not intended to be a high-tech, close tolerance, aero-
space machine. It is a low and slow fair weather baby buggy.
It was intended to be as inexpensive and simple to build as possible
while retaining good flying qualities.
It is not to "go places" in. It's for fun flying in the local area.

That's our Dreaded Mission Statement(tm) and I think we fulfilled those
requirements pretty darned well.


PLANS:

In the first printing...
I had left out the drawing for landing gear setup, but that was added
years ago. Check your copy and see if it's there.

There was one incorrect dimension of a vertical member back in the aft
fuselage. That was corrected years ago also. It was really obvious if
you actually laid the fuselage truss out on a table to build it.

I'm measuring to about 1/16" - not .001" ± a tenth.

I've had people write and ask if I could provide the drawings in DXF
format so they could have the CNC guys cut out all the parts for them.

That is absolutely NOT the way this thing is built.

Hacksaw and file and trim to fit are the orders for the day.
(Although a chop saw and belt sander make the job go a lot faster!)

This is not intended to be a high tech, close tolerance, aero-space
structure. It's basically South Texas farm technology.

It can be built by a single person who is handy with tools in something
like 6 to 8 weeks. First time builders usually take a LOT longer.
Chuck and I had them down to TWO weeks each for the kits. That was
complete all controls hooked up, no engine, gauges, or cover.
Two Weeks...


Lastly, on this particular subject, if you think my plans suck, take
a look at the late Graham Lee's plans for the Neiuport 11 Bebe.
I paid $145 for my copy. It was well worth the money too.
His work motic\vated me to try my project.
(Neither one of us meet Nuclear Regulatory standards though!)


FIT:

There are a few pointers I've described on the Texas Parasol group at
Yahoo Group.

For instance, some people were thinking that the verticals in the aft
fuselage were suppose to be riveted to the laterals as well as the
longerons. But he verticals are at a non-square angle that far back and
the laterals don't fit flat on the faces. If you try to rivet the
verticals to the laterals, IT WON'T FIT.

That seems to upset some people. But that's the way we build them.

I thought I had mentioned that pretty well in the manual, but it kept
coming up, so we posted some pictures to show how its supposed to go
together there. (A picture really is worth a thousand words)


BAD MODS:

One of the detail issues that self appointed experts want to change is
the cabane mounting brackets. Per plans, there are 8 little brackets
cut from 1"x1" angle and bolted to the top of the top longeron.

The cabane struts fit between each pair and are pinned with an AN-3 bolt
running longitudinally (fore/aft).

But the rule of thumb in aircraft design says thou shalt not put bolts
in tension. We violated that one intentionally because it simplifies
the construction - and puts the pin through the bottom end of the cabane
in double shear (stronger!)

One of the proposed "corrections" was to bolt a strap to the outside of
the vertical member near the mount point and bend it to meet the slope
of the cabane. The cabane tube is then bolted to the strap.

Problem with that: First and foremost, the cabane tube would be bolted
in single shear. That would create a serious moment trying to bend the
mount bolt and rip out (twist?) the end of the cabane tube (1" x .058
6061-T6).

This so-called "correction" to our original "mistake" is down right
dangerous and I resent the hell out of it being offered at all.


GOOD MODS:

Wing Strut fittings. Yes, a wrap around fitting would be technically
superior to the through bolted bracket. But if one were to go that
route, by the time he had all four brackets made, he'd understand why
we did it a simpler way. There is currently a BAD MOD sketch on the
Yahoo Group. It's a wrapper, but so poorly designed as to be of
questionable safety. I'd like to have it removed, but I don't run the
group.


WING SPARS:
Replacing the 2" spar tubes with 2-1/4" diameter tubes would be pretty
straight forward simple (if one can find 2-1/8" tube for the internal
sleeves). One clown claimed that would spoil the stall characteristics.

For two seat versions this is going to be absolutely necessary - but NO
we don't offer any help for building a Two. You want to do that, you
are designing your own project. At your own risk.


A better solution here is to simply keep the weight down and use the
wing as drawn. A Rotax 503 (NOT a VW) is the preferred power plant.


FLYING:
This is the kind of flying these very light airplanes are for:
http://www.youtube.com/watch?v=ckjqfUM5xlw
http://www.youtube.com/watch?v=vSxM-...eature=related
http://www.youtube.com/watch?v=eps0z...eature=related
http://www.youtube.com/watch?v=v-jrH...eature=related


EVIDENCE:

Excluding the Canadian two seater that crashed recently (not heard
anything more about it yet) - NO airplane built as drawn has had ANY
structural failures.



So help me out here, Fred.

What's my motivation for making a bunch of untested changes????
Or caving in to vindictive demands?

Not going to happen, folks.


FUTURE PLANS:

I'd really like to travel now. Visit some foreign countries with
interesting cultural hermitages and bitch slap a couple of the Queen's
subjects.

--

Richard

(remove the X to email)

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