Just doodles...

Well, hello again.

"That which doesn't kill me - has made a huge tactical mistake".

Not up to 100%, but I'm still kicking and getting my strength back.
Can't believe how long it has taken, but...
No new tumors!

Only problem now is boredom!
A person can only watch TV for so long before his brains liquefy.

I've dusted off the sketches of the low wing design study and
worked on them up a bit. It seems to be coming along nicely.

All the fuselage bulkhead patterns are finally done.
Wraps up pretty nice.

While it could be powered with a VW (1835 or 2180), I'd love
to hang a Rotax 914 (turbo version) on it with an electric
prop and the long wing option (with 30 gallons of gas?).
And a relief tube!


http://www.home.earthlink.net/~cavelamb/l-one.htm


Richard

"cavelamb himself" wrote in message
link.net...


I've dusted off the sketches of the low wing design study and
worked on them up a bit. It seems to be coming along nicely.

All the fuselage bulkhead patterns are finally done.
Wraps up pretty nice.


http://www.home.earthlink.net/~cavelamb/l-one.htm


Why not directly connect the elevator control linkage to the bottom of the
elevator instead of using that movement reversing thingy (blue moving part)?

I hate moving parts (can you tell?)

Steve Foley wrote:
"cavelamb himself" wrote in message
link.net...



I've dusted off the sketches of the low wing design study and
worked on them up a bit. It seems to be coming along nicely.

All the fuselage bulkhead patterns are finally done.
Wraps up pretty nice.


http://www.home.earthlink.net/~cavelamb/l-one.htm



Why not directly connect the elevator control linkage to the bottom of the
elevator instead of using that movement reversing thingy (blue moving part)?

I hate moving parts (can you tell?)



Hi Steve,

See the side view x-ray sketch.

It's a pretty small ship. A bit larger than a Hummelbird, but still
smaller than a Midget Mustang.

There isn't much (any?) room under the seat!

For what it's worth...
Some people might enjoy a steel tube push rod running through their
butt, but I thought it would be more comfortable to pass it along the
side of the seat instead.

Another point is to keep the long slender pushrod in the aft fuselage
in tension (for postive G loads) rather than compression.


This morning I took out the extra break in the side longeron (frame 2).
It's now a straight shot from the firewall to frame 3.
See w12-04x6 and w12-05x9.
Should make it a little simpler to build.
Maybe?

The skins will still have to be sectioned up there because of the
shape of the bottom curves. I never was happy with a break in the
side skins right at the wing Center of Pressure point.

That change ought so smooth out the cross section plot a bit too.

It's all compromise, you know.


Richard

Some random notes about the stick mechanism from my experience building
and installing a retrofit cockpit control stich mechanism:

* The way the two aileron bellcranks are located below the axis of the
stick's pitch pivot, there will be rather a lot of unintended mixing of
pitch input into the ailerons. The usual way of avoiding that is to
place one or both ends of each transverse aileron PP tube near the
pitch pivot axis. They don't have to be right on the axis, just close.

* That other poster is right, the blue reversal bellcrank behind the
seat is probably something you can do without. Parts you leave on the
ground can't break in the air.

* If you want to see some really elegant ways of implementing control
sticks where you can't fit anything under the seat pan, have a look at
a European sailplane.

Bob K.
http://www.hpaircraft.com

Bob,

Your HP-18 side-stick to center-stick is an example of good design.
http://www.hpaircraft.com/center_sti...22_january.htm
(Complete story http://www.hpaircraft.com/center_stick/)

Other designs that may be of interest to the group are Udo Rumpf's use of a
PIK-20 sailplane stick
http://www.soaridaho.com/Schreder/Co...ter_Stick.html and
Brian Case's HP-16 modification.

Brian need to lower the seatpan in his HP16 to allow more head/canopy
clearance. So he removed the old cable system which ran under the seat and
designed the following modification:
http://www.soaridaho.com/Schreder/Co..._Stick_Mod.htm
(Brian by his HP-16T
http://www.soaridaho.com/Schreder/HP...Mackay_IDa.JPG)

Wayne
HP-14 "6F"
http://www.soaridaho.com/Schreder




"Bob Kuykendall" wrote in message
oups.com...
Some random notes about the stick mechanism from my experience building
and installing a retrofit cockpit control stich mechanism:

* The way the two aileron bellcranks are located below the axis of the
stick's pitch pivot, there will be rather a lot of unintended mixing of
pitch input into the ailerons. The usual way of avoiding that is to
place one or both ends of each transverse aileron PP tube near the
pitch pivot axis. They don't have to be right on the axis, just close.

* That other poster is right, the blue reversal bellcrank behind the
seat is probably something you can do without. Parts you leave on the
ground can't break in the air.

* If you want to see some really elegant ways of implementing control
sticks where you can't fit anything under the seat pan, have a look at
a European sailplane.

Bob K.
http://www.hpaircraft.com

Wayne Paul wrote:

Bob,

Your HP-18 side-stick to center-stick is an example of good design.
http://www.hpaircraft.com/center_sti...22_january.htm
(Complete story http://www.hpaircraft.com/center_stick/)

Other designs that may be of interest to the group are Udo Rumpf's use of a
PIK-20 sailplane stick
http://www.soaridaho.com/Schreder/Co...ter_Stick.html and
Brian Case's HP-16 modification.

Brian need to lower the seatpan in his HP16 to allow more head/canopy
clearance. So he removed the old cable system which ran under the seat and
designed the following modification:
http://www.soaridaho.com/Schreder/Co..._Stick_Mod.htm
(Brian by his HP-16T
http://www.soaridaho.com/Schreder/HP...Mackay_IDa.JPG)

Wayne
HP-14 "6F"
http://www.soaridaho.com/Schreder



The second picture from the top tells the tale.

I'd assume (?) that there is something like a U joint behind the cockpit
to let the push rod line up with the elevator horn?

I'll have to think about this some more.
You guys just could be right!

Richard

"cavelamb himself" wrote in message
hlink.net...
Wayne Paul wrote:

Bob,

Your HP-18 side-stick to center-stick is an example of good design.
http://www.hpaircraft.com/center_sti...22_january.htm
(Complete story http://www.hpaircraft.com/center_stick/)

Other designs that may be of interest to the group are Udo Rumpf's use of
a PIK-20 sailplane stick
http://www.soaridaho.com/Schreder/Co...ter_Stick.html
and Brian Case's HP-16 modification.

Brian need to lower the seatpan in his HP16 to allow more head/canopy
clearance. So he removed the old cable system which ran under the seat
and designed the following modification:
http://www.soaridaho.com/Schreder/Co..._Stick_Mod.htm
(Brian by his HP-16T
http://www.soaridaho.com/Schreder/HP...Mackay_IDa.JPG)

Wayne
HP-14 "6F"
http://www.soaridaho.com/Schreder



The second picture from the top tells the tale.

I'd assume (?) that there is something like a U joint behind the cockpit
to let the push rod line up with the elevator horn?

I'll have to think about this some more.
You guys just could be right!

Richard,

Here are some pictures from behind the cockpit that may help understanding
Brian's control system..
http://www.soaridaho.com/Schreder/Co...ick_Mod_11.jpg
The above picture was take looking forward. It shows the bulkhead aft of
the wheelwell. You can see the series of bell cranks that actuate the
ailerons and the push the stick's push rod as it is routed through the right
side of the bulkhead. The elevator push rod and direction reversal crank
can be seen on the left side of the bulkhead.

(More pictures
http://www.soaridaho.com/Schreder/Co...tick_Mod_9.jpg
http://www.soaridaho.com/Schreder/Co...ick_Mod_10.jpg)

As you can see, there are no "U-joints". The linkage has almost no "slop"
and give good control surface feed-back.

It should also be noted that the ailerons droop and reflex with the flaps
avoiding misalignment during normal cruise and thermaling flap
configurations.

Wayne
HP-14 "6F
http://www.soaridaho.com/Schreder



Richard

Wayne Paul wrote:

"cavelamb himself" wrote in message
hlink.net...

Wayne Paul wrote:


Bob,

Your HP-18 side-stick to center-stick is an example of good design.
http://www.hpaircraft.com/center_sti...22_january.htm
(Complete story http://www.hpaircraft.com/center_stick/)

Other designs that may be of interest to the group are Udo Rumpf's use of
a PIK-20 sailplane stick
http://www.soaridaho.com/Schreder/Co...ter_Stick.html
and Brian Case's HP-16 modification.

Brian need to lower the seatpan in his HP16 to allow more head/canopy
clearance. So he removed the old cable system which ran under the seat
and designed the following modification:
http://www.soaridaho.com/Schreder/Co..._Stick_Mod.htm
(Brian by his HP-16T
http://www.soaridaho.com/Schreder/HP...Mackay_IDa.JPG)

Wayne
HP-14 "6F"
http://www.soaridaho.com/Schreder



The second picture from the top tells the tale.

I'd assume (?) that there is something like a U joint behind the cockpit
to let the push rod line up with the elevator horn?

I'll have to think about this some more.
You guys just could be right!


Richard,

Here are some pictures from behind the cockpit that may help understanding
Brian's control system..
http://www.soaridaho.com/Schreder/Co...ick_Mod_11.jpg
The above picture was take looking forward. It shows the bulkhead aft of
the wheelwell. You can see the series of bell cranks that actuate the
ailerons and the push the stick's push rod as it is routed through the right
side of the bulkhead. The elevator push rod and direction reversal crank
can be seen on the left side of the bulkhead.

(More pictures
http://www.soaridaho.com/Schreder/Co...tick_Mod_9.jpg
http://www.soaridaho.com/Schreder/Co...ick_Mod_10.jpg)

As you can see, there are no "U-joints". The linkage has almost no "slop"
and give good control surface feed-back.

It should also be noted that the ailerons droop and reflex with the flaps
avoiding misalignment during normal cruise and thermaling flap
configurations.

Wayne
HP-14 "6F
http://www.soaridaho.com/Schreder



Richard



Sorry. my bad.
I was refering to the U-Joint in the Elevator pushrods.
(and a word of warning about them...)
http://www.soaridaho.com/Schreder/Co...ll.html#ujoint

That lateral torque tube (actually a walking beam) in my sketch is in
the elevator control system. It takes the pushrod from the lateral
joystick torque tube and inverts it so the long tube to the elevator
is in tension. Also centers up the aft push pull tube.

The lower arm in the center is the attach horn for a MAC servo (elevator
trim) coupled by a "U" shaped fiberglass spring. I didn't dream that
one up - saw it on the net some years back - but I wish I had.

Well, _I_ thought it was a pretty simple setup...

Richard

Bob Kuykendall wrote:

Some random notes about the stick mechanism from my experience building
and installing a retrofit cockpit control stich mechanism:

* The way the two aileron bellcranks are located below the axis of the
stick's pitch pivot, there will be rather a lot of unintended mixing of
pitch input into the ailerons. The usual way of avoiding that is to
place one or both ends of each transverse aileron PP tube near the
pitch pivot axis. They don't have to be right on the axis, just close.

* That other poster is right, the blue reversal bellcrank behind the
seat is probably something you can do without. Parts you leave on the
ground can't break in the air.

* If you want to see some really elegant ways of implementing control
sticks where you can't fit anything under the seat pan, have a look at
a European sailplane.

Bob K.
http://www.hpaircraft.com


Man, Bob, that thing is some kinda slick!
You do really nice work!

It took a while to find the details of the center stick setup.
If you don't mind, here are some links for the gang.

First pics I located.
http://www.hpaircraft.com/center_sti...te_9_april.htm

Now I see what you mean.
Small U joints in the PP tube allows for some angular offset.
You have the advantage here with a Looong tail.
Small angular offset.

Some more pics of the stick and mechanism here...
http://www.hpaircraft.com/center_sti...22_january.htm
http://www.hpaircraft.com/center_sti..._9_october.htm

Aileron (roll) bellcranks - in DOUBLE shear!
http://www.hpaircraft.com/center_sti...704,18-705.pdf

I built some kinda sorta like this once, but with joggled
arms. The spacer approach makes a lot more sense. And more
accurately reproducible too.

But then I found this one...
http://www.hpaircraft.com/hp-24/upda...ovember_05.htm
the DISadvantage of that Looong tail...

92% done - 80% to go???


Richard

Earlier, cavelamb himself wrote:

...But then I found this one...
http://www.hpaircraft.com/hp-24/upda...ovember_05.htm
the DISadvantage of that Looong tail...

92% done - 80% to go???

Yup, something like that!

Funny you should mention those pictures. This weekend I'm going up to
Seattle (Monroe, actually, out beyond Arlington) to help Brad Hill
build the equivalent tooling to locate the elevator PP tube in his
Glidair motorglider fuselage.

Here's the latest Glidair update at my Web site:

http://www.hpaircraft.com/glidair/up...january_07.htm

These pages show us making and installing the elevator PP tube guides
in the HP-24 fuselage:

http://www.hpaircraft.com/hp-24/upda...January_06.htm

http://www.hpaircraft.com/hp-24/upda...January_06.htm

The guides themselves are copies of a standard ACS part - which is a
copy of a standard Rolladen-Schneider part. They're about $10 ea from
ACS. They have an ID of 5/8", which makes for a reasonable light-duty
PP tube in .035" wall 6061-T6.

Thanks, and best regards to all!

Bob K.
http://www.hpaircraft.com