Thorp T18 Plans question

[Stealth Pilot]

I'm helping an aero engineer friend research details of successful
homebuilt aircraft undercarriages. (for some calcs for a book)

I borrowed my mate's T18 Plans, from which he built a honey of a T18.
my mate used a prebuilt and tempered Brock undercarriage so didnt need
or buy the undercarriage drawings. the very drawing I need is missing
and since he bought a fully assembled component he has no real idea
what the materials were that were used in the gear. btw the Brock gear
has done over a thousand hours so far without a single problem so
Ken's work endures as a memorial to his talent.

I have a partial copy of drawing 516 which gave the bolt sizes used to
attach the gear.

Drawing 515 has the details I need.
if you look at the gear leg it starts at the top attach point, runs
down through a sleeve for about the centre 3/5th of the leg, to which
the centre attach point is welded, then down beyond the sleeve it
terminates in a plate to which a cessna style bolt on axle gets
fitted. (the axle and brakes are actually a cleveland set)

is the centre component of the gear leg a tube or a rod? my builder
friend couldnt say. what are it's dimensions, wall thickness etc.
what are the dimensions of the sleeve, wall thickness etc?
what are the dimensions of the crosstube tube?
what is the thickness of the wraparound plate that the neoprene
components and washers are bolted through?
I'm assuming it was all made from 4130, is that correct?

I know it was heat treated to 180,000 psi ultimate.

appreciate a help from anyone with a full plans set.
Stealth Pilot
Australia.

[flybynightkarmarepair]

Pazmany's book on Landing Gear has a detailed sketch of the T-18
landing gear, as well as an in-depth discussion of landing gear
analysis.

http://www.pazmany.com/books/books.html

It's the best book on the subject.

Stealth Pilot wrote:
> I'm helping an aero engineer friend research details of successful
> homebuilt aircraft undercarriages. (for some calcs for a book)
>
> I borrowed my mate's T18 Plans, from which he built a honey of a T18.
> my mate used a prebuilt and tempered Brock undercarriage so didnt
need
> or buy the undercarriage drawings. the very drawing I need is missing
> and since he bought a fully assembled component he has no real idea
> what the materials were that were used in the gear. btw the Brock
gear
> has done over a thousand hours so far without a single problem so
> Ken's work endures as a memorial to his talent.
>
> I have a partial copy of drawing 516 which gave the bolt sizes used
to
> attach the gear.
>
> Drawing 515 has the details I need.
> if you look at the gear leg it starts at the top attach point, runs
> down through a sleeve for about the centre 3/5th of the leg, to which
> the centre attach point is welded, then down beyond the sleeve it
> terminates in a plate to which a cessna style bolt on axle gets
> fitted. (the axle and brakes are actually a cleveland set)
>
> is the centre component of the gear leg a tube or a rod? my builder
> friend couldnt say. what are it's dimensions, wall thickness etc.
> what are the dimensions of the sleeve, wall thickness etc?
> what are the dimensions of the crosstube tube?
> what is the thickness of the wraparound plate that the neoprene
> components and washers are bolted through?
> I'm assuming it was all made from 4130, is that correct?
>
> I know it was heat treated to 180,000 psi ultimate.
>
> appreciate a help from anyone with a full plans set.
> Stealth Pilot
> Australia.

[Stealth Pilot]

On 3 Jan 2005 09:52:54 -0800, "flybynightkarmarepair" >
wrote:

>Pazmany's book on Landing Gear has a detailed sketch of the T-18
>landing gear, as well as an in-depth discussion of landing gear
>analysis.
>
>http://www.pazmany.com/books/books.html
>
>It's the best book on the subject.
>
ok maybe currently the best book on the subject. :-)

I've found that the T18 parts are tubes but still need the wall
thickness callouts.

thanks for the suggestion but I'm after the actual data not someones
published opinions on it.
Stealth Pilot

[flybynightkarmarepair]

Page 163 of Paz's book has all the detail you're looking for. But I'm
not going to tell you, neener, neener, neener!!!


Ryan "Only Too Willing to Spout My Own Opinions, But Not Too Cheap To
BUY Good Information" Young

{Say "I'm a bloomin' snide POM, SIR!" and I'll quote you the diameters
and wall thicknesses}
<and have you tried the T-18 group?
http://groups.yahoo.com/group/thorplist >

[Stealth Pilot]

On 3 Jan 2005 21:09:52 -0800, "flybynightkarmarepair" >
wrote:

>Page 163 of Paz's book has all the detail you're looking for. But I'm
>not going to tell you, neener, neener, neener!!!
>
>
>Ryan "Only Too Willing to Spout My Own Opinions, But Not Too Cheap To
>BUY Good Information" Young
>
>{Say "I'm a bloomin' snide POM, SIR!" and I'll quote you the diameters
>and wall thicknesses}
><and have you tried the T-18 group?
>http://groups.yahoo.com/group/thorplist >

where you go wrong stupid is that I didnt ask for details from
Pazmany's book.
I wanted details from drawing 515 of Thorp's plan set. one of only 3
drawings I dont have sitting in a box beside me just now.

I have no idea whether paz got his details right.
I suspect that you have no idea either.
Stealth Pilot

[smjmitchell]

I have Paz's book sitting in front of me ... and it does not have any
dimensions. Only the tube sizes. It does not contain any details of the
fittings, axels etc.



"Stealth Pilot" > wrote in message
...
> On 3 Jan 2005 21:09:52 -0800, "flybynightkarmarepair" >
> wrote:
>
> >Page 163 of Paz's book has all the detail you're looking for. But I'm
> >not going to tell you, neener, neener, neener!!!
> >
> >
> >Ryan "Only Too Willing to Spout My Own Opinions, But Not Too Cheap To
> >BUY Good Information" Young
> >
> >{Say "I'm a bloomin' snide POM, SIR!" and I'll quote you the diameters
> >and wall thicknesses}
> ><and have you tried the T-18 group?
> >http://groups.yahoo.com/group/thorplist >
>
> where you go wrong stupid is that I didnt ask for details from
> Pazmany's book.
> I wanted details from drawing 515 of Thorp's plan set. one of only 3
> drawings I dont have sitting in a box beside me just now.
>
> I have no idea whether paz got his details right.
> I suspect that you have no idea either.
> Stealth Pilot

[flybynightkarmarepair]

At the risk of acting like a Troll, I'll responde to this: Stealth
Pilot {who can't seem to take a joke, even when it's pretty blatent}
ASKED for the tube thicknesses, among other things, like:

"is the centre component of the gear leg a tube or a rod?"

It is a tube, wall thickness .303, and runs all the way from the top of
the A-frame to the axle attachment in one piece. I'll check the
diameters (which are admittedly about all the sketch has) when I get
back home.

Has anybody else offered this contentious Australian ANY information?

Perhaps he could ask these questions of the current plans distributor -
http://www.homebuilt.org/kits/elkund/elkund2.html

Or any of these people with completed or under construction airplanes:
http://www.t18.net/ambassadors.htm http://www.t18.net/links.htm
http://www.homebuilt.org/directory/eklund.html

Instead, he choses to ask a group known for a very low signal to noise
level, and then complains when he doesn't get EXACTLY what he wants.
Sheesh.

[Stealth Pilot]

On 4 Jan 2005 15:55:44 -0800, "flybynightkarmarepair" >
wrote:

>At the risk of acting like a Troll, I'll responde to this: Stealth
>Pilot {who can't seem to take a joke, even when it's pretty blatent}
>ASKED for the tube thicknesses, among other things, like:
>
>"is the centre component of the gear leg a tube or a rod?"
>
>It is a tube, wall thickness .303, and runs all the way from the top of
>the A-frame to the axle attachment in one piece. I'll check the
>diameters (which are admittedly about all the sketch has) when I get
>back home.
>
>Has anybody else offered this contentious Australian ANY information?
>
>Perhaps he could ask these questions of the current plans distributor -
>http://www.homebuilt.org/kits/elkund/elkund2.html
>
>Or any of these people with completed or under construction airplanes:
>http://www.t18.net/ambassadors.htm http://www.t18.net/links.htm
>http://www.homebuilt.org/directory/eklund.html
>
>Instead, he choses to ask a group known for a very low signal to noise
>level, and then complains when he doesn't get EXACTLY what he wants.
>Sheesh.

I have subscribed to this newsgroup over 10 years. Havent complained
once.
I just inferrred that your post was stupid.

the purpose was to apply some modern engineering computational method
to prediction of the gear deflections. something which pazmany and
thurston's methods dont seem to get quite right.
the only way that these computations can be made is with actual gear
dimensions. not hearsay, not guesses, not text book sketches.
when I finally managed to borrow a set of drawings after months of
just missing the owner on the airfield. the exact drawing I needed
wasnt there.

I thought I posted a quite reasonable question.
Stealth Pilot

[flybynightkarmarepair]

So I'll be reasonable, and avoid the sarcasm, and provide the
dimensions I have - which are not enough for the analysis you plan, but
you can do with them what you will.

The main tube is 1-1/2"OD, .303 wall. The sleeve is 1-1/2" X .120, as
is the cross bar of the this A-Frame. The bolts tieing this into the
longerons are 5/16, and the various fabricated tabs, and wrappers are
..125".

Perhaps you can scale the various lengths off the prints you do have.

You're right about Pazmany at least with regards to deflection. He
spends a lot of time on loads, some on shock absorbers, but little on
deflection. I guess he assumed we'd all taken Strength of Materials,
and Statics.