Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin (Account/Technical Issues)  |  Contact Global Moderator
March 02, 2021, 08:27:40 AM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: [1]   Go Down
Print
Author Topic: "The Answer" at 50" for RC  (Read 475 times)
0 Members and 1 Guest are viewing this topic.
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« on: January 21, 2021, 01:18:41 PM »

Hi all,

I've been flying my 44" Answer (c/w Ritz wing), built from the Cambrian Models kit, for several years now, and it's one of my favourite models.  It has a little outrunner hidden below the dummy diesel, powered by a 2S 1300 li-po, spinning a 9x6 slo-fly prop.  Duration is a relaxed 15 minutes or so.  The covering is tissue over mylar.

Anyway......last year, I took a chance and bought an (Indian) Mills 1.3 diesel from a trader at Old Warden.  It starts, runs and throttles quite readily, which is good.

Quite by chance, I recently stumbled across Walt Musciano's 50"  Answer on the Outerzone, so that was that.  What choice had I got?

Construction started last week with the wing outlines, which were glued together with waterproof PVA glue, before being dunked in the bath for 20 mins.  The outlines were then bent over the curved balsa formers and left overnight.

Tim
Attached files Thumbnail(s):
"The Answer" at 50" for RC
"The Answer" at 50" for RC
"The Answer" at 50" for RC
"The Answer" at 50" for RC
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #1 on: January 21, 2021, 01:24:09 PM »

Cont'd.....

The identical ribs were knifed from hard 1/162 sheet, using a ply template as a cutting guide.  The ribs were located using the datum on the plan, and the ends simply snipped to length.

Today saw the two panels rough-sanded to profile, and then butt-glued together (with 2 1/2" dihedral below each tip).  I'll reinforce the centre join tomorrow!

Tim

Attached files Thumbnail(s):
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Logged
Kevin M
Gold Member
*****

Kudos: 13
Offline Offline

United Kingdom United Kingdom

Posts: 266



Ignore
« Reply #2 on: January 21, 2021, 01:51:13 PM »

Very nice!
Logged
Squirrelnet
Platinum Member
******

Kudos: 54
Offline Offline

United Kingdom United Kingdom

Posts: 1,424




Ignore
« Reply #3 on: January 21, 2021, 02:52:07 PM »

The Answer is a beautiful model, a Mills 1.3 powered one even nicer to my oily mind

I have the original article from Air Age Gas Models written by Gordon Murray and had plans to build one for a Sparkie ...maybe a Bantam 19 if built light ? or maybe an O&R 23 . Not sure where I could even fly a Sparkie powered FF Model these days

I've so nearly bought the kit and now I'm even more tempted for diesel power. Look forward to seeing more of your build
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #4 on: January 21, 2021, 04:45:51 PM »

I've so nearly bought the kit and now I'm even more tempted for diesel power. Look forward to seeing more of your build

The Cambrian kit is the smaller 44" original.  I'm guessing that a .75 diesel would be just right!
Attached files Thumbnail(s):
Re: "The Answer" at 50" for RC
Logged
Russ Lister
Free Flight Modeller .... sub 250g!
Palladium Member
********

Kudos: 75
Offline Offline

United Kingdom United Kingdom

Posts: 4,750


Russ Lister



Ignore
« Reply #5 on: January 21, 2021, 05:52:18 PM »

The Answer looks great  Smiley

I've been tempted by it in the past ... particularly the scaled down version by David Deadman (still owned by Graham or Richard?)
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #6 on: January 24, 2021, 12:47:58 PM »

I've cobbled together the tailplane.  It's a funny thing, and looks a tad clumsy when compared to the wing.

I started by assembling the sheet outline on the plan, and added the laminated leading edge, before leaving to dry overnight.

Today, I lifted the outline free and then placed 1/4" balsa blocks around the periphery of the plan.  The balsa outline was pinned back down.

The tapered spar is cut from 1/16 sheet, attached at the ends.

The 'ribs' are 1/16 x 1/4 balsa strip that butt up against the outline at their ends, and bend around the spars in the middle, giving a symmetrical section.

I've seen this system before (on a Bird of Time glider), but it seems unnecessarily complicated to me. Roll Eyes 

Tim
Attached files Thumbnail(s):
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #7 on: January 28, 2021, 11:20:56 AM »

With the flying surfaces completed, I've made a start on the fuselage.

Two sideframes as usual, joined (inverted) over a drawn centreline.

Tim
Attached files Thumbnail(s):
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Logged
Kevin M
Gold Member
*****

Kudos: 13
Offline Offline

United Kingdom United Kingdom

Posts: 266



Ignore
« Reply #8 on: January 28, 2021, 11:50:41 AM »

Coming along nicely, a good-looking aircraft. I imagine the tailplane is quite torsionally stiff using that method?
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #9 on: January 28, 2021, 12:06:39 PM »

I imagine the tailplane is quite torsionally stiff using that method?

No more so than the familiar vertical ribs and spars, I feel.  It is quite light for its size though, which given the model's short nose, is the main thing!

Tim
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #10 on: February 01, 2021, 09:57:14 AM »

A bit more progress in the engine bay.

I've used a cut-down 20ml syringe as the basis for the fuel, with a tight-fitting washer as a top (to stop the fuel sloshing everywhere).
 
The tank is held against the firewall with a 22mm copper pipe clip, from the local hardware shop.

The Indian Mills 1.3 is mounted on hardwood bearers.  I've eyeballed in a couple of degrees of side and down thrust, to minimise trim changes as the throttle gets twiddled with.

Tim
Attached files Thumbnail(s):
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Logged
DHnut
Gold Member
*****

Kudos: 20
Offline Offline

New Zealand New Zealand

Posts: 893



Ignore
« Reply #11 on: February 01, 2021, 03:56:13 PM »

Tim
That looks a very generous sized tank for a Mills?
Ricky
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #12 on: February 01, 2021, 04:00:15 PM »

Tim
That looks a very generous sized tank for a Mills?
Ricky

It's 15ml in total.  Don't forget that is is an RC model, so I'll want a good 5 minutes flying time.

Tim Smiley
Logged
Squirrelnet
Platinum Member
******

Kudos: 54
Offline Offline

United Kingdom United Kingdom

Posts: 1,424




Ignore
« Reply #13 on: February 01, 2021, 04:29:38 PM »

Quote
That looks a very generous sized tank for a Mills?

I was going to say the same thing, even on an Rc assist model thats going to pretty small by the time the tank runs out... then I noticed the throttle linkage

.. I see - RC model and very nice one too
Logged
DHnut
Gold Member
*****

Kudos: 20
Offline Offline

New Zealand New Zealand

Posts: 893



Ignore
« Reply #14 on: February 02, 2021, 02:17:13 AM »

Tim,
      I stand corrected that tank will give you a very long run. I nearly lost a SAM50 powered Miss35 recently when I launched with a full tank. Fortunately the glide was a right hand spiral from a very great height.
Ricky
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #15 on: February 06, 2021, 05:45:06 PM »

A bit more progress.

The undercarriage has been fashioned from piano wire. P clips are made from brass shim stock and are screwed to a ply plate in the model's belly.

Not my neatest bit of fabrication, but it's fit for purpose, I think.

Tim
Attached files Thumbnail(s):
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #16 on: February 15, 2021, 02:03:05 PM »

The end of the cold snap coincided with the Answer being pinned together for the first time!

Weight, as seen, is 15.5oz.

Tim
Attached files Thumbnail(s):
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Logged
Russ Lister
Free Flight Modeller .... sub 250g!
Palladium Member
********

Kudos: 75
Offline Offline

United Kingdom United Kingdom

Posts: 4,750


Russ Lister



Ignore
« Reply #17 on: February 15, 2021, 02:40:18 PM »

Looking good, Tim  Smiley

I used to love flying vintage style RC .... even if some of the other guys at the RC field would be yawning behind my back!
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #18 on: February 22, 2021, 04:12:06 PM »

Peripheral progress in the form of an engine test!

The Indian Mills was bolted back on the test stand, and the throttle wiggled to check slow speed and pick-up.

Tim

https://youtu.be/3wINxcGF390
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #19 on: February 28, 2021, 01:14:54 PM »

A beautiful weekend got me back out in the workshop!

The cabin area is pretty much glazed.  I always glue the glazing directly to the woodwork, so it becomes a structural component in this highly stressed area.

Because of the wing's flexibility, I'm using tissue-over-mylar as the covering method.  The central open voids were treated to 5 micron mylar, secured with mylar.  Tissue to follow.

What is interesting (to me) is that the tension of the shrunk mylar has caused the wing to bow upwards in an elliptical arc.  I understand that this is typical of a 'Ritz' constructed wing.

Tim
Attached files Thumbnail(s):
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Re: "The Answer" at 50" for RC
Logged
Kevin M
Gold Member
*****

Kudos: 13
Offline Offline

United Kingdom United Kingdom

Posts: 266



Ignore
« Reply #20 on: February 28, 2021, 01:58:07 PM »

Quote
What is interesting (to me) is that the tension of the shrunk mylar has caused the wing to bow upwards in an elliptical arc.

It looks elegant though, and as long as everything is symmetrical I can't see any problem. Did any wash-out develop with the shrinking?
Logged
Squirrelnet
Platinum Member
******

Kudos: 54
Offline Offline

United Kingdom United Kingdom

Posts: 1,424




Ignore
« Reply #21 on: February 28, 2021, 02:16:23 PM »

Looks great to me Tim. I think elliptical dihedral was a positive thing when the Answer was designed so it enhances its looks to me. As Kevin M says if its all symmetrical what's not to like.

I built a half size Skyscraper which had elliptical dihedral in the design and had steam and laminate the elliptical form in. The original gained the elliptical dihedral by covering the wings with wet silk , supporting the tips and weighing down the centre section until it dried. I'm liking the look of your 50" Answer
Logged
Tim Hooper
Bronze Member
***

Kudos: 1
Offline Offline

United Kingdom United Kingdom

Posts: 26

Topic starter


Ignore
« Reply #22 on: February 28, 2021, 04:29:02 PM »

Did any wash-out develop with the shrinking?

I've no idea - as yet.  When the wing has been tissue covered, then I'll pop it back on the curved formers and check that both sides are the same.

Tim
Logged
USch
Platinum Member
******

Kudos: 33
Offline Offline

Italy Italy

Posts: 1,223




Ignore
« Reply #23 on: February 28, 2021, 06:32:06 PM »

Did any wash-out develop with the shrinking?

Most probably not because of the double elliptical planform. This building style you find on Gerry Ritz's model's from 1937 onwards, finishing with his beautiful A2 glider CONTINENTAL in 1959. The "no spar, double ellipse" building tends naturally to sweep upwards on a non symmetric profiled wing without introducing wash-out.

Urs

unfortunately no photo found  Sad
Like the Answer, beautiful design and building  Smiley
Attached files Thumbnail(s):
Re: "The Answer" at 50" for RC
Logged

Fast up-Slow down
Pages: [1]   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!