Spitfire

Started by GuyOReilly, December 01, 2020, 10:38:51 PM

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Andy Hoffer

#15
Quote from: GuyOReilly on December 05, 2020, 07:31:02 PM
More progress.
The engine mount.

Very colourful and cool looking radial engine @GuyOReilly !!   ;D

Andy

Frank v B

#16
Guy,

Now that Pat is getting you the plans, you may want to re-consider landing gear.  It is so much easier to maiden a plane on wheels than hand-launching it. It is easy to retrofit in a fully finished wing.  I have done it several times, even when the plane has already been covered and flown.

How- add a pine dihedral brace to the center section of the wing through the bottom.  Do not open or affect the top of the wing.  Cut a slot 3/4" wide between the ribs outboard of where the landing gear straps are to be per plan.  I use a 1x3 (actual dimensions 3/4" x 2 1/2") clear pine from Home Depot. 

Step 1- locate the slot.  In a tail dragger, put it forward of the bottom main spar.  In a trike gear plane put it behind the main spar. 
Step 2- Cut the brace to between those two outer ribs.  It will probably be 6-8" long.
Step 3- Cut through the ribs.  If the wing has dihedral, the slot will almost touch the top sheeting at the center rib.
Step 4- mark the brace at the wing sheeting.  Do it all the way around because the back end of the brace is thinner than the front edge because of the shape of the ribs.
Step 5- cut and sand the brace to follow the contour of the wing.  Make it flush with the sheeting.  Once you have a reasonable fit- glue it in place.
Step 6- locate the landing gear and drill two holes in the brace to accept the vertical portion of the LG leg.
Step 7- add a wrap of fibreglass around the center section to hold it all together.  This eliminates the need to strengthen the ribs with plywood doublers.
Step 8- drill holes for the two nylon landing gear straps to hold the legs in place.

I could not find photos of a retrofit but it is exactly like the wing brace I added on the Tiger Moth project because none of the spars were continuous at the center joint.  The photos show the slot cut in the ribs.  This plane had swept wings, therefore the angle with the spars.  In a regular wing, this pine brace sits up against the spar.

Just added the photo of the Joy Stick wing that used a pine block for the landing gear and dihedral brace.

Frank

Photo 1- bottom of the wing shows why it needed the brace
Photo 2- Brace cut to shape but not yet installed.  You can see the rib slots forward of the brace that is just resting on top of the ribs.
Photo 3- the brace in place before re-sheeting and fibreglass.
Photo 4- photo of the finished Joy Stick that used this method.  The piece of pine is directly below the landing gear wires.  Note that the white nylon landing gear straps are on an angle.  Two reasons: first- the screws prevent the wire from moving forward or backward.  Second, the screws are closer to the middle of the pine block so it does not splinter.
"Never trade luck for skill"

Andy Hoffer

Quote from: Andy Hoffer on December 06, 2020, 01:06:19 PM
Quote from: Frank v B on December 06, 2020, 11:47:10 AM
Guy,

Now that Pat is getting you the plans, you may want to re-consider landing gear.  It is so much easier to maiden a plane on wheels than hand-launching it. It is easy to retrofit in a fully finished wing.  I have done it several times, even when the plane has already been covered and flown.

How- add a pine dihedral brace to the center section of the wing through the bottom.  Do not open or affect the top of the wing.  Cut a slot 3/4" wide between the ribs outboard of where the landing gear straps are to be per plan.  I use a 1x3 (actual dimensions 3/4" x 2 1/2") clear pine from Home Depot. 

Step 1- locate the slot.  In a tail dragger, put it forward of the bottom main spar.  In a trike gear plane put it behind the main spar. 
Step 2- Cut the brace to between those two outer ribs.  It will probably be 6-8" long.
Step 3- Cut through the ribs.  If the wing has dihedral, the slot will almost touch the top sheeting at the center rib.
Step 4- mark the brace at the wing sheeting.  Do it all the way around because the back end of the brace is thinner than the front edge because of the shape of the ribs.
Step 5- cut and sand the brace to follow the contour of the wing.  Make it flush with the sheeting.  Once you have a reasonable fit- glue it in place.
Step 6- locate the landing gear and drill two holes in the brace to accept the vertical portion of the LG leg.
Step 7- add a wrap of fibreglass around the center section to hold it all together.  This eliminates the need to strengthen the ribs with plywood doublers.
Step 8- drill holes for the two nylon landing gear straps to hold the legs in place.

I could not find photos of a retrofit but it is exactly like the wing brace I added on the Tiger Moth project because none of the spars were continuous at the center joint.  The photos show the slot cut in the ribs.  This plane had swept wings, therefore the angle with the spars.  In a regular wing, this pine brace sits up against the spar.

I will post some photos later of some wings that show some of these details.

Frank

Photo 1- bottom of the wing shows why it needed the brace
Photo 2- Brace cut to shape but not yet installed.  You can see the rib slots forward of the brace that is just resting on top of the ribs.

Photo 3- the brace in place before re-sheeting and fibreglass.

@GuyOReilly   be sure to pay careful attention to @Frank v B 's break-it-over-the-knee technique for opening the wing as shown in his first photo!  8)

Andy

Frank v B

Andy,

re: the break it over the knee trick.

I should have done it to the Tigermoth wing! :)

Frank

ps: just picked up the plans and box of the Spit from Pat MacKenzie.  Thank you Pat.  Will get it to Guy.
"Never trade luck for skill"

GuyOReilly


Frank v B

#20
Guy,

I took a look at the plans and it doesn't show any landing gear or size.  Here is how to determine the size:

1) Add a steerable tail wheel.  The plans show a fixed tail wheel (see photo 80 of plan).  The easiest way to add it is via a Dubro tail wheel bracket (white bracket in photo 83).  It will need about a 1/8" spacer on the top to give the tiller arm some clearance. The finished product should look like this retrofit I added to a .60 size plane (photo 75).  Also a photo of my P-51 tail wheel (photo 81).  Ignore the missing covering on the tail section.  It always blows off at trans-sonic flight speeds. ;D
2) Determine the length of the landing gear- assemble the plane on a table and put the prop on the motor.  Put something under the wing (a box) to determine the ground/prop clearance.  Measure the space from the bottom of the wing and subtract half the diameter of the wheel.  That will be the length of the leg.  Go bend metal.

A Dubro tail wheel bracket and a pair of wheels have found their way into the box.

Frank
"Never trade luck for skill"

Frank v B

Guy takes delivery of Pat MacKenzie's box of Spitfire parts and plans.  Thanks Pat.

Andy was there just to be annoying.

Frank
"Never trade luck for skill"

GuyOReilly

Quote from: Frank v B on December 11, 2020, 05:08:08 PM
Guy takes delivery of Pat MacKenzie's box of Spitfire parts and plans.  Thanks Pat.
Andy was there just to be annoying.
Frank
Thank you @Frank v B for the delivery.
Thank you @pmackenzie for the material, great craftsmanship and would have been a shame to dispose of these parts.
Thank you @Andy Hoffer for the visit and the pictures (surely in focus...)

So much fun to see people, okay 6 feet apart and not being able to offer the comfort of a warm drink in the basement, but that will come soon...
I will post pictures later as the build progresses.

Andy Hoffer

Quote from: Frank v B on December 11, 2020, 05:08:08 PM
Guy takes delivery of Pat MacKenzie's box of Spitfire parts and plans.  Thanks Pat.

Andy was there just to be annoying.

Frank

I would normally just let this sort of thing go, but "normal" and @Frank v B don't get along so well.  I felt compelled to intercede and elucidate the situation to ensure @GuyOReilly  can fully understand what was REALLY going on.

Frank very kindly offered to transport to Guy the Spitfire kit drawings so kindly donated to the cause by super-builder Pat MacKenzie.  When I got wind of this my "Frankincense" told me that I needed to chaperone this transaction to ensure Frank didn't lead Guy out to the back 40 of the bean fields.

So here are photos and the back story:

1945. Frank started with an explanation of how to plant Spitfire seedlings.
1946.  Frank's camera could not bear the thought of being forced to do more close-up photos without using the macro setting.  It went into hiding with his cell phone.
1947.  Frank persisted, and started his lecture with a discussion of what to look for above grade when a plane augurs in. 
1950.  Guy reads back Frank's lesson on unusual attitude ground entry, visual aids in hand.

Frank articulates the finer points of his various plane-planting scenarios, based on years of extensive practice:
1951. "It could be this way..."
1952. "Or it could be that way..."
1953. "It could end up really compressed... "
1954 "Or it could spread all over the place."
1955. "So you have to focus carefully (novel for Frank!) on each segment the debris field so you don't miss any pieces. "
1957. Thoroughly taken by Guy's beautiful part-built Spitfire Frank was overcome with envy.  Guy literally had to wrest the drawings from Frank's hands.
1959. Frank finally let go, but not before showing Guy where the 72 MHz antenna
1966 and 1969.  "You can see why Frank was smitten with Guy's Spitfire.
1960.  "One last longing look..."
1964.  Guy wisely maintains a very firm grip on the box!

Bonne chance Guy!  We will look forward to your well-focused build photos and posts.  Can't wait to do the formal portraits.

"And that's the kind of day it was..." 8)

Andy

pmackenzie

Just to be clear, I didn't build any of the parts left in the kit.
I bought the partially built model at an auction a long time ago, and my recollection is that the original owner was Matrin Irvine from Kingston.
Who, as I am sure those that are familiar with his work would agree, is indeed a "super builder" :).
The model was to the primer stage.

I never finished the model, and a while ago actually tossed it out  :-[.
In retrospect, I should have tried to find it a new home.

To that point, if the weather is better tomorrow I will post a different model that is up for grabs.
The weather needs to be better , because it is big and I need to take the pictures outdoors.
It reminds me of some random guest on a talk show, who told the story about getting a donkey as a "gift".
It turned out to be an expensive gift, and this might be similar.....

Pat MacKenzie

GuyOReilly

More progress motivated by the material supplied by @pmackenzie .
Photo # 7583 - Very happy with the result of forming the cowling using the wet towel suggested by @Frank v B;D
Photo # 7586 - DANG!!! 1/16 all around to tall because I did not reduce to account for the thickness of the balsa...  :'(

Back to square 1...

GuyOReilly

Look what just arrived from China Banggood this morning.
An early Christmas present.  ;D
These were intended for the Lancaster, but they may find their way in the Spitfire instead. ;)
@Frank v B this means that the suggested use of the 2X4 (approximate size) for the landing gear configuration will need to be re-evaluated.  ???

GuyOReilly


Frank v B

Guy,

re: "The retracts work..."

They darn well better after all this waiting. :)

Earlier you were trying to get that bar stool to fly by testing the 4 motors.  Now you want to make it land ......with retracts even. ;D ;D

F.
"Never trade luck for skill"

Andy Hoffer

Quote from: GuyOReilly on December 16, 2020, 02:26:03 PM
The retracts work...
https://www.youtube.com/watch?v=E6HNkgQZG4s&feature=youtu.be

Hey @GuyOReilly

Retracts always work - until they are installed.  If you're lucky, they will work in your shop after installation.  Their true personalities will manifest in undisciplined behaviour at the field just as your adrenalin is rising and  you can taste that maiden flight!!   8)

Andy