Toronto Electric Model Aviation Club Forum

Toronto Electric Model Aviation Club (TEMAC) => Building / Construction => Topic started by: GuyOReilly on December 01, 2020, 10:38:51 PM

Title: Spitfire
Post by: GuyOReilly on December 01, 2020, 10:38:51 PM
Okay,I do not have enough kits to build or projects on the go, now I inherited a Spitfire 2/3 built.
Of course it will be electric.  There are no plans, but the booklet is sufficiently detailed to allow completing the model.
Will decide if I put the Lancaster on hold and finish this one first, or the DR1, or....
Decisions, decisions, decisions...
Title: Re: Spitfire
Post by: GuyOReilly on December 01, 2020, 10:43:20 PM
A quick look at the tail and it looks scale to me.   :-\
Perhaps I should consider a built-up one with more area for stability. ::)
I would rather sacrifice scale for the benefit of safe flying.
Power plant would be a 3-4 cell 35 size motor.
Probably no retracts as the booklet does not provide much details on the landing gear placement.  :P
Title: Re: Spitfire
Post by: Frank v B on December 02, 2020, 08:43:54 PM
Guy,  re: tail section- oversize

A way to answer this question:

guideline- tail feathers on a model warbird should be about 15% oversized verses the real one.
method: calculate the ratio of stab span to wingspan from plans of the full size.  An exact scale stabilizer on the Mark 9 model is 28.8% of the wingspan (48.5") or 14.0".  This model's stabilizer span should be about 33.1% of the wingspan which is 16.1".

With the fin and rudder, I have increased the size of the fin/rudder by adding a 1/4" wide back edge (trailing edge) of the fin and 1/4" to the leading edge of the rudder.  Then cut off the top of the rudder (counterbalance) in line with the top of the fin and make a new counterbalance because it will be 1/2" wider.

FWIIW

Frank

Title: Re: Spitfire
Post by: Andy Hoffer on December 03, 2020, 09:02:47 AM
Quote from: GuyOReilly on December 01, 2020, 10:38:51 PM
Okay,I do not have enough kits to build or projects on the go, now I inherited a Spitfire 2/3 built.
Of course it will be electric.  There are no plans, but the booklet is sufficiently detailed to allow completing the model.
Will decide if I put the Lancaster on hold and finish this one first, or the DR1, or....
Decisions, decisions, decisions...

Hi @GuyOReilly

Ask the guy sitting in the cockpit at the top of photo 7567.  He looks very sagely.  8)

Andy
Title: Re: Spitfire
Post by: Andy Hoffer on December 03, 2020, 09:05:13 AM
Quote from: Frank v B on December 02, 2020, 08:43:54 PM
Guy,  re: tail section- oversize

A way to answer this question:

guideline- tail feathers on a model warbird should be about 15% oversized verses the real one.
method: calculate the ratio of stab span to wingspan from plans of the full size.  An exact scale stabilizer on the Mark 9 model is 28.8% of the wingspan (48.5") or 14.0".  This model's stabilizer span should be about 33.1% of the wingspan which is 16.1".

With the fin and rudder, I have increased the size of the fin/rudder by adding a 1/4" wide back edge (trailing edge) of the fin and 1/4" to the leading edge of the rudder.  Then cut off the top of the rudder (counterbalance) in line with the top of the fin and make a new counterbalance because it will be 1/2" wider.

FWIIW

Frank

Hi @Frank v B ,

You mean FWWII (from World War II), right??!  8)

Andy
Title: Re: Spitfire
Post by: GuyOReilly on December 03, 2020, 11:03:06 AM
Quote from: Frank v B on December 02, 2020, 08:43:54 PM
Guy,  re: tail section- oversize
A way to answer this question:
guideline- tail feathers on a model warbird should be about 15% oversized verses the real one.
method: calculate the ratio of stab span to wingspan from plans of the full size.  An exact scale stabilizer on the Mark 9 model is 28.8% of the wingspan (48.5") or 14.0".  This model's stabilizer span should be about 33.1% of the wingspan which is 16.1".
With the fin and rudder, I have increased the size of the fin/rudder by adding a 1/4" wide back edge (trailing edge) of the fin and 1/4" to the leading edge of the rudder.  Then cut off the top of the rudder (counterbalance) in line with the top of the fin and make a new counterbalance because it will be 1/2" wider.
FWIIW
Frank
@Frank v B thank you for this explanation, very useful.
I know that if the stab is less than 15% of wing area you are just asking for trouble; I will calculate/approximate the surface areas and see where that falls with the suggested 16 inches span for the stab.
I was planning to make a built-up structure (not a slab of wood) for the stab-elevator and fin-rudder.  It should be much lighter.  The L/E and T/E would be laminated from 1/16 balsa, possibly 4 to 6 layers then sanded down.
I am unsure about the size of the rudder still, adding only a 1/2 inch all around seems low.  Perhaps 1 inch all around might be better?
I will keep you posted.
Perhaps the Lancaster can take a backseat...

Title: Re: Spitfire
Post by: Frank v B on December 03, 2020, 06:00:33 PM

Andy,

re: FWIIW

For What It Is Worth..... in your case.... not much. ;) ;)


Frank
Title: Re: Spitfire
Post by: GuyOReilly on December 04, 2020, 05:29:43 PM
As I am no expert with elliptical wings are calculation, I approximated the total area as somewhere between 414 to 475 square inches.
I also looked carefully at the the instruction booklet and noted many interesting facts about this model.
- It has no landing gear by design.  Nope, none, no reinforcement, no material provided, nothing.  Hand lunch it is.
- The wing is sheeted and I have to cut the 10-inch ailerons by sight, with a ruler.
- The motor mounting is straight forward; a box mounted on the firewall.
- The battery installation is also easy, should fit a 4 cells no problem.
- The removal of the battery will require the removal of the fuselage.   :o There are no access hatch provided and the battery is mounted in a box that forms part of the fuselage structure.
- The stab and elevator will be built-up.
- The fin/rudder could be fixed, no rudder servo, no linkage, simple.  @Frank v B question for you: To rudder or not to rudder?
- The fin is three parts as per the instructions: centre piece of 1/32 plywood between 2 pieces 1/8 of balsa, sanded to shape.  Heavy!
- The instructions even suggest that it could be a PSS.  It is light enough, but no hills or ocean cliff nearby.
- For the covering, the manufacturer suggests dope and tissue.  That must be an old kit...

You will see in the attached picture the intended increase in the stab/elevator and rudder/fin.  The rudder may be a little bit to high and will probably reduce the height by 1/2 to 3/4 inch.
Title: Re: Spitfire
Post by: Frank v B on December 04, 2020, 06:22:40 PM
Guy,

To rudder or not to rudder. If it is hand-launched there is no real need for a rudder but I would put one in since it is easy and servos are cheap.
Two reasons: 1) it gives an extra way to trim the plane (to take out building error), and; 2) it allows you to do extra aerobatic moves (hammerhead stall, etc.)

I probably have 10 hand-launched planes that do not have rudders (Tucano, Nooner, Fox).  They are mostly Speed 400 planes and they fly fine.  This plane is larger and and can be flown more accurately with a rudder.

The plywood in the center of the fin/rudder is not required.  I would build it without the plywood and a total thickness of 1/4 is more than strong enough.  That is the same as the stab on the .40 size Skywriter club build project.  Most of us ditched the plywood.

I don't know if it is worth building open structure tail feathers.  I would use the solid tail feathers and add power on the front end. :)

Frank


Title: Re: Spitfire
Post by: Andy Hoffer on December 05, 2020, 11:40:46 AM
Quote from: Frank v B on December 04, 2020, 06:22:40 PM
Guy,

To rudder or not to rudder. If it is hand-launched there is no real need for a rudder but I would put one in since it is easy and servos are cheap.
Two reasons: 1) it gives an extra way to trim the plane (to take out building error), and; 2) it allows you to do extra aerobatic moves (hammerhead stall, etc.)

I probably have 10 hand-launched planes that do not have rudders (Tucano, Nooner, Fox).  They are mostly Speed 400 planes and they fly fine.  This plane is larger and and can be flown more accurately with a rudder.

The plywood in the center of the fin/rudder is not required.  I would build it without the plywood and a total thickness of 1/4 is more than strong enough.  That is the same as the stab on the .40 size Skywriter club build project.  Most of us ditched the plywood.

I don't know if it is worth building open structure tail feathers.  I would use the solid tail feathers and add power on the front end. :)

Frank

Hi @GuyOReilly ,

I can't imagine doing a forward slip on a proper (aligned with the runway) cross-wind landing without a rudder!!!  :D

Andy
Title: Re: Spitfire
Post by: Frank v B on December 05, 2020, 02:07:13 PM
re: Andy's "I can't imagine doing a forward slip"

:D ;D

F.

ps: 9 out of 10 cartoons were backward slips. ;D
Title: Re: Spitfire
Post by: Andy Hoffer on December 05, 2020, 02:27:47 PM
Bien sur, @guy. bien sur.

Touché!!  :D

Andy
Title: Re: Spitfire
Post by: pmackenzie on December 05, 2020, 04:44:48 PM
If this is the 48 1/2" span BalsaCraft kit, I have the plans for that, plus photocopies of some of the sheet wood parts.
Yours if you want it, and can pick it up from me in Don Mills.

edit - for sure it is the same one. I have the same manual you showed in one of your images.

Pat MacKenzie
Title: Re: Spitfire
Post by: GuyOReilly on December 05, 2020, 07:17:19 PM
@pmackenzie WONDERFUL!!!
Thank you.  Please let me know when it would be convenient for me to pick the plans up.
I am so HAPPY!!!
Guy
Title: Re: Spitfire
Post by: GuyOReilly on December 05, 2020, 07:31:02 PM
More progress.
The engine mount.
Title: Re: Spitfire
Post by: Andy Hoffer on December 05, 2020, 07:35:41 PM
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
Title: Re: Spitfire
Post by: 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.

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.
Title: Re: Spitfire
Post by: Andy Hoffer on December 06, 2020, 01:08:19 PM
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
Title: Re: Spitfire
Post by: Frank v B on December 06, 2020, 01:12:14 PM
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.
Title: Re: Spitfire
Post by: GuyOReilly on December 06, 2020, 02:30:51 PM
@pmackenzie  and @Frank v B
Thank you so much.
Title: Re: Spitfire
Post by: Frank v B on December 06, 2020, 06:17:57 PM
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
Title: Re: Spitfire
Post by: 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
Title: Re: Spitfire
Post by: GuyOReilly on December 12, 2020, 09:27:27 AM
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.
Title: Re: Spitfire
Post by: Andy Hoffer on December 12, 2020, 03:23:46 PM
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
Title: Re: Spitfire
Post by: pmackenzie on December 12, 2020, 05:34:52 PM
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
Title: Re: Spitfire
Post by: GuyOReilly on December 12, 2020, 06:18:20 PM
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...
Title: Re: Spitfire
Post by: GuyOReilly on December 16, 2020, 11:33:33 AM
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.  ???
Title: Re: Spitfire
Post by: GuyOReilly on December 16, 2020, 02:26:03 PM
The retracts work...
https://www.youtube.com/watch?v=E6HNkgQZG4s&feature=youtu.be

Title: Re: Spitfire
Post by: Frank v B on December 16, 2020, 03:09:21 PM
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.
Title: Re: Spitfire
Post by: Andy Hoffer on December 16, 2020, 05:17:07 PM
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
Title: Re: Spitfire
Post by: GuyOReilly on December 18, 2020, 03:55:00 PM
A bit more progress.
New cowling made out of blocks of wood, as per plan.
Carved the inside to fit the 32 Flight motor, wires and motor mount.
More sanding to come and then more sanding still.

Title: Re: Spitfire
Post by: Andy Hoffer on December 18, 2020, 10:30:01 PM
Nice job monsieur @GuyOReilly !!

Je ne peux pas attendre!

Andy
Title: Re: Spitfire
Post by: GuyOReilly on December 20, 2020, 12:46:35 PM
The wing is mated to the fuselage.
Remains to do the tail.
The motor was bench tested and runs.
The installation location of an ON/OFF switch on the side of the fuselage will be tricky due to the construction method used, there are many layers and boxes in this construction.
Title: Re: Spitfire
Post by: Andy Hoffer on December 20, 2020, 08:02:35 PM
Quote from: GuyOReilly on December 20, 2020, 12:46:35 PM
The wing is mated to the fuselage.
Remains to do the tail.
The motor was bench tested and runs.
The installation location of an ON/OFF switch on the side of the fuselage will be tricky due to the construction method used, there are many layers and boxes in this construction.

Hey @GuyOReilly

Just remember this is a family show!

Andy
Title: Re: Spitfire
Post by: GuyOReilly on December 28, 2020, 05:42:38 PM
Progress continues, with some snags along the way.

Photo 7601 - I needed a large washer to hold the bold in place to sand the cowling.
Photo 7602 - Holding the cowling firmly in place for sanding.
Photo 7604 - More and mores sanding.
Photo 7603 - Wing fairings, interesting construction: make 6 layers of soft balsa, then sand way 85% of it. (I know @Andy Hoffer that the picture is out of focus.)
Photo 7605 - How to place the aileron servo: the instructions cal for "servo tape" to the wing?!?  Nope, nope, nope, cannot do that.
Photo 7606 - Servo will be sacrificed to the wing.  There is no way to pull it out for adjustments once secured with screws.  Also, the wing sheeting was sanded down from 1/16 to 1/32 and it brakes when trying to cut with a new #11 blade going very carefully.
Photo 7608 - Ailerons cut out.
Photo 7607 - I plan on using plywood base for the retracts - 3 X 2.765 - 1/8 ply -There will be triangular stock holding the ply base against the ribs and the spar and the leading edge.  They will not be in the scale position (as suggested by @Frank v B) they will be more outward and forward of the scale position.  Also, to retain the integrity of the spar, they will retract 90 degrees.

Question:  How do I length the 1/8 diameter L/G wire?  ??? I did not see a set screw or grub screw anywhere.  Any help is appreciated.

PS: I know that the pictures may not be in the preferred sequence @Andy Hoffer   :P
Title: Re: Spitfire
Post by: Andy Hoffer on December 28, 2020, 10:13:10 PM
Hey @GuyOReilly

I love the 45 rpm record spindle adapter (photo 7601)!!  That's almost the same vintage as the Spitfire!   ;D

Andy

Title: Re: Spitfire
Post by: GuyOReilly on December 29, 2020, 11:24:43 AM
Close inspection of the retractable L/G indicate that they cannot fit inside the wing as it is too thin.  :'(
At the thickest portion of the wing: 1 inch, including the 1/16 sheeting top and bottom, the available depth would be .875 inch and much less toward the leading edge.
The measured size of the retract with the 1/8 ply wood base: 1.125 inches.  :(
So, back to square one - fixed L/G.
In my stash of spare parts, I located what should be suitable L/G.  More measurements on the way.
Title: Re: Spitfire
Post by: Michael on December 29, 2020, 12:05:38 PM
Unless your model is super scale, retracts (when retracted) sticking out a quarter-inch or so won't be noticed in flight.

Fixed landing gear is an easier, care-free solution, though.
Title: Re: Spitfire
Post by: GuyOReilly on December 29, 2020, 12:23:12 PM
Thank you @Michael , fixed gear it will be I will keep the retracts for the Lancaster as initially planned.
In the process of selecting an appropriate size of wood for this.
Any suggestions on how to extent the piano wire of the L/G retracts?
Title: Re: Spitfire
Post by: GuyOReilly on December 29, 2020, 03:06:07 PM
Finally decided to use the 2X4 landing construction method suggested by @Frank v B .
@Michael , yes you are correct, a simpler solution, use the KISS principle.

Photo 7628 - Select a suitable piece of massive lumber, thank you @Frank v B for supplying it.
Photo 7629 - Remove the protruding portion - it is more aerodynamic that way.
Photo 7630 - The bottom portion was fitted to prevent removing too much of the center rib laminations.
Photo 7631 - Epoxy curing with appropriate weight.

The wheels will be 11 inches apart, not scale but this should assit with ground handling.   ;D
Title: Re: Spitfire
Post by: GuyOReilly on December 29, 2020, 10:39:07 PM
Standing proud on her wobbly legs (not screwed in yet).
Title: Re: Spitfire
Post by: GuyOReilly on December 31, 2020, 11:19:26 AM
While waiting for glue to dry and filler to set, I added 2 Ikea measuring tapes to the edge of the construction table for easy reference when needed.
Title: Re: Spitfire
Post by: Andy Hoffer on December 31, 2020, 02:36:45 PM
Quote from: GuyOReilly on December 29, 2020, 10:39:07 PM
Standing proud on her wobbly legs (not screwed in yet).

Elle est très jolie @GuyOReilly !

Andy
Title: Re: Spitfire
Post by: Andy Hoffer on December 31, 2020, 02:38:34 PM
Quote from: GuyOReilly on December 31, 2020, 11:19:26 AM
While waiting for glue to dry and filler to set, I added 2 Ikea measuring tapes to the edge of the construction table for easy reference when needed.

Very nice work station up-grade!

Andy
Title: Re: Spitfire
Post by: GuyOReilly on January 03, 2021, 11:41:55 PM
I think that the decals supplied will be used, but the colours will be close to these.
The Spitfire will be painted, light coats with airbrush.
Title: Re: Spitfire
Post by: GuyOReilly on January 04, 2021, 10:29:39 AM
Just had to look at it assembled.
Covering starting today.

PS: @Andy Hoffer, yes the green tape will be removed...
Title: Re: Spitfire
Post by: Andy Hoffer on January 04, 2021, 12:44:59 PM
Bonjour @GuyOReilly

Gee!  At first I didn't even notice your beautiful Spitfire.  I was too busy looking around at all the neat stuff in your shop!!!   ;D

Andy
Title: Re: Spitfire
Post by: Michael on January 05, 2021, 06:56:36 AM
It really looks like a Spitfire now!
Title: Re: Spitfire
Post by: bfeist on January 07, 2021, 01:01:08 PM
This is really looking good. Great progress!
Title: Re: Spitfire
Post by: GuyOReilly on January 08, 2021, 03:32:16 PM
I installed a battery on/off switch on the cockpit floor to eliminate the need to remove the wing to cut-off power to the ESC/motor/radio.  :D
Now I need to figure out how to make the cockpit removable to access the switch.  ???
An infamous case of the "5-Ps" - Prior Planning Prevents Poor Performance.   ::)
The sides are 1/16 so magnets would be difficult to install.  :o
Peanut Gallery, your comments, ideas and suggestions are welcomed.
Guy
Title: Re: Spitfire
Post by: Andy Hoffer on January 08, 2021, 05:25:16 PM
Hi @GuyOReilly

I would use magnets glued into the fuselage just in front of and behind the canopy.  Use a razor saw and X-acto knife to cut 1/2-inch deep x 1/2-inch thick slabs from the top of the fuselage where the front and rear of the canopy meet the fuselage.  Glue support blocks for the magnets into the fuselage, allowing room for the mating magnets to be attached to the slabs while keeping the outside surface of the slabs flush with the outside surface of the fuselage.  Epoxy the magnets onto the internal support blocks.  Fit the slabs cut from the fuselage with mating magnets.  Glue the mating magnets to the slabs.  Glue the front and rear (NOT the sides) of the canopy to the top of the slabs only, not to the adjacent fuselage surface.  You now have a removable canopy which is strongly affixed to the fiselage.  The 1/2-inch slab width and depth will give you a large enough surface to grip for removal of the canopy for access to your on/off switch.

Andy
Title: Re: Spitfire
Post by: GuyOReilly on January 08, 2021, 08:53:15 PM
Thank you Andy for this suggestion.
It will be held with magnets, just not too keen on cutting the fuselage.
Zoom meeting was fun, glad to exchange ideas with you as it provided options and revised strategies.
Looking forward to meeting again soon.
Guy

Quote from: Andy Hoffer on January 08, 2021, 05:25:16 PM
Hi @GuyOReilly

I would use magnets glued into the fuselage just in front of and behind the canopy.  Use a razor saw and X-acto knife to cut 1/2-inch deep x 1/2-inch thick slabs from the top of the fuselage where the front and rear of the canopy meet the fuselage.  Glue support blocks for the magnets into the fuselage, allowing room for the mating magnets to be attached to the slabs while keeping the outside surface of the slabs flush with the outside surface of the fuselage.  Epoxy the magnets onto the internal support blocks.  Fit the slabs cut from the fuselage with mating magnets.  Glue the mating magnets to the slabs.  Glue the front and rear (NOT the sides) of the canopy to the top of the slabs only, not to the adjacent fuselage surface.  You now have a removable canopy which is strongly affixed to the fiselage.  The 1/2-inch slab width and depth will give you a large enough surface to grip for removal of the canopy for access to your on/off switch.

Andy
Title: Re: Spitfire
Post by: Frank v B on January 08, 2021, 09:29:04 PM
Guy,

There is another option. 

In the IC days I always put the RC switch inside the fuse next to a servo.  I then drilled a hole through the switch slider (handle) and led a piece of piano wire through the fuselage via a servo eyelet. A small wheel collar held it all together so the push-pull would work.  I made the piano wire come out through the side of the fuselage, or in some scale planes made it come out behind the canopy of a Spitfire as an aerial or as a control column in an open cockpit.

Two photos of the mock-up.  Nylon landing gear straps allow the switch the be screwed to a servo rail.

Frank
Title: Re: Spitfire
Post by: Andy Hoffer on January 08, 2021, 09:35:13 PM
Quote from: Frank v B on January 08, 2021, 09:29:04 PM
Guy,

There is another option. 

In the IC days I always put the RC switch inside the fuse next to a servo.  I then drilled a hole through the switch slider (handle) and led a piece of piano wire through the fuselage via a servo bushing. A small wheel collar held it all together so the push-pull would work.  I made the piano wire come out through the side of the fuselage, or in some scale planes made it come out behind the canopy of a Spitfire as an aerial or as a control column in an open cockpit.

Two photos of the mock-up.  Nylon landing gear straps allow the switch the be screwed to a servo rail.

Frank

Nice @Frank v B !  Another elegant solution! 

@Guy is now caught between a rock and a hard place!!  ;D

Andy
Title: Re: Spitfire
Post by: pmackenzie on January 08, 2021, 09:44:34 PM
I seem to recall some used to use things like the machine guns or other scale features to activate the internal switch.
But I would always worry that the weight could cause the switch to activate when you didn't want it to  :o

There are high tech options as well, Zepsus magnetic switch being one. They even have BEC versions:

https://zepsus.com/product-category/product/
Title: Re: Spitfire
Post by: Frank v B on January 08, 2021, 09:52:41 PM
Pat,

I learned from first principles that to push the switch "in" would be "on" especially in hand-launched planes where brushing up against it when launching could turn it "off" if done the other way.

The discipline was to leave the RX battery disconnected until ready to fly.  Always answer the question "what could possibly go wrong". ;)

Frank
Title: Re: Spitfire
Post by: GuyOReilly on January 09, 2021, 12:06:04 PM
@pmackenzie I like the magnetic switch.... mabe for the next project as the switch is already installed.
@Frank v B yes, push is on and pull is off.  However, as you can see in the pictures, the swich is mounted with on forward and off back.  Adding the suggested and, might I say, elegant pushrod would result in locating it forward of the canopy, which would be unsightly.  It could not be mourned toward the rear as there is no access due to the fuselage shape and armour plate.  I thought about side mouning it, but that too has its problems.
As per my Zoom meeting with @Andy Hoffer, the canopy will be removable, and mounted on a plywood base for rigidity and support. The canopy will be held with magnets and pins for alignment. Pictures will follow once assembly and construction is completed ✅.
Thank you all for your ideas and suggestions, they allowed me to crystallize a solution by talking through the problem / challenge. 
Title: Re: Spitfire
Post by: GuyOReilly on January 09, 2021, 08:06:52 PM
Inspired by @Andy Hoffer 's suggestion to use magnets to hold the canopy in place.

Here is a quick video showing the firm grip of one set of magnets, another set will be added later.
https://www.youtube.com/watch?v=MYUshGSyp_k&feature=youtu.be

Photo #7646 shows the canopy under pressure to ensure good epoxy fit and bonding.

Thank you for all your great ideas and support.

Title: Re: Spitfire
Post by: GuyOReilly on January 15, 2021, 06:25:21 PM
The aileron servo motor hums when connected, and not a nice tune at that...  >:(
Seems that the pushrod is putting some pressure on the output arm.
Considering changing the setup to 2 servos, but that would require opening the wing skin.
Any suggestions before I proceed with the the surgical operation?  ???
Title: Re: Spitfire
Post by: GuyOReilly on January 21, 2021, 06:51:52 PM
It is not perfect, but I am very pleased.
@Gregor77 thank you for your help.  It turned out better than I ever expected, thanks to your tips.
A few touch-ups needed here and there; I am a happy camper!   ;D
In the end, I decided to go with Tamiya paints XF80-XF81-XF82, diluted approximately 30% with 90% alcohol.

#7666 - all taped up...
#7668 - a piece of tape left a straight line on the left side, touching up with a brush.  50/50 rule @Frank v B .  :-X
#7779 - not bad, not bad at all, paint peeled off just behind the cockpit - DARN!  >:(
Title: Re: Spitfire
Post by: octagon on January 21, 2021, 07:10:04 PM
Looks great Guy. I am looking forward to seeing it, or for that matter any planes fly.
Title: Re: Spitfire
Post by: Andy Hoffer on January 21, 2021, 07:21:00 PM
Beautiful @GuyOReilly !  Easily better than the 50/50 rule.

I would not be surprised if you received a sheepish call from @Frank v B seeking your fine finishing services!

Way to go!

Andy

Title: Re: Spitfire
Post by: Frank v B on January 21, 2021, 07:26:30 PM
Andy,

re: my requirement for finishing services?  I can mess it up all by myself.

re: : Guy getting a sheepish call from me.  Guy, Andy will translate:

https://www.youtube.com/watch?v=xfl9z9drce4

Guy, the plane looks great.  The Spit has nice lines.  Yours is the perfect size as well.

Call me for maiden day.  8) 8) 8)


Frank
Title: Re: Spitfire
Post by: Andy Hoffer on January 21, 2021, 07:36:04 PM
Quote from: Frank v B on January 21, 2021, 07:26:30 PM
Andy,

re: my requirement for finishing services?  I can mess it up all by myself.

re: : Guy getting a sheepish call from me.  Guy, Andy will translate:

https://www.youtube.com/watch?v=xfl9z9drce4

Guy, the plane looks great.  The Spit has nice lines.  Yours is the perfect size as well.

Call me for maiden day.  8) 8) 8)


Frank

Me too, @GuyOReilly! Me too!!

(That is going to be one baaaaad-ass plane!  ;D)

Andy
Title: Re: Spitfire
Post by: GuyOReilly on January 21, 2021, 08:10:43 PM
@Frank v B lama call you about the maiden...
Title: Re: Spitfire
Post by: GuyOReilly on January 24, 2021, 10:37:24 PM
Questions about velcro: how to ensure the velcro stays put on bare wood?
Add epoxy to bottom of vecro strip?

Title: Re: Spitfire
Post by: Andy Hoffer on January 25, 2021, 12:47:07 AM
Quote from: GuyOReilly on January 24, 2021, 10:37:24 PM
Questions about velcro: how to ensure the velcro stays put on bare wood?
Add epoxy to bottom of vecro strip?

Hi @GuyOReilly

I have found that a thin coat of epoxy on the wood provides an excellent substrate for the velcro adhesive.  Of course, allow the epoxy to fully cure before applying the velcro.

Andy
Title: Re: Spitfire
Post by: Frank v B on January 25, 2021, 05:01:07 PM
Guy,

Depends on the size of the battery:

small batteries (<800 mah, 3S)- I use epoxy onto wood but make the glued part (usually the hooks) on the fuselage side bigger than the battery for more glue area...after cutting off the corners (so they don't catch).  The longer part on the fuse also allows you to move the battery fore and aft for CG reasons.

medium batteries: (up to 2200-ish, 3S) I use straps but glue the continuous strap under a piece of wood (hard balsa if there is space or good ply if space is tight) and then epoxy the wood to the balsa fuse side.

large batteries (4S-6S  2600 mah plus) I build a box out of balsa that stops it from sliding fore or aft and then strap it in with a continuous loop of velcro (hooks on one side, fuzzy on the other- available at Princess Auto).  I use this in my large P-51, Ef-1 racer and .60 size 6S pattrn plane.

FWIIW

Frank

Title: Re: Spitfire
Post by: Andy Hoffer on January 25, 2021, 06:17:20 PM
Quote from: Frank v B on January 25, 2021, 05:01:07 PM
Guy,

Depends on the size of the battery:

small batteries (<800 mah, 3S)- I use epoxy onto wood but make the glued part (usually the hooks) on the fuselage side bigger than the battery for more glue area...after cutting off the corners (so they don't catch).  The longer part on the fuse also allows you to move the battery fore and aft for CG reasons.

medium batteries: (up to 2200-ish, 3S) I use straps but glue the continuous strap under a piece of wood (hard balsa if there is space or good ply if space is tight) and then epoxy the wood to the balsa fuse side.

large batteries (4S-6S  2600 mah plus) I build a box out of balsa that stops it from sliding fore or aft and then strap it in with a continupous loop of velcro (hooks on one side, fuzzy on the other- available at Princess Auto).  I use this in my large P-51, Ef-1 racer and .60 size 6S pattrn plane.

FWIIW

Frank

Hi @GuyOReilly

For extra large batteries, I trowel in a 1/4-inch layer of thick micro-balloons/epoxy mix on the battery plate, bond an aluminum heat sink to the top of the battery, plant the battery in the filler, fill in the space between the inside walls of the fuselage and the sides of battery with more epoxy/micro-balloons mix, then add another 1/4-inch layer of filler on the top of the battery, around the heat sink.  Make sure to allow for good air flow through the fuselage to cool the battery via the heat sink.  I have never had one of these batteries move inside the fuse, even with aggressive aerobatics.   You just set your C of G once, and forget it.  A pair of booster cables and an extension cord for your balancing lead come in handy for charging the battery right inside the fuse.  None of that hassle of fastening and unfastening velcro straps and fighting to get the battery to come off the velcro hold-down.  If the battery dies, a fine jig-saw blade will make short work of doing a LiPo-ectomy, allowing you to install a replacement with more epoxy/micro-balloons grout!.  @Frank is a master of the art of filling with a whole range of compounds (construction adhesives, mastic, Sheetrock 90, etc.  Check with him for advice on the finer points of this technique.   ;D

Andy
Title: Re: Spitfire
Post by: GuyOReilly on January 25, 2021, 10:54:40 PM
Thank you for these great tips, @Andy Hoffer and @Frank v B .
I coated the floor of the box with epoxy.
A piece of velcro will be added to the bottom once set.
The front, top and sides will be lined with foam blocks so the battery does not move in these directions.
The opening to insert and remove the battery will be closed with a piece of wood, held in place by pressure and friction - pictures to follow later in the week.
Have a great evening.
Guy
Title: Re: Spitfire
Post by: GuyOReilly on January 26, 2021, 11:06:14 AM
Don't you just hate it when you run out of thin CA in the middle of a snow storm?!?   >:(
Title: Re: Spitfire
Post by: sihinch on January 26, 2021, 03:15:47 PM
Me too!  :-[ :'(
Title: Re: Spitfire
Post by: Andy Hoffer on January 26, 2021, 04:15:41 PM
Quote from: GuyOReilly on January 26, 2021, 11:06:14 AM
Don't you just hate it when you run out of thin CA in the middle of a snow storm?!?   >:(

Mon dieu!  You'll have to use @Frank v B-brand white glue!!  My condolences @GuyOReilly .

Andy
Title: Re: Spitfire
Post by: GuyOReilly on January 27, 2021, 09:39:01 AM
Looks like I have a bad connections somewhere...power does not go to receiver.  ???
All solder joints to be examined.   ::)
Better on the ground then at 100 feet...  :o
Title: Re: Spitfire
Post by: Andy Hoffer on January 27, 2021, 02:48:46 PM
Quote from: GuyOReilly on January 27, 2021, 09:39:01 AM
Looks like I have a bad connections somewhere...power does not go to receiver.  ???
All solder joints to be examined.   ::)
Better on the ground then at 100 feet...  :o

Yikes! Definitely a COVID-19 variant @GuyOReilly .  Better wear a mask and soak your receiver in alcohol!  ;D

Andy
Title: Re: Spitfire
Post by: GuyOReilly on January 27, 2021, 08:50:50 PM
Source of power problem located: defective switch.   8)
I have another and will replace easily.  ;D
Title: Re: Spitfire
Post by: GuyOReilly on January 29, 2021, 09:27:09 PM
Ready for Maiden Flight.
RTF weight: 3 pounds 14 ounces.
Design weight: was 3 pounds 6 ounces.
The additional 8 ounces, more glue, and one more servo and wiring and...  ::)
Not perfect, many flaws, but happy with the end result.
It should still fly, hopefully land safely, and then repeat many times.  ;D

Picture #7672 - Surgery on the bottom wings to add servos for ailerons.  I did not like the single servo seat-up.
Picture # 7675 - Servos installed and weights to keep plane light... err... to hold the pieces to cover the holes in place.
Picture # 7676 - Ready to fly, decals applied, Monokote stripes - what a $&@% to put down.

Looking forward to a calm, spring day for Maiden Flight @Frank v B

PS: Oh, yeah, I forgot one small thing remains to be done: figure out how to prevent the battery from sliding back, currently only velcro on bottom of battery.  ???
Title: Re: Spitfire
Post by: Frank v B on January 29, 2021, 10:39:56 PM
Guy,

The caption under photo 7675  should read "These bolts will keep the wing in place."  Joe Overkill or what?
Great weights.

re: "Not perfect, many flaws, but happy with the end result."  You over-delivered on the 50/50 rule*. 8) 8)


Frank

* if you can't see it at 50' and 50km/hr it is good enough.
Title: Re: Spitfire
Post by: Andy Hoffer on January 30, 2021, 09:30:04 AM
Quote from: Frank v B on January 29, 2021, 10:39:56 PM
Guy,

The caption under photo 7675  should read "These bolts will keep the wing in place."  Joe Overkill or what?
Great weights.

re: "Not perfect, many flaws, but happy with the end result."  You over-delivered on the 50/50 rule*. 8) 8)


Frank

Darn!  @Frank v B beat me to it.  (Perfect bait monsieur!) Looks gorgeous @GuyOReilly .  And that wing is never coming off!!  ;D

Andy

* if you can't see it at 50' and 50km/hr it is good enough.
Title: Re: Spitfire
Post by: Michael on January 30, 2021, 11:44:13 AM
Quote from: GuyOReilly on January 29, 2021, 09:27:09 PM
PS: Oh, yeah, I forgot one small thing remains to be done: figure out how to prevent the battery from sliding back, currently only velcro on bottom of battery.  ???

Perhaps a block of Styrofoam?
Title: Re: Spitfire
Post by: GuyOReilly on January 30, 2021, 02:34:58 PM
Quote from: Michael on January 30, 2021, 11:44:13 AM
Quote from: GuyOReilly on January 29, 2021, 09:27:09 PM
PS: Oh, yeah, I forgot one small thing remains to be done: figure out how to prevent the battery from sliding back, currently only velcro on bottom of battery.  ???

Perhaps a block of Styrofoam?

Thank you Michael, a simple solution sometimes is the best option!!
Guy
Title: Re: Spitfire
Post by: GuyOReilly on March 28, 2021, 12:50:36 PM
@Frank v B should I reduce the movements?   ???  This is low rates...  ;)

https://www.youtube.com/watch?v=sQwmafNXuxY
Title: Re: Spitfire
Post by: Frank v B on March 28, 2021, 04:34:47 PM
Guy,

Great to be able to judge it via video.


If you were to ask me to maiden this airplane I would adjust the low rates as follows:
1) reduce elevator travel by about 60%.  A Spit is very short-coupled.
2) reduce aileron throw by 30%.
3) leave the rudder as is.  It is small relative to the plane so it may be required for take-off.

Two nits:
- the elevator halves are not lined up.  When the port half is neutral, the starboard half has about 3 degrees "down".  You had a joiner wire.  Grip the elevator halves with thumb and forefinger at both 90  degree bends and twist the elevator halves to neutral.  This easy to overcome with aileron trim but you would lose "neutral" when you change air speed.
- the starboard aileron has a lot more "down" than "up".  The port aileron is fine.

Remember that I have a different approach to maidening.  I set my throws at the minimum that would allow the plane to take off, fly circuits and land.  Once the first flight is complete, then add throws to your liking.  The reason...you can't do this on a second flight if you crashed on the first flight. :)

Also, I never switch rates on a maiden flight so the low rates and high rates are the same for me.*

FWIIW

Frank

* it is different for leaf blowers because they do not have prop/jet wash over the control surfaces.  They rely on pure air speed for control and may need dual rates.
Title: Re: Spitfire
Post by: GuyOReilly on August 08, 2022, 10:22:53 AM
Spitfire maiden flight did not go as planned.
The motor cut-off when attempting to takeoff as pe @Frank v B .
We suspected the ESC to be the culprit so I pulled it out.
Looks that it can handle the power based on the label on the ESC.
Any suggestion?
Guy
Title: Re: Spitfire
Post by: Michael on August 08, 2022, 09:10:04 PM
Do you know how many "amps" were being drawn?

I haven't read the entire thread, but, you mention you are using a "32" motor, I think with a 4-cell battery pack.

It is possible you are using too large a propeller.

It is also possible your motor is not adequate for the job. I have an OS 32 motor that is rated for only 3 cells. An E-Flite 32 can handle up to 5 cells, with a suitable (smaller) propeller.

What are the brand and ratings for your motor, and is the propeller size (you are using) appropriate for the motor on 4 cells?


Title: Re: Spitfire
Post by: GuyOReilly on August 09, 2022, 10:22:46 PM
The culprit was found!  ;)
This switch has resistance where it should have none. :-X
This results in the engine shutting down at full power.   >:(
When bypassing the switch, no problem whatsoever.   ;D
Need to figure out how to replace this switch with something more reliable; it was changed before and the same problem happened.   :o
Title: Re: Spitfire
Post by: Frank v B on August 12, 2022, 08:07:52 PM
For the record and to answer Michael's questions- we put a wattmeter to it. 
It drew 44.6 amps max.  The ESC was 60 amps.  It was well within range and a good reading.
When we put a voltmeter to the switch wires, one read fine.  The other one drew a blank when both "on" and "off" proving that the switch did not do its thing properly.

Frank
Title: Re: Spitfire
Post by: GordPayne on August 13, 2022, 05:47:44 AM
That's interesting. I have a similar switch and was having problems. I'll leave it out for a while. Thanks!