f-86H,f-86D,1/48,Revell

[plasticpilot]

In a thread on the F-86H, primarily on 1/72, there is a discussion on whether you could convert a Revell F-86D to an F-86H.  A thought I had a couple of months ago.   So I am posting some photos of my build so far.

The first photos are plans of the F-86H over the F-86D.  I took these from the Air Force Legends books on the F-86D and F-86H.  

 

 

 

 

 

 

A cut was made from the nose to behind the cockpit to cant the cockpit area down to match the F-86D.  Then v cuts from the nose back on the top to shape the nose in.  Its under the mulliput.  The entire back end was cut out under the fin and rudder from the jet pipe to just behind the air brakes.  The fairings for the elevators were cut off and re-positioned before the new jet pipe was added.  The fuselage of the H is squarer at the bottom behind the trailing edge of the wing.  Hence the milliput there to build it up.  The cross sections from the books match well in the mid section of the fuselage.  The nose still needs some work.  The intake fairing was done by taking a moulding of a F-86F and then cutting horizontally and gluing on with a gap that was filled.  Intake trunking from a F-86F was used as a master and the copy deepened.  A lot of shaping was required.

 

Next picture is the wings.  I am doing it as a late service model with the ANG in vietnam colours.  So it has the 6-3 slatted wing as per a F86F-40 with the 12 " extension.  The Revell wings have the wrong sweep on them so that is still to be corrected.  The  main wheel wells on the 86D are different from all other sabres.  On the others the door hinges are in line with the centre line.  On the 86D they are angled so I need to change that.

 

The different main wheel positions on the first drawing are a bit suspect.  The wing root positions on the side view do not match the plan view.  The 86D had the original slatted wing so should appear further back than the 86H.  Which shows on the plan vies.   So if it has been mis-drawn to far forward that explains why the 86D main wheel is ahead of the 86F.  Well that is what I am working on  

 

There is a Hasegawa F-30 wing underneath which shows Revell incorrect wing sweep.

 

 

 

This will  not be a quick build.  The tail shape and the nose need a lot of shaping to get them right.  I will post again when I have some significant progress.

 

 

[Silver Fox]

Not a quick build, thats n understatement. Good luck.

[Terry1954]

One to follow guys @RidgeRunner and @Sabrejet, although John is of course using the wrong scale 🤪

 

Terry

[Corsairfoxfouruncle]

As I've considered doing this very same thing mind if I follow ? 

[SAT69]

Thanks for showing that it can be done. Really looking forward to the end result.

[exdraken]

nice project!

 

[plasticpilot]

On the subject of the sabres wing sweep  This is an interesting analysis.

 

http://www.clubhyper.com/reference/sabrewingsjh_1.htm

 

 

[Shorty84]

Quite an ambitious conversion you are showing here. I've also thought about doing this multiple times so I will follow with interest. And of course it is the right scale

 

Cheers

Markus

[plasticpilot]

I have also got the new Kittyhawk FJ-2 which matches the Hasegawa and Academy wing sweep.

[plasticpilot]

This post was supposed to be to show the progress on converting the F-86D wing to a late 6-3 slatted wing.  Including the correction of the wing sweep of the Revell/Monogram wing.  Sadly that is not the case and the wings I was working on have gone to the great plastic scrap merchants. 

I had commenced the conversion based on the well published principle of a slice that should be removed to a 6-3  the wing to get the original chord.  Usually quoted when converting a Hasegawa or Academy F-86F-30 hard edge into an earlier slatted F or E.  In the case of the late F-86H, or F-86L, I am going the other way in that the slice has to be added to take the F-86D early slatted wing to a F-40 slatted wing. But once one starts to look in a little more detail the position and width of the slice is not so clear. 

Running spanwise , behind the leading edge, is a distinctive join line.  It consists of a castellated edge on each side that knit together when the leading edge is attached to the centre section of the wing.  Monogram did a very good job of representing this on the F-86D.  Ditto Hasegawa on their F-86F-30, although a bit fainter.   This forms the baseline from which the leading edge, slatted or fixed, is attached.  In photo 1 the F-86A has the early slatted wing.  You can make out the castellated line just to the left of the edge of the slat recess.  There is a narrow strip then the castellated line.  A subtlety is that it is not straight.  Inboard it has a bend.  You can see this more clearly on the bottom left photo of the F86F-40.  Monogram and Hasegawa have correctly detailed this.   There are several drawings that incorrectly show this as straight.  Osprey’s Korean Aces book is one.  The Air Force Legends series and the Squadron Signal F-86 Walkaround being others.  This can lead to the illusion that the leading edge is tapered.  In fact they are constant chord other than inboard where the castellated line bends backwards slightly .  Fixed or slatted. 

It is worth noting here that there are variations in slats.  It could be the angle but the F-86D slots for the arms seem to be larger and deeper than the F-86A.  Although in both cases the arms and slots appear uniform.  It can be clearly seen on the bottom left F86F-40, that the arms nearest the camera are different to the others.  Look at the inboard arms and they also are larger.  I have a KASL set of slats for the Hasegawa F-86F-40 and these are correctly modelled to show the different outboard  two arms but not the two inboard ones.  I have not found a photo of a Japanese Sabre that shows the slat arms.    These larger inboard and outboard arms are on F86F-40 and Canadair Sabres and can be seen in picture 2.  Note bottom right picture  under the wing shows the lower castellated join.  Monogram missed this completely.

So now the question, where is the 6-3?  Looking at the bottom left F86F-40 wing in picture 2 the addition between the slat recess and the castellated line is constant.  Not tapered.  This is very clear in photo 2 of an F86F-40 wing..  I have drawn some green guides on picture 1 to calculate the size of the addition.  The slat is about 12 inches wide which makes the addition about 3 inches.   Its not exact but its tricky getting an exact measurement given the perspective and without a plan view.  So there we have the 3 in ‘6-3’.  Note that this 3 is perpendicular to the spar line.  NOT the centreline of the aircraft. 

So now where does the 6 in ‘6-3’ come from.   Move to picture 3

These are close ups of the area around the leading edge and the ammunition door. Both are square on photos and have been sized to match the door length which is 24 inches.  The red lines are the leading edges where they meet the fuselage.  This scales, from the hatch length, as 6 inches.  So there is the 6 in ‘6-3’.  But if we have added a constant addition of 3 inches between the spar and the slat, how can the difference be 6 inches at the root?  This 6 inches has been measured in line with the centre line of the aircraft.  The 3 inches was measured perpendicular to the spar line.  So it forms a right angle triangle with the 3 inches forming the adjacent to the wing sweep angle and the hypotenuse being aligned with the aircraft centreline. So the effective move forwards along the centreline comes out approximately 4 inches.  So where are the other 2 inches?

The fuselage side that the wing root joins to is not parallel to the centre line of the aircraft.  It has a curve inwards as the fuselage tapers to the nose.  By moving the existing leading edge forward 4 inches a gap would appear between it and the fuselage.  To resolve this the leading edge has to be extended inwards and shaped to meet the fuselage.  In doing so it moves the point it meets the fuselage further forward.  So the 4 inches actual move forward gets extended.  It crosses the edge of the ammo hatch.  So the designers fill the gap partly by a detachable extension to the leading edge and partly by a fairing built onto the ammo hatch.  The combination of making it a separate assembly with a fixing at the back will have an incremental effect.  Plus this is not perfect engineering, as anyone who has been close up to an aircraft of this era.  Can I make this add up to exactly 6 inches? No.  But this is all done from photos.  What would be perfect is if we could access the manufacturer’s engineering drawings for the wings.  But we probably are not.  If I get the chance of access to a real F-86 I may be able to get to the finer points of that leading edge  tip.  What I am very confident of, based on the photographic evidence, is that the leading edge extension is a constant 3 inches from the original f-86E one.

I do not have the Airfix 1/72 Sabre so the following comment is based on review photos of the wings.  Airfix have done the castellated line straight from the wingtip to the wing root.  They appear to have used the correct point at the wing root that the real castellated line comes to.  This then gives the impression of a tapered strip between the castellated line and the slat housing edge.

The Hasegawa 1/32 Sabre has the correct constant chord leading edge and the bent castellated line. 

The Academy 1/48 has a straight castellated line and a subtle taper. 

The Kinetic 1/32 has a bit of taper on the outboard leading edge but does have the bend in the castellated line.

The Hasegawa 1/48 is spot on.  Probably because they measured a real aeroplane.  Constant chord leading edge.  Where they have made a mistake is the engraved line on the extended inboard tip of the leading edge for the detachable tip.  It is too far back and does not align with the ammo hatch.

After explaining how the castellated line joining the leading edge to the centre section of the wing has a bend in it there is an exception.  It would appear that when the F-86H was designed the wing was changed.  On the F-86H the castellated join line IS straight.  Picture 5 shows this.  It also shows the castellated edge.  Another interesting point on these photos is the slat arm slots.  These extend all the way back to the edge of the slat housing and the slat arms and slots appear narrower.  Also the fuel filler shown in the left hand picture is closer to the castellated join than on other wings.

Of course all this flies in the face of much published wisdom.  There are numerous ad hoc drawings showing the tapered  leading edge.   In a comprehensive article where the 6-3 insert is described it states …..and the angle of leading edge sweep increased slightly to 35.7 degrees.  It is true that if a tapered 6-3 insert was added it would increase the leading edge sweep.  Except the leading edge does not have 35 degrees sweep.  It’s the 25% chord line that is 35 degrees.  The leading edge sweep is more like 38 degrees. Get your Hasegawa Sabre out and measure it.  So the ’35.7’ statement is questionable and we have to ask where did it come from.    I have an insert to an Aeromaster decal sheet that advises that to convert the Hasegawa 1/32 F86F-40 to a ‘real’ 6-3 wing you should split the wing down the centre and add a tapered there?  One, the addition to the Sabre wing was done by extending at the leading edge, not the centre section of the wing.  Two, the Hasegawa Sabre is an F-86F-40 6-3 slatted wing already?

Right so that is my view on the subject and I will now get on with first of all correcting the F-86D wings sweep for use on a F-86D. Then as a F-86F-40 for a F-86L and lastly the F-86H wing.  It was all so much simpler when I was young.  I just stuck them together.  🤔

 

 

 

 

 

 

 

 

 

 

 

 

[plasticpilot]

A slight addendum to my post.  In Picture 1 the title F86F-30NA of the the top left photo is incorrect.  It is in fact a F-40 wing as can be seen by the extended wingtip and straight pitot tube.

[plasticpilot]

Had a look at the Kittyhawk 1/32 F-86K  which is of the later ones with the 6-3 slatted wing.  Has a constant chord insert and the bent castellated join line for the leading edge.  They must have looked at a real one  😃However they have missed the different slat arm sizes.   😪  Google F-86K walkaround and you wlll hit some good photos of a dutch one that shows the K had the differing arm sizes.

 

[plasticpilot]

Well here is the start on correcting the sweep of the Revell Monogram F-86D before changing for the F-86H.  The objective is to cut the wing so as to preserve the detail.  A diagram has been drawn with the new wing sweep on as a guide for rejoining the parts.  Here is the lower wing with cuts done and laid over the diagram.  The cuts were done with a scalpel and steel ruler.  

 

Now starting to assemble with 10 thou tabs.  Use 10 as you need some flexibility.  All the cutting and gluing will lose the air foil shape so you will need to manipulate it a bit afterwards to get it back.

Not the corrected line shown is the leading edge with the slats.  Hence only the inner leading edge and tip leading edge are touching it..  The wingtips were carefully removed before using a scalpel and the engraved line.

Fully assembled.  It will need some filler but after  the air foil has been re-shaped and glued to the upper wing halves.

 

Next picture shows the tabs used for assembly.

 

And now an upper wing.  When you assemble the upper wing after cutting check it against the new lower wing.  The white plastic card is two sheets of 60 thou to support it as the slat arms need to be protected.

Plastic card tab under the upper wing.

Next post will be putting the wings together.

[Sabrejet]

Wing sweep does change with addition of the 6-3 wing since the 25% chord line also moves; by 1.5 inches at the root and 0.75 inches at the tip. The change is stated in numerous NAA documents and not a recent error. NAA also make a point of stating that the sweep is at 25% chord, so any leading edge statements are recent mis-interpretations.

 

I did a post on leading edges a while back, which I shall post a link to if I can find it.

[plasticpilot]

@sabrejet Completely agree that the wing sweep must have changed with a constant addition along the leading edge.  Confusing though when, as I referenced, they describe it as the leading edge  With a constant width addition along the castellated line it would not increase the leading edge sweep.   I scaled the wing root and wing tip chords of the Revell F-86D and adjusted for 6-3.  I took the F-86D as being the same as the F-86E original slatted wing.  Well it better be   Came out bang on the 1.5/0.75 first time.  Back now on trying to get the Aerofoils back into shape of the butchered wings.

 

 

Re the slat arms.  Have you seen any photos of the Japanese built ones with the slats open sufficiently to see the arms?

[Sabrejet]

Will have a look. For info, the 'castellated' part is a hinge line; the leading edge is retained by circa 18 SWG hinge wire top & bottom, as with many aircraft (C-130 for example).

[Sabrejet]

3 minutes ago, Sabrejet said:

Will have a look but all F-40 wings are the same. For info, the 'castellated' part is a hinge line; the leading edge is retained by circa 18 SWG hinge wire top & bottom, as with many aircraft (C-130 for example).

 

[plasticpilot]

@sabrejet Well that would make the KASL slat set incorrect.  It has the outboard two arms different but not the inboard two.  Which I think from the photos is the case.  I thought it may be a characteristic of the Mitsubishi built ones.

[Sabrejet]

Hopefully these will be of use. First off the F-86F-40 slat tracks & part numbers:

 

 

Then F-86H equivalents (different PNs):

 

 

And verification that the wing sweep changed with the 6-3 & F-40 wing on F-86H (highlighted):

 

 

And a narrow-chord diagram showing various dimensions: note what appears to be a leading-edge sweep shown as well (you'd need to re-calculate for 6-3):

 

 

Some wing/leading edge stuff from the F-86H Structural Repair Manual:

 

 

 

Fuselage and wing Stations:

 

 

And finally wing skin materials; should help when painting NMF:

 

 

Enjoy!

[Chemguy3000]

This is why I love BM. Such amazing resources shared with each other.

 

David

[plasticpilot]

@sabrejet I have many of these in the Air Force Legends but the slat assemblies I have not seen.  There is some excellent info in these drawings although they raise a few questions.  The dimensions given are extremely useful in particular the Stations for the slat arm slots.  As scale diagrams though they are questionable.  These are not drawings scaled from blueprints.  These have been done by an illustrator and as such you cannot use them to check outlines etc.  The last figure 1-9 of the airplane stations has a distorted tail.  Scaled to 1/48 using the centre line 0 to jet pipe 429.3 the rudder hinge line 10.6 to 63 should be 2.77 cm.  In fact on the diagram it is 3.25 cm.  The illustrator has drawn the rudder base to low.  Comparison to photos bears this out plus the figure 1-4 GA.  The GA in the Air Force Legends book is more reliable.  It highlights that these diagrams from manuals were never meant to be 'true scale' diagrams and as such cannot be used for that.  The slat diagrams are not isometric projections nor accurate perspective drawings.

You mentioned that Figure 1-4 has some leading edge sweep information but I cannot see anything on it.  It has some interesting dimensions but again is not a scale diagram.  The wing x and y axis are not at 90 degrees on the diagram.  There is some odd annotation which shows the angle between the airframe x axis and the wing y axis as 90 degrees?  Which it cannot be.  It shows the wing sweep at 25% chord as 35 degrees although above the table states 35 degrees and 40 minutes.  I would say that the wing in this diagram is from an an earlier slatted one before the F-30 hard edge and then been changed..  If you use the airframe axis to jet pipe station numbers of 429.3 inches the span comes out at just short of 37 feet.  .  Whereas the f-86H should be 39 feet. They have however sketched in what looks like the extended wingtip of the extended wing. 

 

The slat diagrams are very good.  The F-86H shows the arm slots going all the way across the slat recess which is born out by photos.  The F86F-40 looks like it is an F86E diagram that has been used.  It shows the arm slots uniform and going half way across the slat housing.  You can see this is the case on F-86A and F-86D photos.  Monogram have modelled this correctly on the F-86D.  All the photos of F86F-40 wings show the slots to be of varying sizes and the slat arms to protrude in varying degrees.   

 

Modelling wise if you want to do slats open then the F-86D slats can be used for an A or E.   For an F86F-40 wing the slots will need to be modified and the different arms made.  The KASL set go some way on this but do not fully show the level that some arms now project above the slot when extended.  For the F-86H all the slots need to extended and new arms fitted.  If using the Monogram slats on another wing a consideration is that the slats and the housing are too long.  When they swept the wing too much Monogram 'stretched' the slats a bit.

 

[plasticpilot]

Well a bit of progress on the wings.  The wheel well parts have been added and these give the wing a bit more solidity after all the cutting and gluing.   I set out to do this wing as the F-86H wing.  However from the research it will need more serious butchery.  So I am going to complete it as a F-86D wing.  I will start another one that will have more support internally to cope with the added cutting.

 

When Monogram swept the wing too much they maintained the correct wingspan.  This meant the leading edge got a bit longer.  In doing this they moved the outer most slat arm outwards.  This means before the wing can be trimmed to the correct span it needs the last slat arm and the end of the slat housing moving inboard.  The following picture shows the housing and slat cut out.  The piece between the end slat and the next has then been trimmed on each end and glued back in with the slat.  Needs a bit of tidying up.  When the wings are glued together plastic card will be inserted in the gap and sanded to shape.   Note that on the underside of the wing Monogram have inscribed a notch matching the position of each slat arm.  These actually denote small coverings that are affixed to each arm.  As the slats deploy they move out with the arm.  So if you are modelling the slats open these notches should be opened up before gluing the two wing halves together.  The position of the outermost one has been adjusted to match the re-positioned slat arm.  At the beginning of this article I posted a picture of slats.  One is taken from below and you can see how on the F86F-40 wing the slat arm protrudes through the notch and one can make out the cover on the slat arm.  

 

[plasticpilot]

Well a major re-think on how to do the wing.  In assembling the cut parts it is very difficult to regain the aerofoil profile of the wing.  So much cutting and gluing has made the wing very flexible so I went back to the drawing board based on providing some internal stiffening.  The next two pictures show how it was done.  Rolled milliput was added to the uncut wing and then covered in cling film.  Then the wing closed up.  Not glued.  After a while it is opened and cling film removed.

 

After this some is cut and removed where the cut lines will go and joining tabs.  Cut lines are a shown in previous photos.

When re-assembling the wing start with the lower wing and use the fuselage as a guide.

When re-assembling the upper wing trial fit to the lower wing.

And finally the wing closed up.   The joins have been filled with sprue melted in with liquid glue.  Getting a uniform join is easier if all material are the same hardness.  When re-assembling the wing it is important to get the joins as flush as possible to minimise work at this stage.

 

Edited May 10, 2020 by plasticpilot
spelling

[Gene K]

On 4/14/2020 at 8:03 AM, Sabrejet said:

Hopefully these will be of use. First off the F-86F-40 slat tracks & part numbers:

I'm not seeing any of the pictures, and clicking on the "links" gives me Flickr 404 error. I'm using Chrome - anyone else have this problem, or is it my system?

 

Thanks.

 

Gene K

[Corsairfoxfouruncle]

6 minutes ago, Gene K said:

I'm not seeing any of the pictures, and clicking on the "links" gives me Flickr 404 error. I'm using Chrome - anyone else have this problem, or is it my system?

 

Thanks.

 

Gene K

No I can see the photo’s fine. Im on an iPhone 10 so that may make a difference, not the same type of programming.