Curtiss MF Flying Boat

[Skyking]

I enjoyed building my NC4 so much a while back I promised myself I will one day do another Curtiss Flying boat. I came across a set of Paul Matt Drawings for a Curtiss MF (Modified F) in a set of Historical Aviation Albums I got off Ebay, so it rekindled the spark and I've jumped in with both feet. This is going alongside making a master to cast some resin Edo Floats for a TBD-1a Devastator float plane conversion I am also working on. I guess I am returning to my favorite era of Pre WW2 US Navy aircraft after doing a rash of WW1 subjects. I also have a set of plans for a Martin T4M that I will begin after I finish the MF Boat. US Navy Yellow wings forever.

This is pretty much straight up basic scratch-building, nothing new or outlandish. I carved the hull master from a block of basswood and I am waiting for Pete Fleischman to stop by next week with his wonderful little vacuuform machine to pull the hulls. I am making my own vacuuform, and have it together, but I need a better heat source than the old electric griddle I attempted to use. It gets the plastic just soft enough to deform, but not soft enough to pull over a mold. I am looking around for an electric griddle with exposed elements. That should do the trick. Anyways, back to the model. I carved the main hull first, then carved the little wedge shaped sponsons on either side of the hull, glued them on and sanded them to final shape. I thought it was easier to do it that way than to try to carve them out as one piece. The wing blanks are modified Lindberg Curtiss Jenny wings. I will be using two kits for the wings. The upper wing of one kit was used for the two outter upper wing panels, and I used one of the lower wings to cut the upper center section out of. I had to fill in the cutouts in the upper wing, and I used bits of the other lower wing and glued them in place and filled them with CA before sanding smooth. All wing ribs were sanded off as they were a bit on the heavy side. I am debating whether I will re skin the wings like I did on my DH-10, or if I will apply decal strips for the ribs as I did on my Curtiss N9H. Curtiss wings didn't have much sag in between the ribs, so I am inclined to go with the decal strips over re-skinning. The Horizontal stab is a chunk of 1/16 basswood sanded to shape and skinned with .005 plastic, and I'll do the same with the Rudder and Fin. I didn't emboss them very deeply, as again, they were quite tight with little sag between the ribs. I am waiting for another Jenny to arrive that I purchased on E-Pray. I will use the top wings in that kit to make the lower wing outter sections, and then all my major airframe components will be finished. I have bought 4 Lindberg Jenny kits over the past few years, and have yet to build a Jenny! They were all sacrificed to build other projects, first the N9H conversion, and now this. I really need to get another one and actually build a Jenny

There won't be many updates on this one for a while, until I get the hull halves pulled and begin construction, but you get the gist of what it will look like. I am very fortunate to have the Curtiss Museum less than an hour away, and they have an actual MF Flying boat on display, that I have taken copious pictures off to aid me in my construction. After this is finished and I've done the show season with it, my plans are to give it to the museum to display in the same case as the NC4 I gave them a few years back, and bring home my N9H that is on loan.

Enjoy the pictures.

Here's the basic hull without the sponsons after basic carving. I have yet to final sand it to shape. The drawings I am using are behind them.

Here I have the sponson blanks glued on but not carved yet. It was much easier to do them separate than it was to try to carve around them. I think I would have lost some fingers if I tried.

Final hull after sanding. I laid it over the plans and I am very happy with the results. It is a smidge undersized to allow for the thickness of the plastic when it's vacuuformed.

This is the upper wing, with the right and left outter panels and center panel all made from one donor kits wings. I used a chunk of the other lower wing to fill in the notches....

... and here is the final blanks. I have to cut out the ailerons yet, but the wing strut locating slots and holes are all filled. I will plot out new locating holes after I get the lower wing blanks made. The 12 inch ruler gives an idea of the size of the model. I temporarily glued the lower wing center sections in place to check for alignment and fit.

And lastly, here is the Horizontal Stab. 1/16 basswood core sanded to an airfoil, then skinned with .005 plastic, with the edges sealed with CA to "plasticize" the basswood. The CA soaks into the wood and after it cures the wood can be sanded and painted just like plastic.

That's all for now. I'll post more after Pete stops by and we can pull the hull halves.

Cheers and Happy Holidays

Mike

Edited December 21, 2006 by Skyking

[Louis]

Another classic Flying boat gets done by Mike, looking forward to seeing the result.

Merry Christmas.

[mbittner]

Awesome, quite awesome.

And another bit of evidence for the men in the white coats.

[Skyking]

Thanks Matt and Louis, appreciate the comments. By the way Louis, thank you for the excellent pictures of the MF at the museum in Ottawa. I am going to replicate that airplane with this model, and your pictures posted at Seawings were most helpful.

Well I decided to bite the bullet and I re-skinned all the wings. I was afraid that the tail feathers and wings wouldn't be consistent in look or appearance so I took the plunge and cut and embossed 8 .005" wing skins for the tops and bottoms. The end results you see below. I also cut the elevators, made the fin/rudder, and pinned them together temporarily to check for fit, etc.

All my airframe components are done, so now I will begin making the engine. The real aircraft used a Curtiss K-6 6 cylinder inline watercooled engine, and there is nothing like it in any kit or aftermarket so I need to make one. I have some good drawings and photos of it so it shouldn;t be too much of a job. I could take the easy route and use the Hispano V8 from a Lindberg SE5, as it was an available optional engine, but then it wouldn't be accurate for the machine in Ottawa. I'll post some shots of the engine after it's complete.

Completed airframe components, with the exception of the actual hull halves. Pete will be over some time next week to vacuform those for me from my masters.

Closeup of the Fin/Rudder. I used .020 brass wire for locating pins and spars, and everything fits and lines up nicely. I could probably go ahead and paint these now and set them aside.

Cheers and Merry Christmas.

Mike

Edited December 24, 2006 by Skyking

[S1b]

Truly Amazing!!! Looks great!!

[Skyking]

I've had a few offline comments about the cleanliness of my bench, and wondering how I manage to keep it so neat when I am working. Well truth be told, I don't. I have just gotten into the habit of putting things away and cleaning up after I have finished working for the day. I've found it's a lot easier to keep a bench clean and tidy if you do it as you work, rather than let things pile up and try to do it once in a while. To give proof that I can make as good a mess as anyone I've included this shot just to show I am no Felix Unger. :)

This shot shows how I plot out my strut locations and rigging holes. I use a square. straightedge and compass to mark out my locating holes, and use a pin in a pin vise to center punch the hole to prevent my drill bit from wandering off center. Keeping the top and bottom wing lined up, I simply use the square and mark off both wings at once, then square off those lines for the rigging holes. It takes a little more time, but this ensures that my struts stay lined up and parallel with each other.

Here's the beginnings of my engine. The machine I am modeling uses a Curtiss K-6, 150HP in-line 6 cylinder engine. This engine was unique in that the cylinders and upper half of the crankcase were cast as one piece, then steel liners inserted for the cylinders. Two cylinders were siamesed together and a one piece cast aluminum head, with a single overhead cam opening and closing a 4 valve per cylinder arraignment, with hemispherical heads was bolted atop of them. It's kind of odd how auto manufacturers boast about the "latest" technology with their fuel efficient engines, when the basic concept they are using dates back to 1918. Glen Curtiss was ahead of his time for engine design, obtaining more horsepower at less weight than anyone else at the time. I've used bits and pieces of evergreen, contrail tube, and the snout off one of the Lindberg Jenny engines to make my engine. I have yet to make the intake and exhaust, cam drives, and carb, but the basic engine is pretty much there. Seeing as it all hangs out in the open with no cowling, I have to make it look as complete as I can. The overall length of the engine is about an inch.

I'll post some more shots as work progresses,

Cheers

Mike

Edited December 26, 2006 by Skyking

[Skyking]

The engine is coming along so far so good considering all I have to work from is a fuzzy photo and a written description, as I was unsuccessful in locating any drawings of the K-6. I was able to locate some of the Curtiss C-6 engine, which was developed from the K-6, the biggest difference is that the C-6 used separate cylinders and had the spark plugs on either side of the head, as opposed to both being on the right side on the K-6. Everything else looks the same, or near enough that I can use the C-6 references to make this from.

I had to remove about .125" (4mm) off the back end of the block, as it was too long. When I installed the waterpump, the cam drive was too far away from the rear cylinder, and according to the one picture I have, it's very close. I popped off the waterpump, the two rear lugs along the block and oilpan, and sanded off the amount needed. I glued everything back on that I removed, and had to make a new water-pump as the first one was deformed in the "popping off process". I've got the Cam Drive finished, the Mags and water-pump are in place, and the beginnings of the intake/exhaust manifolds are set in place. I through drilled the head and used .030 solder for the exhaust and intake, running them all the way through so that I can keep them aligned and straight with each other side to side. In these pictures, they are not glued in place yet, just slid into place for photo purposes. In progress now are the pipes to deliver coolant to the cylinders, and the ignition harness to the 12 spark plug holes just underneath the Intake Manifold. I have to make the downturn portion of the manifold and the carb yet, but should have all those parts done by this weekend.

Cheers

Mike

Edited December 28, 2006 by Skyking

[Barneydhc82]

Mike: Great looking build! Now I'll have to finish with the vac-forming on the "Alley Cat". I found some .015" Evergreen plastic sheet and that will be used to skin the wings.

I'll be following this one very closely

Barney

[Skyking]

Mike: Great looking build! Now I'll have to finish with the vac-forming on the "Alley Cat". I found some .015" Evergreen plastic sheet and that will be used to skin the wings.

I'll be following this one very closely

Barney

Hi Barney,

Thanks for the comments. PM inbound.

Cheers

Mike

[Skyking]

The engine is finished, with the exception of plumbing the cooling lines after I get it mounted in the mounts and get the radiator made. I am quite happy with it. I am not sure if it 100% accurate, but it looks close enough to a K-6 for me.

Next to get tackled will be all the interior fittings such as control column and wheels, rudder bars, etc. I managed to find an old electric BBQ grill on EPray that has an 1800 watt exposed element, inside of a stamped aluminum dome, that I think will provide me with a good heat source for my homemade vacu-form. I should get it later this week, so hopefully next week I can pull the hull halves. If not they will be placed in the capable hands of Pete for him to take care of.

Cheers

Mike

[Old Man]

Great to see you back on the horse and busy through the holidays, Mr. King!

This is shaping up splendidly. The motor is spectacular. I am glad to see from the drawing that it will be wholly exposed when the model is complete.

I am quite unfamiliar with the Curtiss range of flying boats, outside the "Americas" that the English used in the North Sea. Was this a war-time design, or is it from the twenties? It looks a little like the French F.B.A. types.

[geedubelyer]

Holy smokes Mike...... :blink:

You sure know how to set yourself a challenge.

This one nearly slipped in under the radar but I found it ;) It just shows I don't spend nearly enough time in this forum.

I remain very impressed by your plasticard skinning technique. It certainly is convincing.

I can't wait to see further updates on this build. Keep 'em comin'

Happy New Year.

[Skyking]

Hi Old Man,

Was this a war-time design, or is it from the twenties? It looks a little like the French F.B.A. types.

The MF Seagulls are trace their roots back to the Curtiss F Boats of WW1. Bigger, heavier, more payload and with more power, it was designed in late 1918, and its first flight was early 1919, so even though it was designed in wartime I guess you could call it a postwar airplane. They were produced as two variants, the MF version, or Modified F , and the more "upscale" civilian version, the Seagull. Powered by either the K-6 or C-6 inline engines or the V8 Hispano's they were quite popular with bush pilots and explorers. In fact, this particular machine I am modeling was the first aircraft to explore the upper Amazon Valley in Brazil. During 1924-25, it also conducted an aerial survey of the Parima River headwaters. It is now on display at the Canada Aviation Museum in Ottawa. The machine at the Curtiss museum is a Modified MF. It has a full Clark Y airfoil, new wing floats and an upgraded Hisso engine, and is on loan from the Ford Museum in Detroit MI. I choose not to build that one, mainly because the polished mahogony, brass and forrest green trim of the Canadian machine is much more visually appealing.

Hiya Guy,

I remain very impressed by your plasticard skinning technique.

I wish I could take credit for it Guy, but it was pioneered by a true craftsman and modeler, Harry Woodman. If you want to read more on his techniques, check out this link. It is by the Master himself and my bible for scratchbuilding.

I am mocking up the engine mounts and radiator support, so that it can be finished as a subassembly and installed once the hull is together. I am used .060 plastic strip, Contrail strut and .040 sheet for the different bits and peices. The radiator itself is started, but not completed. I have to make the header tank and frame, louvers, and plumb the hoses to the engine. I made a jig from plastic sheet to set the height of the engine mount, then cut my struts to length while it was jigged in place. I made them a smidge long on purpose to compensate for the thickness of the plastic hull, I'll adjust them to correct length one the hull is formed.

Thanks for the comments everyone, as always they are welcome.

Cheers

Mike

[Skyking]

The engine unit is just about finished. All I have to do is add the radiator return hose from the pump to the bottom of the radiator, and touch up some oops with aluminum paint and I can set it aside until final assembly. I used ModelMaster Dark Tan for my wood, overcoated with Tamiya Clear Yellow to give it a varnished look. It looks OK, but I am going to try Clear Orange instead and see if I like that better. The green will really contrast nicely with the mahogony and brass.

This is the actual subject I will be modeling. It looks like a peice of fine furniture as much as it does a flying machine.

http://www.aviation.technomuses.ca/collect...ssSeagull.shtml

Cheers

Mike

[geedubelyer]

The engine unit is just about finished. ........................ The green will really contrast nicely with the mahogony and brass.

This is the actual subject I will be modeling. It looks like a peice of fine furniture as much as it does a flying machine.

Cheers

Mike

Whoa..... :blink: That is some seriously "sudden" green. :blink:

The rad. elements look very convincing, can you tell us what you used please Mike?

Great link BTW. All of that beautiful, varnished wood reminds me of expensive Riva motorboats. Lovely!

[Skyking]

Hiya Guy,

The rad. elements look very convincing, can you tell us what you used please Mike?

Nothing more than a slab of .040 plastic, edged with .005 and a header tank made from a shaped scrap of Contrail strut Guy. The mesh on the front and back is from an old pair of Nylons I pilfered from my wife as a paint strainer long ago.

Today I did more mocking up of the airframe. I had some concerns of the upper wing center section clearing the engine. I measured my struts and stuck them in place and actually have some room to spare, so my worries were for naught. My next goal is to get the upper wing sections mocked up in place and get the struts cut, then drill the wing roots for the spar wires and set everything in place for a final alignment check. I hope to have my vac-u-form up and running here soon. I'd like to get my hull halves formed so I can begin putting everything together.

Cheers

Mike

[Skyking]

Eureka! ( Or in my case... Shop Vac! ).... my vacu-form really sucks! OK OK Sorry about the puns guys.

I was able to find an electric BBQ Grill on Epray for 10 bucks, and with the exposed element it throws out enough heat to really get my plastic nice and soft. I am easily able to pull .030 sheet and get nice tight corners with just my Shop-Vac for a vacuum source. Needless to say I am greatly relieved, and can now proceed on hull construction.

My total expenditure on the vacuuform is about 30 dollars. I found an old filing cabinet at a used furniture place for 10 dollars, 5 dollars for a piece of pegboard already cut to size, the 10 I spent on the BBQ, and another 5 on the aluminum for the frame and hardware to bolt it together, and scraps of trim lumber I already had. It took me about a day and a half to conceive the layout and build it, and it works. What more could I ask for?

Here's my completed hull halves fresh after pulling. I checked around the edges and there's no gaps and everything is nice and tight. I can now begin hull construction in earnest.

Various parts needed to build Vacform.... 30 dollars on Master Card

4 x 8 foot plastic sheet cut to size... 15 dollars on Master card

Being able to post bad puns on the internet... Priceless.

Cheers

Mike

Edited January 13, 2007 by Skyking

[mbittner]

<chuckle> Good ones, Mike.

The vac parts look good! So, willing to vac stuff for the rest of us? :unsure:

[Old Man]

Very impressive, Mr. King! The parts produced, as well as the scrounging and contriving the means of their production. I would also echo, only partly in jest, Mr. Bittner's question, as lack of a good greenhouse is keeping a Mk. I Blenheim kit in the stash instead of on the table.

Thank you for the background on the machine you are modeling: a most interesting career.

As for the other, these words of wisdom: "People who make puns should be drawn and quoted."

Edited January 13, 2007 by Old Man

[geedubelyer]

Wow.....very innovative Mike. That looks like it'll open up all sorts of possibilies for your future projects.

I hope the fuselage halves come out nice and clean, I'm looking forward to seeing more progress on this beauty.

[Skyking]

Thanks for the comments everyone. And yes Matt, if you need anything done let me know. I'll try to help you out. Same goes for you too OldMan, if you have a Master of the canopy you need I'll try to do it for you.

Guy the halves came out cleanly, but the ones in the picture I did using .030 sheet and they are a bit too thin for my comfort. I redid them using .040 and forming one half at a time instead of both, and it pulled the .040 without a fuss. In fact they came out nicer than my first set, so to be safe and cover my backside I made 2 more sets of the .040.

When I planned the vacuform out I wanted it to be able to do larger pieces. I have two base plates and two sets of frames, so I can make parts as long as 14 inches, which will be plenty for most of my projects.

My next plan of attack is to get the halves cut out and sanded to shape and begin interior component construction. I'll post some shots as I progress.

Cheers

Mike

[Pete "Pig" Fleischmann]

Dude! you strain your paint too!? maybe that's my problem.

Anyhoo-Sweet vac set-up you've made! I guess you and I will have to come up with another excuse to have a few beers...wait..we never did need a reason.

Gorgeous model BTW! You are still the man!

Regards,

Pig

[Skyking]

Hiya Pete,

Dude! you strain your paint too!?

Just the first time I reduce it Pete. After that I just mix it with a Badger mixer thingie and it's all it needs.

Thanks Pete

Mike

Today I made some good progress on the Hull. I redid them in .040 and they are nice and thick and reasonably stiff, which makes them easier to work with. The down side is the edges tend to get round instead of nice and square, but I got a trick up my sleeve that will fix that.

The cockpit basics are done. I made separate sidewalls with the stringer and former detail added before putting in the fuselage. It made it easier to cut and measure them. I CA'ed the side panels in place after I was finished adding the structure. The ribs for the bottom of the hull are there, as the floor is a slat floor and you can see down between them to see the bottom of the hull. I have to make the keel yet, and that will go in before I glue the halves together. The floor is finished but not glued in place, I just set it in for photo purposes. The instrument board is also just tacked in place. I will remove it to add the instrument dials and other assorted bits. So far so good, I am happy with the progress and the results so far.

The side panels are .005 with .010 and .020 strip for the stringers. I found some really nice pictures online of an MF without any fuselage planking so I could see exactly how this thing was built. I copied it from the photos and it looks pretty convincing. The floor slats are .020 strips with 3 .030 x .030 square strip for cross pieces. There is about a 1/16 inch gap on either side of the floor for the control column. The ends go below the floor for the attachment of the elevator cables, and the aileron cables also go underneath.

This shot shows the floor sitting in place and gives an idea of the layout. Next I have to make the seats, which are basically wooden slats, much like a park bench. I can only imagine how a rough water landing must have felt sitting on a hard Worden seat. Ouch.

Here's the hull sitting together, nothing glued yet. I have to "sharpen" the edges yet, and make a few more cockpit items. Then I can begin painting the cockpit and start final assembly.

Cheers

Mike

[geedubelyer]

Once again, I take my hat off to you Mike.

This is what modelling is all about in my books. Crafting a scale replica from scratch!

In your company I consider myself to be a scale model assembler and feel most humbled.

What a treat to watch something start life as nothing more than a few sheets of plasticard and some plastic extrusions and develop into this. A genuine model aeroplane....

Marvellous... ^_^

I'm waiting for your next update with baited breath, keep at it sir

[Skyking]

Once again, I take my hat off to you Mike.

This is what modelling is all about in my books. Crafting a scale replica from scratch!

In your company I consider myself to be a scale model assembler and feel most humbled.

What a treat to watch something start life as nothing more than a few sheets of plasticard and some plastic extrusions and develop into this. A genuine model aeroplane....

Marvellous... ^_^

I'm waiting for your next update with baited breath, keep at it sir :wub:

Wow thanks Guy. I appreciate the comments. Now pardon me a second while I squeeze my head back to it's normal size...lol.

Seriously though, I hope this doesn't sound contrite, but I find scratchbuilding easier than putting most kits together. If I follow my drawings and take my time measuring and double checking as I go, my parts fit together better than most kits do. Now if I get in a hurry and begin rushing things, that's when things can begin to unravel pretty fast and all bets are off. That's why I try to limit myself to an hour or two a day of modeling, just to force myself to take my time and not rush things just for the sake of getting something done. I take a great deal of satisfaction knowing I have created something from, as you say, bits of plastic sheet and extrusions, but I also have a great deal of respect and admiration of those that take a mundane kit and turn it into a really nice model, much as you are doing with your Camel. My experience has taught me that a poorly fitting kit or poorly engineered kit, is much more work than scratchbuilding.

Cheers

Mike