Scratchbuilding a 1/32 1927 Ford AT-4 Trimotor

[geedubelyer]

Mike,

The collector turned great!

Rocky

Hi Mike,

I'm with Rocky, that exhaust collector is da' biz! What a simple yet brilliant solution. Your ingenuity is boundless.

Can't wait to see the heated metal finish on that.

This Ford continues to impress. You raise the bar with every update, great stuff.

[Timmy!]

Mike,

Congrats on the engine - looks really good. I'm anxious to see the photo etch parts. Drawings look spot on!

Timmy!

[Skyking]

Wow I really had to blow the dust off this one..lol. *Sneeze*

Timmy, Guy, Rocky, Mareku,

Thanks for the comments guys. I hope to have the PE back done in about a week so I can begin putting the interior bits together and get this flying garden shed together. I've begun the jig to rig the outter nacelles and get the struts cut to length and I've taken some pictures along the way. I'll post a few later this weekend as time allows.

Thanks for following along. Admittedly this part of the build is pretty ho-hum, but there's better stuff coming on the horizon.

Cheers

Mike

[Skyking]

I've started the engine nacelles and the supporting strut work that suspends them under the wings. To make sure everything is the same dimension and uniform with each other, I made a jig to hold everything in place while I cut struts to fit. The jig is nothing more than a hunk of birch ply scrap (no expensive hardwood this time Bob ;)) with reference lines drawn on for my Main Center Line, the wing edges and Lead Edge, centerline of each nacelle, and strut locating holes. These were squared off with a small Tee Square to ensure accuracy and parallelism. Once I had the lines drawn, I had to mount the engines to the correct height.

I began by cutting two balsa strips and gluing them together to form a 90 degree angle. I then took the dimension of the engine thrust line to the bottom of the wing from my plans, measured up the upright, and squaring off to my engine nacelles centerline I drilled a hole for the prop shafts to poke through. The engines are now mounted to the correct height (drop from the wing, everything is being done upside down) and the nacelles can be mounted.

Before I could do that, I had to put them together. Earlier I had turned masters and vacuuformed the nacelle halves. These were trimmed from the carrier, cleaned up, and made ready for assembly. I made two cutouts in my nacelle masters. One for the landing gear to be mounted to, and I lopped off the tail "cone", as the rear of the nacelles are open on the actual aircraft. I sheeted inside the landing gear well and tail cone with .010 plastic, drilled the hole for the support wire, and then painted the inside Zinc Chromate green as the real airplane. After the paint dried, I epoxied my vacuform shells to the master, making sure my landing gear struts were centered in the holes. The tube going all the way through will be the main support strut, bearing the weight of the model. It's a piece of 1/16th brass tube, that will telescope into other sizes to form the struts. I will bury this inside the main support strut for the nacelle. I filled the seams with CA, sanding and polishing them smooth, and will paint them later. I also added a firewall of .030, filling and sanding it to match the circular cross section of the nacelle, then bored a 1/2" hole for the engine to mount inside.

Here's a shot of the completed nacelle, with the engine mounted in place on the main support tube.

Here's a back view of both. You can see the openings in the rear of the nacelles from this angle. These were simply made by sanding the end flat, going through the plastic.

One last look. Next I'll begin marking out my other strut locations on the nacelle and forming the struts, then build the landing gear. All this will be made from brass tube and wire for strength, as this is going to be a pretty heavy model. Thanks for following along. As always input and suggestions always welcome.

Cheers

Mike

[theseeker]

Mike,

Stellar stuff as usual! That is a great jig and the engines are the cats pajamas.

BTW, just so you know, there is more than one way to fly a Ford!

Keep it up!

Rocky

[Bob Beary]

Mike, Well, ya, Baltic birch will probably work out for you, but I'm a little surprised that you didn't put about 5 coats of hand rubbed marine spar varnish on it ;)

I'm still trying to figure out how to put my latest bike together and spray a flat coat on some parts

Between this and Pete's T-38 I'm just going to fall on my sword.

Great craftsmanship Mike.

Bob

[Pete "Pig" Fleischmann]

Mike!

The jig is a brilliant necessity-super job on that! The nacells came out wonderfully too! Looking great-

Regards,

Pig

[Skyking]

Hi Rocky thanks for stopping by.

BTW, just so you know, there is more than one way to fly a Ford!

Yep I agree, however I think if I had the means to afford the new GT, I'd spend it instead on one of the top grade GT-40 replicas and go for a '66 MkII, which I think are the essence of the '40's. The new ones are still a great car, and I think of all the retro styling, Ford does it better than anyone, although the Dodge Challenger looks pretty good too. I was a bit dissapointed at the new Camaro. IMHO I think Chevrolet could have done better in the styling of that one. The front looks weird to me, and the sides are way too high in relation to the roofline.

Hi Bob.

I'm still trying to figure out how to put my latest bike together and spray a flat coat on some parts

Between this and Pete's T-38 I'm just going to fall on my sword.

Oh I'm sure you will figure it out Bob, and don't be too quick to do anything with that sword. Your bikes are always amazing.

Thanks Pete. Appreciate it.

OK moving on, I've got a few struts added, plus the main landing gear struts are cut to length and fabricated.

I used three different sizes of brass and aluminum tube to make these from. The main support strut buried inside is 1/16th, over which is telescoped 3/32". For the oleo portion I have a section of 1/8 sweat soldered in place, with a piece of 1/8 aluminum tube CA'ed in place for the oleo section. I then wrapped the foil tape around them to add the raised portion as found on the real Main strut.

I've also got the main load bearing struts in place. The one underneath is a section of Renshape, sanded to shape, with the 1/6th main support tube running up through it. I'll epoxy this whole assembly together, and it will be the main load bearing part of the landing gear. The rear support is another piece of 1/16th tube, with a .032" length of wire soldered to the end for a pin to go into the wing. The front strut is a length of Contrail strut with the .032 wire running the entire length inside. I have to add the secondary supports at the rear and sides, but I'm a little puzzled at the arraignment of them because of the geometry. I'm doing a little more research into them so I can get them as close as I can

The other part to the jig I have to add yet is fake fuselage sides for cutting the landing gear side struts to length. I made the jig the same dimensions as how they will be mounted, so I can put a full sized fuselage section in the middle to tie into. Once I'm ready to mount everything, I'll just transfer all my measurements from the jig to the model and all my stuff will fall into place. At least that's the plan... Who knows what will happen when I actually attempt it.

That's all for now. As always, thanks for taking a look.

Cheers

Mike

.

Once they are done I'll paint the nacelles and add the little details to them, then set them aside for final assembly.

[BOC262]

Amazing--a how-to course on how to jig for struttage! Thanks for posting!

[GreyGhost]

Fantastic work, Mike ...

Gregg

[HOLMES]

AMAZING ...SUPERB work Mike..

HOLMES

[Skyking]

Thanks for the comments guys, I appreciate you following along.

The eagle eyed among you will notice a change in the nacelle configuration now from what it was in the previous post. One of the hazards of working upside down, is that you can quickly forget things are upside down and make a part right side up and when you install it, it's upside down. Confused? Good. So was I..:wub:. I did that with the main support pylon. It wasn't a big deal, I just had to sand the angled end flat, add some replacement Renshape and sand the end to shape and I was good as new.

One of the challenging things about doing the Trimotor, is that no two airplanes were built exactly the same way. Engine nacelle arraignments and fittings were largely custom to each aircraft depending on engine choice and other factors. My drawings show two distinctly different strut arraignments for the nacelles, but neither one of them jived with the pictures of the airplane I am modeling. After a couple of hours of study I was able to figure them out based on knowing where the spar attachment points are and a couple of other constants. Seeing as these needn't be structural, I made them from .040 Evergreen rod gluing them together with plastic cement, then reinforcing with CA flowed into the joints to simulate a welded structure like the real airplane. I hunk of .060 channel for a mounting plate completed them.

All the struts are done now, so I can pull them apart and do the detail work to the nacelles themselves. I have to add panel lines, cowl fasteners and several openings for oil tank filler, inspection panels, etc, then paint them blue. I'll post some shots of them once completed.

Thanks for following along.

Cheers

Mike

[Skyking]

The last few days have been spent adding more details to the nacelles. They are quite a busy little assembly, and I want to get all of the small items added before painting. I had to add an oil filler cap for the oil tanks, as well as the oil cooler intake and exhaust scoops that are present on both sides. The scoops on the right side of each nacelle face forward, and the scoops on the left exhaust the cooling air and face aft. I also had to add the carb intake and plumbing. These came with the engines, but were pretty crude with huge dimples in the intakes. I filled these with CA and filed them smooth, then opened up each intake with different size drill bits and grinders.

I wasn't sure how to replicate the scoops, as it's not just a single scoop, but two in tandem, one behind the other. My first inclination was to vacuform them, but I didn't want to waste 8 sheets of plastic on a part that is 1/4 inch square, so I made them from .005 brass. Here's the step by step process I used to make them to insure they are all uniform.

I started with a strip of brass the proper width to compensate for the width of the scoop, plus the height of the sides. I then scribed a line down each side to show where to fold for the sides, and then marked off and scribed to show where to cut the strip apart into individual bits.

Here's a shot after I cut them into individual bits. I needed 8, but I made 10 to compensate for any I might screw up in the process of folding.

Here I've scribed the angle of the scoop to show where to cut. No rocket science here, just scribe a line with a sharp X-Acto from corner to corner with a straight edge.

Then with smooth duckbill pliers, I form the scoops themselves. Sorry about the blurred images, I couldn't get my auto-focus to focus on the pliers instead of the background. One of these days I'll spring for a new DSLR.

And here we have the finished scoops. They are all pretty uniform, but it's a good thing I made extras as there's 2 in the bunch that I won't use. (Always pays to plan ahead for screw-ups)

To insure that I attached them in the correct locations, I made this locating drawing. Nothing more than a simple circle with a centerline for reference. I then measured up the sides of the circle from the bottom, and made a mark on either side. I set the nacelle on top of the circle, and with a flexible square drew reference lines up the sides, and then made a mark 1/4 inch back from the panel line. I also marked the location for the oil filler cap and did the same for that.

Here's the nacelle with the varous bits added. You can barely see the reference line along the bottoms of the scoops. Before I CA'ed them in place I drilled the oil cooler intake and exhaust holes. The oil filler is nothing more than a length of 1/16 aluminum tube with a punched section of .040 plastic for the cap glued on. I also have the carb intake mounted. Drilling the hole for that was a bit unnerving as I didn't want to split the thin vacuuformed shells, so I used a Dremel with a small grinder bit instead. Worked like a charm.

Holy Dusty Engine Batman. I didn't realize how dusty this got until I saw the enlarged picture. The unforgiving eye of the macro lens is apparent here. Anyways here is a view from the front showing the relation of the intake scoop to the center of the two bottom cylinders. I need to find some small screen for the intakes yet.

And in the "Just for kicks" Department, here's a shot of the first time the nacelles have been mated to the basic model. A lot of fine tuning remains to be done yet, but the effect is there.

Well that's all for now. As always thanks for looking, and I hope I'm not boring you all with trivial stuff here. Admittedly these small details aren't as exciting to watch as the airframe will be, but I think their absence would be even more obvious, and I thought some of you might like to see how I make the small bits.

Cheers

Mike

Edited April 3, 2010 by Skyking

[BOC262]

"boring"? "trivial"? NO WAY! It's all good. Thanks for posting.

[mareku]

Fantastic scratchbuilding mate Keep it comeing.

[geedubelyer]

Lovely stuff Mike. :D

Don't ever worry about boring us my friend, just keep doin' what your doin'.

It is an edumacation watching you at work so please feel free to go into as much detail as you want.

I look forward to every update.

Way COOL!!

[richter111]

I have said it before, and I will say it again,

AMAZING!

[Youngtiger1]

Mike, this is coming along very nice. I am blown away with what you have done and are doing. ;) I hope someday I will be skillful enough to tackle such projects. Keep up the good work.

Mike

[ventura_kelley]

Actually, there's a Ford Trimotor that's beautifully restored at the McMinnville Spruce Goose Museum.

sprucegoose.org

I've done a few walkarounds on it. I'll see if I can find the pictures.

[Blackcollar]

Brilliant work, nicely executed

-Al

[geedubelyer]

Hi Mike,

We've not seen you around these parts for a while

I guess the annual "Honey-Do" list is longer this summer?

I was missing this build and wondered if you'd made any progress at all?

Keep well.

[D_IcarUS_]

Stuning work. Hope to see more progress on this one a.s.a.p.

Edited July 11, 2010 by D_IcarUS_

[Skyking]

We've not seen you around these parts for a while

I guess the annual "Honey-Do" list is longer this summer?

I was missing this build and wondered if you'd made any progress at all?

Hiya Guy,

Thanks for breathing some life back into this one..lol. You must be psychic or something, because the day you posted this reply, This came in the mail:

'Tis the custom Photo Etch I've been waiting for ( for almost 5 months *ahem*) but I have to say the wait, albeit a bit frustrating, was worth it, as Fred has pulled of his usual mastery of the etching solutions and these are darn near perfect. What you see are the wicker seats for the passenger compartment, the side window frames, a window template to cut my windows out with, and some assorted odds and ends detail stuff. I can now resume work on this bird that's been on hold since March. I am also working on a 350th scale USS Arizona, so I'll have to split my time between the two. I've given up trying to get the Ford done by September, but I can definitely get it done in time for next year.

I wish the Honey Do list was the main reason, but even that's been put on hold as we've not had a good summer so far. First it was an expensive repair to one of our cars, then it was having to have the septic system to our house dug up and redone - to the tune of 3800 dollars. I guess I could take a philosophical look at it and realize my wife and I are now financially able to bury almost 4 thousand dollars in the back yard and then crap on it..lol. It could have been a lot worse, as we didn't have to replace it, just clean it out, so for that we are thankful.

The worst setback though was the passing of my dad at 87 years of age, on June 24th. World War 2 US Army Air Corps veteran with the 20th Air Force, he was an electrician and flight Engineer on B-29's, plus he was also an instructor in Aircraft Engines and Airframe Mechanics. I've found all of his stuff as I've been cleaning out the house, including his uniforms and all of his notes, books, manuals etc. I also found his log books, and one interesting flight in a BT-50 in Florida has this in the "remarks" column - "Fire in Left engine, unable to extinguish. Had to abandon ship, picked up by Navy Cat. Going to catch hell". It doesn't say why he was going to catch hell, unless it was something he missed during preflight, or maybe the old US Government warning about the taxpayers airplane and taking care of it, but seeing as the airplane is at the bottom of the Atlantic off the coast of Florida, we'll never know. Obviously he didn't catch too much hell as he wracked up another 400 or so hours after the fact, but Dad never told me he had to leave an airplane in flight. I guess to him it was no big deal, just all part of the job. As I go through his stuff I am learning things about him I never knew. Clear Skies and Tailwinds Dad.

Thanks for checking in Guy. Once I get started on the brass again I'll post some updates.

Cheers

Mike

[Kostucha]

B-E-A-Utiful! OH Those look great!!

I do feel for the passing of your father. Though it wasn't my father but rather my grandfather, going through his old books and logs, and notes and finding out the side of him I knew very little while he was around proved to put a very interesting feeling in his passing. I said goodbye to someone I knew very closely and had all the respect in the world for, to learn about someone new who I wish I could have spent more time getting to know personally rather than through history, but enjoy greatly spending hours on end discovering so many new and unique things that he did that blows me a way.

Blue skies forever

[geedubelyer]

Hi Mike,

So sorry to hear about the loss of your father, my sincere condolences my friend. *

I never know what to say in these circumstances but at least it's good to know that you found out some cool stuff about your Dad.

Sorry to hear about the other troubles too. Oh man, this will certainly be a summer to forget. I hope that things steady down for you all now.

I guess the etch arriving was a nice surprise after all of that time. It looks good and will add some lovely details to your Ford. I'll keep my eyes skinned for your updates and look forward to seeing how these metal bits look under a coat of paint.

Keep well Mike and thanks for letting us know how you are.