1/48th Scale B-17C/D Conversion

[Mgawa]

She is so cute

[the330thbg]

http://www.acepilots.com/ww2/color-pics/color-yb17.jpg

http://www.acepilots.com/ww2/color-pics ... -bombs.jpg

A couple of cool early YB-17 shots.

I have never seen these before.

Best,

Smiz

[Second Air Force]

I like the O.D. scheme on the YBs. I gave some thought to camouflaging the model in this scheme but then it would be just another shark fin B-17 if I displayed it anywhere. I also like the B-18 and A-20 in the background!

S

[the330thbg]

I know this is not your YB-17.., but GOLLY, what a beautiful shot of the detail and connections of these aircraft from this era!!!

[Second Air Force]

I love that photo.

Even though the B-18 may not have been the finest war machine of all time, notice the workmanship that the Douglas employees put into that nose section. The riveting and sheet metal finishing is just great.

On an unrelated subject, I'm almost ashamed of that picture of Mickey further up the page . She's been put on a "doggie-diet" since then and is back down to a little less than 75 pounds. She was tipping the scales at around 84 when that picture was taken........

Scott

[the330thbg]

MICKEY!!!

LOL!

You live and breath by that DARN B-17 of yours!!!!!

Cheers,

Smiz

[WIXerGreg]

Any updates on the model, Scott?

[Second Air Force]

Nope, at least not yet. The grass is almost done growing and the hummingbirds have migrated south for the year. Hopefully I'll get to start working on the model again fairly soon. I may re-do the nacelle interior I destroyed and then move on to the aft fuselage as my next part of the project.

Scott

[WIXerGreg]

Looking forward to it!

[Second Air Force]

It's raining today so I did a little sanding. Here's a photo of the left fuselage half after removing most of the flash. You can see a little pigtail of material on the edge, a sign that you're just about at the correct sanding depth. From this point on you have to use a very light and even pressure on the part so as not to go too far:


A couple of shots of test-fitting of the two halves after sanding. Notice that there is a tiny bit of a gap at the vertical fin/fuselage juncture--I still needed to touch up the top of the vertical fin to finish this part of the process. On larger parts it is sometimes difficult to uniformly sand all the surface at one time because vacuform pieces are usually a little bit more flexible than their styrene molded cousins.




The same process, this time on the horizontal stabilizer halves. I usually start by sanding the entire half as a unit, keeping it on the sandpaper with even pressure (providing that the part doesn't have dihedral, of course).



After getting through the flash it's time to fine tune the process. For this part I sand only the left and right halves of each piece individually so as to get a uniform leading and trailing edge thickness.




And here are the two halves after sanding and finessing.




You can see from the last photo that the trailing edge is still a bit thick. With careful sanding you can achieve a knife-edge on most vacuform surfaces, especially on a Koster kit. In this case I'm going to be cutting the elevators and trim tabs loose from the stabilizer later and I'll finish the thinning of the trailing edges then.

More later,
Scott

[Second Air Force]

I followed the tip that Steve posted about outlining cutouts with a Sharpie and it is a good guide for trimming, indeed. On a Koster kit there is a nice outline molded into the parts such as where the horizontal goes through the aft fuselage. I simply ran the marker around the perimeter of the molded-in guide marks in this instance.


I should mention for those who haven't done much vacuform modeling that you have to be careful when cutting holes into the fuselage halves for wings and stabilizers. Study the particular kit you're building to make sure that the left and right halves agree with one another. I once built a Wyvern that was molded with the left wing opening 1/4" further aft than the right. If I hadn't done some measuring first I would have made a mess of it. Today's kits, and especially the products I've gotten from Koster, are very accurately molded but some of the old vacuforms weren't quite so precise. It makes building vacuform all the more satisfying when you are able to build a poorer quality kit into a presentable model, but it can also be exasperating to make cuts that don't line up. Measure twice, cut once!

Here's the stab cutout during trimming. Lots of filing and test fitting, but the process isn't anything difficult.


After making both cutouts I slid the horizontal into the fuselage. Notice that it isn't 100% perpendicular to the vertical in this photo. A tiny bit of tweaking will make this come into line. I'll probably build a little fixture so that I get it just right.


Just because I could, I assembled the sections together for the first time to get a feel for how the airplane will look someday. I haven't built a 1/48th B-17 for twenty years---darn it's big!!!!




Scott

[the330thbg]

Awesome 'tail' there Scott, my lad!

Now, for 'foiling' vacuform? How does that work? Is the vacuform too thin to correctly burnish the aluminium?

Side Note:

Have you decided on the paint scheme? Is she going to be a full blown YB-17 or a B-17A?
The 2nd one down is my favorite!


Here is a B&W of her flying.

[WIXerGreg]

Lookin' good Scott!

[Second Air Force]

This evening I tackled the problem of making the gun blisters. I first got out the calculator and calipers, figured the size of each emplacement in 1/1 and copied Mgawa's profile view of the lower blister, scaling it to 1/48. Here's some of my math project and the final size of the lower blister:


I then laid the drawing up against the fuselage to get an idea of the dimensions before committing to making parts:


I used clay to make the mold for the first master part. If I'm not happy with the effort it'll be easy to make a new mold:


The first male die just after being popped out of the mold. Now I will start the shaping and fitting process, and once I'm happy with the result, I can use this piece of resin as my male die to vacuform the clear parts. If I make a mistake, I can always pour as many more pieces as needed to get the four enclosures.


Scott

[Mgawa]

Is it Squadron Clear Thermaform still available?