B-25 Mitchell 60”

[noahangel11]

The next step before attaching the two fuselage halves is to build the wing. The wing has an anhedral profile as opposed to dihedral. Basically it’s a flattened M shape, like seagull wings.

Start the wing by gluing together the wing spar pieces. There are 2 foam pieces and 6 plywood pieces. If it was easy to buy and cut one long sheet of ply, I would have done that. But I limited the part lengths to that of the 12”x24” sheets I can buy locally and will fit in my laser.
In retrospect I should have made the 2 center plywood spar pieces one, and in the final plans I release it will be that way. So there won’t be an overlapping center pice to tie them together. But for now it’s what I have cut out so I will show the assembly of the wing with the older 2 piece center section of spar.

Lay the foam parts out on the bench in the anhedral shape, with the tabs that fit into the wing skin facing down. Glue on top of the foam the matching plywood pieces, and then overlap each plywood butt joint with the small ply pieces that tie it together.

 

[noahangel11]

Find the 2 center wing left bottom and center wing right bottom pieces. CWLB and CWRB. There are 4 tab holes cut all the way through to mount the engine nacelles to. The cutouts for the wing spar tabs should be cleared out only on the top of the sheet (inside of wing), and the paper left on the outside for a nice finish. I use a bbq skewer to pick the foam out. Use clear tape to tape the 2 halves together, but only on one side, the bottom of the wing. That’s the side that you cannot see the spar tab holes on.

 

[noahangel11]

Ok, gotta quit for tonight. Need sleep for work. Will try to post more tomorrow evening.

 

[CrshNBrn]

Following closely! This is the most detailed set of build instructions I've seen in a while.

 

[noahangel11]

During the wing building process, since you will be working with an anhedral wing shape, it may be necessary to have only sections of the wing in the bench at a time, so make sure you have a big enough work area that allows you to sometimes hang half the wing off the bench.

Glue the spar to one half of the center wing section, placing it flat on the bench. Then press and glue the wing spar onto the other half of the center wing section, pressing it flat against the table. Once dry, use the bench to glue on the bottom wing outer sheets, you may need to do one end at a time, letting the wing stick out past the bench.

 

[noahangel11]

Grab the two center wing top sheets. The trailing edge of each sheet does NOT get the paper removed. Only the front half that covers the bottom wing should have the paper removed. The plans will indicate where to remove paper and where not to. Remove the paper and start shaping the center wing skins onto a wing shape. It’s better to exaggerate the shape a little than to not curve it enough, particularly on the leading edge. After shaping the pieces, cut a real sharp angle bevel on the leading edge of the sheet so the sheet sits flush on top of the bottom sheet. Test fit all sheets before gluing in place.
glue each sheet in place on top, applying glue to leading edge, the wing spar, and the small section of the trailing edge that mates up to the bottom sheet. Afterwards I added a clear tape strip to give the center of the wing more strength. This will be hidden inside the fuselage anyways.

 

[noahangel11]

Before gluing the outer top sheets on, don’t forget to fold over the ailerons on each sheet and make a 45 degree bevel cut on the aileron, being careful not to cut into the paper, then smear on a coat of glue to make a glue hinge.
Next test fit the outer top sheets and adjust as necessary for fit. Once satisfied with the placement, glue just like you did the inner sheets. You may need to adjust the aileron fit afterwards by trimming the gap a little.

 

[noahangel11]

Find the top skin marked F4-F6, remove paper from the side with the label. It’s the sheet that has a wing shape cut into it on 2 edges. Shape the piece to fit the shape of the F4 and F6 formers, rounding it some. Use the tick marks on the center of the sheet to align with F4 top tick mark, and one side at a time, glue it down to F4 on the front fuselage back end, using masking tape to hold it as you go. Centering this sheet is important, as it is the saddle the wing will sit against. Once the glue fully dries, glue the skin to the F6 former on the tail piece of the fuselage in a similar manner, making sure tick marks line up. This joins the front half and back half of the fuselage together.
Once dry, I put tape across the gap to pull in and line up the saddle edges with the fuselage so they’re re not bulging out. When you glue the wing down, just don’t put glue where the tape is, and after the wing is fully glued in, release the tape from the fuselage sides and just pull it out from the side!

 

[noahangel11]

I don’t have a lot of photos of this step, so I will do my best to describe it. With the fuselage upside down, set the wing on top of the saddle F4-F6 skin, testing the wing for fit, and for centering in the wing saddle. You may want to make marks on F4 and F6 center, to aide in centering the wing. The wing should sit just below the servo tray cutouts on both F4 and F6 formers. Hold the plane in the air, with the wing sitting in the saddle, and check for wing alignment with the fuselage, making sure that the wing tips don’t tilt up or down too much to one side or the other. Now is the time to make any saddle adjustments before gluing the wing in place. Sometimes it’s a matter of adjusting the cross pieces of tape on the saddle, sometimes you may need to trim the saddle a little, especially if it wasn’t centered well.
When happy with the fit of the wing, apply a good bead of glue to the F4-F6 skin saddle area except for where the support tape crosses the saddle, and firmly hold the wing in place for at least 4 minutes to ensure a good glue dry. Once dry, recheck the wing level and adjust if you need to. Also check wing level with elevator, making adjustments on wing or elevator if it didn’t line up right. Taking your time in the build and making sure parts glue correctly will lead you to a satisfactory build.
Remove the cross pieces of tape that held the saddle position by loose ing them from the skin and pulling them out. Next apply a bead of glue where the wing meets the skin on the outside of the airframe.
The servo tray will then pop into place on top of the wing as pictured, with the servo cutouts towards the tail of the plane .a little compression or stretching is needed to make it go in, but once it sits in the servo tray notches, it Locks the wing in place. When happy with the fit, apply glue anywhere the servo tray meets the wing or the formers.
The bottom fuselage sheet doesn’t go in until after the electronics, so we will turn our attention to the engine nacelles.

 

[noahangel11]

And now for an intermission of random pics from when I was building this plane out at John Overstreet’s Shop.
The remaining build pics will be from my messy and tiny bench at home. Sorry Lol

 

[noahangel11]

IMPORTANT: The engine nacelles have some parts that are unique to the side of the plane the nacelle is on.
The nacelles parts are all labeled with an ‘N’ designator, and the parts that are unique to a side of the plane are labeled Left and Right with the last letter of the label being L or R. For example Former N1AL is for the left side, and former N1AR is for the right side. This is important not to get them mixed up. Also, on all my formers, I put the label on the side of the former that faces towards the front where the engine is. Since the wing has slant to it where it meets the nacelle, this is important when gluing the part on. Some of the parts such as N0 and NE are identical for each side. Also, when I say left nacelle, I mean the left engine from the perspective of sitting in the cockpit and it’s the engine to your left.

now that we got that out of the way, I like to separate all the parts into their left and right sides and build each nacelle at the same time.

You should have for each side:
The two plywood engine former pieces
N1A-L/R former depending on side
N1B-L/R former depending on side
N2A-L/R former depending on side
N2B-L/R former depending on side
Qty 2 N3-L/R former depending on side
Qty 2 N4-L/R former depending on side
Skin N0
Skin N1-N2
Skin N2-N3-L/R depending on side
Skin N3-N4-L/R depending on side

 

[AIRFORGE]

Jonathan, this is a well thought out MS styled design, brother!
Excellent info/log! Impressive! Thank you, for taking the time to post this, Sir!

 

[noahangel11]

Jonathan, this is a well thought out MS styled design, brother!
Excellent info/log! Impressive! Thank you, for taking the time to post this, Sir!

Thank you for your kind words!

 

[noahangel11]

For the next steps I will describe building the Left engine nacelle (pilots perspective). The same steps should be followed along for the right nacelle, keeping in mind that some of the parts are mirrored do to the anhedral angle of the wings.

 

[noahangel11]

Start by building the left Nacelle motor mount tray NT-L.
Do an A fold where the side pieces sit on top of the center piece. Glue it together. Notice one side is taller than the other, this is to match the angle of the wing, and all the other formers should be mounted with their labels facing the front and the angle the same as the Tray.

 

[noahangel11]

Take the wooden engine mount N1A-L and lay it on top of the foam former N1B-L. Center it and use a pencil to draw an outline of where to apply glue, then glue the 2 together. mext glue N2A-L to N2B-L, lining up the tick marks and the opening for for the tray. Notice how the back former N2B-L is smaller in diameter.

 

[noahangel11]

Slide N2 former assembly onto the tray fist, stopping at the nubs that fit into the wing. DO NOT GLUE N2 yet. Make sure label N2A-L is facing forward. Forward on the tray is the end that does not have the nubs on it. Once N2 is loosely slid on, then you can glue the N1 former assembly with the motor mount to the front of the tray. The slanted part of the opening in N1B-L will align with the tray being longer on one side wall, so you know the orientation is correct. Also the former wording should be upright and the tray sitting upright like a U.

 

[noahangel11]

Take the paper off one side of skin N1-N2. Shape it on the edge of a desk and glue the ends together. Next, press the tray and M1/N2 former into the skin, N1B-L foam former should be flush with the edge of the skin and the ply N1A-L should stick out. It’s a tight fit. Take it slow and work it. You can also roll the edge of N1B-L former along a desk to smoosh it a little. Line the time k mark on the bottom of the N1 former with the seam in the skin, so the seam is at the bottom of the nacelle. when happy wit the position, run a bead of glue along the ply former and skin where they meet, and wipe off excess with a piece of scrap.

 

[noahangel11]

Now slide the N2 former assembly in from behind and let N2B-L stick out while N2A-L fits in. Make sure the tick marks line up on the skin and former. Run a bead of glue and wipe off the excess with a piece of scrap.

 

[noahangel11]

Find the next skin N2-N3-L. It’s next in line to add to the nacelle. The narrower side goes to the front on The N2 Former Assembly, and the wider side goes towards the rear on the N3 former assembly.
Take the paper off the inside surface and shape it to a curve. Using the tick mark to center the skin on The N2 former assembly and glue it in place. Use tape to hold the skin while it dries.
Next find the top N2-N3-L smaller piece that has a label “L”. Take the paper off the label side, shape it to have curve, and glue it onto N2 former assembly and across the top of the nacelle.