B-25 Mitchell 60”

[noahangel11]

Next glue the 2 N3-L formers together, and place them in the nacelle at the rear of the tray, and let skin N2-N3-L overlap half of the assembly so that there is a lip for the next sheet. Remember that the lettering on the formers faces forward. On gluing this, I had to get creative and pinch the skin down onto the former but also hold apart the tray side walls so they didn’t get crushed in. Hold for a good 3 minutes until glue is completely dry.

 

[noahangel11]

Directing our attention to the front of the nacelle, there is a skin N0 to add to the front. Remove paper on one side, roll form it and glue ends together. You can glue this onto former N1A before or after mounting the motor. The motor mount will still go in with this skin in place.
Take the cross shaped piece of the motor mount and bolt your motor to it. The hole pattern is the typical 16mm/19mm hole pattern used on power pack C motors. Use screws that are long enough, but not so long that they enter the motor too far and push against the windings. set the speed controller wiring for the proper motor rotation. This is critical to do now.
On a twin plane, when looking at the props as if I am in the pilots seat, I make the left nacelle motor turn clockwise from that point of view, so that the prop blades are turning in towards the fuselage.
I make the right nacelle motor turn counter-clockwise so that the prop blades are turning in towards the fuselage.
You don’t want to have to tear this apart later to change the wiring, although if you leave some slack in the wiring you can fish the wires out the front of the motor mount and swap 2 wires.
Run the wires for the ESC from the center wing access to the nacelle mounting area holes in the wings.
Make a power Y cable. I made my cable 12” before The Y and then 16” for each Y branch. That left enough length on each nacelle to be able to pull out the ESC if I needed to, and enough length for the run to the battery tray.
I also made a throttle signal wire Y cable that would reach and fed it through the wing to the nacelle also. On twins I like to lift one power red wire on one of the ESCs so that the BECs for the receiver aren’t paralleled. Only one ESC will be the BEC. But feel free to wire it however you typically do twins. Just test your setup before closing everything up.
After testing the wiring and verifying motor rotation direction, mount the nacelle to the wing. The left one is on the left of the plane from the perspective of the pilot sitting in the seat.
The 4 tabs fit into the wing, and the wing slides into the pocket crested by the top and bottom N2-N3-L skin pieces.

 

[noahangel11]

Next glue the two N4-L formers together.
On the back half of the N4 former assembly, cut a 45 degree bevel onto the former for the cone that goes on the end of the nacelle. The other half of the former flies into N3-N4-L skin.
Take the paper off of the N3-N4-L skin on the label side, and start shaping it. The wider end of the sheet will get glued onto N3 former assembly, as the nacelle starts to taper to the rear. Use the tick marks to glue the skin narrow end to the N4-L former assembly, leave half of the former sticking out for the next sheet.
Use the tick mark on the skin wider end to fit the skin and N4 former to the nacelle and wing underside surface . When satisfied with the fit, glue it in place. Have tape ready to hold the sheet as you glue it. When dry, run a glue bead where the skin meets the wing. Sorry no pictures of this step.

 

[noahangel11]

Next and last skin at the rear of the nacelle is the one labeled NE. Take the paper off one side. Take your time slowly working the part to roll it, the exit point of the cone is a tight roll. Once you have it rolled tight glue the ends together. Cut a sharp bevel cut into the big end of the NE skin. Test fit and glue the cone onto N4 former.

 

[noahangel11]

That’s all for tonight folks. My posting has caught up to my build progress. Next time we will be mounting the nacelles and running wiring.

 

[noahangel11]

Use an exact knife to glue 2 servo shaped cutouts into the servo holes on the wings. These act as spacers to lift the servo up a little.
I then added servo wire extensions on to my 2 aileron servos, got the servo arms centered, and gravity fed the servo wires from the wings to the center fuselage opening.

 

[noahangel11]

Next I mounted my 2 elevator servos. I deliberately mounted them different. Servos, when centered, allow the servo arms to go on perfectly at no degrees to the servo body only to one side of the servo. This is due to the number of teeth on the servo shaft and servo arm being an odd number of teeth. I wanted my servo arms to be exactly 90 degrees to the servo body, so I mounted them like I did to accomplish this. The control arms can be different lengths. It’s the length of the servo arm, the hole that you use for the control wire, the hole you use on the control surface horn, that all need to be the same, along with one servo arm not being off of 90 degrees compared to the other servo arm when they are in center no trim position.
So I did mine this way. Feel free to mount your servos whichever way works for you. My radio, like most, is very programmable and Amy difference can be programmed out. I just decided to make it easier on myself.

Next I mounted the receiver with some Velcro, plugged in all the wires, and programmed and setup the receiver on my radio.

 

[noahangel11]

That’s all for tonight, next step will be the control rods and control horns.I did a lot of editing on the steps for the nacelles as I had made some part changes. So those steps are now up to date.

 

[noahangel11]

Center all the servos using a servo centering tool or the radio.
Of the aileron glue hinges are stiff, bend back and forth until it moves easier and can maintain center position. Cut away any interference material on the wingtip that interferes with the aileron movement.

For the servo linkage on the Ailerons, put a modified Z bend on the servo end of the control wire and slip it into the control arm of the servo. Use a BBQ skewer to widen out the slot for the aileron control horn and temporarily set it in place so you can mark the spot on the control wire for a Z bend when the Aileron is in its center position. Take the aileron control horn out, slip it onto the control wire Z bend, and place it back into the aileron to check fit. Once you have the aileron surface flat, glue the aileron horn into place. I add a bead of glue on each side afterwards.

 

[noahangel11]

If you have not done so, trim the elevator control tubes to where they only stick out 1/2” from former assembly F6.
For the elevators, push the wire in from the tail end, and where it exits, put a Z bend or modified Z bend and insert it into the centered servo control arm. I chose a Z bend here because I plan to bury the servo in the fuse with the last skin. If you make an access panel or Bombay doors, you may want to use a modified Z bend for maintenance.
with servos centered, fit elevator control horns and mark for Z bend. Insert wire and glue control horn in place.
on the final plans I will move the tube holes in the former so the control wire is more in line with the servo arms.

 

[noahangel11]

Once you are certain the electronics are working and set up correctly, you can put on the last fuselage skin F4-F6. Please ignore the improperly placed F4-F6 label, there will be no label on the final plans as I don’t know what side of the sheet may be used. I put lines on the sheet for Bombay doors. So you have lots of options here. Cut doors and make all they work, don’t cut doors, invert the sheet so lines don’t show (assuming you cut on a laser per plans, which scores the paper), don’t add the lines at all if you are hand cutting parts from templates, etc.

I chose to use the laser scored lines on the outside to show the Bombay doors, and if I need access later, it’s a good guide to follow for cutting access.
I reinforced the lines with tape and removed the paper off the opposite side of the sheet for shaping. shape the skin to fit on formers F4 and F6. You may need to trim this sheet to fit against the wing. Use the center tick marks and line them up with the former tick marks. Wrap each side around and check fit. Trim the ends of the sheet if needed to get a clean fit against the wing. When satisfied with the fit, glue the skin in one side at a time, use tape to help hold while glue is drying. After the skin is secure, Put a bead of glue along the joint where the skin meets the wing.

 

[noahangel11]

Theee are some side gun accents that you can glue to the fuselage in front of the wing. Gun barrels not included.
There are also 2 small pieces for a tail skid accent that you can glue together and add to the tail of the fuselage below the horizontal stabilizer.

 

[noahangel11]

There are 2 rectangle pieces and some side pieces as shown in the pictures. Remove the outer foam strips from the rectangles, leaving the paper. Take the paper off the middle section and shape a slight curve into it. Glue the side pieces on as shown. Trim the tapered end of the foam to match the side pieces profile. When dry, glue assembly to engine nacelles.

 

[noahangel11]

Grab the sheet for the tail gun canopy. Take the paper off one side and shape it into a sharp curve, eventually pressing it in half to get the right curve needed. Glue in the end windshield piece. Trim the edges that mate to the tail of the plane with a razor, removing the excess foam from the bend. Glue in place on the tail.

 

[noahangel11]

Lastly, find the 22m diameter nose plug and glue it into place on the nose of the plane. My nose is a bit beat up from working in tight quarters and not having a large table to sit the plane flat on as I worked on it. Hopefully you will do better ;-)

 

[noahangel11]

So that’s what I have so far to get it to a flying plane. I’d like to work on a gun turret for the top, and I’d like to add pieces that make it look like the wing slides through the engine nacelle. but I think this is a good stopping point to get some plans out and see what others do. Meanwhile I will continue to refine and eventually have version 2 set of plans.
Hopefully I will have time this coming week to get the plans from dxf onto some format where I can add colors to indicate what’s a cut, score, foam removal, etc….not sure how to do all that. I will likely also make the raw dxf files available for for cutting, but the problem with that is those plans don’t contain the cut vs score vs lettering info. That info is in a set of plans I made from the dxfs in LightBurn, which is my laser burning software. I can make those available too if anyone uses LightBurn.

 

[ScottInIowa]

Dang this is awesome! For at least the needle cutting folks like me a PDF works the best. I'd be more than happy to do some testing. I use Inkscape.

 

[noahangel11]

Dang this is awesome! For at least the needle cutting folks like me a PDF works the best. I'd be more than happy to do some testing. I use Inkscape.

For a needle cutter, do you have a Z axis under SW control, for doing score cuts?

 

[ScottInIowa]

For a needle cutter, do you have a Z axis under SW control, for doing score cuts?

It's actually color based, at least with the setup I have. So using the same drawing colors that Sponz used in the original FT drawings. Do have Z axis controls kind of - there is a setting for cut, score, and etch.

 

[noahangel11]

I am working with a friend to finalize the plans. Stay tuned. Thanks Scott for taking a stab at it.