The wing on the 337 gets build in three sections, a left and right outer section, and a mid section with the tail booms. The photo below shows the completed outer sections. The stringers for the top of the wing section are specific and not just stock square stringers. I put these stringers in so that the inside chord edge of the stringers end on R2 which is the inside rib for each wing section. The notch in these stringers faces up, so that balsa sheeting added later will fit flush.

Next… tail booms and center wing sections…

Keep 'em comming Scott, nice build, Is this your first twin!

Mike,

Thanks for the note I appreciate it, ya know sometimes you work on these build threads and wonder... is anyone reading it, so its appreciated. As for the twin, indeed it is my first twin, its really only my third balsa build as well. So far so good, I only started to build two left side wings, but caught it before I glued it.

_Scott

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It's looking great Scott! Excellent work!

Zeke, this ones for you: The 337's designed for stick mount gearbox's, I'd like to do one with two 20mm Custom Cdr's, about 21 grams each with firewall motor mount. Do you have a modification that would handle a firewall mount? Also whats the distance from the end of the motor mount stick and the prop thrust nut on the gws shaft?

Originally Posted by mike3976

Zeke, this ones for you: The 337's designed for stick mount gearbox's, I'd like to do one with two 20mm Custom Cdr's, about 21 grams each with firewall motor mount. Do you have a modification that would handle a firewall mount? Also whats the distance from the end of the motor mount stick and the prop thrust nut on the gws shaft?

Two BL motors would really be overkill IMO. With a BL motor, I would highly recommend setting it up with just the rear motor. I can make a solid front firewall if you'd like. Do you have any info on dimensions for the Custom CDR?

Okay, some more progress being made here. The right and left tail booms are pretty straight forward. You need to watch the orientation of the side sections though to be sure you have a right and a left, and they are right side up. Also you need to put the control cable tubes in place before gluing the booms together. The right side boom gets one rudder cable, and then I used a piece of fishing line to pull the antenna through, and the left side boom gets two cables, one for the rudder, and one for the elevator.

After the booms, put together the center wing section. It is pretty straight forward, the only bit of a trick here is that you need to use some scrap 1/16th inch balsa as a spacer when gluing. The spacers are to make sure you have room for the first wing rib after you have sheeting the mid section.

After sheeting the top of the center wing, its time to put the tail booms in place. The front edge of the boom fits against the back of the main wing strut, and up against the second rib, R1. While putting the booms in place, you will need to route the control cables through the ribs and under the center wing section.

The rear wing strut WS3 goes through the boom so that the notch cut into it sticks out of the other side. (See the photo below, the arrow on the right.) This step is made slightly more difficult because the control cable to the elevator and the fishing line for the antenna run directly through the space which needs to be occupied by the outside of the strut. It is however not an impossible task, and I found that by pushing the cable back into the boom it would arch up and out of the way enough for me to get the strut in below the cable. (There is more then enough room for them both; it just takes a little work.)

With the tail booms in place, the outer wing sections fit onto the outer section of the main strut, and the trailing edges fit into a slot in the tail boom. Once the wing sections are in place the center section gets sheeted while held with some weights to ensure that the booms are level and true. I happened to have some ‘soft weights’ from scuba diving which we just about perfect. The sheeting goes on both top and bottom and makes a big difference in getting the wing straight.

Per Zeke’s recommendation I used a 6-32 nylon screw and nut to mount the wing. There is a section of triangle stock right under the leading edge of the center wing section, and another opposite triangle at the front of the cockpit section; the two fit together to form a square which allows the hole to be drilled straight down through the two pieces.

The tail sections don’t get added till after they are covered, so right now its time to do some sanding, and then hopefully start in with the doculam this week.

_Scott

WOW! Looking GREAT! I may have to give their Pitts a try.

Big,

Thanks, I am really excited about it at this stage, it's a pretty cool looking design.

As for the Pitt's, a flying buddy of mine has one and it is a real nice performer.

_Scott

Scott, it looking great! have you decided on a paint scheme yet?

Thanks Zeke, on paint... I am not a huge fan of white, but wanted to do something with a lighter color. It just so happens I have some 'Malted Milk' color pain which is on my living room wall which I think will work pretty well. When looking at images of 337's I have seen a few which were light color body with a dark color over the front engine section, so I think I am going to go with dark blue over the engine and then accent in dark blue and burgandy. Not sure if I am going to spray the accent colors (stripes and such) or if I will make decals just yet. I do have some decal paper on order, so will at least explore it as an option.

_Scott

Originally Posted by zbrubaker

Two BL motors would really be overkill IMO. With a BL motor, I would highly recommend setting it up with just the rear motor. I can make a solid front firewall if you'd like. Do you have any info on dimensions for the Custom CDR?

zeek, I disagree with the power output being too much, the thing about cdr's is you can wind them to produce the kind and amount of power you want. I'd be looking for about 24 or 28 oz.'s of thrust output from both motors. I'll have to get back to you on the dimentions. Thanks!