1923 B3 'Charlotte II' in 1:3 Scale

[blake]

Michael

Check out this forum, they do a lot of similar type stuff that you do. You might find something useful for this or future projects.
They have a flying models section that has some pretty cool stuff in it.

http://www.theaerodrome.com/forum/showthread.php?t=35983

Blake

[ingrahal]

Yes you got some good shots of the one I needed, thanks!

What joins the wire where the two ends meet?

[blake]

Michael,

Just find some round objects around your shop to use as a mandrel. Now with the music wire the springback is going to be excessive so the mandrel will probably be a lot smaller diameter than 8". Use full lengths of wire so you have "handles' to hold onto and concentrate on the centre part of the wires length to achieve the proper circle you are looking for. But please wear safety glasses when doing this, as you know music wire is a beast to work with. And I would wear leather gloves so you can "follow" the wire around the mandrel so it stays true.

Like the photos show.



Best of luck

Blake

[ARUP]

Michael, don't be surprised if the Smithsonian calls wanting to that thing on display.

Yeah... how to build a piece of junk! Thanks Art! Did you get what you needed from the SD card. I don't wanna spoil the surprise (if it is gonna be one) for you know who!

Anybody got any ideas for making music wire bend in perfect circles of ~8" diameter? I can just see the 3/32" music wire kinking around a grooved wooden form. I don't have any large oven, roller dies or machine shop stuff for this...yet!

[ingrahal]

Michael, don't be surprised if the Smithsonian calls wanting to that thing on display.

[ARUP]

The LE can get scratched off the list! Most of the day was used sanding these to shape. After getting the hoop skid mount plates fabricated a pair of struts will get built. These are needed so that after rigging wings to fuselage the height of the hoop skids can be determined. They seem a little short in the drawing. Plus, the control surfaces have to clear the ground if a wing tip drops. The control surfaces aren't robust enough for that kind of duty!

[ARUP]

Some spacers were made in order to set the distance of the hinge rods. These same spacers (to be modified somewhat) will serve duty for installing the control surfaces at the field, too! The control surfaces have a long removable hinge pin. Wing rods were fabricated. Brass tubes were let into the spars to receive them. This was fussy business for the wing rods have to be pretty much parallel to each other. The brass tubes were installed on one wing and only one tube was installed on the other. Then the wings were 'joined' and the remaining tube was secured. I used a bubble level to make sure they had the same incidence and a spacer was used to make sure the rods didn't angle in or out from each other. The LE are getting installed. Items are getting crossed off the list!

[ARUP]

Len, that's a great idea! I can leave the 'opener' magnet in the cockpit.
Art, thanks! And...no hurry since I have a spare SD card, now, lol. Hope the pics download okay. It is Cannon EOS software driven if that helps.
I got one set of control surfaces' hinges installed. I'll fabricate the skid and attachments then finish the other wings' accrutiments! After this then rig pull-pull cables, drill wing rods holes, install LE then cover.

[ingrahal]

Nice work Michael!!! Sorry, I didn't realize I had your only SD card. I'll get it back to you asap. I have bunches of them and it just didn't occur to me.

[lenb]

Oh my....

You're ridiculous, really cool stuff Michael.

I was thinking about the hatch covers you're making. What if you glued a "stout-er" magnet to the underside near one corner, then when you wanted to open the hatch you could use another magnet from the outside to lift the edge enough to break the other magnets hold... Just as thought.

Len

[ARUP]

The TE wire is installed! Once everything was secure I 'set' the little aluminum wire guides at the ends of the ribs against the TE wire using a little hammer. It really worked a treat and it's rewarding when a design plays out as intended! Lord knows, I've had my share of work shop re-dos! Instead of soldering the wires mid span they just got 90 degree bends strategically placed. The two 'L' bends pull against each other with the end of a rib as their packing.



Here are the two wires 'loose' then 'tight' and in place.



TE wire passes through root end and has another 90 degree bend to anchor it forward.



On to the hinge reinforcements, running cables, drilling for wing rods, hoop skid and mountsand... lastly... the LE! Good night!

[ARUP]

I bought another SD card for my camera and got some more construction pics. I made a hatch on the underside of each wing near the root end so the pull-pull cables and servo links can be adjusted. A magnet keeps it secure. A small handle will be added to help get the hatches open... those magnets are stout!



Balsa cladding surrounds for strut attach points so that fabric can be attached. Pull-pull cable fairleads finished.





The trailing edge is going to be music wire. First, the ends will get anchored then the two 36" long wires needed will get joined mid span. Hard maple will be let into the TE near the control surface. The hard wood is drilled and grooved to receive the TE wire bent to shape.



Once this is completed on the ends then the wires will be 'massaged' fair then soldered mid span. More pics to come.

[ARUP]

Eric, glad there was no damage! I look forward to more flight vids! I have calculated c.g. to be ~20-25%, the control throws will be minimal (around 20 degrees) and 'exponential' via the transmitter. What are your settings if I might ask?

After a marathon painting session this weekend with two languishing projects I have put the Charlotte back on the board! Whoopee! Here is a short checklist to finish wing construction.

1) install LE.
2) add 4 marine ply gussets at root ends so the last four drag and anti-drag cables can be installed.
3) finish fairleads for pull-pull cables. Then route cables.
4) finish 'hoop' skid attach points and fabricate the skids.
5) fabricate balsa surrounds at the strut attachment points so the covering has a place to seat.
6) fabricate hatches on lower surface at root ends so as to access bell cranks and cables.
7) re-do the hinge anchor points using carbon fiber tubing. They may be a little weak in their current form.
8) install cable TE.
9) cover. with fabric

When the SD card I loaned out for my camera is returned I'll be able to take some pictures.

[eric spore]

In order to fix this yaw problem, i decided to add a servo and i built a new steerable rudder. Not very scale, but i expect better control.
In fact no damage at all during the first uncontrolled landing. I was really lucky.
the patch under the wing is not a damage. One of the aileron's cable jumped from the pulley when assembling the wing to the fuselage. I was then obliged to cut the covering to fix this on spot.

[eric spore]

Sorry guys, it's me at the 7-second mark. len is my secret twin.