Midwest Citabria - Build Thread
07-27-2008, 09:52 PM
#5
RE: Midwest Citabria - Build Thread
More fuse pics.
Thats it for tonight. The firewall epoxy can cure overnight. I'll be working on it in the evenings after I get home from work. More pics to follow sometime this week.
Tomorrow I will start the tail feathers and then move on to the wing.
Thats it for tonight. The firewall epoxy can cure overnight. I'll be working on it in the evenings after I get home from work. More pics to follow sometime this week.
Tomorrow I will start the tail feathers and then move on to the wing.
07-28-2008, 10:52 AM
#8
RE: Midwest Citabria - Build Thread
Engine will probably be a TH .75. I was going to try and use a small gasser, but after looking at the size of the plane, I don't think even a G20 would be small enough. I would have preferred a gas engine, but I don't think the plane will fly very well with a 3lb engine.
Servos:
Not sure yet. Probably some JR911 coreless on the ailerons. Hitec 225 on each elevator___maybe a single JR8231? Not really sure yet. I'll probably just grab what will work and toss them in there. I've got so many servos lying around that I haven't given it a whole lot of thought. I'll just grab some good, strong ones and slap 'em in there.
Guidance will come from my JR8103 and a Hitec 8ch PPM RX. Probably a 1500mah RX battery.
I'm shooting shotguns tonight after work, so no progress to note for today.
Servos:
Not sure yet. Probably some JR911 coreless on the ailerons. Hitec 225 on each elevator___maybe a single JR8231? Not really sure yet. I'll probably just grab what will work and toss them in there. I've got so many servos lying around that I haven't given it a whole lot of thought. I'll just grab some good, strong ones and slap 'em in there.
Guidance will come from my JR8103 and a Hitec 8ch PPM RX. Probably a 1500mah RX battery.
I'm shooting shotguns tonight after work, so no progress to note for today.
07-29-2008, 04:05 PM
#10
RE: Midwest Citabria - Build Thread
You're only saying that because it's YOUR shop. 
I don't have room in my apartment for much of anything. Pete and I finished out a spot in his basement and I get to use the workbench. It's pretty nice to have a flat/level work bench that's 22 foot long and 2 foot wide. Flat as a piece of glass and level all the way around. It's also nice to have a buddy who will let me come over and make a mess.
I don't have room in my apartment for much of anything. Pete and I finished out a spot in his basement and I get to use the workbench. It's pretty nice to have a flat/level work bench that's 22 foot long and 2 foot wide. Flat as a piece of glass and level all the way around. It's also nice to have a buddy who will let me come over and make a mess.
07-29-2008, 10:02 PM
#12
RE: Midwest Citabria - Build Thread
Pics of the horizontal stab and elevators. Too tired to sheet them tonight. [&o]
I altered the elevators a bit. I want them to have a counterbalance and look a bit more like the Decathlon. I need to add a few triangle balsa gussets here and there on both the stabilizer and the elevators. The elevators are twisting really bad, so I plan to run some triangle braces to add torsional strength. Also need to add some hard points in the elevators for the control horns. I am still undecided, but I might put a couple hard points in the horizontal stabilizer for flying wires.
I altered the elevators a bit. I want them to have a counterbalance and look a bit more like the Decathlon. I need to add a few triangle balsa gussets here and there on both the stabilizer and the elevators. The elevators are twisting really bad, so I plan to run some triangle braces to add torsional strength. Also need to add some hard points in the elevators for the control horns. I am still undecided, but I might put a couple hard points in the horizontal stabilizer for flying wires.
07-30-2008, 10:03 AM
#13
Senior Member
Join Date: Oct 2007
Location: Milton,
WI
Posts: 704
Likes: 0
Received 0 Likes
on
0 Posts
RE: Midwest Citabria - Build Thread
It looks like its coming along great ! My dad built one last year as a winter project. He had a build thread going -
http://www.rcuniverse.com/forum/m_58...tm.htm#5864269
TakingFlight96
Heres the pics -
http://www.rcuniverse.com/forum/m_58...tm.htm#5864269
TakingFlight96
Heres the pics -
07-30-2008, 11:22 PM
#14
RE: Midwest Citabria - Build Thread
I remember that build. Nice lookin' plane. [sm=thumbs_up.gif]
Pics of the stabs and elevators. I got some balsa gussets in place tonight and sheeted the stabilizer. Added some diagonal cross braces to the elevators. That stiffened them up a LOT. Combined with the corner gussets everywhere, I feel they are plenty strong for what I plan to dish out to this airframe.
I added some balsa to the hinge line. I wanted a bit more wood to hold the hinges. It's a slight weight gain, but worth it to me.
Started on the wing. Each piece of spruce spars material had a slight curve on one end. I laid them all out and got all the curves facing the same way. Then set each piece so that when glued to the wing the curves will point towards each other. They will point to the center of the wing. The top spar curves down on top of the rib. The bottom spar curves up to the bottom of the rib. Hopefully this will yield a straight wing. The table and building board are all perfectly level. So as long as it's all pinned down, I feel it will come out straight when I yank all the pins out.
I punched out all the W2 ribs and laid them out flat on the bench. I sorted through all the ribs and found matching pairs based on wood grain density and overall stiffness. I set them up with the heavier ribs to the root side and the light and flexible ribs at the tips. I labeled all of them 1-8 to prevent mixing them up later.
Got all the W2 ribs glued to the bottom spar on the right wing tonight. Forgot to take a pic.
Pics of the stabs and elevators. I got some balsa gussets in place tonight and sheeted the stabilizer. Added some diagonal cross braces to the elevators. That stiffened them up a LOT. Combined with the corner gussets everywhere, I feel they are plenty strong for what I plan to dish out to this airframe.
I added some balsa to the hinge line. I wanted a bit more wood to hold the hinges. It's a slight weight gain, but worth it to me.
Started on the wing. Each piece of spruce spars material had a slight curve on one end. I laid them all out and got all the curves facing the same way. Then set each piece so that when glued to the wing the curves will point towards each other. They will point to the center of the wing. The top spar curves down on top of the rib. The bottom spar curves up to the bottom of the rib. Hopefully this will yield a straight wing. The table and building board are all perfectly level. So as long as it's all pinned down, I feel it will come out straight when I yank all the pins out.
I punched out all the W2 ribs and laid them out flat on the bench. I sorted through all the ribs and found matching pairs based on wood grain density and overall stiffness. I set them up with the heavier ribs to the root side and the light and flexible ribs at the tips. I labeled all of them 1-8 to prevent mixing them up later.
Got all the W2 ribs glued to the bottom spar on the right wing tonight. Forgot to take a pic.
08-02-2008, 12:30 AM
#16
RE: Midwest Citabria - Build Thread
Frenzied 
Wings construction:
Got all the W2 ribs in place with medium CA and also put in the shear webs and leading edge piece.
The kit is designed to have 2 dihedral braces made from 1/8" hard plywood. These braces go in front of the spars and behind the spars. Nothing in the middle of the spar. It's just an empty pocket with the braces in front and back. This is where I will need to drill the holes for my wing dowels. I don't like the idea of just drilling through a piece of 1/8" ply to hold my dowels, so I had to make an additional brace from 1/4" hard plywood. The spars are 3/8" wide, so the 1/4" brace will not fill the entire space (front to back) between the spars. I decided to glue my added brace to the front piece of 1/8" ply. When I drill my holes in the front of the wing for my dowels, I will go through the front piece of 1/8" ply and through the 1/4" ply. When the bit comes out the back of the 1/4" ply, I will stop. There will be a 1/8" void between the 1/4" ply and the rear dihedral brace. I plan to use Gorilla glue on the dowels, so this void in between the pieces of ply will allow the glue to expand a bit without blowing anything apart. That's the theory anyway.
I marked out where the 1/8" ply and 1/4" ply will need to be glued together. Then I applied the 15min epoxy to the spars and plywood. Clamped it all in place. Watching glue dry now.
Wings construction:
Got all the W2 ribs in place with medium CA and also put in the shear webs and leading edge piece.
The kit is designed to have 2 dihedral braces made from 1/8" hard plywood. These braces go in front of the spars and behind the spars. Nothing in the middle of the spar. It's just an empty pocket with the braces in front and back. This is where I will need to drill the holes for my wing dowels. I don't like the idea of just drilling through a piece of 1/8" ply to hold my dowels, so I had to make an additional brace from 1/4" hard plywood. The spars are 3/8" wide, so the 1/4" brace will not fill the entire space (front to back) between the spars. I decided to glue my added brace to the front piece of 1/8" ply. When I drill my holes in the front of the wing for my dowels, I will go through the front piece of 1/8" ply and through the 1/4" ply. When the bit comes out the back of the 1/4" ply, I will stop. There will be a 1/8" void between the 1/4" ply and the rear dihedral brace. I plan to use Gorilla glue on the dowels, so this void in between the pieces of ply will allow the glue to expand a bit without blowing anything apart. That's the theory anyway.
I marked out where the 1/8" ply and 1/4" ply will need to be glued together. Then I applied the 15min epoxy to the spars and plywood. Clamped it all in place. Watching glue dry now.
]
08-02-2008, 01:00 AM
#23
RE: Midwest Citabria - Build Thread
Servo lead tubes in the wing panel. Made from 8.5x11 printer paper split in half (longways) and rolled up. 2 pieces here to make it long enough to reach out to where the servo mount is located. Couple drops of thin CA and it's done.
Some pics of the leading edge sheeting. I used thin CA to tack it in place. Actually my friends wife put the CA on while I held the leading edge of the sheeting in place. She didn't even glue my fingers down. Pete would have dumped CA all over my hands and left me stuck to the sheeting. ON PURPOSE!!! [>:]
Thats what buddies are for, I guess.................
After the leading edge of sheeting was stuck down with thin CA, I went back and ran medium CA along the tops of all the ribs and a thin bead of CA down the main spar. Hold it all in place for a few minutes.
I set up a jig to hold the back of the ribs in place while I put the trailing edge piece on. The ribs have tabs to keep them elevated off the bench. I wanted it all to be pinned down while I put the glue on the trailing edge piece, but I didn't want to put pins through the ribs. A piece of balsa about 3/16" thick and one thin piece of sheeting was the right thickness to provide support under the trailing edge of each rib and also made a nice flat surface to glue my trailing edge piece on. Not sure if that makes sense. I made a jig and it worked really nice.
Sanding the trailing edge piece to match the rib profile on top. Some trailing edge sheeting and center section sheeting.
Took it off the board and checked it for alignment. It's straight enough.
Some pics of the leading edge sheeting. I used thin CA to tack it in place. Actually my friends wife put the CA on while I held the leading edge of the sheeting in place. She didn't even glue my fingers down. Pete would have dumped CA all over my hands and left me stuck to the sheeting. ON PURPOSE!!! [>:]
Thats what buddies are for, I guess.................
After the leading edge of sheeting was stuck down with thin CA, I went back and ran medium CA along the tops of all the ribs and a thin bead of CA down the main spar. Hold it all in place for a few minutes.
I set up a jig to hold the back of the ribs in place while I put the trailing edge piece on. The ribs have tabs to keep them elevated off the bench. I wanted it all to be pinned down while I put the glue on the trailing edge piece, but I didn't want to put pins through the ribs. A piece of balsa about 3/16" thick and one thin piece of sheeting was the right thickness to provide support under the trailing edge of each rib and also made a nice flat surface to glue my trailing edge piece on. Not sure if that makes sense. I made a jig and it worked really nice.
Sanding the trailing edge piece to match the rib profile on top. Some trailing edge sheeting and center section sheeting.
Took it off the board and checked it for alignment. It's straight enough.
08-02-2008, 01:04 AM
#24
RE: Midwest Citabria - Build Thread
You can see the little jig in this first pic. I used a VERY TINY drop of medium CA to glue the little rib tab from each rib to this jig. Pinned it al down and glued the tabs to the jig. Then set the trailing edge piece in place and glued it to each rib with medium CA. Worked great. Everything is straight and true.
Thats all for tonight. [8D]
Thats all for tonight. [8D]
08-02-2008, 09:06 AM
#25
RE: Midwest Citabria - Build Thread
A little skin sacrifice is good for every kit build. PRICE ENJOYMENT [sm=teeth_smile.gif]
A cut on the finger while building a kit. PRICE RELAXATION[sm=shades_smile.gif]
Gluing your buddies fingers to his airplane. PRICELESS[sm=wink_smile.gif]
A cut on the finger while building a kit. PRICE RELAXATION[sm=shades_smile.gif]
Gluing your buddies fingers to his airplane. PRICELESS[sm=wink_smile.gif]
