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Sig Citabria Build

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Sig Citabria Build

Old 02-02-2020, 03:09 PM
  #201  
Starwolf2
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Default Getting ready to cover the wing

It was a beautiful day today so I was able to get out in the garage and work on the Citabria. I started preparing to cover the wing by measuring the center section to cut a door in the bottom for the servo bay.

Next, I cut the opening and found that I was a little conservative and could have made the door a little wider. Therefore, I widened it a bit with my trusty x-acto knife.

My last task was to ensure the points of attachment

The lines drawn for cutting.

The cut door. You can see that it can be opened up more.

Points of attachment for jury struts.

Blocks for struts.
for the struts and jury struts were ok.
Old 02-09-2020, 05:46 PM
  #202  
Starwolf2
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Today I was able to start covering the wing! I started with the white color that covers the majority of the wing. I will add red to the wingtips later. I had a pretty good sized wrinkle in the top that I was concerned about. I thought I might have to redo the center section. However, I was very pleasantly surprised that the dryer got rid of it!

Marching on to the red!

This is the bottom of the wing.


This is the top view. No wrinkle!

Old 02-15-2020, 08:09 PM
  #203  
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Default Covering the wing tip

I was able to cover the first wingtip today. This wingtip is more complex that the Sig 4 Star 60 that I previously built. The Citabria wingtip requires more patience and care when covering.

I started out by covering the bottom with red Monokote. I used an iron to attach the inward portion, and then went around the edges. After that, I cut tabs in the Monokote near the wingtip that I pulled on while I used a heating gun to apply the Monokote around the wingtip. I was very happy with how that worked.

Next, I repeated the process with the top portion of the wingtip. It went OK, but not as good as the bottom. The Monokote got a little stiff toward the end, leaving some ugly ridges. Also, I managed to put a nick in the Monokote when I was trimming the excess.

I hope to do the other wingtip tomorrow, hopefully with more success!


The top of the wingtip.

A closer view of the top.

The bottom of the wingtip in which the wrinkling/crackling of the Monokote and the cut are visible.
Old 02-16-2020, 08:14 AM
  #204  
acdii
 
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Almost finished the wing on mine last night. Monokote is a joke after using Ultracote and the Hobby King covering. It does not stretch well at all and wrinkles way too easy. Same issues as you had with the edge wrinkling, but it came out 10' perfect and that's all that matters. I tried to use the monokote adhesive, made a mess as the color squeezed out, so went back to ironing it on. Now I have to get some acetone and clean up where it bled, bottom of the picture you can see it.





Old 02-16-2020, 05:06 PM
  #205  
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ACDII, your wing looks good! I see that you have also installed the aileron hinges. My job for the coming week (?) will be to add the ailerons and the remaining stripes.

This is only my second kit. I think I used Monokote on the first one (a Sig 4 Star 60), but am not sure. That was more than 10 years ago.

Does the ultrakote use a lower temperature? Is that one of the things that makes it easier to work with?
Old 02-16-2020, 05:10 PM
  #206  
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I added the red Monokote to the other side of the wing today. I started out using the same method as yesterday. I first tacked the covering on the bottom of the wing. Then, I used the iron to secure the perimeter of the covering and rolled it over a somewhat straight part of the wingtip. Next, I cut several strips to use as tabs to pull out the covering as I heated it with the dryer and pulled it around the curved portions of the wingtip. I was pretty satisfied with the end result.

Finished securing the perimeter.

Wrapped the covering around a straight portion of the tip and cut "pull tabs."

Top of the wing after I finished the bottom covering.

The bottom of the wingtip.
Old 02-16-2020, 05:22 PM
  #207  
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I moved on with the project to attach the covering to the top of the second wingtip. I tried an experiment as I did it. In an attempt to reduce the amount of hardened, crinkled covering that wrapped over the bottom, I tried to attach the covering only using the iron. I did it, but I am not satisfied with the results. The surface of the tip is not as smooth as the first wingtip.

I have decided that I will not try this method again!

The completed wingtip from the side with the bottom of the wing facing up..

This is an enlarged version of the previous picture. It looks like the top covering looks a little better where it overlaps onto the bottom.

The top of the wingtip. You can see some wrinkles towards the front of the side.

An enlarged view to show off my mistakes!

My next plans are to attach the ailerons. However, I need to think about how it will be done as the ailerons will not be horizontal. The plans state that they must be angled upward and that they are to be installed towards the top of the aileron. Wish me luck!
Old 02-16-2020, 05:58 PM
  #208  
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Yes, the Ultracote is lower temp and the adhesive remains tacky once activated, unlike the monojoke. It also stretches much easier and doesn't crinkle like the plastic on packaging. From now on, either Hobby King or Ultracote for me, no more of the monokote.
Old 02-20-2020, 07:46 PM
  #209  
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I have loosely attached the ailerons! Now, I can line up the rest of the red striping.

Old 03-28-2020, 04:12 PM
  #210  
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Default Wing Striping

I've been cooped up in the house thanks to the coronavirus. However, I have spent all my time on work-related projects. Today, I finally made it out to the garage to work on the wing. The stripes looked pretty good at first. However, when I used the blower to tighten them up I noticed that a couple of stripes did not stay in place. I was really disappointed. I will probably leave it be because I do not want to make the covering look even worse.

The top of the wing before I used the blower.

Front view

Bottom view, after using the blower. I would like to know how to prevent the shrinkage of the edges of the stripes.

Old 03-29-2020, 12:21 PM
  #211  
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Default Ailerons!

I made more progress today. I hooked up the aileron control linkages. This was not to difficult, although the wire has to hang down quite a bit so that the linkage does not hit the wing when the aileron is in the up position. The next job is to install the servo in the wing. I need to spend a little time thinking about this one!





Old 04-05-2020, 02:42 PM
  #212  
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I built the mount for the aileron servo today. I used blind nuts (4-40) behind piece of plywood. I will glue the mount down later and attach a wire between it and the wire running the length of the wing.



Old 04-05-2020, 02:49 PM
  #213  
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Default Motor Mount

I began thinking more of the motor mount. I have an E-flite Power 52 brushless motor. I also purchased a Great Planes Brushless Motor mount for medium sized motors.It says that it will work with 0.40 to 0.70 sized engines. However, I can't figure out how to attach them! The holes in the back of the motor do not match the holes in the motor mount. To make matters worse, the holes in the mount that came with the motor do not match the motor mount either!

I do not think that I want to drill new holes in the motor mount. Does anyone have any ideas of how I can work around this?



Old 05-13-2020, 09:31 AM
  #214  
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I have attached the elevator!

I received a new adapter from Horizon Hobby that was suppose


d to be used to attach the motor to the motor mount. However, it still doesn't have holes that line up with the motor mount. I am now thinking of making a mount myself. I drawing of my general idea is included below.
Old 05-13-2020, 10:40 AM
  #215  
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Not done yet? Gee with everyone staying home... LOL I should talk, I actually have done less being home because I now work more at home, not realizing its time to "go home". My Citabria is at my friends shop, and with the stupid lockdown, can't go there.
Old 05-13-2020, 05:40 PM
  #216  
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That's great! I thought I would be able to get a lot done. However, the switch to on-line classes was even more problematic that I expected. I had hardly any time to do anything other that work. I think my airplane was just sitting in the garage laughing at me!

I am still thinking of how I am going to attach the motor. I have to order a few more nuts and bolts. Once they come in, I can make some progress. In the meantime, I am doing as much as I can. I have also attached the fin and rudder and today I started working on the struts. I will not add the jury struts though.

Next steps include adding a door in the side of the fuselage and installing the servo trays.
Old 05-16-2020, 07:35 AM
  #217  
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I just realized that I have made a bit of progress, but have not written about the steps here. In the last few days, I have:

1. Attached the fin and rudder.
2. Attached the tailwheel mount. I had to make a new mount as my fuselage was shaped a bit different where the mount attaches. The picture of the mount on the plans was a little difficult to udnerstand.
3. I cut the struts to the correct length, shaped them, and then used a miter saw to notch the ends. The notch was not quite wide enough for the brass shims so I used a cut-off wheel on my Dremel to widen them. I glued the shims in place and drilled a hole through the ends.

I need to attach the struts to the wings and the wings to the fuselage in order to continue on to the next step of strut assembly. I have run into 2 problems. First, I am having trouble locating the strut attachments points in the wing because the covering is hiding them. I will try to shine a bright flashlight through the wing to see if that helps. Second, I have found that the holes in the fuselage that are supposed to receive the bolts to hold down the wings are too small to accommodate the bolts!





Old 05-16-2020, 08:30 AM
  #218  
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Taking a minute to think can really make a big difference! A few minutes after the last post, I went down to the shop and thought a bit more. The wing bolts were not fitting right because I added a few drops of thin CA to the holes. Clearly, the CA clumped up a bit and prevented the bolts from fitting. So, I got out my trusty 1/4 inch tap and reopened the threads. The bolts fit fine now!
Old 05-17-2020, 05:22 AM
  #219  
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I clumsily knocked over the wing last night and to make matters worse, another model fell on top of the wing! Two large and a few small holes were poked into the Monokote. Leaving me with the extra project of repairing the wing.

Two holes in the center and some small gashes along the front.

The covering has been removed and edges attached to the sides of the ribs.

Repairs complete!

Old 05-17-2020, 07:44 AM
  #220  
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At least you didn't smash the rudder into something carrying it around and then have to cut the covering away to repair the mashed up wood. Speaking from experience.
Old 05-17-2020, 07:50 AM
  #221  
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Ouch!
Old 05-17-2020, 06:44 PM
  #222  
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I made some progress again today. I started out by drilling the holes for the inboard screws on the struts. The next job was to cut open the holes in the fuselage for the aluminum pieces that the struts attach to. These aluminum pieces are supposed to be bent. However, the plans don't actually depict the location of the aluminum pieces very well. It took me a bit to even figure out how to orient the fuselage to be in the same position shown in the manual. Looking at the side and top views of the fuselage on the plans, I can see where the aluminum pieces stick out of the fuselage, but not how they fit into the fuselage.

I ended up using the dremel to cut a hole straight into the fuselage. This will not require bending of the aluminum pieces.



The orientation of the plane to match the manual. I am looking to the bottom of the plane.

The aluminum piece stuck into the beginning of the hole I cut.
Old 05-20-2020, 01:33 PM
  #223  
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I have continued to move forward! I spend yesterday and today building a tray for the rudder and elevator servos as well as the receiver. I was really excited to test the receiver and servos out. I had not turned on my transmitter for almost 5 years. It was nice to see that I could still link up the receiver to the transmitter and make the servo arms go back and forth!

I have ordered rods and linkages for the rudder and elevator. Hopefully, they will arrive early next week.

The hardware for the motor mount arrived today so I was able to work on that. I will upload pictures in a bit. Right now, there are a few pieces that I am waiting for the epoxy to dry on.

Acdii, have you installed the windows in your cockpit yet? I would be interested in seeing how you did so. I have been trying to think through how I will attach them as the directions are not very helpful. For example, do I cover the fuselage and then attach the plastic for the windows outside of the covering? Or, do I sandwich the plastic between the covering and the frame? But this would be difficult to do on a plane like yours which had the covering installed without the plastic. Finally, another option would be to attach the plastic inside of the fuselage frame.



It's was very satisfying to see some servos and the receiver installed!
Old 05-20-2020, 05:45 PM
  #224  
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I think it is the SIG way to glue them on after it is covered. The Rascal was that way. Since they are cut from flat sheets, and not formed, that is what i will be doing.
Old 05-21-2020, 11:51 AM
  #225  
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Acdii thanks for the response! I thought that might be what you had in mind.

I managed to get enough of my home made motor mount together to hang the whole thing. My idea seems to have worked!

Well, it only worked in theory because it pushes the motor out too far and prevents the cowling from attaching properly.

I have several options now, I would appreciate the thoughts of anyone that is actually following along on the build.
1. I can remove the existing firewall and push it back towards the cockpit. I am not sure that I want to do this as I think it would open up a can of worms, leaving me to rebuild the entire front section.
2. I can extend the balsa behind the cowling to cover up the gap.
3. I can enlarge the hole around the propeller shaft a bit so the cowling can be moved back.
4. I can cut off a bit of the inside portion of the metal motor mount so it can slide back a little more.
5. I can completely rethink how the motor attaches to the model.

At this minute, I think I am leaning towards option 4. However, I am not sure how difficult it will be to cut off part of the motor mount.




The gap between the cowl and the fuselage can be seen here.

The motor is right up against the cowl.

This view of the mount shows the two inner pieces that can be trimmed a quarter inch or so to allow the motor to slide backward a little more.

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