I’ve decided to attempt a rebuild of the Byron Originals Pitts S-1 that I crashed earlier this summer.

My initial goal is to repair the airplane to “flyable” condition. I will not spend a lot of time on cosmetics until I determine if the airplane can be made airworthy.

Challenges are:
1. Badly damaged fuselage front end. With no plans to guide me, I will have to decide whether to rebuild with foam or balsa/ply. I will start with this because it’s the most difficult challenge. No point in wasting time on the easier repairs until I determine if I can successfully rebuild the fuse.
2. Need to limit amount of weight increase caused by repairs. The plane was already a little underpowered.

Desired Improvements:
1. Add aileron servos to top wing. Original design used one large scale servo for all four ailerons. This change will eliminate having physical linkages between top and bottom ailerons resulting in reduced pre-flight assembly and servo redundancy.
2. Move location of rudder and elevator servos closer to control surfaces.
3. Change the design of the “I” wing struts to make pre-flight installation and alignment easier.
4. Smaller fuel tank - may reduce flying time but will save weight. I don’t fly for long periods anyway.

These pictures are of the plane prior to starting any repairs.

The first order of business was to remove the damaged firewall so I could use it as a pattern for a new one. Since I wasn't sure if I would be able to reuse any of the fuselage pieces, I wanted to remove the firewall without damaging the foam. Not an easy task since the firewall is epoxied into a recess in the foam and then fiberglass tape and resin are wrapped around the inside and outside of the firewall.

Fortunately, most of the fiberglass came off pretty easily...possibly due to the age of the airplane. The outside was more difficult to remove than the inside. After a couple of hours of work, the firewall was out.

Well, any hopes I had of reusing the foam pieces of the fuselage are fading fast. While I was able to piece a lot of the front end back together, the foam is too compressed, distorted, mashed, and otherwise pushed out of shape to maintain any kind of alignment. So, I guess I have to make a plan for replacing the entire front end. That may take a while.

After a couple of days of trying to figure out how to proceed with this mess and how much of the damaged foam I should try to salvage, my daughter came down to the basement last night and said, "Are you going to try and fix that?". I told her yes but that I wasn't sure how. She said, "Dad, just cut the damaged part off in front of the cockpit and start over from there." I slept on that suggestion and decided this afternoon she was right. So, I got out the coping saw and the razor saw and a large sanding block. At least now I am settled on a starting point for the repair.

Still lots of things to figure out, but that's what makes it fun.

Did you decide what you will be using, wood or balsa? Any more progress?

I haven't had a lot of time to work on it since the last post. I've had a couple of ideas but no definite plan yet.

I'm going to try and rebuild the front of the fuselage using primarily foam. In order to do this, I decided to build a hot wire foam cutter. The cutter is complete except for the nichrome wire which is on order. I will post pictures of the setup once the wire is installed.

The foam cutter is complete. Here are a couple of pictures. The first picture shows the cutting bow with the variable output power supply. My dad built this PS for his HAM radio gear years ago. You can also use a 12v battery or a 12v battery charger that will allow you to select the amperage. The variable output PS is nice because you can fine tune it so that the wire is hot enough to cut but doesn't melt away too much foam in the process. The bow itself is made from two yardsticks from Lowe's, some 1x2 furring strips, and a 3' piece of threaded 3/8" steel rod. The nichrome wire is 26 gauge, purchased through E-bay, $4.00 for a ten foot roll delivered.

The second picture shows one of the alligator clips hooked to the nichrome wire. Positive on one end, negative on the other. It also shows how I secured the wire at each end using a screw with the wire twisted a couple of times around it in between two washers. Tension on the wire is fine tuned by adjusting the nuts on the threaded rod at the top of the cutting bow.

The third picture shows the counterbalance system. There are two pulleys, one right above the center of the work table and the other behind the work table. The inset pic shows the bag of nails I am using for counterweight. This system allows me to not have to support the weight of the bow while cutting. It will "float" in mid air because of the counterweight.

This setup is great for cutting foam wing cores or for cutting larger foam blocks, etc. The cutting width is a little less than 35" so you could cut cores for a wingspan up to 68" or so.

Now I just have to figure out the best way to make templates so I can use this to create the front of the fuselage for the Pitts.