Dad's Pitts Special Model 1951 - 2017

While visiting my parents for my Mom's 90th birthday party I noticed my Dad's old Pitt's Special model.  Going with Dad to the flying circle was one of my favorite treats.  Watching him fly that Red and White Pitt's is just one of those great memories.  The plane has always hung in his workshop a never fails to remind me of going to the flying circle and watching him and all his friends flying, dog fights, jets and stunt jobs.  It was great fun!  I think is was a major reason all I ever wanted to do was build and work on airplanes.  We built a Fly Baby and fixed op an L-2 Taylorcraft while I was in High School.  Fifty plus years later as an A and P, Private Pilot, and Aerospace Engineer, I still have the Fly Baby, and 2 other projects.

We were looking for something in his shop in the barn and I asked him when he built the Pitt's, since it just always seemed to be a part of our lives.  He couldn't remember exactly but he always took pictures of models he built and has the pictures all in albums, many albums.

We got to searching and sure enough there was a picture of my older brother David (right) holding the plane in 1951.  Dad's in the middle and uncle Peter, 2 years older than David on the left.

We did some more searching through all Dad's well organized magazines and found an add for the Pitt's on the last page of the January 1951 issue of Model Airplane News.  The add for the McCoy 29 was on the back cover.  The kit was $4.95 but the engine was $11.95.  Dad, a retired cop, always worked part time at a hobby shop so I suspect he at least got a small discount.

The model appears to be one of the few which never crashed.  I think the real hobby is fixing busted planes.  All the paint job on the wings and tail is done with the original decals.  I never realized it was all decals until we got looking at it.  He was thinking he should recover it.  I suspect there aren't many models that old and still so original.  The only change has been to rotate the engine to the outside.  I wondered if it ran better that way or if it's a different McCoy than originally installed.  Engines moved from model to model and had a way of occasionally getting damaged in the dirt, usually at high speed.  Ah the excitement of watching airplane parts flying in all directions, when it's someone else's plane.  The truth is much simpler, the control lines didn't stay tight with the engine facing into the circle.  Turning the engine to the outside solved the problem.

We decided to recreate a couple of the pictures of the Pitt's.  The spiffy shirt is long gone but their current house has  the same shingles as the old one.  The tissue paper is starting to fail but other than the pilot, added some years later, it's all original, and in very good condition.

The day we took these pictures dad was getting ready to start working an a large scale P-40 kit he got in a deal for his P-51 model which the other fellow should enjoy flying as much as dad did.  The P-40 has retracts and all so it should keep him busy for a few days.

I'm glad he still has the Pitt's.  The memories it brings back are treasures.

Brace Cable Length Fixture

Having figured out how to make the wire wrapped cable ends the way I wanted, I needed a way to make sure the cable length was correct.  Wrapping and soldering the ends was too much work to remake one because I messed up the cable length.  When we assembled the plane the first time we did it in the barn, and just made each cable to fit the plane with the wings held in position.  When I started this it was fall and I didn't want to leave the plane assembled in the driveway for weeks.  I also wanted to recover the wings while I made new cables.

To control the length I made a simple fixture from 2x4s and some pieces of angle iron.  The block and angle bracket on one end is screwed to the 2x4.  The other end can be positioned to the desired length of the cable and just clamped to the 2x4 frame.

I assembled the plane and rigged all the cables tight.

I measured each cable length from the edge of the fitting, at one end,to the center of the pin, on the far end of the turnbuckle, at the the other end.

The fixture is set up to duplicate cables using the distance between these same references, the edge of the fitting and the pin at the far end of the turnbuckle.

I made a bracket at the fixed end to hold the fitting.  It's screwed to a piece of 2x4 which is screwed to the 2x4 base.
I found I needed to protect the fitting paint from scratching so I made a protector from a plastic blister pack.  It had a nice fitting square corner.

The 3 holes are for socket head cap screws which keep the fitting from sliding off the end of the bracket, which it did without them.

My length measurement starts from the fitting side of the bracket.  If I had been thinking, I would have positioned the angle bracket on the block so the fitting side of the angle was in line with the edge of the block

I took all my measurements in centimeters because it was easier.

The movable block was made so the measurement between the edge of it and the edge of the fixed block is exactly the length of the cable.  As a result all I have to do was measure from the fixed block, draw a line for the front of the movable block and clamp the movable block on that line.

The bracket on the movable block has eye bolts for the turnbuckle pins.  Since all my wing brace cables are double I used 2 eye bolts.  In the end I did each cable as a separate piece so I could have done this with 1 eye bolt.

One advantage I found to 2 turnbuckles was the ability to easily lock the turnbuckle barrel so it wouldn't unscrew while working.

I crimped the Nicopress sleeve on the free end of the cable but did not wire wrap it until cutting the cable to length.  You can't spin the cable while it's still attached to the reel of cable.

With the length set and the turnbuckle at zero threads showing, I pulled the cable snug, then cut it off about 8" past the fitting end bracket.

The turnbuckle end was then wire wrapped and soldered.

I found a couple nails and a safety pin made simple stops to keep the cable end from turning in the barrel.

Slip the Nicopress sleeve on the cable, pull the free end of the cable around the thimble on the wing fitting, then back through sleeve.

To grip the free end of the cable, so I could pull it tight, I modified a cheap pair of Vise Grip type pliers.  I used a chain saw file to make a groove to fit the 1/8" cable.  I felt it gripped better than flattening the cable end in the jaws.  The groove needs to be such that there is a slight gap when the jaws are tight.

This works really well.

I removed the adjustment screw on the pliers and installed a 5/16" eye bolt so I could use a ratchet strap to pull the cable tight.  The cheap pliers had a metric bolt with threads very close to 5/16 UNC.  I just ran a tap down the threads to clean them enough for the eye bolt to turn freely.

The ratchet strap works well to pull the cable tight.  To keep the 2x4 from bending I screwed another 2x4 to the bottom, forming a "T" section.

I also added some 2x4 feet so I can clamp it to saw horses at a convenient working height.

With the cable tight the Nicopress Sleeve is positioned with a 1/16" gap to the thimble, as on the other end, and squeezed.  I had to take the cable out of the fixture to make the squeeze closest to the fitting.  If you don't you just can't see what you are doing to position jaws.

My original idea was to leave the first cable in position while crimping the second cable.  With very little thinking I would have realized the 2 cables were too close together to squeeze the second cable with the first one tight.

Tip it back out of the way and do the second cable.  You still need 2 slots in this bracket for everything to fit.

The cable is then ready to finish wire wrapping the ends as discussed in the previous posting.