Lift, Drag and Center of Pressure Curves for the Aeromarine 2-A Airfoil

It's like Christmas again, first the radiator and now this.  I've search all over for this chart.  I knew the airfoil was tested at MIT in December 1922 but they say they threw away all their old files.  With this I should be able to recalculate the Longitudinal Stability and Control so I can determine a safe range for the center of gravity.  I have all the original weight data.  Nothing indicates they ever calculated where the CG should be, just where it was at gross weight.  Everything says the plane is tail heavy and the engine probably should move forward a little.  This is so cool.

I was searching the WACO Drawing CD from Steve Curry for some drawings for John LeBlanc and there it was.  I've had it for 3 years and didn't know it.

A Radiator Arrives

One of the things I didn't have for the plane was a radiator.

 Awhile back John LeBlanc and I worked out a deal for one of the radiators he had for his WACO TEN project.  Today a heavy wooden crate arrived.  I just realized that's probably how the first radiator arrived from Rome-Turney when When Clayton Bruckner and Sam Junkin were building the first NINE around this time of the year in 1925.

 The last owner of John's plane had removed part of the shell from the core to make a radiator with a modern core.  That didn't work out so well.  John is sending their radiator so I can strip off the original parts to turn this into a NINE radiator.  The differences between the NINE and TEN have to do with how the radiator mounted and where the inlet and outlet were located.
While parts have been removed the core appears to be in excellent condition so it all should be fixable.

 The radiators for WACO were made by the Rome-Turney Radiator Company of Rome, New York.  They used a patented square tube design for their radiators.  At one time they had a collection of one each of every radiator they made.  During WWII they donated the collection to be melted down in a Brass for Bullets campaign.

The drawing is a pieced together photo of the original drawing WACO sent to Rome-Turney to order the radiator for the prototype NINE.  It's dated March 11. 1925 which is when they were building the first NINE.  The drawing paper is a piece of heavy manila packing crate paper which someone roughly cut with a pocket knife and then drew the radiator in pencil, dated it and gave it a number.  This is the oldest known WACO drawing.  It's in the Rome-Turney collection of the Rome Historical Society.

Wire Tinning Solder Pot

 I need a way to tin the hard wires which brace the internal structure of the wings and fuselage.  When the WACO was built the wire was available already tinned.  Today they only sell it un-tinned.  The wire comes wound as a coil about 2 feet in diameter. The easy way to tin it is to tin it while it's in a loose coil by slowly winding the strand of wire through a long skinny solder pot.  It would also help with soldering the wire wrapped ends of the external brace wires.  To make a long skinny solder pot I bought an 18" piece of zinc plated steel Strut Channel from McMaster-Carr.  The channel is 1-5/8" wide x 1-5/8" deep, perfect for a solder pot.  To close the ends I cut a tab on each end and folded it over.  I cut along the bottom with the band saw and then cut off the tab on one side. To make the tab fit, when bent over, I used the die grinder to cut 45 degree notches.  It's not shown in this picture but I did cut the end of the tab as well.

 To make the bend I fit a block of hard wood in the end and clamped it so it wouldn't move.  Then I just hammered the tab over to fit.  Before I made the bend I sand blasted off the plating where I needed to weld the edges to seal it.  The tab sticking out on the bottom is there to mount the pot to the heating element. I drilled a 1/4" hole in each end to line up with the holes in the heating element.

 I also bent up and welded a support for the pot so it would all set up away from the wooden base I used to mount everything.  The piece setting between the support and the pot is the heating element.  It's a strip heater from McMaster-Carr which is used to heat dies and othe machine tools.  It fits perfect under the pot being 1-1/2" wide.  It's a 400 watt heater which runs on 120volts (3.3 amps).  It heats to a maximum of 1200 degrees F. so I went to Lowes and bought a dimmer designed to handle 600 watts.

 The parts are welded here and the heater is setting on the support.  The white stuff is Heat Sink Compound from Aircraft Spruce.  It helps transfer the heat from the heater to the pot neither of which is perfectly flat.

 All the parts are assembled.  I still plan to pack the box with fiberglass insulation to reduce the heat needed to maintain the temperature.  I also need a thermometer to monitor the temperature in the solder (50/50) so it's just hot enough to flow well.  I may add a light so I can tell if the electricity is on.  The dimmer is designed so you push it in to switch it on and off, but without a light you have to wait for it to get hot to know which way it's switched.

It works!  The solder bar is melting.  I bought 5 lb. bars of 50/50 solder through Amazon.

Now I need to build a stand for the wire coil and work out a method to feed it through the pot.

OX-5 Exhaust Manifold

 I've been working on making exhaust manifolds for the OX-5.  I don't need them for a long time but John Gaertner needs a set for the Jenny project, so they moved to the front of a long line of tasks.

The whole story is on my OX-5 blog.

 I finally have the first shell half successfully formed.  It came out very well.  Check it out in my latest OX-5 posting.

Fin Forward Brace Wire Fitting

 The brace wires on the stabilizer cross.  The wires at the front of the fin and fuselage go to the rear spar on the stabilizer.  The wires at the rear of the fin and fuselage go to the front spar on the stabilizer.  The fittings for the wires on the lower fuselage longeron are welded to the longeron. The fittings for the stabilizer and rear of the fin are bent tabs bolted to the structure.  We'll get to them in another posting. The fitting at the top front of the fin sets on the top tube and is held in place by the clevis pin welded into the front spar.  The brace wire angles back 15 degrees and down 23 degrees.  I used the string to double check my math for the angles.

 The fitting is made from .095" steel.  It can't just be bent in place because bending it would damage the tubes.  Instead I bent it around a 3/8" pipe nipple.  I used the nipple because I'm going to use a piece of it for a spacer under the fitting.  The spacer is needed because of the weld bead where the pin stick through the top tube.

The fitting was bent cold with a hammer until it matched the paper gauge I made to check the angles.

 The ends of the nipple were cut of and the cuts cleaned up on the belt sander.  The tube was split by slipping it over a piece of dowel to make it easier to hold.  Again the cut surfaces were cleaned up on the belt sander.
A 5/16" hole was drilled to fit the pin and the underside was ground out to provide clearance for the weld.

 The spacer fits nicely over the tube providing a nice mount for the without grinding out the fitting to fit over the weld.

The pin was left long so it could be cut to fit all of this.  A new cotter pin hole was drilled and the end of the pin cut off to a nice length.

I need to make up all the brace wires.

Tail Surface Welding is Finished

 The last parts to weld to the stabilizer are the fittings which hold the front spar of the fin to the front spar (or as WACO called it, the Front Beam) of the stabilizer.  The rear spar goes into the tail post of the fuselage.  The bolt which holds that together also holds the rear of the stabilizer.  When it's done there is no adjustment to the fin for rudder trim or to the stabilizer for elevator trim.  They solved those short comings on the Model TEN (GXE).
A fitting is welded to the stabilizer spar 7/8" apart  on each side of the fin and a bolt passes though it all to hold it together.  The fittings are 3/4" wide made from .0125" steel.  The 1/4" bolt hole is 15/16" above the top of the stabilizer spar.  It's taken some research and the help of Frank and Rich to find all these dimensions since most are missing from the factory drawing of the tail surfaces.

 To carry the loads better and to prevent distortion to the fin front spar I welded a piece of 5/16" x .028" tube into the bolt hole.  The rear spar mounts in a way that a bushing would not help and welding it in would just cause more problems than it's worth.
The rear bolt was installed and some string used to hold the fin in positions to tack weld the fittings.  I tacked them at each end, and in the middle.  With the fittings tacked I bolted a 7/8" spacer tube between them to help assure the spacing didn't change during welding.  It worked great.

 Welding was easier with the stabilizer tipped by setting it on some bricks.  Welding these on warped the spar a little.  It shrunk on the fitting side.  The trick of heating the back side of the spar and letting it cool took out the warp.
It all fits perfect.  With the bolts in the fin is square to the stabilizer.

My first tail surface is sand blasted, ready for priming.  This is so cool to finally have the tail surfaces made.

I've go some modifications to make to my blast cabinet to do the other parts and the prime them.

Wing Strut Attachment Fittings Finished

 When I made the fittings I used 3/16" pilot holes for the 5/16" bolt holes at the ends where the wing flying and landing wires attach, as well as for the 3/8" spar bolt holes at the other ends.  I didn't drill them to finished size at that point because I didn't want to buy large bolts to ruin during welding and I wanted to use small cheap pieces of tubing for the spacers.  The drilling was no more difficult after welding then before.  I drilled them out with center drills because the steep angle on the cutting edge helps them center better on the pilot hole.  The 3/8" hole was then drilled slightly (.002") larger with a letter V drill.

 I've decided to go back to using Zinc Chromate for primer except where I need to protect the finish for applying fabric.  There are wood blocks around these fittings for attaching the fabric so they're well protected.  The epoxy primer is much more easily scratched than Zinc Chromate.

I finished them with Black enamel, for the same reason, and then baked them in the sun.  I still need to paint all the small fittings and form the drag and  anti-drag wires.