Bulkhead Alignment.

Spent today "adjusting" the bulkheads for the top skin installation.  Instructions talked about stretching a fine wire across the top of the bulkheads from station 114.75 to the vertical stabilizer along the CL.  While at the Mustang Open House someone mentioned needing piano wire for this.  Well, I found some very fine varnished coated wire the kids and I used to make crystal radios in the 90s.  It worked great!  So, very fine wire, when you get to this point, will work.

It was hard to get a clear picture of the fine wire.  Each time I adjusted a bulkhead I forgot the wire was there and hit it.  It was easy to tighten and readjust.

I found the factory made slots in the bulkheads for the skin stiffeners was to tight and adjusted each one.  When I completed, I inventoried how much of the stiffener material I had left.  I have enough for all of the plan's recommended installation.  Some kit builders recommend more for the tail cone skins.

The skin stiffeners, 240.371-?, look like a J.  Drilling rivet holes can be a challenge due to the shape.  Holes are located on 2" centers.  I marked the remainder of the stiffening material and drilled the holes for AN426AD-3 rivets.

Looking forward to getting the top skins down and slapping them on the tail cone.  I still have a lot of questions as to the installation of the bulkheads.  Getting there slowly but surely!

BWW

Tail Cone Work Surface

So, to construct the tail cone the instructions said to mount the vertical stabilizer to a 2x4 and mount the 2x4 from the ceiling to the floor.  (Kind of like that.)  Well, I didn't want the garage door blocked for months while I constructed the tail cone so, I approached the problem a little differently.

The goal is to support the vertical stabilizer in the vertical position, on the CL with bulkhead 209.5 on the HRL.

My first run at the problem I clamped the last three bulkheads to the construction table and started after the problem.  It seemed to hold everything OK.

Another shot of the "monstrosity" clamped in place.  Kind of an inverted triangle.  Everything seemed to hold OK and lined up nice with the CL & HRL.  Until I placed the bottom skins and rear doubler into the fray.

That is when everything went awry.  It seemed placing the doubler on the inside threw dimensions off enough to make the bulkheads not fit correctly on the inside of the skins.  Once I removed the doubler,  everything fit up nice.

With the rear doubler removed, all the bulkheads fit up nice along the HRL.  I anchored the rear work surface to the concrete floor and called it a night.

Kind of looking like a real airplane.  Tail cone formers clamped in place almost ready to drill holes for Clecos.  I need to measure again before drilling.

I should be able to bring the tail cone top skins down from the upstairs soon.  I just don't know if I have enough Clecos to hold the whole plane together.  I may have to backtrack and rivet the forward fuselage to get some Clecos.

We'll see what tomorrow brings.

BWW

2012 Mustang Aero Open House

On August 18th I was able to make the pilgrimage to my first Mustang Aeronautics Open House in Troy, Michigan.  It was fun and I gained a lot of "tribal" knowledge in the construction of my Mustang II.

Mustang Aero moved into a larger facility recently.

Chris Tieman and crew threw out a spread of stuff to look at and touch for novices as well as experienced builders.

An example of some of the parts Chris had out was a center section "quick" build kit.  Chris also had several starter flap kits ready for expectant builders.

A short ride over to Troy Airport and we found several examples of completed aircrafts.

The aircrafts, all similar, had a varying degree of options installed by their owner/builders.  From avionics to canopy installations.  Being able to view and photograph the many examples helps a builder, like me, to plan how to tackle future items that need to be built.

(Infamous Larry Kinder plane above.)

Not sure whose plane.  I did like the deeper yellow color.

I thought this one was interesting.  Instead of a sliding canopy, it swung up and back for cockpit access.

A shot of Wayne Norris' plane.  One of the many excellent examples of flying Mustang IIs available to view and ask questions of the owner/builder.

All the owners provided very detailed information and encouragement to keep building your project.

Wayne departing late Saturday afternoon.

All in all I had a great visit to the factory and met a lot of nice people.  My main purpose for going was to pick up my completed wet wings.  They are now safely in my garage.

So, with the excitement of Oshkosh and the MII Open House over for 2012, all I have left to do is keep building.  My hope is someday I will fly into Troy Airport for the Open House in a completed Mustang II to share with other builders.

BWW 

The instructions say to build the tail cone on the airframe and on a table/work surface.  I had some left over plywood from the MII kit and built a work surface today.

My big question was what is the angle from station 114.75 to 209.5?  How many degrees?  As near as I could tell from the plans it is approximately 4 degrees.  So, I picked this as a starting point.

The work surface is about 4 degrees.  It may be a little steep.

I braced it for my weight when I get inside for riveting at a later date.  It will be anchored to the floor with some Hilti concrete bolts on the center line when all is good.

Test clamped the 209.5 and 205 bulkheads to the work surface.  Tomorrow I will setup the spinning laser and see if the HRL lines up.  Could be an interesting day.

I made a doubler for the tail end to support the landing gear and a heavy landing.  I only hope the work surface lines up OK with the HRL.

Later,
Brian W.

Rear Bulkheads

This last weekend I started sizing up building the epinage section.  Last fall I assembled and riveted  most of the bulkheads.  Stations 205 & 209 I drilled and Clecoed together until now.

The first step is to mount the vertical stabilizer spar for the rudder to bulkhead 209.

BLARG!!!  The three holes I drilled last fall do not line up with the factory assembled spar!  Not the factories fault.  It is mine.  (Old bulkhead at right.)

I missed two of the holes by about 1/6th inch.  I could just drill them out to the next size, but that wouldn't be right.  So, I found some .032 aluminum stock and made a new 209 bulkhead.  

Here is my home made bulkhead.  The bending brake came in handy.  I used the factory assembled spar to "match" drill the holes in my new bulkhead.

Corrosion protected and riveted the bulkhead looks pretty good.  I need to mark the CL and HRL on the bulkhead.

I corrosion protected and riveted up the 205 bulkhead and the adjoining parts.

This made for a full weekend.  I will have to start making the assembly "table" for the epinage section so I can start assembling from bulkhead station114.75 to bulkhead station 209.

Still have to get my wings from the factory.  They are having an open house August 18th & 19th.  I may go that weekend.

More to come......

BWW

Station 114.75 In Place

OK, I'm plugging right along.  I aligned station 114.75 bulkhead with the CL and the HRL today and clamped in place.

After clamping I drilled 1/8th inch holes for rivets.       Some of the bulkheads come from Mustang Aeronautics with pilot holes drilled in them.

So, I started drilling from the inside out.  I used a #40 drill going from the inside out making my own pilot holes in the skin.  Clecoed the assembly up with the silver Clecos.

Next, I drilled from the outside in using an 1/8th inch drill, or a #30.  On the way in, I made sure the drill was perpendicular to the skin to get a nice straight hole through the structure.  Looks pretty good.

I have decided for now to go with the bench seat. If I don't like it, I will change it out to something else later.

The bench seat requires a right and left seat attachment bracket, 280.302.  You have to find some scrap .040 aluminum to make these yourself.  Sounded like an opportunity to use the new 30" brake.

I cut two pieces of aluminum 4" by 7" nice and square.  Marked it up for bending and bent away in the brake.  The first two bends went great.  The third bend I could not do in the brake due to its location.  BLARG!!!  I bent it in the vice.

They came came out pretty good.  When I went to mount them in the aircraft something didn't look right.  I couldn't quite put my finger on it right away.  I had placed the right on the left and the left on the right!  I was fortunate though.  I had made them so well I was able to move them and Cleco them into their correct positions.

Pilot side.....

And the passenger side.

Not bad for a couple of hours.

I am getting close to calling the EAA Technical Councilor for another inspection.

I will try and figure out how to do the tail cone this weekend.  I have all the bulkheads made up.  That should help to speed things along once I get going.

BWW

360 Degree Spinning Laser

I have been relying on measurements from various locations to keep the fuselage assembly running true to the Horizontal Reference Line (HRL). The Center line (CL) has been easy to locate.  Just drop a plumb bob and gravity does the rest.

So, I bought a fairly cheap rotary laser from Harbor Freight.  Out of the box, it comes with a tripod, rotating leveling laser head, and batteries.

The tripod is a little wobbly and needs to be adjusted carefully.

The laser is designed to mount to the tripod in either a vertical or horizontal direction.  Here, I am adjusting the two bubbles for use in a horizontal direction.

The adjusting knobs allow for a fine adjustment.  I was able to get the bubbles right where I wanted them.

There is a target type bubble on the tripod, but I found this one to be way, and I mean way out of adjustment.  It was useless.

When ever using this system, I will have to be very careful.  It is so wobbly.  I may use some CA glue to "stiffen" it up.

Adjusting the horizontal bubbles.

Bubbles level and the laser is turned on.

I put on the red glasses that came with the laser so I can see the line.


BLARG!!!  My worst fears have come true.  The HRL is................

PERFECT!!!!

Right on the money.  The laser showed up on my marked line all the way around the forward fuselage.

Although the tool is a little finicky, it will work great for the rest of the build.  Now I can attack the tail cone and epinage.

One more tool coming from Harbor Freight this week.  A pneumatic flanging press.

Later,
BWW