F704-Spacers - New Trick

Here is something new I learned today. When cutting aluminum tubing, it is difficult to get a perfectly square edge. The method in the Plans worked out great.

First make a mark where the length should be. You can see the dot here.


Chuck the tube up in the drill press and spin a line around the tube with the sharpie.


Make a rough cut with a hack saw leaving some extra space as the cut will never be perfect.



Put the tube back into the drill press and spin it on some sand paper until down exactly to the line.



And there are two perfect spacers  1  and 28/64 (or 1 and 7/16)

Finishing Up F704 Main Bulkhead

Rivets are now in the F704 Main Bulkhead

F704 - Main Spar

After finishing the Spar behind the seats, this spar (F704) is the main spar which contains main wing attach points and is located under the knees of the occupants. All priming completed. and nut-plates installed.

F705 Bulkhead

Continuing on with the F705 Bulkhead, I have primed all parts (previous post) and have assembled the pieces.

Rear Wing Spar attach points:



Flap Control System bushings:





and Seat Belt attach points:

Assemble F706 Bulkhead

After priming, I can assemble and rivet the F706 bulkhead. Again this will live at the back side of the baggage compartment.

Priming - Using the HVLP system

The priming up until this point, I have been using Duplicolor Self Etching Primer in a standard rattle can. This is the stuff that is available right around the corner for $5 per can. I find it funny that many people swear by this stuff including the editor of Kit  Plane magazine. After using this on the interior components of the tail section, I have concluded that IT SUCKS!!! It seems to scratch off way to easy. The issue is that I need to rivet the pieces together after priming. This absolutely destroys the coat. It probably is not designed quite right for this application or something. So I have asked around and the other builders locally are using a product designed by Dupont. It is called Variprime Self etching primer. Surprise suprise it come in at around $400 per gallon!!!

 This is a two part self etching primer that is fast drying and provides excellent corrosion resistance and direct-to-metal adhesion. Blah blah blah. Anyway after trying it out, it is wonderful. And it should be for price!!!

This is applied with the new fanged HVLP gun that I picked up from harbor freight complete with a regulator for $30.

 

Check out my first attempt. These are the majority of the bulkhead components that I will be assembling of the next few days. (Oh, and another lesson. Don't paint at night.) 

F706 Bulkhead

OK, OK, so I am getting lazy. Not with building. I am getting lazy with my documentation. I get moving along with cranking out parts, I hate to stop to write in the log book and post my progress here. Don't worry though. I have been snapping pictures along the way.

So, the next bulkhead is the F706. This is located behind the baggage compartment and is the main support for the elevator push rod bell-crank. There is some fabrication here as well. The angle aluminum needs to be cut out and shaped.



Then all the pieces are put together, match drilled and fitted.




Good times.

F705 Bulkhead

The 705 bulkhead sits around the rear of the seating area. This also is the attach point for the seat belts and the seat adjustment points.

First make some small spacers.



Clamp a couple of bars in place and position the spacer. This will be the rear attach point for the wings as well.



Then drill all the rivet and bolt holes



These are the seat belt attachment brackets. I got smart and made a rough jig in the drill press to make sure all the holes are in the same location. This made the job very quick as I only needed to measure one of them.



Next to shape the bar doublers. Again used a hack saw for the rough shape and finished up with the files and wheel.

Fabricating the Control Stick Attachment Points

This piece is the attach point for the control stick assemble. This guy is a pain in the but as there is a "complex" shape that needs to be cut out of the raw material.

Used a hack saw to rough out the shape and the files to clean it up. Then a spin on the scotch brite wheel to shine it up.

Here is a before an after shot of the piece. And yes, I need to do the other one too.

F704 Main Bulkhead

Tonight I'm working on the F704 Main Bulkhead. This is the main section under the seats where the wing will attach to the plane. Starting with the brackets which will attach the floor panels, these must be match drilled to the main section.



After this, a rear stiffener must be fabricated from raw angle aluminium. This will attach from the back side on the brackets.







Each of these requires several nutplates attached which will allow the use of screws from the top side the the floor boards are installed.

After about 4 hours of work, here is what I have ended up with.



I have to make a run to Harbor Freight to buy an HVLP sprayer and order some primer. Until then, these parts will go into the "almost finished" pile.

Tomorrow, on the the control sticks.

Rivet the Firewall

Finished riveting the firewall today. This took nearly 5 hours to complete. I am sure this would have only taken an hour or so if there were two of me.

Attach Elevator Trim Tab

The Elevator Trim Tab is now attached and actually came out pretty well.






Also working on the Firewall. Dimpling has begun



Will be riveting tomorrow.

Firewall Assy

Today the firewall assembly is underway. Now all fabricated pieces are complete. All holes drilled together and clecoed.

Now on to dimpling and the rivet.