Tail Cone Longeron Work

Back to work on the plane!  Been sick and out of town for a couple weeks!  Tonight I got started by marking the longerons for cut to length.  They are shipped a little long.  Measure about 10 times on this one because you don't want to screw this up!

I used the cut-off wheel for this job.  To long and wild for the band saw.

Then I marked the HS stab mount bar relief holes and punched them for drilling.

Started with a smaller drill.

Then went up to 1/4".

Next I marked for the relief cut.

And used the cut-off wheel to cut out the material.  Then used a few files to clean it all up.

Next comes the whack a mole method to bend the longerons 2° down at just the right spot.  I just followed the directions and it works.  Seems brutal and it is but it works.  Did the same thing back when I built the RV-7.

Here you can see the slight angle starting at that line when compared to a straight edge.

And once the second one is done, here are the two back to back.

Been sick....Got new tool!

Been sick as a dog for over a week!  Very little getting done on the plane....

So I built an entire RV7 with a cheap, slow and noisy Harbor Freight pneumatic drill motor.  I decided I had had enough of that and bought this Nova 4000 rpm motor!   This thing feels like a very quality tool.  It is very lightweight, compact, and feels great in your hand.  Half the price of its nearest competitor.

While the new drill motor is only 1/4” capacity, it is much more compact vs the old motor.  The Nova has a feathering trigger/throttle which is awesome!  The old one is basically on/off.

The old motor weighs 2 lbs 8.6 oz.

The Nova is almost a pound lighter at 1lb 9.8 oz.

I tested the speed of the old motor and it came in at 1475 rpm.  The Nova turns 4058 rpm!  The higher rpm is better for small holes in aluminum.  The high speed helps minimize the pressure required and gives you a rounder hole.  The high speed is an advantage on drilling thick stock like the million holes in the longerons.

The old motor is very loud,  the Nova is almost as quite as my battery powered drill!  

I did a test with a dB meter 1’ away from the motors.  The old motor averaged 100dB while the Nova averaged only 78dB!  

Sick

Been sick and not able to work on the plane. 

Tail Cone Bulkhead and Stringer Work

 So my wife bought me this time saving tool for my birthday.  Definitely a luxury tool!  I tried it out on a few holes and it seems to work as advertised.   May have to get a #30 sized one as well.  Basically this lets you deburr both sides of a hole with one quick motion.  Works also for blind holes and holes where you can't get normal deburr tools to the backside of a hole like close rib flanges and stuff.

 Started today by fabricating this stiffener that goes on top of one of the bulkheads.  The ends are to be cut at an angle.

 The bandsaw made this easy.  Just used a piece of wood to hold the aluminum angle up as required for the cut.

 Next was separating these doublers.  I think these were added to the kits as a SB at some point because this bulkhead was cracking.

 Used the bandsaw to separate them, then deburred them.

 Now I marked center and the 1/8" line on the aluminum angle I cut above.

 And clamped it to the top of the bulkhead after clecoing the doublers on.  I used the center line and the 1/8" offset line to center and properly position the angle.

 Then I match drilled the angle to the bulkhead.

 Next I cleco'ed this bulkhead together.

 And match reamed the common holes.

 The next bulkhead got the same.

 And match reaming.

 And punching up these holes to 5/8" with the unibit.

 Then the largest bulkhead.

 Only the top cross part gets match reamed at this point.  The bottom ones don't get done at this point.

 Finally I cut all the J stringer's to length.

And cut the ends at the 45° angle per the directions.

Tail Cone Aft BulkHeads

 Started by laying out this angle that holds the clamps that hold the rudder cable exit tubes I think.  It also serves as a stiffener for this bulkhead.

 Ordered this new automatic center punch that is actually supposed to work.  Most of the really cheap ones don't!

 Got a slightly early Christmas present.  These things are a luxury item I know!  I now have a regular and one armed nutplate version for #6 and #8 screws.  I realized after I got them that you can actually use the one armed nutplate version for both one armed and two armed nutplates.  Bummer!  I imagine though that it is best to have the regular two armed version for tight clearance areas because the single armed version is wider.  I need to order two more for #10 and 1/4" bolts.  I will likely just get the single arm version of those.

Another Christmas gift had these plastic storage boxes inside of it.  It was a tackle box cooler thing that we plan on using only as a cooler.  SCORE!

I used it to start organizing some more of my hardware properly.  This one got nutplates.

 So since I don't have the #10 version, I had to do it the old fashioned way and use the nutplate itself for the jig.  Just stick a bolt in partially and side grip cleco one side.

 Then drill the other and put a cleco in the hole.  Then drill the others side.

 So then I slightly countersink the mounting holes for the NAS1097 oops rivets I use to mount nutplates.

 Next I marked this short bulkhead stiffener.  It gets cut from one of the six foot J stiffeners.

 Cut it on the bandsaw.

 Then Deburred.

 Whack a Mole to straighten these bars that mount the HS to the tailcone.

 Checking them for straightness.

 Then cleanup the edges on the 3M wheel.  They are rough out of the gate with huge shear marks.

 Cleco'ed to the bulkhead.

 Match reamed to #30.

 Next this stiffener gets drilled to the assembly.  I put a line on the stiffener to align in the holes on the other side.

 Centered the part on the bulkhead and centered the lines in the holes and then match drilled the stiffener to the bulkhead.

 Punched this hole up to 5/8" using a Uni-bit.  One on each side.  The rudder cables pass thru this hole.

Next I marked the angle the same way and drilled it the same as well.