Sunday, November 19, 2017

Landing Gear Attach Points

Now on to the landing gear attach points. First started by installing the gear leg into the assembly. There is a hole at the top which takes a AN4 bolt to hold the gear leg in. This hole must be drilled to match the leg.





Once that is complete, the assembly can be installed in the fuselage. This may look easy, but there was 4 hours of filing, sanding and drilling to make this piece fit. I was only able to finish one of these today.

I still need to drill to the side of the fuse. 



Horizontal Stabilizer Attachment

OK, this one I have been thinking about for quite a long time. The H Stab attachment to me seems difficult because there are no predrilled holes. The assembly gets thrown on and you do your best to line things up then clamp and drill. I worked for several hours getting this positioned correctly.




The instructions state that you should measure from the back corner of both sides of the H Stab to a common point on either side on the forward fuselage. The problem here for me is that after deburring the skin on the rear H Stab, there is know way to know if both sides were sanded the same. There could have been more material taken of one side than the other. In this case, there would be no way to measure this as square to the fuse.

So my approach added some criteria to the equation. I first found and marked the center point of the H Stab. I also found and marked the center point of the fuselage rear deck where the H Stab would be mounted. Lining these two marks up ensures that it is at least centered on the rear deck. Clamp!!! Next I measured from both rear H Stab corners per the instructions. I first measured to the top of the 704 bulkhead. After some jockeying, I was able to get the two sides within 1/64 of an inch of the same measurement. This would require a counter clockwise rotation of the H Stab to fix when viewed from the top. Next I measured to the rear of the firewall on both sides. This showed a difference of 1/64 of an inch in the opposite direction, clockwise. Checking several other points, I always came up with the same result, within 1/64 of every measurement but never in the same direction. I must be as close as i can get with this one.

So i ask myself, what is the net effect of being up to 1/64 inch off (I don't care to do the math to figure out how many degrees off, certainly less than 1). Really this is defining the longitudinal plane which the vertical stabilizer will be positioned. If this surface is canted in one direction, the plane will always yaw is the opposite direction as if the rudder will always deflected. This can be corrected with a rudder trim tab if necessary.

*** OK, so I went back and did the math. Lots of math. Pages of math before I came to the conclusion there is no way to accurately measure from the rear corner edge of the H Stab to a point on the center line of the forward fuselage. This poor measurement always skews the calculation. Without even calling support, I can already hear them telling me "Just drill the damn hole!!!"
That is what I did. Clamped and drilled. I know I am within 1/64 inch, but who knows what direction.






Continuing to Drill the Elevator Horns

Continuing on drilling the elevator horns, I needed to find a suitable drill bushing to protect the center bearing. The elevator horn does not have any of the holes drilled so it is necessary to use the bearing as a guide. The plans call for a 1/4 inch outside diameter, 2/32 inch inside diameter drill bushing. I did find such a beast on line for around $50. I am not about to spring for that plus shipping for a one time use thing. Searching around, I was lucky to find a 1/4 OD, 1/8 ID spacer over at Ace Hardware. Since this is a spacer, the tolerances are completely off. The 1/4 OD was larger than published so I chucked the piece up in the drill press and sanded down to an exact fit. The inside diameter was also no where near. For this I went through my collections of drill bits to find a good match. Turns out 11/64 was a good match.



And the finished product. Looks to line up very well.

Sunday, November 12, 2017

Fitting Elevator

I'm back to an item which I should have done when I was originally working with the elevators. I must have missed the instruction section to actually fit the elevators to the horizontal stabilizer.

Start by mounting the elevators to the stab.







This notch needed to be cut out to fit the forward section of the counter weights. The skins were designed for the RV-8 and need a little adjustment.



Then drill the control horn for the push rod attachment.






Electric Flap Hardware

I've been working on the Electric Flap mechanism lately. This consists of an electric driven ram between the seats which drives the assembly.

First to drill the actuator bars. Holes to accept AN3 bolts.



Then the plastic mounting block is prepped.



Mounting pieces fabricated per plans.



Fit the flap motor and ram to the assembly and drill.





Fit the assembly in the plane between the seat locations and test run.



Sunday, October 22, 2017

Forward Cover Plates

Today I am working on the forward cover plates. These are covers that hide all the fuel lines, wiring and cables in the cockpit. I plan on spending extra time on the components that are directly visible to the occupants. Just for a better experience when flying the plane. Having said that, I am not looking forward to deburring this piece. This is probably the most complex single part I have worked on yet. I plan on queuing up a couple of movies and hopefully it will be done  by the end.





Sunday, October 8, 2017

Priming Rear Seats and other parts

Full day of prepping and priming a bunch if parts that have been building up for a while. After priming I attached the seat back attach points and riveted the rear seat pans into place. hard to believe this is 9 hour of work.











Thursday, October 5, 2017

Center Tunnel Cover Supports

Time for a little fabrication. We start with a z channel piece of aluminium. The cut marks are traced out and using the cutoff wheel, it is easy to cut out the required shape. I think it has become my new favorite tool.



Seats - Rear

Putting together the rear seat structures. These have the seat back adjustment points which are simply piano hing attach points. There are three hinges attached to move the seat back or forward a total of about 3 1/2 inches. Enjoy the pics.












Next I installed the Crotch strap brackets for the seat belts.