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  #11  
Old 03-26-2013, 12:43 AM
xblueh2o xblueh2o is offline
 
Join Date: Apr 2011
Location: SF East Bay
Posts: 716
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I am going to do the Showplanes Fastback conversion so I needed to modify my vertical stab. It involves trimming a bit off the area on the bottom of the leading edge forward of the spar. In this picture I have actually drawn the line in the wrong place. I started the angle from the front face of the spar instead of the rear per the instructions. I cleaned the marks up and re-drew them but forgot to take a new picture. What I was doing here was checking MED on existing holes to see what problems I might run into.


I could never find a simple solution to the MED problem plus the stock rib just didn't fit very well in the new shape of the leading edge so I decided to make a new nose rib with wider flanges to solve my MED problem. The first thing I did was cleco up the complete vert stab and then just cut and trimmed a piece of cardboard to the shape of the new rib area. I compared it to the old rib and checked it for symmetry. After some minor adjustments I had a shape I was happy with so now it was time to convert it to metal. I made a buck from wood to the shape I wanted and undersize by the thickness of the material I would use to make the new rib. I made a test rib out from non-heat treated hardware store alloy to ensure my buck was the right size and shape.


As I mentioned earlier I knew I would have MED issues with the standard flange width so I made my new rib with a 3/4" wide flange. You can't see it well in the picture but the wood you can see in this stack up is dimensionally slightly smaller than the buck, then the test alloy, then the actual buck and then a third even smaller shaped piece of wood on the bottom.


Here is a picture of the first test rib after about a minute of shaping. You can see the stack up. You will also notice I forgot to shape the end correctly in the flat pattern so I ended up with an incorrect final shape after forming. This is why I wanted to make a test rib from cheap stock first. Get the pattern right before you make it for real.


I think this is test rib number two (I did three test ribs) installed. I can see marks to further adjust the pattern.


Once I had the flat pattern right I made the real rib out of the correct heat treated allow and finished up the vertical stab. Unfortunately I cannot find any assembly pics. The only thing I have is this shot with the fixed surfaces complete.
__________________
Sam
RV-8 with the Showplanes Fastback conversion
Emp completed except for glass work
Wings completed except for bottom skin and glass work
Fuselage underway
N18451 reserved

Last edited by xblueh2o : 03-26-2013 at 02:04 AM. Reason: typo and clarification
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  #12  
Old 03-26-2013, 01:47 AM
xblueh2o xblueh2o is offline
 
Join Date: Apr 2011
Location: SF East Bay
Posts: 716
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The rudder was interesting. After I started building it up to do the initial metal work I started looking at the lower spar/rudder horn area. I knew this was going to interesting to build up so I spent quite a bit of time searching the forum, asking questions and reading other build logs. Got some great tips from VAF folks and found lots of good ideas.

One of the first things I found out the hard way was to not blindly follow the directions. I trimmed my R-710 the way the plans showed then installed it. Out of curiosity I took a sharpie and drew the hole locations on it through the skin. That old MED monster had struck again, not even close. Came home and found out through searching that I was not the only one to make this mistake. I opted for the $10 dollar lesson learned and ordered a new one. When the new one arrived I slowly started taking it down until it just fit. This is the point where it just fits. The drawn line is the MED from the edge to the center of the rivet holes. The dots are where the holes will be when drilled using the skin as a guide. The short perpendicular lines are the MED from the skin rivet hole locations to the ends or the hole in the middle.



Once everything was mocked up, all the metal work was done, everything prepped and primed it was time for assembly. I had used this trick for placing rivets in hard to reach places before on other projects and saw it mentioned in another builder's blog. It works well for installing these rivets with the orientation of the factory head on the thinner material. I used the pneumatic squeezer with a longeron yoke and a 1/2" set to get the rivets in this area.


Once I had the stiffeners back riveted to the skin and the skeleton done it was time to bend the trailing edge. I took an 8' 2X6, sawed it in half and planed one side of the 2" surface flat and square.


I had read the opinions regarding using a dowel during the bending process and decided to try it. I tried to put the dowel in the bend but I found that it was most likely going to cause damage to the ends of the stiffeners when I started squeezing (or at least it looked like it would) so I ditched that idea. I ended up using the the dowel though to set the trailing edge straight and square in my brake. The other advantage is that it gave me a repeatable installation position so I wasn't worried about taking the skin out to check.


Lay the dowel against the hinge, put the bend against the dowel and hold the skin down then remove the dowel. Viola, your skin is in the same place every time with the added bonus of not being able to crush the bend flat.


On the first squeeze I ended up with the skin holding this sort of shape with regard to the spar.


When the assembly was cleco'ed together the trailing edge was shaped like this. Not bad but I knew I had room to improve it.


I squeezed the skin a little more and got very nice results on one side but the other still showed a slight bend towards the edge. I realized that the straight side had always been on the top while the curved side had always been on the bottom in the brake so I turned the skin over and kissed it again. Worked like a charm. Side one.


Side two.


To compare, this is how the skin lay with no clecos in the top after the final squeezing.
__________________
Sam
RV-8 with the Showplanes Fastback conversion
Emp completed except for glass work
Wings completed except for bottom skin and glass work
Fuselage underway
N18451 reserved
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  #13  
Old 03-26-2013, 01:57 AM
xblueh2o xblueh2o is offline
 
Join Date: Apr 2011
Location: SF East Bay
Posts: 716
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Once it was all cleco'ed up I took a look. The picture sort of makes it look like there is a slight bend but according to a long straight edge it is bang on straight.


I ended up using four blind rivets. Two in the very nose of the bottom rib (seen here at the top of the picture) and two in the very back of the rudder horn brace where I couldn't get any squeezer I had in there and there was no way I was getting my hand through the hole. Right now the rudder is done except for rolling the leading edge and obviously the glass work which I will leave for later. I am busy all this week so I won't get back to work on it until the weekend or next week. I have all the metal work done for the right elevator and the parts are at the house waiting for etch alodine and prime.
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Sam
RV-8 with the Showplanes Fastback conversion
Emp completed except for glass work
Wings completed except for bottom skin and glass work
Fuselage underway
N18451 reserved
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  #14  
Old 06-20-2013, 03:10 AM
xblueh2o xblueh2o is offline
 
Join Date: Apr 2011
Location: SF East Bay
Posts: 716
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Work has a way of getting in the way of getting solid build time in.
Finished off the right elevator and began on the left. I spent quite a bit of time reading about the trim tab and the never ending debate of bending or riblet. I decided to try bending and if I just could not make it work for me I would build riblets. I bent up my first end and was pleased with the results. I had just put the bending fixture in the other end of the tab when the lunch bunch dropped by so I stopped and joined them. When I got back everything was ready to go so I got out the hammer and hardwood block and started bending. Turns out I hadn't quite got the fixture secured tight enough before going to lunch. Oh well, I took it as a $20 lesson.
The second trim tab turned out nice.


It fit well on the elevator.




Once the left elevator and trim tab were done it was time to mount everything to the horizontal stab.
I had not yet trimmed the skin on the ends in the area of the counter balance because I didn't know exactly how far I needed to go. Once I had the elevators on and adjusted I removed the excess. I ended up removing right at 1" of material.


With the elevators adjusted and the horizontal stab skin trimmed the counter balance arms look like this.


After tons of futzing I ended up with the elevator horns being very very close but not quite equal. I asked Van's and they said it's normal. Build on.


I drilled the horns for the center bushing. I have seen in threads and build logs where some people experience bolt clearance issues here. I must have been lucky. It is close, I can't get the box end of a wrench on it but an open end or socket works just fine.


Washer wrenches, my new favorite tool.
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Sam
RV-8 with the Showplanes Fastback conversion
Emp completed except for glass work
Wings completed except for bottom skin and glass work
Fuselage underway
N18451 reserved
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  #15  
Old 08-07-2013, 09:58 PM
xblueh2o xblueh2o is offline
 
Join Date: Apr 2011
Location: SF East Bay
Posts: 716
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QB Fuselage and wings arrived today. Didn't do anything other than take out all the packing paper (remind my to buy stock in weyerhaeuser or whoever supplies that stuff to Vans because they most go through a ton of it).
Took this picture after I had rolled up half a dozen or so sheets of the packing paper.


Sweet Mother of God! The landing gear must weigh over 50 pounds. Starting to seriously consider the Grove gear. One piece, two piece, airfoil. Time to research.
__________________
Sam
RV-8 with the Showplanes Fastback conversion
Emp completed except for glass work
Wings completed except for bottom skin and glass work
Fuselage underway
N18451 reserved

Last edited by xblueh2o : 08-07-2013 at 10:26 PM. Reason: Forgot to add picture.
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  #16  
Old 01-18-2014, 12:50 AM
xblueh2o xblueh2o is offline
 
Join Date: Apr 2011
Location: SF East Bay
Posts: 716
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Good news bad news.
Good news. Was given an additional position at work today that includes a not insignificant raise.
Bad news. I will have even less time for building than I have had over the last few months which has been not much to begin with.

I have only managed to get the pitot mount mocked into place, but at least it is forward progress so I will take it.
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Sam
RV-8 with the Showplanes Fastback conversion
Emp completed except for glass work
Wings completed except for bottom skin and glass work
Fuselage underway
N18451 reserved
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  #17  
Old 10-21-2014, 01:39 AM
xblueh2o xblueh2o is offline
 
Join Date: Apr 2011
Location: SF East Bay
Posts: 716
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Realized I have not made an update in a while.
Little bits of progress and some random pictures.

I was an early adopter of the Aero LED Aerosun VX.
Here is the nearly finished hole and the cutout. Sorry about the lousy pic. Trying to hold things and manage the camera didn't work very well.


The more or less completed installation.
I have a small 12v battery in the hgr for just this kind of stuff. I went out one night and hooked the lights up and was impressed by the amount of light. I walked out onto a dark taxiway and I think it will be great.


Fun with fuel tanks.
I took a look at the fuel pickups that came with my QB wings. When they were made they were bent, cut to length, ends crimped closed and then the multiple slices were made. The insides were so full of swarf that I decided to go with the optional screen type. My first go with proseal. Gotta say, not a fan.
__________________
Sam
RV-8 with the Showplanes Fastback conversion
Emp completed except for glass work
Wings completed except for bottom skin and glass work
Fuselage underway
N18451 reserved
Reply With Quote
  #18  
Old 10-21-2014, 01:51 AM
xblueh2o xblueh2o is offline
 
Join Date: Apr 2011
Location: SF East Bay
Posts: 716
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I decided to go with welding the short aileron bellcranks. I got everything prepped for welding and went to visit a friend who is fabricator extraordinaire. In this pic you can sort of see a tool he built years ago for welding tubes. It is essentially the jaw from a small metal lathe mounted to a geared motor that he can control the speed of rotation. The idea is to have the part turning slowly but steady so you need merely strike the arc and not move the welder. The tube moves automatically.


The parts as welded before further prep for re-paint.


Installed in the wing.
__________________
Sam
RV-8 with the Showplanes Fastback conversion
Emp completed except for glass work
Wings completed except for bottom skin and glass work
Fuselage underway
N18451 reserved
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  #19  
Old 10-21-2014, 02:03 AM
xblueh2o xblueh2o is offline
 
Join Date: Apr 2011
Location: SF East Bay
Posts: 716
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I have decided to use AOA and not use a stall vane. Since the QB wings came with holes pre-punched for the installation of the stall vane I needed to close them up. Many suggestions on technique were offered and I decided to fill them with rivets. I countersunk the skin for NAS1097 rivets and went to work.
There are two rivets in the leading edge. One is visible in the pic. The other, not so much. I am very pleased with the end result. Once primer is applied for paint you will never know there were holes there.


This pic is the same two rivets as the pic above. I have set them both and have just started to dress them smooth.


Getting the pitot mast installed.
__________________
Sam
RV-8 with the Showplanes Fastback conversion
Emp completed except for glass work
Wings completed except for bottom skin and glass work
Fuselage underway
N18451 reserved
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  #20  
Old 10-21-2014, 02:20 AM
xblueh2o xblueh2o is offline
 
Join Date: Apr 2011
Location: SF East Bay
Posts: 716
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I mounted the ailerons and got everything pretty much set then went about getting ready to mount the flaps. The trailing edges are nearly perfectly aligned. They were perfect before drilling the hinge but now there is an ever so slight difference on the order of a couple thou of an inch. Less than the thickness of a piece of paper.
Flap trailing edge. The two vertical sticks are 1/4" dowel setting the distance to the aileron.


I elected to go with the split pin mod for the flap hinge. Shamelessly stole other builders idea for controlling the loose ends of the pins.


That's about it for pictures. I have started in on the fuselage. Pics as interesting things happen.
__________________
Sam
RV-8 with the Showplanes Fastback conversion
Emp completed except for glass work
Wings completed except for bottom skin and glass work
Fuselage underway
N18451 reserved
Reply With Quote
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