Saturday, May 24, 2014

More Wing Spar Prep for Nut Plates

Once all the Nut Plates were finished along the flange, the last two are located on the root end of the Spar. The construction manual instructs you to set the flush side of the rivet on the aft side of the Spar.


Before finishing the countersinks on the first Spar, and looking forward to the number of them to go, I order from Cleveland Tools a single fluted 3/8" #40, #8 and #6 cutters. Below the two are side by side, note the single fluted cutter edge verses the 3 fluted cutter. After using each, I prefer the single cutter as it makes for a much smoother countersink.


With my new #8 single fluted cutter, the countersinks along the Spar flange look very smooth and the cutter when it bites, really takes off, much different than the three fluted cutter.


There are four holes in three different areas along the bottom flange that gets #6 countersinks that will hold the three access plates down. Again the single cutter and the temporary alumimum angle was used and all holes turned out very good. 


The picture below shows the how close the finished countersink holes are to the edge. The manual tells you to use #30 cutter to countersink the holes but I believe that by using the 3/8" single fluted cutter that is made for the #6 screw, the edge distance works out better.


As with any hole drilled in alumimum, each one will need to be deburred. The thickness of the #8 and #6 holes are thinner and care is needed when deburring them as not not to enlarge the holes anymore.


All countersink holes will need to be spot primed. I took my rattle can 7220 primer sparyed some in a small containier and useing a Q-Tip dabed each hole with the primer. Next step will be fastening the Nut Plate to the flanges.


Since the holes for the 6 access plate were countersank, I went ahead and preped the 6 access corver plates. Be sure that the four holes along the top are drilled and dimpled for #6 screws, while the remaining holes are dimpled for #8 screws.



Total time this session, 10 hours.

Build Meter: 305 hours.



Saturday, May 17, 2014

Wing Spar and Nut Plates

Well it has been a few weeks since the arrival of the wing kit. Since that time I have spent looking at the plans, reading the construction pages and looking at other builder sites to get familiar with the first few steps in the wing construction.

The process starts with the prepping the wing spars for many nut plates that will get set along the top and bottom flange of both spars. Again I cannot say enough, that the part should be very secure to the table before you begin work of any type. My table was not long enough so I use the piece of plywood to secure the spar to the table.  



A closer look at the clamping of the spar is below. I always like using a small block of hardwood to place the clamp on. The most important part to remember is to always secure the part to the table. I have read many posts from other builders of parts jumping off the work table and hitting the floor. A part hitting the floor is never a good thing. 


All of the nut plates that get fastened to the spar flange need to be machined countersink. All of which, but just a few, will secure the gas tanks, one 21 gallon on each wing.

The depth of the countersink has to be set according to the size of the rivet that is to be used. To do this, the countersink will need to be adjusted. Use a scrap piece of sheet aluminum, drill a few holes and test the countersink. Keep making very small adjustments until the shop head of the rivet feels flush when you take your fingernail and drag across the head.


I have read on another’s builders blog, to take blue tape and seal the joint (crevasse) between the spar and the spar reinforcement doublers to keep the aluminum chips from falling into the space to help keep any possible damage to the really great looking spar. I read somewhere, "Treat them (the spars) as if the gold anodizing was really GOLD".


The cutters used with the countersinks has a tip that helps guide the cutter and keeps it from moving around and making a mess of things. Van's is not very clear in the instructions how to prevent this other then stating that the Nut Plate once installed will help keep the cutter on track. This is again where others builder sites have helped by outlining one way of solving this issue.

That process is very simple. Take a length of aluminum angle, say 3/4" or 1" from your local Home Depot or Lowes aviation store and drill and then fasten it along the underside of the flange with a few Cleco's. Match drill the holes, I did all the #40's first. In doing this, the tip of the countersink cutter will stay centered due to the extra thickness of the aluminum angle. After all holes have been countersunk, the angle will be pretty much useless. That is a small price to pay then to having a messed up Spar.
 

Below is where I was matched drilling the holes in the Spar to a #40, and continued through the aluminum angle.



I added Cleco’s along the way to secure the angle to the flange.


Once all the holes were drilled, I took one of two countersinks I have and started countersinking them. The extra thickness makes this process painless. I took the correct size rivet and test the fit on each hole. I had to go back on some rivets and go over the hole with the countersink to make sure all holes were the same.


Below is the countersink in action. I used my cordless drill set on a high torque setting. The key here is to operate at a slow speed, not a fast speed.



It is nice to have two countersinks so you can have to different sizes, and depths set up. The other holes along the spar will get either #8 (#28 drill bit) or #6 countersink depending on the location on the spar. Only the holes that hold the three access panels on the bottom side of the wing will get the #6 (#19 drill bit) countersink. Below the second cage is being set for the #8 depth.




Total time this session, 6 hours.

Build Meter: 295 hours.

Monday, April 28, 2014

Drilling The Control Horns

After a call to fellow builder Charlie, we were able to set up a Sunday afternoon to get together and look at my method on setting the elevators “in trail” position and drilling the elevator Control Horns. After spending some time explaining the alignment process and making a few measurements, we were ready to drill the first hole using an aluminum bushing placed into the bearing and a #30 drill bit.

After that, we followed it up with a #21, and then a Unibit was used to enlarge the hole to 3/16”.



The bolt slipped right in, and the elevator moves freely, with no binding noted.



With the first Control Horn drilled the full range of movement up and down was checked against the range outlined by Van’s.



With the right elevator complete, it was time to remove it, place the left elevator on the stab, set it in its “in trail” position and drill it.

With the right elevator complete, it was time to remove it, place the left elevator on the stab, set it in its “in trail” position and drill it. That too went well with Charlie’s help. Thank you Charlie for the help with this task, I am sure as the build progresses I will call upon you again. 


After drilling the left we attached the right one again to check the bold alignment. The bold was just a bit tight but it went in with some finessing.  Both Control horns seem to align very well with each other and the bolt sit far enough away from the weld as to not to interfere with anything.


I am not very happy with the fit and the gap at the tip of both ends. The counterweight skin drags on the left side and the two edges are not parallel with each other.  Will need to think about how I will correct this or just let it go as is. Well, just one more item to spend some research time on finding out how others did theirs.





Total time this session, 3 hours.

Build Meter: 278 hours.





Sunday, April 27, 2014

Setting the Elevators "In Trail" Position

The last step other then the fiberglass tips on five tail surfaces is drilling the control horns on each elevator. The construction manual tells you to place each elevator “in trail” meaning that the center of the tip rib is aligned with the center of the elevator. In reading builders sites, one idea was to use a laser level to aid in that alignment. That said, and the fact I am a registered land surveyor, and spent a lot of time running level loops, that method seemed logical to me.

So I went down to our local survey equipment dealer to see what type of laser equipment they had available. A self leveling unit would be great, and sure enough they had one. The owner was there the day I stopped in and after updating him on my task at hand; he let me take it home for the weekend.



After getting the structure level on my table, and the elevators clamped in the trail position, the self leveling unit was adjusted in height until the alignment looked good.



I ended up adjusting the position of the clamps a few times and checked the trailing edge of the elevators with a remote unit which was part of the laser level. Once I was happy with the alignment of both elevators, it was time to drill the control horns.



Both control horns lined up very well with each other at the center bearing and it appears that the 3/16" hole once drilled in the control horn will be positioned well forward of the weld and not interfere with anything.



Before I drill the control horns I will call my friend Charlie who is also a land surveyor, and RV-7 builder/pilot to come over and check my work on aligning the elevators. Once I am satisified with everything, I should be able to drill them and call the stab complete.


Total time this session, 4 hours.

Build Meter: 275 hours.



Thursday, April 17, 2014

Wing Kit is Delivered

Today the second of kits for my RV-8 slow build was delivered. No visible sign of damage to either crate was noted.


Once the tops are off, one can see the care Van's put into every kit they ship. Both crates were organized and padded very well.


The paper padding was removed to revel the contents of the kit. Each part will need to be unwrap each part and check them off the packing list and then take each part downstairs and place on the rack according to the sub-assemblies.


The fuselage longerons were shipped along with this kit as they are 15 feet long and saves Van's from having to build and ship another really long crate.


All but two wing skins fit nicely under the work table. I will add some of the packing paper to the top to help protect them until I am ready for them.


A large hardware bag will need to separated into the separate containers and labeled.


All the small parts, ribs, tank, flap and aileron skins, fit on three shelf's.


I was able to make some hangers and get the 15' Fuselage Longarons, Pushrod tubing, and the two rear Tank Spars up and out of the way before moving them to the workshop.


The fiberglass tips will sit upright on the floor until I can construct something to get them off the floor and out of the way.


The two Main Spars are already anodized and pre-assembled. The two skins that did not fit under the work table should be fine laying flat on top of a this old work service covered with some packing paper.


The workshop will need to be moved around and the jig for the wing will need to be constructed once the ribs are prepared and are ready to placed on the spars. I am planning on building the jig so that both right and left wings can be constructed at the same time.

Sunday, April 6, 2014

Fitting Elevators to Horizontal Stab

The right elevator was the first to be secured to the horizontal stab. I order some 3/16" temporary hinge pins to fasten the Rod End Bearings to the stabilizer. This will allow me to attach and detach the elevators very easy while fitting them to the stab.


Both the top and bottom stabilizer skin at the tips will need to be trim to allow the counterbalance arm to swing. I used a small Dremel tool with a cut-off wheel to make the cuts. Then finished them with a hand file and a Scotch-Brite pad.


The plans call to notch out the rear spare to allow movement for the Elevator Horn to move. Again cut with the Dremel tool and wheel. Note that the manual states not to get into the spar doubler.


Both Elevators are attached and the skin has been trimmed. The left elevator is a little light and the right one is a little heavy. At this time it is not important the they balance in the trailing position.


I believe the structure came out very nice and look forward to get started on the wings.


With the two Elevators clamped to the horizontal stab at the tips, the Control Horns align very well. The last step is to drill a pilot hole in the Control Horn using a 1/4" drilling bushing as a guide. Once both are drilled and the holes enlarged, the two gets bolted together. 


Total time this session, 4 hours.

Build Meter: 271 hours.
 


Saturday, April 5, 2014

Left Elevator Final Assembly 2

The gap between the trim tab and elevator needed a slight adjustment, so after little filing toward the trailing edge, the gap came out really nice.


The threaded stainless steel rod is still rubbing on the skin, will need to extend the slot aft some more. 


Rolling the leading edge is next, so I used the edge roller to taper the edge down so it will lay nice and flat when the two sections are
joined. As I found out, over working the edge is a bad thing, there is a fine line as to what is enough and what is too much.


As with the other structures, I used 3/4" steel conduit, Gorilla Tape, clamps and a monkey wrench to bend the two surfaces. Again I perferred to work on each small section at a time rather than trying to do the entire length all at once.


The outboard tip was the first to bend, this went uneventful and the two sections turned out really nice.



All but the middle section turned out really nice, and when Clecoed together the edges laid down flat against each other but one. That darn middle section. I had a bad feeling that would cause me some trouble after over working the edges with the edge roller.




A close up as to how nice the two sections turned out. Not bad, not bad at all if I say so myself.



Once all sections have been bent and Clecoed, each hole was increased to #30 so the blind rivets can be set.


Blind rivets along the leading edge are set and the elevator is almost complete.


A overall view of the elevator, the middle section gave me some trouble and turned out less than expected. The only good thing is that the leading edge is not seen as it is hidden by the trailing edge of the horizontal stabilizer. 



The last step is to install the control bearings. Make sure before screwing them in for the first time, you use some type of lubricant such as Boelub to help them go in smooth the first time.


Control bearings are complete and set to the proper length as per the plans using the special homemade tool.


Before fitting the elevators to the stabilizer, I wanted to temporary wire the Trim Tab servo motor, rocker switch and indicator light to see the trim tab move through the full range. Below the tab is moved to full nose down position.



And then to full nose up position, no binding or rubbing was noted. All is good.


Total time this session, 12 hours.

Build Meter: 267 hours.