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Archive for August, 2010

Building the Wing Assembly Stand – 2 hrs

August 31, 2010 Leave a comment

Tuesday Aug 31, 2010

Last night I didn’t get any work done on the wings but I went to Home Depot and bought about $75 worth of lumber, aluminum angle, nuts, bolts, and washers for the wing assembly stand. I’ve been putting this off but now is the time to get it done.

Tonight I began constructing the stand by erecting two 2×4 posts from floor to ceiling. I plan to have the other end free-standing so I can raise my garage door with the stand in place. I started with a beam across the ceiling anchored to three joists. Then I measured and cut two 2×4’s from the floor to the beam. The posts are two feet apart, aligned vertical and parallel, screwed to the cross beam with drywall screws and will be bonded to the floor later. I will also double up the 2×4’s to make the cross section 4×4.

It’s not done by a long shot, but it’s a start.

Categories: Wings

More Wing Rib Prep Work – 2.5 hrs

August 29, 2010 Leave a comment

Sunday Aug 29, 2010

More rib prep work today. I was able to complete a full set of main ribs for the left wing so I just had to cleco them together to see the skeleton. Awesome! I really like this part.

Here is a view right down the lightening holes.

But there are still many ribs to go. That part is not nearly as fun. It is also about time to build that wing assembly stand. I still have crates on the floor from the wing kit shipment so I need to clear out some space. One problem is the 15 foot long aluminum angles for the fuselage that are shipped with the wing kit. I needed a place to store them for months until I finish the wing kit and order the fuselage. So I screwed some slats into a beam in the ceiling to make a shelf of sorts. Six slats spaced 2.5 feet apart provides support for the longest angles and four shorter ones as well. I’ll make some clips to put on the ends of the slats later to keep the parts from slipping off the end. For now, they are stable…as long as we don’t have a significant earthquake that is.

Categories: Wing Ribs, Wings

Started Preping Wing Ribs – 5 hrs

August 28, 2010 Leave a comment

Saturday Aug 28, 2010

Next I started preparing the wing ribs by marking, deburring, squaring up flanges, and fluting. Wow, there are a lot of ribs! The first step was to smooth the edges of the flanges using the scotchbrite wheel on my bench grinder. I also decided to scotchbrite scrub the flanges before fluting because on the empennage kit I found it more difficult to do after fluting. That adds more time to the prep but I will make it up later when preparing to prime these parts.

About five hours later I had about 20 ribs completed, seven of which are main ribs (not leading edge or tank ribs). That is about 15 minutes per rib. Ouch!  The rest are in a partial state of completion. So I installed five of the ribs onto the left main spar with clecos to make sure everything looks straight and true.

Categories: Wing Ribs, Wings

Riveting The Rear Spars – 3.5 hrs

August 28, 2010 Leave a comment

Saturday Aug 28, 2010

I was looking at one of the web sites of a builder last night and saw that he dimpled the holes on the rear spar flange that mate with the W-707E and W-707F doublers before assembly. I could not find any instruction in the plans to do this but I didn’t see any reference as to how or when to dimple them later either. I searched the Vans Air Force forums and found that this question has come up before and one post even quoted a response from Vans Builder Assistance. According to Vans you can drill and dimple before riveting these parts together or you can machine countersink just the spar flange later. The forums really are a great asset to a builder.

You can see the seven holes adjacent to the W-707E flange below. These mate to the top skin of  the wing.

I decided to try drilling out one hole and dimpling it. When I did I found that the W-707F doubler is very difficult to dimple without distorting it. The holes are just too close to the web. So I decided that machine countersinking would be easier and less likely to damage the parts and I can do that later after fitting the skins. So I left the rest of the holes undrilled and undimpled. I hope I will be happy with that decision later.

I cleco’d all the rear spar parts together and put tape on all the holes that should not be riveted now.

Then I started riveting. All these rivets could be squeezed with the 3-inch yoke on my pneumatic squeezer. Here are the finished parts with rivets in the required locations. I put the factory heads on the side with the thinner material where applicable. In the case of the W-707E/F doublers both parts are the same thickness.

Rear spars done!

Categories: Main Spars, Wings

Priming Rear Spar Parts – 4 hrs

August 27, 2010 Leave a comment

Friday Aug 27, 2010

Today was the day to prime the rear spar parts. The basic steps are:

1) Scotchbrite scrub W-707A rear spars for priming

2) Scotchbrite scrub remaining rear spar parts for priming

3) Clean rear spar parts for priming

4) Prime rear spar parts

There is a lot of surface area on the rear spar parts to scotchbrite scrub so I tried putting a strip of scotchbrite on my orbital sander. It did a great job of covering the flat areas of the spar channel. You can see in this picture the area on the right that was scrubbed versus the shiny area on the left. This will help cut down on the time it takes to prep these large parts.

The next step after scrubbing all the parts was to wash them and scrub again lightly with Simple Green. That cuts the grease and gives a water break free surface. Then I set up the spray gun and applied a few light coats of Stewart Systems white water-based primer. Here is one set of parts for one rear spar primed.

After a couple of hours the parts were assembled with clecos in preparation for riveting tomorrow.

Categories: Main Spars, Wings

Finished Fab Steps on Rear Spars – 2.5 hrs

August 26, 2010 Leave a comment

Thursday Aug 26, 2010

Build steps completed tonight were:

1)  Mark rear spar parts with location and orientation for later reassembly

2) Mark and cut out holes for the aileron pushrods. Deburr Edges

3) Drill holes in the W-707A upper flange along length of W-707G and dimple

4) Machine counter sink holes in W-707F for flush rivets

In the picture below you can see the cutout pattern marked on the W-707E doubler and I have roughed out the two major radii with a unibit. The finish work was done with a dremel (rotary) tool and a small sanding drum attachment.

Here you can see the final cutouts which match the cutouts in the W-707A quire nicely.

Then I drilled out and dimpled the holes in the W-707A flange next to where the W-707G will be installed because you can’t get a dimpler in there after the W-707G is installed.

Here are the machine countersinks in the W-707F doublers for rivets that will be underneath the aileron brackets.

All done fabricating the parts I cleco’d each set together and stood the rer spars next to their front spar companions.

Categories: Main Spars, Wings

Match Drilling the Rear Spar Parts – 1.5 hrs

August 25, 2010 Leave a comment

Wednesday Aug 25, 2010

First step tonight was to deburr the edges of the right rear spar. Like the left spar, it was time consuming taking almost 45 minutes to complete. Then I cleco’d all the parts of the right rear spar assembly together per the instructions and matched drilled all the mating holes. I also match drilled the left rear spar assembly I cleco’d together last night. Here are the inboard ends.

Here are the holes for the W-707E doublers. I still need to cut out the oval holes for the aileron push rods.

Here are the holes for the W-707F doublers.

Categories: Main Spars, Wings

Trimming and Deburring Rear Spar Parts – 2.5 hrs

August 24, 2010 Leave a comment

Tuesday Aug 24, 2010

I got back from a four day business trip last night (1:00 AM actually) and I was eager to get some work done on the wings. The next logical step was to finishing trimming the rear spar forks and deburr all the rear spar parts. So I trimmed the second W-707G fork on the band saw and I used the belt sander to smooth out the edges. Then I buffed the edges with the scotchbrite wheel. I also deburred all the edges of the W-707E and W-707F doubler plates.

The W-707A spar channel has a lot of edges to deburr. The part is too long to deburr with my scotchbrite wheel where it is bolted down so I used a file to remove the rough edges and a scotchbrite pad to smooth out the surfaces. That took almost an hour for the left rear spar only. So at that point it was getting late so I cleco’d the W-707G and W-707D to the left spar.

Then I aligned the W-707E doubler based on the measured distance from the outboard end of the rear spar and clamped it in place with two C-clamps.

Finally, I aligned the W-707F doubler flush to the end and clamped it down also.

I flipped the spar over and marked the oval shaped hole pattern on the W-707E doubler so I can cut it out later.

Categories: Main Spars, Wings

Rear Spar Prep – 1 hr

August 19, 2010 Leave a comment

Thursday Aug 19, 2010

Only a little time in the shop tonight because I am preparing for a business trip tomorrow.

So I installed the second tiedown bracket on the left main spar but I only torqued the upper and lower most screws. The inboard screws will wait until I check the instructions for the Dynon roll servo bracket. I think I saw that it installs in place of one of the standard bell crank brackets.

Then I began preping the parts of the rear spar. The W-707D and W-707G doubler plates must be trimmed per Sheet 38 of the drawings. So I measured off and trimmed the W-707D doublers first. Then I deburred all edges. Here you can see the W-707D on top, the W-707G in the middle and the W-707A-L left rear spar cleco’d together.

Here you can see the trimmed W-707D on top of the untrimmed W-707G.

Categories: Main Spars, Wings

Finishing Tiedown Brackets – 2.5 hrs

August 18, 2010 Leave a comment

Wednesday Aug 18, 2010

Tonight I finished tapping the 3/8-16 threaded holes for the tiedown rings in the tiedown brackets. To gauge the depth of the tapped holes I just counted sixteen turns of the tap handle to get a 1-inch depth.

I mentioned yesterday that I drilled 3/4 inch holes in the spacers instead of 1 inch because I don’t have a 1-inch metal bit. So tonight I drilled four 15/64 holes in each spacer around the 3/4 inch hole to take a little more weight out of the parts. Now the parts are within 0.4 ounce (total for all spacers) of the weight if I had drilled 1 inch holes. You can see the additional holes in the photo below.

I scrubbed the parts with scotchbrite and Simple Green, dried them and then shot a coat of Dupli-Color self etching primer. Here are the primed parts.

Next I riveted the parts together with the nut plates.

And intalled the left tiedown bracket onto the left spar. I torqued the bolts to 25 inch-lbs and applied torque seal.

Here is the aft side of the spar showing the brackets for the aileron bell crank. Notice that I forgot to apply torque seal to the four nuts. After I saw the photo I went back and applied it. That’s one good thing about keeping a photo journal. You get a second look at everything.

Categories: Main Spars, Wings