| 43 | Office Max Store Closings | 4/15/2006 |
| | This is not as off-topic as it sounds. There are only a few days left and everything in the store is marked down. I bought a digital scale that measures up to 300g on the internet for around $50.00. Office Max had a whole rack of postal scales for 60% off. I bought a spring scale that measures up to 2lbs. In a couple days the discount should go up to 80-90% off and I'd like to get the 5 and 10 lb. digital scales for keeping track of part weights. Check to see if an Office Max near you is folding up. |
| 42 | Inspection of Grain | 4/14/2006 |
| | Looking at the capstrip, I have a good number of pieces where the top and bottom sides have pretty straight grain (well within the 1:15 spec). Advisory Circular 43.13 indicates the rule also applies to the 2 side faces. I thought about it and the only way you could get the same type of grain on the side as the top is if the grain is diagonal (quarter cut). If the grain is vertical the saw is following the annualar ring down the length of the cut. Instead of seeing grain you will see a blotchy random pattern which is the annualar ring weaving through the path of the cut. If there is tight grain and it's vertical is that acceptable? Infoquest for the moment. Drawing shows 2 pieces. Both have good straight grain on top and bottom. Sides are in question.
Man hours: 2 |
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| 41 | More on Questionable Wood | 4/8/2006 |
| | I read through the paragraphs of Advisory Circular 43.13 on selecting airworthy wood and then went through my supply of capstrip and carefully inspected each piece. I was REALLY disappointed at how much of the order was unusuable. Because I didn't think it was possible to have received that much unusuable wood in 1 order I asked another builder in my EAA chapter for his opinion. He agreed that what I showed him was unacceptable for flying.
Man hours: 2 |
| 40 | More Gussets | 4/8/2006 |
| | Spent the day in Boston with my wife so didn't get back home until 8:30PM. Went out to the shop for a couple hours and knocked out another batch of gussets. The gusset bins are filling up. The progress, albeit slow, is steady and visible. Today, aside from my visit with a fellow wood plane builder (wood wing), 2 hours was all I could get into the project. It was peaceful end to the day on a chilly night.
Man hours: 2 |
| 39 | Gusset Madness | 4/2/2006 |
| | Yes, gussets are maddening. Don't get me wrong, I cherished the time in the workshop but I spent 11 hours and only got 40% of them done. With the 3 piece wing there are 32 ribs. In each rib there are 30 gussets. I made a couple spares of each gusset so that makes 990 gussets I have to make. Today (all day) I made 396. I followed this process.
- Made a cardboard template for each gusset
- Made a ripping fence for the benchtop bandsaw and ripped 1/16" Finnish Ply to the appropriate width.
- Traced the gusset in the most efficient pattern possible onto the ripped strips
- Cut out each gusset
- Tapped the gusset on the belt sander to smooth off the ragged edge left by the saw.
- Placed each gusset in a bin numbered for the gusset. Nearly each gusset is unique. (I now regret not using the hole saw approach and making round gussets)
I numbered every gusset on the jig and keep the gussets organized in bins. I was hoping to have my first rib made today and had no idea that the gussets would take this long. I've read posts about things taking longer than expected, with a multiplier effect when beer is present. Today there was nothing but coffee in the shop, and I didn't even pause to marvel at my work!As long as I finish the project in my own lifetime I'll be happy (I guess). The thing with gussets (or anything you have to make 990 pieces of) is that it's just incredibly repetitive. Here you can see the aluminum press plate (for the clamp), the cardboard template and the finished gussets. Only 9 more bins to go (594 more gussets).
Man hours: 11 |
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| 38 | Questionable Wood | 3/29/2006 |
| | I received a shipment of capstrip for the wing ribs a while back. I pulled out a couple pieces at random for my prototype rib and noticed one had a small knot in it and the other had a sudden change in grain direction. The grain swirled like wood surrounding a large knot, which was almost perpendicular to the cut at one place. In both pieces the saw's cutting properties changed moving through grain change taking a divot out at the place in question. I called my supplier to inquire and they said they would replace any bad wood. I ordered and received Advisory Circular 43.13 Acceptable Methods, Techniques and Practices - Aircraft Inspection and Repair (also available as a download from the FAA site) as advised by EAA hotline. I bought the book to have it around for reference because it covers a variety of applicable topics. Chapter 1 covers how to select wood. (rings per inch, slope of grain, etc.) I'll provide some digital photos to prove the legitimacy of my findings and hopefully the exchange will be a peaceful one. Come back later to hear how this chapter ends. The representative I talked to didn't give me any reason to believe there would be a problem. So far so good (except for the bad wood). I'll go through all 96 pieces and see how widespread the problem is before I contact them again. The point is that even though you might expect aircraft grade wood to be perfect, you still need to inspect. ...and no, this wood will never leave the ground. This rib is going to be a wall hanging. |
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| | | Advisory Circular 43.13 w/Shipping | Non-Material Project | $27.00 |
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| 37 | Rib Jig Overview | 3/28/2006 |
| | I used the measurements provided on the Pietenpol family plans. I then laid out my pre-bent top piece and bottom piece of capstrip and working from top to bottom, front to back, I used fixed blocks screwed into the MDF material the jig is built on to define the profile. Loose circular clamps are located inside the perimeter of the profile to push the capstrip to the exact location marked on the jig and the wing nut is then tightened to lock the piece in place. I "borrowed" this idea from pictures of the jig Bill Church put on MyKitPlane.com. My design deviated a little with the clamping of the gussets. I wanted a way to keep the rib free of nails AND a way to fine tune the clamping pressure. (great enough to hold it together but light enough not to force out all the glue) I made paddles out of pine to be the clamp arms. I made a hinge by resting the arm on a piece of thin gauge aluminum angle bracket over a groove in the paddle. This prevents any lateral movement. I used #90 springs from the local hardware store and the pictures show the rest. I cut aluminum plates just undersize of each gusset so that the clamp will evenly distribute the pressure over the whole gusset. I hung a bunch of small plastic bins on the wall, one for each gusset size. The bins, the jig, the clamp and the aluminum pressure plates are all numbered to keep the gussets and the clamps organized. We'll see if it was worth all the work...
Man hours: 3 |
| 36 | Finishing Up Jig | 3/25/2006 |
| | Lately time has been the most scarce resource. I do manage to put a little time in on the project on the weekends but nothing significant. Have also been neglecting this site. I stuck to my original plans to create a jig that will allow nail free ribs. I figured that spending the additional time up front would help me achieve 3 goals..
- Weight reduction - no nails
- Capstrip completely unmolested by any type of splitting force (nails, staples, etc)
- Spring loaded/hinged clamps will keep everything securely in place and allow me to produce ribs more quickly
Soon I will produce the sacrificial rib to see how the process works. Ken Terrio of my EAA chapter gave me a demo and allowed me to "help" build a rib to see how the process goes. I felt like more of a hinderance than a help, but Ken is very patient and a good teacher. Ken's preferred method, stapling, seems like another very sound approach to completing this task. If I'm unsatisfied with my clamping method I will go with the stapling approach. I guess I'm just stubborn.
By the way, I'm not actually using cardboard gussets. Those are templates for the gussets I'll be cutting this weekend.
Man hours: 5 |
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