Watch and enjoy this 60-minute interview with Burt Rutan on the future of transportation — in both air and space (via Big Think).

For the past few days, I’ve been jumping-out-of-my-shoes excited from reading the cover story of the February 2010 issue of Wired magazine entitled “The New Industrial Revolution,” by long-tail theorist Chris Anderson, and the related issue of Make magazine, the theme of which is “Desktop Manufacturing.”

The Wired article is simply a must-read for anyone interested in making things — in turning ideas into physical reality.

The basic premise is this: The tools of digital design and fabrication — which traditionally were high-priced, closed-source, corporate-entity terrain — are now becoming cheap enough to find their way into the hands of small startups, hackerspaces, and even individuals.

Digital Fabrication and the MakerBot

What is digital fabrication? 100kGarages says it best:

Digital fabrication allows a precise design to be created using computer software and then passed to another computer attached to a fabrication or CNC tool, which are capable of producing the 3D design with high precision and detail. This fidelity to the design means that the parts or components are cut, drilled, or machined exactly as expected and exactly the same each time.

Both Make and Wired profile MakerBot Industries, and their associated physical and virtual communities, NYC Resistor and Thingiverse. MakerBot is a three-person startup in NYC which sells kits for their “Cupcake CNC” 3D printers — computer-controlled devices that can take a digital file of a 3D object and “print” the real thing right on your desktop — all for under $1000.

NYC Resistor is a Brooklyn hackerspace where the MakerBot founders met and tested ideas for their prototype device, and Thingiverse is their online repository of downloadable and printable objects — all created and uploaded by their community of MakerBot users.

You can learn more about MakerBot and Thingiverse from the video below:

Open-Source Hardware and the Long Tail

What this means is that more and more garage and basement hackers are going to be able to bring their ideas to marketplace. They’ll be able to create the “long tail” of products that the big corporations can’t, while retaining the flexibility to change direction swiftly and iterate more often.

What’s more, the shared nature of what Tom Igoe calls “open fabrication” will allow makers from all over the world to collaborate on open-source hardware projects, just like they do with software today.

Big changes are coming.

Cool Links

Some popular 3D CAD software:

• SolidWorks The (pricey) real deal.
• Rhino 3D Free trial.
• Alibre Design Free (Xpress version).
• Google SketchUp Free.

Some Personal CNC tools:

• Lumenlab “micRo” universal fabricator.
• ShopBot Shop-sized mill/router.
• Tormach Bench-top CNC mills.

Riveting began by wrestling the HS-707 nose rib into place on the left skin. This baby does not want to squeeze its way forward very easily, and takes some muscle to get the skin into position over the holes. Then, once it’s finally in place, the forward nose of the rib doesn’t like to “sit down” on the skin. We had put a flew clecoes in the bottom side of the rib as well, just to hold things together while riveting the top side.

This was our first real test of riveting skin to ribs since completing the Van’s airfoil practice kit. We set the air compressor output to roughly 38 psi, and adjusted slightly down from there with the Brown Tool swivel regulator on the gun. We also followed the advice of several builders on the VAF Forums, and covered the factory head and surrounding skin with a couple short strips of masking tape to help eliminate slippage and scratching from the flush rivet set.

Everything worked beautifully. I think we may have drilled out one rivet with a malformed shop head due to lifting the bucking bar off the rivet too early, but other than that I think our confidence and skill are definitely improving. Oh, and we’re also getting pretty good at drilling out rivets.

Then, while moving things around in preparation for the next few steps, we dropped the rear spar assembly, causing one of the HS-603s to bend about 20° toward the flanges, just outboard of the ends of the riveted HS-609s.

Using the hand seamer, we were able to mostly straighten it back out, but there are still some damaged areas visible from the bend line. I was concerned that we may have caused unseen structural damage, so I decided to email some photos to Van’s.

Several hours later, Van’s Aircraft builder support rep Ken Scott returned my email, with this reassuring statement:

Probably not any disaster. Certainly the fix is straight enough to use. There’s no way of knowing what the future holds, but it seems unlikely that there will be problems. If that’s not enough reassurance, simply taking the spar apart and installing a couple of new HS-603s will eliminate all uncertainty. It might add a day’s work to your airplane project …

So we decided to at least cleco the spar to the ribs and skin, to see if we could salvage the part.

We got everything to align fairly well, and the damage seems minor, so at this point I think we’ve decided to “build on” after a brief hiatus. The right side of the rear spar on the stab will just have to be a place we keep our eye on down the road for any abnormalities.

I’m sure this little catastrophe is only the first of many to come.

The squeezer yoke bench mount and Cleaveland Main Squeeze made setting the -4 rivets a breeze — or, at least, as breezy as manual squeezing can get.

Van’s rivet callouts for this section are just a hair too short, but the instructions are adamant that you stick with what’s called for, so we ended up with shop heads that were just a bit too small, but adequate.

We had trouble getting the squeezer yoke over the HS-814 angle, so we ended up breaking out the gun and bucking bar. Yep, we had to drill out a couple of rivets as a result.

Things look pretty scratched up, but close enough for government work. (I hope.)

SEM 39683 Self-Etching Primer (Gray)

Well, today was the big day — priming day. I’ve been thinking about how I’d do this properly for nearly a year, so it was great to finally get started. I had read just about everything I could find on priming and corrosion control, and while I had initially considered going all out with alodine and a two-part epoxy primer, in the end I followed the logic of builders like Randy Lervold, who determined that a good self-etching primer was the best compromise between corrosion protection and ease of use.

So I ordered two rattle cans of gray SEM Self-Etching Primer from Amazon, and decided to see how it worked out. Our prep and painting process is detailed below.

Surface Preparation

(1) Dry abrasion with maroon Scotch-Brite pad to remove the Alclad coating, smooth surface anomalies, and give the part some “tooth” for the primer. The part should have a dull, matte gray finish — the shiny Alclad surface should be totally removed for proper adhesion.

(2) Abrasive wash and rinse using maroon Scotch-Brite pad, hot water, and Dawn dish liquid to remove surface contamination and aluminum particles left from step one. The hot water rinse should “sheet” off the surface, rather than beading up, indicating that it has been properly cleaned.

(3) After drying, a final wipedown with a wet cloth soaked in naphtha, followed immediately by a wipedown with a clean, dry cloth, to remove any residual oils and contaminates left from the previous step. Impermeable gloves must be worn from this point on, to keep skin oils away from the parts.

Primer Application

It’s a good idea to read the MSDS before using any product like SEM self-etching primer. We picked up a pair of 3M 6000 Series respirators with 6001 organic vapor cartridges for lung protection and all-around Darth Vaderness. Eye and skin protection are recommended as well.

Temperature, moisture and dust control are important for any painting process. As you can see, we had none of the above. The SEM has such a strong odor that we couldn’t bear to set up any kind of paint booth indoors, but temperatures outside today were in the single digits. Our solution was to spray each part individually outdoors — a process taking roughly 90 seconds per coat — then rush it back inside for drying before the primer started to freeze. Ideal? Hardly. But the SEM dries so uniformly that it seemed to work okay.

The SEM dries well enough for recoating in five to ten minutes, and we put on three coats per part. We also prepped and primed the rivet lines on the inside of the skins, since we’d scratched up the Alclad so badly during layout and drilling. All in all, we used almost all of two 15.5 oz. rattle cans for the horizontal stab.

I’m very happy with the end result, although we got a run or two and a few spots that could have used a bit more coverage. As you can see, even with the poor conditions, the SEM is very forgiving of amateur painting techniques. Next up, riveting!

Today we finished layout and drilling of the right stab, and then we moved into the tedious but necessary job of deburring and dimpling.

The Avery and Brown swivel deburring tools worked great for everything, skins included, and the extensions enabled us to access the inside flange of all the ribs and spars.

The real heroes of the day, however, were the Brown Tool C-Rex squeezer yoke and bench mounting bracket, which we used with the fabulous Cleaveland Main Squeeze hand squeezer.

Having the squeezer mounted solidly to the bench made short work of the dimpling process, and with one person handling the part and one person operating the squeezer, I doubt a pneumatic unit could have done the job faster. Good stuff.

Tomorrow, final edge finishing and Scotch-Brite surface prep, then — gulp — priming!!

Following Van’s instructions, we prepped and fluted the ribs, then assembled the understructure and match drilled all the rib-to-spar joints. We put the HS-801-PP skin on the skeleton and clecoed it into place — a two-person job unless you enjoy frustration. The nose ribs are a very tight fit, and we found it easiest to cleco from the leading edge aft, and from the inner ribs out toward the edges. We found it nearly impossible to move misaligned nose ribs once the spars were clecoed in place.

Next we test fit, marked, fluted and clamped the HS-404 and HS-405 ribs into place, carefully ensuring that the skin’s pre-punched holes aligned with the centerline we had drawn on the rib flanges, while also attempting to align the flanges as closely as possible to the edge of the skin, with no under- or overlap.

Once the 405 was where we wanted it, we match-drilled it to the HS-603 spar, and then drilled it to the skin, two holes at a time, alternating top and bottom, working from the rear spar forward (or “up” in the photos). It took a little tweaking after drilling each hole to keep the un-drilled section of the flange aligned where we wanted it.

When it came time to drill the inboard section of the HS-702 forward spar, we disassembled the skeleton from the skin so we could draw a centerline on the 702. I don’t think this step is called out in the instructions (either that or we missed it), but it would have been nice to do beforehand. Either way, we learned our lesson and did it correctly on the right half of the stab.

We called it a night at this point, then reassembled the left stab the next morning. Using the centerline on the 702 made it easy to keep that aligned as we match-drilled it to the skin, working outboard to inboard.

When we finally drilled the last hole in the 702, we encountered our first big “issue.” Although we had been as careful as possible to ensure things were aligned before drilling to maintain proper edge distances, we ended up with a hole too close to the forward edge of the flange on the HS-405 (red circle in the photo gallery).

There was simply no way to avoid this problem, since the hole position is set by the pre-punched skin, and the 405 was pre-formed at the factory. I put an SOS post on the VAF forums, just to make sure it was okay to build on, and the consensus was that the 405 is simply “built too low” (to quote Foghorn Leghorn), and many other builders have encountered this problem. In fact, one builder even received this reply from Van’s regarding the same issue:

The HS-405 rib flange has been slightly short ever since the first kit RV-4. Engineering is OK with that rib and the less than perfect edge distance. Ignore the edge distance in this case and move on.

So that’s what we did. The next step was to drill from the aft side of the forward flange of the HS-405, through the 702 and 404. This is where other builders had encountered problems with over-trimming and edge distance.

Per the instructions, we had already marked and pilot-drilled the four holes in the 405 forward flange, so we just verified that the locations were going to give us proper edge distances. We had to move and re-flute the HS-404 a bit to get the aft flange to sit where we wanted it before drilling.

To get things lined up properly, we simply measured from the inboard end of the HS-702 spar (the end that touches the right stab’s 702) to the center of our pilot holes in the 405 flange (on the aft side of the spar), then measured the same distance on the forward side of the 702 to the aft flange on the HS-404 to make sure we weren’t going to drill the holes too close to the edge.

Then we clamped everything down and drilled with the 12″ #30 bit, from the aft side forward through our pilot holes. To get the right angle on the drill bit I needed to remove the rear spar (HS-603), since it was getting in the way. An angle drill might have been nice for this task, but the 12″ worked fine.

Thanks to everyone for pointing out the potential pitfalls in this critical area! We’d definitely have screwed the pooch had we not read these other blogs. You can see the results in the photos, and while the edge distance might not be perfect 2X diameter, we’re calling it good.

Finally, we match-drilled the skin to the rest of the understructure and then moved on to the right side of the stab. The last few photos illustrate the process we used to layout the pilot hole spacing on the 405 flange. Van’s measurement callouts are correct and accurate, but they assume you’ve trimmed the aft flange of the 404 perfectly, and no one does. This layout method seems to work a little better, and it really helped me to visualize exactly what was going to get drilled and what the problems could be.

Dad had already done a great job of tapering the HS-810 and HS-814 while I was away at work, so we started by filing out the cut marks and cleaning up the edges with the Scotchbrite wheel, then match-drilling them to the HS-702 front spars.

We then measured the 4 7/16″ from the centerline of the 810 and 814, in preparation for bending. We jigged the parts up in the vise, and then just gently bent the six degree angles by hand.

Although not specifically called out in the instructions, I noticed that other builders had fabricated bend relief holes in the HS-702 front spars prior to bending those. If you look closely at View A-A on DWG 3, you can see these relief holes, but had I not read other builders’ logs, I’d have missed it. We drilled out the holes with the #30 bit directly centered on the bend line, then cut and filed the notches. They’re far from perfect, but I think they’ll do the trick.

Next we dimpled and countersunk the four holes for the AN426 flush rivets as called out in the plans. The countersink cage worked flawlessly when mounted in the drill press, and I think that might be the “official” technique from now on. We drilled about ten holes in some scrap angle to dial in the correct countersink depth before moving to the real parts. The new bench mount for the squeezer made accurate dimpling a breeze.

Lastly, we fit and trimmed the HS-404 nose ribs per the plans. However, instead of using the plan’s measurement callouts, we simply test fit the 404s to the front spar. The idea was to avoid the over-trimming problems noted by other builders. We’ll see how it comes out when we final-drill the parts.

EAA Hints for Homebuilders: The Homebuilder's Library

EAA Tech Counselor Dick Koehler recommends a few must-have books for every kitplane builder’s library.

Via the VAF forums: Check out Steve Schulte’s awesome full-screen photo gallery featuring some outstanding air-to-air shots of an RV-4 and a Lancair in close formation.