Roee Kalinsky's RV-7A Project

2004.01.18: (4.0) Construction work begins.  Smoothed out the edges of the rear spar reinforcement bars (HS-609PP).  The first one took a few iterations of trial and error, as this is still a learning curve.  I was initially not aggressive enough with the file, and ended up obliterating an entire small scotchbrite wheel (1"x1" 7A-medium mounted in a drill press) to finish the job.  The second bar went much more efficiently with generous use of the file followed by a couple of quick passes on another scotchbrite wheel (2"x3/4" 7A-medium).  The reinforcement bars lay flat in proper alignment in the rear spar channels (HS-603PP).

2004.01.19: (2.0) Rounded the ends of the rear spar reinforcement bars (HS-609PP) using a file, then scotchbrite wheel.  Started smoothing the remaining surfaces with a maroon scotchbrite pad, but found that it didn't have enough bite to remove some of the pits and scratches on the surface of the bars.

2004.01.21: (1.5) Working on the surface finish of the rear spar reinforcement bars (HS-609PP) using 3M roloc discs mounted in the drill press.  The discs are doing their job, but it seems that I'm removing a substantial amount of material and still not eliminating the worst of the surface defects.  Will consult the RV email groups and Van's support.

2004.01.22: Took pictures of the worst surface defects on the first rear spar reinforcement bar (HS-609PP) and sent to Van's tech support.  This is after a good amount of work with the 3M discs.

2004.01.23: (2.0) Van's responded that the defects are typical of this bar stock, and that if required, as much as 10% of the bar thickness may be removed and still maintain design strength.  Earlier in the morning I also went to visit Reuven Silberman for some expert advice.  He promptly went to work on the worst defect and buffed it out in less than a minute using a small flexible 3M disc mounted in a pneumatic drill.  The disc was applied at a slight angle to the work, and with more pressure than I had applied in my earlier attempts.  So it's all in the technique, and not being too shy in working the material.  Making good progress now, but had to call it a day with the air tools and let the neighbors get some sleep.  Thanks also to Phil Anderton and Dana Overall for their assistance via email.

The picture above demonstrates the technique, except that using two hands to steady the drill works much better than one (here my left hand is holding the camera).  Notice in the very left edge of the picture that the bar is clamped to the workbench.

2004.01.24: (2.5) Finished buffing out the rear spar reinforcement bars (HS-609PP) and checked that they still sit flat inside the rear spar channels (SH-603PP).  Final-drilling the reinforcement bars with the rear spar channels.  Placed the assembly on 1" high blocks of scrap delrin I had laying around so that it won't sit on the clecos.  Used one of the delrin blocks for backing material as I drilled each hole.  Still have 1/3 of the holes to go (where the clecos currently are).

2004.01.25: (3.0) Finished final drilling the rear spar assembly with elevator hinge brackets HS-412PP and HS-413PP.  Match-drilled (#30) the center elevator hinge brackets (HS-411PP and HS-411BPP) to the spar, and match-drilled the HS-411PP bracket with the pre-drilled HS-411BPP bracket and VA-146 flange bearing.  Since the four aft holes are drilled with the bracket assembly clecoed to the spar assembly, I moved some of the clecos to the opposite (forward) side of the spar for better access.  The pneumatic drill is so compact that I could have drilled all 6 holes with the brackets still in place, but decided it wasn't worth the risk of gouging the spar with the chuck.  Match-drilled the forward two holes with the bracket removed from the spar per the instructions.

My squeezer is still on back order from Avery, so I'll have to wait on riveting the HS-411 assembly.  Will get started on vertical stabilizer in the mean time.

2004.01.25: (2.0) Got started on the front spar while work on both rear spar and vertical stab is stalled waiting for tools.  Match-drilled the spar channels (HS-702) to the reinforcement angle (HS-710) and splice angle (HS-714), all holes inboard of the rib (HS-404 and HS-405).  Marked the end radius and taper on HS-710.

2004.01.26: (0.5) Marked the end radius and taper on HS-714.

2004.01.26: (0.5) Back to the rear spar.  Deburred the HS-411 elevator bearing assembly components before riveting.

2004.01.29: (2.5) Cleaned off the VA-146 flange bearing and HS-411 brackets and riveted the assembly together.  Used my newly arrived Avery squeezer with a no-hole yoke.  Figured out a way to make this an easy one-man job even without using a vice, at least for a small part like this.  Squeezing AD4 rivets is not so bad if you can put your weight into it.  The left knee is keeping the squeezer from sliding back as I press the part against the set with my right hand.  Funny-looking but effective.

First six rivets on the airplane.  Woohoo!

Clecoed the HS-411 assembly back on the spar and match drilled the four bolt holes to final size.  Initially attempted using a handheld power drill, but the bit had a tendency to bind when first cutting into the steel.  Plan B worked flawlessly.  Used the drill press, with the ends of the spar supported by 20-pack boxes of scotchbrite pads.  This is so easy and the results are so perfect, I wish I had done every hole on the spar this way.

Disassembled the spar and cleaned up the shop.

2004.01.30: (3.0) Cut the taper and end radius on the forward spar reinforcement angle (HS-710) and splice angle (HS-714).  Rough-cut on a band saw, then finished with a vixen file (pictured below).

Pictures that actually show yours truly doing the work may be required as evidence by the FSDO in order to obtain the repairman certificate.

2004.01.31: (5.5) Bent the outboard sections of HS-710 and HS-714 six degrees.  To do each bend, placed the outboard section between two pieces of particle board with a rounded edge for the bend radius.  Since the free end (center section of the part) still had the right-angle cross-section, it was rigid enough to push down by hand without distorting it.  This actually worked better than the prescribed mallet, which tended to bounce.

Trimmed the inboard section of the front spar channels (HS-702).  Straightened out the extra flange with a hand seamer before cutting it free of the web.  Otherwise, the flange bend would have been difficult to eliminate without removing more of the web.  There's still some fine finishing to do.

2004.02.02: (2.0) Cleaned up the trimming of front spar channels HS-702 and made the six degree bends.  Test fit the front spar channels with the HS-710 and HS-714 angles to verify that all the bends match up nicely.

2004.02.03: (2.0) Practiced dimpling and countersinking on some scrap.  Just learning how to use and adjust the tools properly, no actual progress on the airplane.

2004.02.04: (1.0) Countersunk the four center holes in the front spar for flush rivets.  Dimpled the HS-702 spar channels and machine-countersunk the HS-710 and HS-714 angles.  After a couple of single click adjustments on the countersink cage, the fit is just about perfect.  But it just occurred to me that after buffing out some minor scratches from the angle stock, the holes will probably have to be countersunk a little more.  Should have done the finishing work first.

2004.02.05: (1.5) Edge and surface finishing the HS-710 and HS-714 angles.  Had to first use a file to level the outboard web regions where the flange has been machined away.  Then used the same set of techniques as for the rear spar reinforcement bars (see 2004.1.23).

2004.02.06: (2.0) Finished buffing out the HS-710 and HS-714 angles.  Re-countersunk the center rivet holes to compensate for the slight amount of removed surface material.  Now a perfect fit again to the dimples in HS-702.

Started trimming the HS-404 forward root ribs.  Drilled the inner radii, then made the straight cuts using a little Dremel cutoff wheel in the pneumatic drill.

2004.02.08: (1.5) Done trimming the HS-404 ribs using files.  Started edge-finishing.

2004.02.09: (1.5) Done edge-finishing the left side HS-404 rib.

2004.02.10: (1.5) Done edge-finishing the right side HS-404 rib.  Started edge-finishing the HS-706 ribs.

2004.02.13: (1.0) Edge finishing the HS-706, HS-707, HS-708, and HS-405 ribs.

2004.02.14: (2.5) Edge finishing the HS-706, HS-707, HS-708, and HS-405 ribs.

2004.02.17: (1.0) Noticed that the HS-706 tip ribs have substantial defects on the aft flange.  There are what look like cracks or grooves on the forward (bent in) face, and slight protrusions on the opposite (aft) face.  The defects on both ribs are identical.  Probably some debris was between the flange and the form when the parts were pressed.  Time to talk to Van's.

2004.02.20: Spoke with Tom Green (president of Van's) about the HS-706 defects.  He requested that I send him the parts for inspection.  Unfortunately, I forgot to take photos before sending away the parts.

2004.02.23: (1.5) Done edge finishing the ribs, except for HS-706 which are on their way back to Van's.

2004.03.3: Called Tom at Van's to follow up on the HS-706 issue, and to discuss another two defective parts that I've found after closer inspection.  He said he had sent me some new HS-706 parts, although he insisted the "markings" were benign and told me to expect the same markings on the new parts.  He said the markings were actually part of a serial number embossed on the press dye.  When I came home in the evening, a UPS package was waiting at my door.  While the same type of markings were present on the new parts, they were not nearly as deep as those on the original parts, and I'm satisfied that these are superficial and could easily be buffed out.

The other two parts we discussed are one of the HS-702 front spar channels (the right), and the VS-707 rib.  The HS-702 had shear-like defects on the edges of two flanges, extending about 1/8" into the flange.  I should be able to remove enough material to eliminate the defect and still maintain proper edge margin.  The VS-707 has sharp punch-like deformations on both of the small flanges that go inside the front spar channel.  In this instance, there is no way to remove the defect without significantly weakening the flange.  After (and before) seeing some photos, Tom insisted that these defects also are nothing to worry about, and that I should just use the parts as is.  I'm still skeptical and plan on getting a second opinion.

2004.03.6: (4.0) Edge finishing the new HS-706 ribs and left HS spar channels.

2004.03.7: (2.0) Done edge finishing the left HS components.  Straightened out all HS ribs except for the center ribs by fluting.

2004.03.9: (3.0) Adjusted the fit and match drilled the left HS spar skeleton (spars and ribs).  Used the HS-601PP skin for alignment.  Clecoed together the entire left HS including skin.  Fluted the HS-404 and HS-405 root ribs.

2004.03.11: (2.0) Drilled through the left HS-601PP skin to the HS-405 rib and inboard section of the HS-702 front spar channel.  The most forward hole of the HS-405 flanges (where all three HS-601, HS-405, and HS-702 are riveted together) does not meet normal edge distance requirements, with an edge distance of only about one hole diameter.  This issue has been discussed on the message boards, and apparently Van's gives it the standard "don't worry about it".  In this particular instance, that's probably the right answer.

Clecoed on the HS-714 and HS-710 angles.  There may be a slight interference between the HS-714 angle and the flange of the HS-404 rib, depending on how deep into the HS the rib is positioned.  I may just trim the rib flange slightly so I can position it where I think it should go.  Will consult with other builders.

2004.03.15: (0.5) Trimmed the bottom flange of HS-404 slightly to prevent interference with HS-714.

2004.03.16: (0.5) Drilled the four holes between HS-405, HS-702, HS-710, HS-714, and HS-404.  Used a right angle drill attachment with a six inch extension shaft to drill the holes as perpendicular as possible.

2004.03.18: (2.5) Final drilled all remaining holes through skin to skeleton of the left HS.

2004.03.22: (3.0) Drilled the outboard holes through HS-710 and HS-714, then onto the right half of the horizontal stabilizer.  Drilled skeleton, clecoed on the skin, and drilled HS-405 aft inboard rib and HS-702 front spar.  Ready to drill through the rest of the skin.

2004.03.24: (2.0) Final drilled all remaining holes through skin to skeleton of the right HS.

2004.03.25: (0.5) Removed the skin and drilled the outboard holes through HS-710 and HS-714.

2004.03.28: (2.0) Disassembled the HS and deburred the holes.

2004.04.03: (1.0) Dimpled the left HS ribs using a tank dimple die, which is slightly deeper than a standard die.  This allows the dimple in the skin to be fully seated within the dimple in the substructure.  A tip I picked up from other builders on the message boards.

2004.04.06: (1.0) Dimpled the right HS ribs.

2004.04.11: (2.5) Dimpled the spar channels using a tank dimple die.  Edge finished and dimpled the right HS skin using a standard dimple die.  Noticed that dimpling using the C-frame setup produced better results than using the squeezer, with less distortion to the skin around the dimple.  So I used the C-frame to dimple all the holes in the skin, even those along the edges that would be accessible with a squeezer.  Stacked some packing foam to support the skin on either side of the C-frame at the height of the dimple die.

2004.04.16: (1.0) Dimpled the bottom side of the left HS skin.

2004.04.17: Help!  I screwed up...  Dimpling the top side of the left HS skin, I made what I now know is called "the dreaded dimple eight".  It's what happens in a moment of inattention when you let the dimple die slip out of the hole right before smacking it with the hammer.  It punches another perfect little hole (and dimple) right next to the hole where the dimple should have gone.  Notice the two adjacent holes look just like the number "8".  This happened on the most forward hole in the row that connects the skin to the HS-707 rib, which is somewhat hard to get to with the C-frame (takes some flexing of the skin).

I was able to flatten out the misplaced dimple using a flush set in the C-frame, but was still left with the "8".  I concluded that I could clean up the hole so that it wouldn't create a stress concentration, so long as I didn't put a rivet through it.  So I was left with the question of whether the skin was still usable or not.  The best option I could see for salvaging the skin was to make a new rivet hole a little forward of the damaged hole, as there was sufficient area left on the HS-707 flange to do this and still meet edge margin requirements.  However, the new rivet hole would be even more difficult to get to, both for dimpling and driving the rivet.   The other option would be to buy a new skin, but I was concerned about fit issues since all the understructure has been match-drilled to the original skin.  Discussing this with Van's, I was assured that the pre-punched skins match closely enough to be interchangeable at this stage.  I therefore decided to opt for a new skin.

2004.05.20: (1.0) Went to work on a shiny new HS-601PP skin.  [I've been out of action for a month because of my day job, not waiting for the new skin.  Van's took just a week to deliver.]  Final drilled and deburred the holes on the new skin.

2004.05.22: (3.0) Edge-finished the new skin, then dimpled it without incident.

2004.05.23: (4.0) First try at aluminum surface treatment for corrosion proofing (commonly referred to as priming, incorrectly in my opinion since no additional topcoat will be applied).  The process I chose is as follows: 1. clean with acetone, 2. alumiprep 33 etch while scrubbing with maroon scotchbrite, 3. alodine 1201 conversion treatment, 4. AKZO 463-12-8 interior epoxy primer.  RV-7 builder Dan Checkoway documented his experience with basically the same process, and I borrowed some of his techniques.

Did a trial run on a piece of scrap to debug the process, then did the five ribs of the left HS.  The surface prep and alodine are a no-brainer.  Using a zip-lock bag for the alodine worked great (thanks Dan!).  I found spraying the AKZO to be a little more tricky.  The first attempt on a piece of scrap resulted in a very heavy and uneven coat.  After adjusting my technique, I was reasonably satisfied with how the ribs came out.  The coat thickness was still not completely even, but all areas had what I think is a an acceptable coat thickness.

2004.05.25: (4.0) Another evening session of corrosion proofing.  Getting improved results and working more efficiently, but this is still a very time consuming process...

2004.05.29: (4.0) More corrosion proofing.  Common sense perhaps, but I found that it really is much easier to spray an even coat in daylight.  I was very pleased with how the parts came out from this session.

2004.06.05: (6.0) Finished corrosion proofing the last of the HS components - the right side ribs and both skins.  I chose to use the same process on the interior of the skins as I did on all the interior components.  But the exterior side of the skins should stay pristine for whatever exterior paint system I'll end up using when the time comes.

To prevent alumiprep from getting on  the exterior, I put blue 3M painter's tape on the exterior along all the rivet lines.  When done scrubbing with scotchbrite + alumiprep, I quickly removed the tape and washed the entire skin.  I then applied tape again, brushed on the alodine for 3 minutes, quickly removed the tape again and washed the skins.  The tape may have been unnecessary for both these steps, since the exterior alclad would have probably not reacted much with the chemicals (the exterior didn't get the scotchbrite, so the alclad is all still there), but masking it gave me the warm fuzzies.   I went even further for the AKZO.  I masked the exterior along all the edges and rivet lines with 3M tape, then masked pretty much all the exterior surface with paper to prevent overspray from making its way there.  Doing this actually didn't take too long, but it turned out to be completely unnecessary.  After spraying, I inspected the exterior side of the masking tape and paper and found no evidence of overspray.  Still, again, warm fuzzies.  Anyway, nice to be done with all these nasty chemicals for a while.  Time to start putting this thing together.

2004.06.06: (4.0) Clecoed up the left HS for a test fit, just to make sure there are no issues with the replacement skin.  Everything mated up perfectly, tight and straight.  Gotta love CNC.

Now finally to some assembly work.  Riveted the rear spar using hand squeezers.  As the manual says, squeezing 1/8" rivets takes a bit of grunt.  Not too bad on the first few, but after a hundred or so I was pretty worn out.  Still, what's nice about the squeezers is that you can work late at night, solo, and without making a sound (other than the occasional grunt).

2004.06.07: (1.5) Riveted up the forward spar and inboard ribs, again using the hand squeezer.

2004.06.12: (8.0) Riveting the HS-707 nose rib to the left HS skin.  Opted for all solid rivets, no problem at all.  Found that with a little practice, driving and bucking solo is actually not very difficult.  For riveting the skin to the forward spar I fashioned a crude jig consisting of two padded vertical posts clamped to the edge of the workbench, just to stand the HS up on its leading edge.

2004.06.12: (2.0) Riveted the HS-707 nose rib to the right skin.  Clecoed the right HS skin to the front spar, currently all standing up on the trailing edge for support.  Will have to come up with a support jig.

2004.06.19: (1.0) Vay had a good idea to stand the HS up on its trailing edge, hang it off the edge of the table and put up another support at outboard end.  An adjustable height pedestal from Home Depot did the trick.  This leaves the HS "box" open to buck from underneath.

2004.07.04: (4.0) Riveting the right HS skin to the front spar assembly, about 2/3 done.  Vay driving and me bucking.

2004.07.11: (2.5) Finished riveting the right HS skin to the front spar assembly with Vay's help.  Clecoed on the rear spar assembly.  Kept the HS standing on its trailing edge, now on blocks due to the elevator hinges protruding past the skin.  Riveted the skin to the root and tip ribs using the squeezer.

2004.07.17: (3.0) Riveted on the rear spar assembly.  Positioned the HS horizontally on the workbench with the trailing edge clecos just hanging off the edge of the table.  Riveted the skin to the spar in an alternating pattern, periodically flipping over the entire HS assembly.  Riveted the spar to the ribs.  Construction of horizontal stabilizer complete.

2004.07.18: Used acetone to clean off paw prints, air tool oil, and other miscellaneous gunk from the skins.  Moved the completed HS back to upstairs storage.  Negotiated the stairs with help from my neighbor Buzz.

2006.12.18: (0.0) See "Attaching the Empennage" for fitting elevators to the horizontal stabilizer.