Right Elevator Skeleton Assembly

Friday 30th Nov 2hrs 40min

Assembled the right Elevator and match-drilled skins, spars and ribs. Disassembled and deburred the skin. Deburred spar and dimpled the top flange. Deburred and dimpled E-906 root rib (except 4 holes at aft end)

Visually, there was a lot more progress this evening. The work seemed to go much more quickly than yesterday.

You have the choice of using solid rivets to attach the skin to some sections of the bottom of the spar - where you can access them through the hinge openings. I had a look at this and what bothered me was that the pattern would look random. So, I decided I had nothing against pop rivets and chose to use a full line of them across the full width of the spar. This meant driling out to #30 and dimpling accordingly.

There was the usual problem with dimpling the narrow end of the root rib and I had broken all the nails that came with my pop-rivet dimple dies. I will have to go looking for some tomorrow. I hope I can find them as they look longer and thinner than any I have seen in the stores.

Right Elevator Counterbalance Assembly

Thurs 29th Nov 3hrs 20min

Adjusted counterbalance rib flanges to 90 degrees. Fluted ribs. Assembled counterbalance ribs and skins and matchdrilled ribs to ribs and ribs to skin.

I had a little difficulty 'stretching' the counterbalance skin over the ribs, probably because I left the vinyl on the inside. It is amazing the difference this can make. Perhaps if I took it off, I would be able to fit the skin with less difficulty and wouldn't need the protection against scratches that it provides.

No photos again this evening because of my camera problems. However, while messing with it later, I found that if I turn the flash intensity down the photos are fine so hopefully that will be the end of the problems.

Elevation

Sunday 25th Nov 7 hrs 45 min

Cut and edge-prepped 16 E908 stiffeners for the right Elevator. Match drilled stiffeners to E901-R skin. Dimpled Stiffeners.

Building the elevators, particularly the right elevator, is like a lot like building the rudder. Much of the time today was spent marking out and cutting the stiffeners and then preparing the edges after match-drilling. This time I didn't have to worry about the length of the stiffeners as they are all the same.

The main difference is that the skin is pre-bent so that it wants to stay closed. This makes it quite awkward to gain access to the inside, particularly if you are working alone. I am quite sure that Dorothy (my wife) would be happy to help out if asked but she was away visiting her mother as she does on most Sundays and in any case, I don't want to call on help too often so that I have lots of 'credit' left for the times when I can't do without a second pair of hands.

So I rigged the set-up you see pictured here (actually this is the left elevator). I used the wooden cradle from the horizontal stabilisers, clamped one trailing edge to the bench and placed one of my lengths of teak seating rail running between the two cradle blocks. The spring tension in the skin kept the length of teak fairly securely in place. I was working on my sacrificial slab of chipboard again as I needed to drill into the surface. The piece of scrap timber you see under the drill is placed so that the far edge just overlaps the trailing edge where it is 'indented' to allow space for the trim tab. It is screwed down into the chipboard to hold that section of the trailing edge firmly.

The tension in the skin is such that it bends up between the clamped trailing edge and the leading edge so it was important to work systematically from the trailing edge forwards and from left to right ensuring that the stiffeners hold the skin perfectly flat.

I kept the blue vinyl in place for this operation as there is a lot of potential for scratches from the stiffners whose edges have still not been polished.

Dimling the stiffeners was done with the pneumatic squeezer.

Rudder Assembly

Monday 19th Nov 2hr 10min

Assembled rudder and match-drilled skins to ribs, spar and trailing edge. Trimmed rudder brace Fitted and match-drilled rudder brace.

The manual suggests that you prime and rivet the stiffeners to the skins before assembling the rudder to match-drill the remaining parts. However, I am delaying priming so I clecoed back on the stiffners in order to prevent bowing of the skins. There sure are a lot of holes in this thing.

Trimming the rudder brace was easy and it fitted without any problem. The Orndorff video shows a trim line etched in to the sides of the brace but these have been replaced with twohalf-holes in the edges which you join up with a line, just like on the skin stiffeners. There are also a lot more pre-punched holes in this kit. For instance the R405PD rudder horn to R710 rudder brace holes are now pre-punched in the horn.

Tool Trouble

Thurs 22nd Nov 3hr 50min

Prepared edges of R-901 skins, R-913 counterbalance skin and rudder ribs. Deburred and dimpled skins and ribs. Set countersink cage for #40 holes on R-916 trailing edge extrusion.

Dimpling the last 3-4 holes at the narrow end of the R-903 and R-904 rudder ribs is very tricky. Even the pop-rivet dimple dies are no use as there is not enough separation between the flanges to get the long nail that pulls the dies together into the holes. I looked on Doug Reeves Vansairforce forums and found various approaches. One is to drill and countersink a piece of mild steel and use it as the female die to make the dimple. Another builder had adapted his DRDT2 dimpler as pictured here.

While machine countersinking the hole in the steel with the bench drill and the #40 countersink cutter mounted in the hex adapter (that I usually use for my deburring bit), I managed to break the pilot off the countersink cutter. This was because the steel piece was not held securely and the pilot jammed in the hole when it came up off the table and the hole being countersunk moved out of the vertical plane. That will mean that I can't countersink the R-916 rudder trailing edge until I replace the countersink cutter (or borrow one temporarily from someone else).

I got down to the last two holes on each rib using the pop-rivet dimple dies and I tried using the mild steel die on the final holes with the normal male #40 dimple and a light hammer. However, I am not happy with the results. The test rivet did not sit properly into the hole. This is probably because the countersink cutter did not do its job properly before I thrashed it.

The final solution I came across was from Dan Checkoway, whose own website is legendary. He says simply bend the flanges out until you can get at them and then bend them back again. However, I wonder if the metal will be work-hardened by this process. In the end, I decided to partly follow Dan's advice. I gently parted the two flanges until I could just get the female pop-rivet die and nail into the last hole. The flange sprang partly back into position once the nail was in, leaving only a small 'permanent' deflection from its normal position. Once the dimple was made, I had to spring the flange slightly further out of position to get the nail head back out. However, after all the dimples were made, I was easily able to get the flanges back to square using the flanging tool. this picture shows a test rivet sitting in the last hole of the R-903.

What goes together, must come apart

Wed 21st Nov 2hr 20

Completed R-918 attach strips, fitted and match-drilled them to R-901 skins and R904. Disassembled the rudder and began "DDEP" (Deburr, Dimple, Edge preparation)

Ken Scott replied to an email I had sent Yesterday to Vans support. He says I should replace the HS-902 spar on which some of the countersinks are too deep but the others three spar halves can be used. He also suggested two additional rivets through the skin and stiffeners either side of the double-holes created by mistake when dimpling the stiffeners. I don't like this as I believe the eye will be drawn to the anomaly in the rivet pattern. However the part is very cheap and as I am having a HS-902 shipped across anyway, there will be no additional postage or packing charge. Once they arrive, I can completely eliminate that ding. I also copied my examiner Mick Bevan on this correspondence and he concurs.

Yesterday evening was also the monthly meeting of the SAAC. I always bring a notebook along to record all the useful information and contacts that I get. Yesterday, I got a lead on a torque screwdriver that can handle the very low torque values necessary for the AN3 bolts in the central HS hinge brackets - 20-25 inch pounds. Charles O'Shea also took me through the builders manual that I will be completing with Mick Bevan.

I had already cut the bottom attach strips to length as they come from the same piece as the R-917 shim. As George Orndorff recommends, I cut the two R918 attach strips from the ends of this piece, leaving more than enough for the R917 in the middle. This evening, I cut off the angled ends that butt up to the rudder brace and filed and polished the edges.

They are held in place initially with side-jaw clecos (you need the longer 1" type to reach) and then clecoed as the holes are drilled. The lower holes are not drilled at this stage. The plans simply specify "2" approx spacing" - one of the few places I have seen the abreviation "approx" anywhere on these plans.

Taking the rudder apart took a while as there were so many clecos but that is because I had the stiffners clecoed in as well. I also deburred the skins very lightly.

No photos this evening - The camera is acting up and just could not be persuaded to perform.

Dimple Doh!

Sat 17th Nov 5hr 10min

Cut stiffners and match drilled to left rudder skin. Prepped stiffner edges and dimpled them. Fluted and prepped tip and counterbalance ribs.

I ordered a spray gun from a British firm on ebay. It looks to be very good value and comes with the correct 1.5mm nozzle to suit the primer I am using. However, it will take a while to arrive and I also need to construct a demountable spraybooth, so I moved on again and made a start on the rudder.

The first job is to cut out two stiffners from each length of angle. After trying the band saw, I decided I did not like the way it dealt with the very light material and began to use the snips instead. Initially, I was keeping well away from my lines but I gained in confidence and was soon cutting to the line itself. It was really quite slow and a bit repetitive and tedious to cut them all out and then trim them to length and polish all the edges.

The Orndorff videos suggest working from one end along each stiffner while match drilling them and cleco every hole as you go. This is to make sure they lie flat inside the skin with no excess skin material between stiffner holes. While I agree with this, I found it necessary to check the correct alignment of all the remaining holes on the stiffner and hold the free end of the stiffner in place while drilling each hole up to the mid point and maybe beyond. Otherwise, I felt that there would be a tendency for a right-left miss-alignment to become established and the holes might not match by the time you reach the far end of the stiffner.

I had another 'unforced error' when dimpling the stiffners. I don't find the trigger of the pneumatic squeezer easy to use and this caused me to fire the squeezer before I was in position. As a result, I got a brand new dimpled hole adjoining the pre-punched one. A few moments later my wife came into the shop abruptly and gave me a start, causing another missed hole. At least the skins are not affected. I reckon I can make small doublers from the same material and put them behind the affected holes or even spanning three holes. Anyway, I have emailed support at Vans for their opinion.

Despite careful fluting of the flanges and checking them for 90 degree alignment, I found the rudder counterbalance skin quite difficult to attach. It needs quite a bit of persuasion to match up with the holes in the two ribs. I eventually got it all together. I used a small awl to help align the holes. I put quite an amount of strain on the parts but not to the point of deforming the holes or the skin

Edge prep, Countersinking and Dimpling

Wed. 14th Nov 4hr 20min

Stripped vinyl from VS 901 skin. Deburred and #40 dimpled skin. Deburred, dimpled and edge preped spars. Prepped edges of skins and VS 808PP doubler. Countersunk fwd side of VS808. Dimpled #30 fwd side of Aft VS803 spar.

I had to go to Roscommon (West of Ireland) for a conference so I rearranged my schedule to work on the project during the afternoon and travel in the evening.

I dissassembled the VS and got down to preparing the edges of all the parts. I am particularly pleased with the technique for holding and supporting the edges of the large parts. Even the top and bottom edges of the VS skins proved to be very easy. Those engineering type vices that I got in Lidl and which attach to the edge of my bench were invaluable again. this time, I used some lengths of teak either side of (and between) the two skin edges. Wehn doing the top and bottom, which are a continuous V shape, I just used a shoter piece of timber in the middle..

You need to be careful about which holes to countersink on the VS808PP and dimple on the VS803 spar. It helps if you know how the finished unit will be fitted to the fuse. That makes it obvious that the lower end of the forward side of the VS803 needs to be flat so it can can be fitted tight against the bulkhead. That means it has to be dimpled in that area to take countersunk rivets and the doubler plate behind it needs to be countersunk to accept those dimples as it is too thick to be dimpled itself.

Angle of Attachment

Sun. 11th. 8hrs

Measured, cut and finished the HS908 attach angles. Match-drilled them to the forward spar.Started on the HS by assembling the skeleton and match-drilling the skin. Prepared the main nose and cap ribs

Friday was my son’s graduation ceremony (Mechanical Engineering – Trinity College Dublin) so no work on the plane. On Saturday, I just felt like a full day of goofing off and spent some time with my wife for a change. However, today I wanted to tackle this outstanding attach angle project. It went much better this time and I have two perfect attach angles to show for my efforts. I really need to get a finer Sharpie marker however. The so-called ‘fine’ tip is not really fine enough at all and the lines are not precise enough for my liking. It would be good to be able to use a metalwork scribe but that would be to invite stress fractures so its better not to have one in the shop.

That completed the work in the HS up to primer stage. While I have the primer in stock, I don’t yet have the other elements organised for the priming job.
So, being unable to move on to the assembly of the HS until priming is finished, I moved on to begin the preparation of parts for the next major structure; the Vertical Stabiliser. I believe I may prepare all the emp parts up to primer stage and do all the parts at the same time. This would mean setting up a spray booth just once.

The VS skeleton went together without problems. I thought about using the cradle blocks for the skin and then slipping the skeleton down inside. The manual is silent on how the skeleton should be wrapped. In the end, I just stood the skeleton on the bench and placed the skin over it and then just clecoed the skin on, beginning at the leading edge of the nose spars and working back. This seemed to work really well. It is in huge contrast to the complex assembly method that George Orndorff shows in his video. He was obviously dealing with an earlier kit in which the ribs were formed but not match-drilled. I would safely say that having the skin attachment holes on the rib flanges pre-punched saves at least two hours, if not four.

I see from his website that Smitty used some 4in foam blocks between the clecos on the underside of his VS to hold it off the table while he match-drilled the top. I decided that the number of clecos involved would distribute the weight well enough. Besides, the clecos are all attached into ribs and/or spars, where there is a lot of structural strength, rather than free-floating skin. Also, the pressure applied to the drill in match-drilling existing pre-punched holes is very small. I was glad that I saved myself the effort of locating suitable foam as the results were perfect.

Countersinking feeling

Thurs 8th Nov. 3hrs 10min

Countersunk forward and aft spar flanges #40. Countersunk spar doublers and aft spar web #30.

Another evening of mistakes. Firstly, I had difficulty working out how to adjust the microstop cage and set it to the correct depth for the intended rivet. There is no measurement gauge (at least on the model I have) so this is a trial and error process and I went through a lot of scrap pieces to get it right (as I thought). Then moving on to the actual work piece, my first countersink was way bigger than the test pieces. Perhaps I did not push the drill fully home on the test pieces. The very first hole is definitely enlarged. I corrected the setting of the cage and went ahead. Looking from the top, it seemed that the countersink was removing material right through to the other side and when I put a #40 drill bit into the hole, it seemed to be very slightly undersized. I rang my inspector about this and he reckoned if that was the case then I should stop. However, when I looked at the holes very carefully with a jeweller’s loupe, I could see that the holes do indeed have a cylindrical section remaining so the countersink did not go all the way through the material. The play that I experienced between the hole and the drill bit was probably because I was using the fluted cutting end . If I had tried with the shank it would probably have been tight. Overall, I have one enlarged hole and I don’t think that will unduly affect the strength of the skin-spar join. After all, it is one of twenty or more along that flange. I will use an oops rivet or make one by slightly compressing an AD3 rivet in the squeezer so that its shank ‘thickens’ while the head remains the same size.

Next mistake was to countersink some of the wrong holes on the forward face of the aft spar doubler. I now have three additional holes that should have stayed flat. There is plenty of warning about this on builder’s sites and I did look carefully at the drawings. I just mis-identified the holes on the actual work piece. I guess I should be more liberal with my markings before I commit to removing material. In sporting parlance, this would be an ‘unforced error’. I think the best thing to do now is to use a countersink rivet in those positions. It’s strength will be similar to a universal head. It is just that the pattern of rivet heads on the finished structure will not be perfect. However this will eventually be hidden under the tailplane fairings.

Left Right, Left Right

Tue. 6th November 2hrs 30min

Stripped plastic from around holes on the outside of the left HS skin. Deburred and dimpled holes. Deburred and dimpled the #40 holes on the main and nose ribs, both sides.

Yesterday, I emailed Vans support about my problem with the slightly elongated holes in the nose rib. Today, I got an answer from Bruce suggesting that I just go ahead and use the part.

I also posted a question on the RV squadron about polishing the edges in the narrow slot between the tabs and the rest of the flange on the main ribs. I got a variety of suggestions from Scotchbrite pads to 2" Scotchbrite wheels to wet&dry paper. What a great support network!

This evening, I went back to the left HS skin, which was first out of the jig, to bring it to the same stage as the right. So, I stripped off the plastic along the lines of holes, deburred and dimpled. I find the deburring bit mounted in a hex adaptor in my electric screwdriver to be very fast as it is easier to position than the dog-leg manual type. I only need to press the trigger for the briefest moment and then lift off. As the deburring bit has three flutes, one third of a revolution in full contact with the hole is enough to completely remove the burr. It is actually very difficult to restrict the tool to this. I reckon I am getting about one full revolution at a minimum. Still, the holes do not seem to be over-deburred. A deburring bit with only one sharp flute balanced by one or two rounded polished flutes would be a useful tool but I am not about to divert my attention to alter my one and only deburring bit.

This was also the first use of my pneumatic rivet squeezer. I fitted the dimple dies and used it to dimple the rib flanges. It does a superb job very quickly. I need to be careful that the die is properly positioned as it would be so easy to punch trhough beside the hole. I would have preferred to reverse the male and female die but the only way I had space to fit them was with the male die on the plunger. This meant that I was fitting the male die into the hole before pulling the trigger and the work piece would move with the plunger as it travelled up to meet the female die. I would prefer if the work piece was stationery on the male die and the female die did the moving to close the gap (I know you are all thinking up smart double entendre remarks on this theme and all I can say is "Stoppit"!). Anyway, nothing went amiss and I ended up with 16 perfectly dimpled ribs. I even managed to carefully avoid dimpling the tabs on the main ribs as they match up with the inside of the spar flange, which will be countersunk and therefore do not need a dimple in the tab underneath.

Deburred, Dimpled and De-wildered

Tue. 6th November 2hrs 30 min.

Deburred and dimpled the flange holes for skin attachment in the main and nose ribs. Stripped vinyl from left HS. Deburred and dimpled #40 holes

Smitty found that he had to buy dimple dies with a smaller diameter to dimple flanges where the hole is too close to the web. I didn’t have this problem. Perhaps my dimple dies were of a smaller diameter to start with, though they don’t look nearly as small as the ones he eventually bought. I used my pneumatic squeezer for this and it works well. It can feel a little heavy after a few minutes so I found myself sitting down and resting it on my lap as I worked.

For dimpling skins, the DRDT 2 really is a fine piece of equipment, particularly if you go to the trouble of making up the table according to the drawings they provide. I did have to adjust the height of the table in order to match the height of the lower (usually female dimple dies in their holder so that the skin being dimpled . I did this by attaching ‘skids’ planed to the necessary thickness underneath the feet of the table. I took a measurement after the top surface had been covered with carpet. You do need to be constantly vigilant in positioning the skin so that the male die goes straight through it’s intended hole. It would be so easy to miss the hole and punch straight through the skin.

Dimpled Skin

Mon. 5th November 2007 3hr 55 min

Match-drilled the Right HS. Disassembled. Prepared skin edges. Cut plastic from around holes on the outside of the Right HS skin. Deburred and dimpled the skin.

I ran into another problem this evening with the centre HS 905 nose rib on the right HS. It seems to have moved as I was changing clecoes during the match-drilling operation and I have four elongated holes. Using a digital calipers, I get a measurement of 0.1135 inches by 0.098 (the narrow dimension is correct for a #40). The corresponding holes in the skin are okay. I will have to consult Vans about this.

The DRDT2 dimpler came into its own for the first time this evening . I clamped the flat metal 'leg' at the rear to the table, which improved stability. The carpeted table also works quite well, sliding in and out nicely and adding support where you need it on larger skins like this. It does tip up when extended all the way forward because I have it on a 2ft deep table, which is not deep enough. I should have moved the other table in front of this one to give me 4ft of depth but I have the two tables set level and I did not want to disturb that. Instead I used a piece of scrap timber between the back of the table surface and the top arm of the dimpling frame, which prevented it from tipping. The results are really excellent. It just feels much better to use than whacking your skins with a hammer using the normal C frame dimpler. The motion is like pulling pints of Guiness, which I suppose is genetically implanted in all of us Irish. It is much faster and the quality is consistent. The downside is that it can't be used for riveting, unlike the C frame model. However, I think the speed and repeatable quality is a fair trade for this very rare requirement.

From Left HS to Right

4th November 4 hrs 40 min

Match drilled the HS skin to the skeleton. Disassembled. Prepared edges of skin. Assembled the Right HS skin and skeleton.

Today was punctuated by another trip to town for lunch and to avail of a homewares sale we found during yesterday's trip. I think it is important to continue spending lots of time with the family, even when you are itching to get back into the shop. My son brought his girlfriend around for dinner again. I gave her a tour as she hadn't seen the workshop going up and had only heard about the project. Both the shop and the project seemed to impress.

On the building side, everything went smoothly. I found that I did not have to do any heavy fluting of the nose ribs to get them to fit. They just went right in. I had removed the plastic from inside the skin as it would have interfered with the fit. It will get scratched of course but I intend to prime it anyway.

Skinning the HS

Sat. 3rd November 6hr 45min

Match drilled the HS-904 ribs and HS-905 nose ribs to the spars. Disassembled. Prepared the spar edges. Fabricated the wooden jig and assembled the skin and skeleton of the left HS.

This was my first full Saturday working on the project. As it turned out, I was also able to find time go into the city centre with my wife to have some lunch and shop for some household items.

In preparation for the project, I would regularly drop into my local Lidl and aldi stores to see what they might have. As a marketing man, I would have told you ten years ago that the idea of a shop that did not have regular stock but instead offered whatever was cheapest from time to time was plain crazy and would never work. Shows you how much I know. In fact, not knowing what they may have increases the 'mystery' and brings me back regularly just to see what they have in. What they have in stock very often includes tools that I would never have thought of owning. Much of it is amazingly cheap stuff probably made in China. However, for very occassional use, it is perfectly fine. I got a router and an electric staple gun that were of great help in building the workshop. All of the plastic storage bins you see in the photos came from this source. I also got a digital level, digital calipers and two engineering-type vices with brackets to attach them to the the side of a bench. These last items really came into play this evening, holding the spars steady while I preped the edges. They will also be used to hold sheet material clamped between two lengths of timber for edge preparation; the rudder skins for example. I will have to see if I can fit them to the table of my bench drill because the vice-grips type clamp I got earlier won't hold thin or small pieces.

Again, the edge preparation technique I am using involves using the file to get a consistent shiny edge with no shear marks, then deburring and finally polishing. I use the bench-mounted Scotchbrite wheel where possible but, if not, I use the 1in wheel in a die grinder. That die grinder sure uses a lot of air.

The HS Skeleton

Fri. 2nd November 2007 3hrs 10min

Prepared edges of HS-905 nose ribs. Adjusted flanges to 90 degrees. Straightened ribs by fluting flanges. Fabricated the HS-909 shims. Clecoed the skeleton together.

Even though there was plenty of the required .040 material in the bundle of trimmings, I was taking no chances this time. I marked out the HS-909 shims with great care, cut them out with a reasonably wide margin (about 3/32) and filed them back to the line, measuring the dimensions with a digital calipers as I came near to the final dimensions. Overkill, I know but it was as much about developing the skills of getting a part absolutely right as it was about these two minor parts. After all, the key dimension is the thickness of the metal they are made from rather than the width or height.

I held the shims in place in the ends of the appropriate ribs with side-jaw clecoes and match drilled them. I should have immediately marked them for position and orientation but I was able to match them up perfectly later on, as it turned out.

The skelleton of spars and ribs went together without any trouble and gave me a nice point on which to end the evenings work.

Main Rib Edge Preparation

Thurs. 1st November 2007 3hr 35min

Filed, deburred and polished the edges of the 10 HS-904 main ribs. Checked and adjusted the flanges for square. Fluted the ribs until straight.

Another evening of relative calm. Harry Hopkins had laid great emphasis on edge preparation in the metalworking course I took with him back in July and I was determined to get it right. I used the magnifying lamp pictured here to ensure that I was getting a good surface.

In the main, it went well but there are two very narrow notches, top and bottom, separating the main part of the flange from a tab that goes under the flange of the forward spar. These lead back to a relief hole on the actual web and they are so narrow that they are very hard to polish. I got a small file in okay but it was nearly impossible to get at them with the scotchbrite wheel. a small sanding wheel on my Dremel might have done it but I was reluctant to try. I felt I was more likely to increase rather than decrease the chances of creating a weak point where a stress tear might begin so I eased off on the filing in this area. I think the best solution would be to use a sheet of fine abrasive paper folded to give me a profile to match the notch.

I found the 1 inch Scotchbrite wheel on the die grinder invaluable for polishing the edges of the lightening holes but I used the big wheel on the bench grinder for all the rest.

Were it not for the novelty of the project as a whole, this process would have become quite boring. My shoulders ached at the end of quite a long session.