Wings!

Having stored the fin, rudder and tail plane, I've started to prepare parts for the wings.

I'm working slightly out of sequence as I'm meant to deal with the spars first but that will mean re-arranging the garage.  The main spars are about 15 feet long as they overlap inside the fuselage, and the rear spars are 11 feet long, so I have to create a temporary painting tent as the spars won't go upstairs to the regular spray shop.

So, first job is to prepare the front stub spar and all of the aft spar hinge brackets for the flaperons.

 Here are the hinge parts and also the front stub spar and aft spar  fittings that engage into the fuselage.

Now all the parts primed and ready to start riveting parts together.

 End of the front stub spar with the doubler riveted in place.  Note the three countersink rivets in the fuselage tongue  - these are flush-riveted on both sides which was a pain as the specified rivets were slightly too long.  The empty holes in the face of the stub spar are where the front of the wing ribs will be attached.  The countersunk holes in the flanges are for the wing skins.  Doing the countersinking was awkward even with a machine countersink cage, as the depth still seemed to vary and I was quite worried about wrecking one of the spars!

Flaperon hinge brackets complete with bearings.  I wonder how you replace the bearings in service?  Unlike the rudder hinges which are bolted to the airframe,  these hinge brackets are riveted in place to the rear spar.  As with the stub spar, there are double-flush rivets adjacent to the bearing.

The next major items to prepare were the wing ribs.  Well over 30 hours spread over a couple of weeks sitting at the bench, cutting, filing, deburring, fluting and scuffing over 50 ribs prior to painting!    I have many cuts and grazes from sharp metal, plus raw fingers now from the scuffing with purple ScotchBright. 

There are two types of forward rib supplied, but after trimming tabs, flanges or both, you end with 6 different versions.  Same with the aft ribs as well - 2 standard types but you end up taking the aft flange of all right versions and have two differing left versions.  I guess it simplifies manufacturing for Vans but I think it's going to be pretty confusing when it comes to final assembly! 

A forward rib before and after fluting.  The curve is an unfortunate by-product of the manufacturing process when the edge flange is produced.  On the right side you can see the dimples between each hole which pulls the metal straight.  These are all done by hand using a special pair of pliers, but only once the deburring is complete (yes, I did one in the wrong order - big mistake!).

 Forward ribs on the painting bench.  

All of the forward ribs complete and stored below the bench ready for wing assembly.  The long pieces still covered in blue plastic are the spars for the flaperons.

The final 13 aft ribs ready to be painted.  There's more than full day's work preparing these.

Over the next week I have to paint the remaining aft ribs and create the temporary paint tent so I can paint the main and aft spars.  I also have to paint the top of the rear fuselage below the fin  - unfortunately overlooked during that stage,  before I can finally store the tail cone assembly.  After that, I'll have the space to pull the bench out from the wall and start wing assembly.  Exciting times ahead!

A good start to the new year.

After the Christmas break and successful stage inspection, I've managed to make some good progress throughout January and have completed the first kit!

First job in the new year was to skin the horizontal stabiliser.  This was really quick - just over a day's work, as I'd already match-drilled, deburred and painted the skins, hinges and trailing edge ribs, so just loads of riveting.

 Here's the HS on the bench with the main skins fitted and waiting for the trailing edge ribs and hinges to be installed.

Now with the hinge halves clecoed ready for riveting

An exciting bit comes next - assemble the empennage with fin, rudder and HS to see if everything aligns and clearance of moving controls is OK.  The fin cap isn't installed at this point as it hits the garage ceiling!  First the fin and rudder are installed. This meant adjusting the previously chosen spacer washers in the rudder hinges as the fin didn't line up close enough to the top of the rudder.  A bit of juggling whilst still complying with the build manual requirements and everything lines up to my satisfaction.

  The paper with orange tape has the correct washers/bolt combination drawn on for each hinge so I don't have to work it out again on final assembly!

Next comes installation of the horizontal stabiliser, initially without the trim tabs fitted.

Now we move on to a part I'm not very keen on - trimming fibreglass.  Previously I'd trimmed the fin and rudder caps to size.  This time it's to make the two halves of the tail cone fairing. You're supplied with 2 moulded pieces - each like 1/2 an egg and with very feint scribe lines to trim to.  I did the initial trimming using a fine high speed cutting disc in an air grinder - a bit like a Dremmel. Once close to size, I then had a lot of fitting/removing/filing and sanding to get a satisfactory fit.  Only then can I start to join the two halves together.

Here are the two pieces held in place with clamps whilst the joining plates are aligned and drilled.  The rudder is offset to the left which makes the cone appear distorted.  Also, the slot for the trim tab actuating arm still has to be cut-out.

Another view of the joining plates.  These will eventually be riveted to the inside surface of the lower half of the fairing and anchor nuts fitted on the top half of the plates.

Anchor nuts have to be fitted to the skin around the rear bulkhead to hold the fairing halves to the airframe. It's an awkward job as they're on the inner face of a curved skin, are dimpled and it's very difficult to get a drill in to match some of the holes to the skin.  

Moving on, I have to assemble the trim tab motor and actuator assembly, and for the first time, a bit of my own type of work, aircraft wiring to do!  (well I did put the nav antenna cable in as well).

The motor on it's base and wired to mate with the cable already installed in the fuselage cone.  Note the loom string and not tyraps for those who have a clue.  Perhaps a bit old-fashioned, but I hate cutting my hands on sharp tyrap stubs!  The split pins are temporarily fitted as the nuts won't be finally tightened until the assembly is finally installed and rigged.

The complete trim assembly.  I've painted the actuator arm in white epoxy as it will be visible where it protrudes through the tail cone fairing and attaches to the trim tab.

There is one small outstanding item, which is to fit and adjust the trim assembly to the bulkhead and HS, but I'm short of one 1/4" nylon bush and don't want to pay huge freight for such a small item, so will wait to consolidate it with more parts later. The small amount of work for this item can be done during final assembly.

I had to remove the refit the HS 3 times to complete the fibreglass work and fit all of the fuselage anchor nuts. Finally, I put it all back together again for one final interference check.  

All parts assembled, and end of empennage construction.  All surfaces move without interfering and all the gaps are pretty consistent.

Wow!  It actually looks like the back end of a real aircraft.  I have to say that it does generate a real sense of satisfaction to have completed this first major part, in just over 5 months. Now I move onto the wings and I reckon they will take me to around the end of June, so another 5 months.  Before I can lay out the wing main spars, I need to dismantle and store all of the empennage so I can get the construction bench into the middle of the garage (the wings are longer than the bench and it fits into a recess currently). 

The horizontal stabiliser, fin and rudder have gone upstairs in the garage.

The fuselage cone is going to hang from the ceiling above my MGA.  I wont need these parts again now until the fuselage centre-section is complete and needs to be joined to aft fuselage cone., so probably around the end of the year.

A bit of Chrismas cheer.

Welcome to my last post of 2015.  Although it's the Christmas holidays and I didn't foresee much progress, I got in a few hours before Christmas Day and a few more since then, so I have been able to get the tail cone completed and my next stage inspection passed by Jerry.  As I don't have a target for completion (it's meant to be a fun hobby after all), I'm pretty pleased with progress so far.

First task since the least visit was competing preparation and painting of the remaining skins and top rib.  

Fitting anchor nuts to the fin attachment rib which will go on the top tail cone skin

After the upper side skins were pinned in place, it's time to start out-fitting the tail cone. There's not a great deal in the rear - control cables for rudder and elevator, wiring for the electric trim, nav antenna cables and static pipework.

Strings fitted to pull-through the elevator and rudder cables (in about a year!).  Also installed the pitch trim electric cable loom and the static port pipes to the ADAHRS. 

You can just make out the inside of the left static port.

This is the right static port from the outside - it's a pop rivet with an over-sized head and the mandrel pushed out. 

Now the final top skin is pinned in place, all holes match-drilled and then the skin removed again to deburr the holes.  Finally, it's back on again and ready for riveting.

Top skin clecoed in place and ready to rivet. 

You can see the remaining pins securing the skins to the fuselage frames.

The completed tail cone ready for inspection.

A top view of the fin attachment rib.  The skin below the rib has been primed to prevent corrosion.  The antenna connector is for the nav antenna in the fin cap, and allows for easy installation or removal of the fin.

Inside the completed tail cone.

My next job is to skin the horizontal stabiliser (HS).  The skins are already prepped and painted.  Moving on, it'll be a trial-fit of the fin/rudder and HS to the tail cone.  At this stage, it will look like the complete rear-end to an aircraft!  Once this is done, I have to deal with the trim motor mountings and then make the tail cone fibreglass fairings fit (apparently a bit long-winded to get good alignment with all of the securing brackets) .  I reckon this will take me to the end of January, and then it'll be time to start on the wings.

To all readers - thanks for visiting and my best wishes for a Happy New Year.

Back underway

Unfortunately I've had an unscheduled delay due to hand and knee pains.  

After a bit of medical investigation, it transpires that I've got arthritis in the hands and right knee, and other problems with my left knee!  However, after a large steroid jab in the backside and a couple of additional weeks waiting, my hands at least are improving, so it's back to work.  Fingers crossed the jab will work long-term - only time will tell.  

These problems all started before the kit arrived, so I can't blame the aircraft.  The physio looking after my knees reckons it's because I've stopped flying a desk and got active after many years being sedentary.  

First job on re-start was to complete the trial fit of the horizontal stabiliser skins and match-drill all final holes prior to painting.

This is 8 feet wide.  I think we might have a problem getting the aircraft assemble in the garage!

Next job was to assemble the rear bulkhead which has the hinge bearings for the horizontal stabiliser, plus the rear tie-down bracket, hinges for the trim-tab motor and the main attachment for the fin.  It's a double-skinned assembly with loads of rivets of different types and sizes, so great care needed to get the right ones in the right holes.

So moving on and it's time to deal with the biggest part so far - the rear fuselage cone.  This is about 9 feet long (it goes from the back of the cabin to the tail) and has nine individual skins and three frames plus the bulkhead.

First step is to assemble the previously painted frames.

The finished frames.  The V-shaped bracket at the top of the smaller frame is where the front of the fin attaches to the fuselage.

In preparing the skins, I came across an issue which turned out to be a factory error - a first in what has been incredibly accurate production.

We have to fit some J-section stringer extensions to the bottom skins.  As you can see, the holes don't line up.  I thought it must be my mistake as the holes are fine with the stringer outside the skin, but the pictures suggest otherwise.  A review of the builders' forum showed this to be a known issue and my assembly was correct.  It then became a simple re-bending exercise with a couple of blocks of wood and a rubber mallet and all is now good!

Next is to trial-fit the bottom skins.

Then after final match-drilling and deburring, it's time to assemble and rivet together:

The finished product with all lower skin panel rivets installed.  The ones marked with tape and kept for joining this section to the main fuselage.

Now we get to turn it the right way up and start building up the sides.

 Looking inside at the rear bulkhead.  A large counter-balance will protrude through the bulkhead when the horizontal stabiliser is finally installed.

The rear view showing the horizontal stabiliser bearings.

The next job is to add the wiring and plumbing for electric trim and static system, plus the nav antenna cable, before the final skins are fitted.  The next few weeks probably won't see much too progress as the day job beckons with deadlines and of course it's only 11 days to Christmas!

Steady progress

No big visible changes this week, but lots of preparation of parts which will hopefully lead to a sudden blitz of riveting!

I finished preparing the rear fuselage frames and painting them on one side. 

I also filled pinholes in the fin and rudder fibreglass caps and painted them as well, so these can now be installed.

All parts for the rear fuselage bulkhead have been prepared.  Plenty of trimming and polishing, countersinking for anchor nuts (which support the fin), plus match drilling and deburring all holes.   I trial-assembled the whole thing including the horizontal stabiliser hinge bearings (but unfortunately didn't take a picture).  All parts have been scuffed with red Scotchbrite prior to painting. 

I also completed the tail tie-down bracket which is riveted through both bulkhead sections. This meant cutting the 45 degree chamfer (good use for the bench sander to get the finished surface flat and square), plus notching the side, drilling and tapping the hole at the opposite end where the tie-down ring will be inserted, radiusing all corners and match-drilling all rivet holes to the bulkhead. My metalwork skills are definitely improving (shame about the state of my hands from sharp edges)!

The final task this week was to trial-fit the horizontal stabiliser skins.  All holes (several hundred) need match drilling to the finished size (the delivered punched holes are slightly under-size and won't take the 1/8th rivets) and then it's taken apart again for deburring and for all rough edges to be finished. Then the whole thing is finally cleco'd back together. Everything lined up perfectly.  The accuracy of the kit continues to amaze me!

The plain anti-servo-tab hinge halves fixed to the stabiliser needed to be drilled-off using the guide supplied by Vans.  I messed up the first hinge section by putting the drill guide on upside down (it's the reverse way round from that used on the servo-tabs themselves and identified by some small notches on one edge), resulting in two holes being too close the the hinge pin before I realised my mistake.  I had to get a replacement section of blank hinge and re-do this step.  This time I marked the drill guide with red and green on opposing sides so I didn't repeat the error.  I need the HS semi-assembled so that the rear bulkhead hinge alignment can be checked.  The skin riveting won't happen until Jerry has inspected the skeleton (which means taking it all apart again).

If things go to plan, I'll have the rear bulkhead, three fuselage frames and three lower skins fully painted and maybe even assembled by my next post!