8.6.8 + 10 Drill flap bearing and debur F-705 parts

More work on the F-705 bulkhead this afternoon starting with the flap bearing. This plastic part holds the flap bar but comes without holes for the bolts. It needs measuring and marking as per the plans. Spot the mark…

Once marked I then clamped it to the desk along with the drill guide and drilled one hole in each of the two blocks.

Once the first hole in each block was drilled I then bolted it to the F-705 vertical spars and back drilled the second hole. Next I drilled and dimpled the holes for the nutplates.

Then I spent the rest of the session deburring all the parts of F-704 & F-705 bulkheads. Man that’s a lot of parts!

That’s all for today’s session.

8.6.5-7 F-705 Fabricate more parts & assemble upper spar

This F-705 bulkhead is proving to be a lot more complicated than I first anticipated. It needs lots of parts fabricating from scratch. I think this is the most parts I’ve fabricated for one assembly.

I started off by making two spacers at 16.25″ long as per the plans. That was easy enough as the stock was the right thickness and width and just needed trimming to length. Next I fabricated the F-705K plates which again where the right thickness and width. However, as well as trimming to length they needed to be bent at 4 degrees lengthways. 4 degrees is a tiny amount of bend and it took me a while to find a good method. In the end I opted to clamp the strip to the workbench using the back riveting plate and then make the bend using the flat faced hand seamers.

Once that part was made it was time to make the F-705J stiffeners. Again this involved trimming them to size but, for the first time, I had no holes to act as a template. The plans give dimensions of where the holes should go so I carefully marked the part, punched it with the automatic punch and then drilled no. 40 first and then final sized it to number 30. That was the easy bit.

The next instruction is to clamp everything together and drill everything to the top channel. I think I used pretty much every clamp I had to get this lined up. This was particularly tricky because the angle must have a 1/8″ gap between it and the frame so I found some aluminium bar that was exactly the right thickness and clamped that in place before drilling the angle to the channel. The whole task was very meticulous and nerve rackingly tricky. But, with oodles of patience, and triple checking, twice(!) I finally drilled all the holes and cleco’d everything in place. Verdict: I’m pretty happy with the results considering how difficult this was.

The next task for this session was to assemble the F-705 bulkhead and match drill the F-705G brackets I made earlier this week. There is absolutely no guidance in the instructions or drawings on how to do this so it was all done by eye and experience. For example I noticed that the outer corner of the angle was interfering with it seating properly so I rounded the outer corner so it fit much better. Next I drew warning lines a 1/4″ in from the outer edges so I could see if the holes would be within edge distance limits. Finally I clamped everything together in every dimension and then drilled all the holes using the predrilled holes in the channel as a template. Once the holes in the brackets were all match drilled I drilled the slots for the canopy latches into the brackets too.

Lastly, I match drilled all holes that had not already been match drilled and gave the workshop a good tidy up.

8.6.2 & 3 F-705 Drill seat belt attach points and fabricate brackets

My son Jake joined me in the workshop today so I set him the task of sorting through the bags of rivets that’s came with the fuselage that I hadn’t gotten round to putting away in their pots yet. It was fun watching him work out all the part number conventions.

While he was sorting the rivets I worked on the seat belt attach brackets. These are steel powder coated brackets almost fully prepped except they’re missing the hole for the bolt that attaches them to the spar. The drawings mark out exactly where to drill the left hand brackets. The bracket is then bolted to the spar and then the right bracket is clamped to the left bracket and then drilled. It is said that you can never have enough clamps and that was certainly true this afternoon.

I had so many clamps on this this I could hardly move. After a while I had all seat belt brackets drilled.

Next the instructions have you trim a few of the steel brackets to clear other rivets. So I did.

Next I countersunk holes for the rivets that sat under the outer most bracket.

And finally I fabricated the two F-705G brackets.

That’s all for today.

8.6.4 F-705 Fabricate F-705G brackets and countersink doublers

Another session today working on the F-705 bulkhead first fabricating the F-705G brackets. These are required only for tip up canopies and not required for slider. As my RV will be a tip up this part needs to be made.

Next I countersunk two holes where the seat belt bracket will overlap the rivet.

Finally I trimmed one side of each of the outboard brackets to clear a different rivet. Very complicated but all part of the plan.

That’s all for tonight’s sessions, this bulkhead is really quite complicated!

8.6.1-2 F-705 lower section

The drawing for bulkhead F-705 mentions some aluminium bar but I couldn’t find the part I needed anywhere so when that happens there is only one thing for it. A bloody good sort out and reorganisation.

All the parts on the storage shelves were pretty much as they came out for the shipping crate with no real order to them. So today I started my session by taking each part off the shelf and putting it back in part number order. I now have all parts in numerical order and a well organised pile of stock to make other parts from. That made it much easier to find the aluminium bar I needed.

The bar needed to be cut to a precise measurement so that was the next task. Measure, measure, measure, cut…

Next, the instructions say “clamp everything together and match drill”. Sadly, it’s nowhere near that simple so I took some time to think about the best approach. I decided to build the assembly up in layers starting with just the bar and bottom spar. I used the prepunched holes in the spar to match drill the bar only as far as the next part. Then I located the next part and drilled a single hole as per the dimensions on the drawing. I clecod the part on to the bar and spar and then match drilled the remaining holes.

Once everything was match drilled I made two spacers as required on the plans. Next I dismantled everything and shaped the reinforcement bar according to the drawings.

A fun session today.

8.5.11-14 F-704 Spacers

The instructions tell you to make two tube spacers from aluminium tube but don’t tell you which stock to use it from so I sifted through the entire inventory of fuselage parts to check which stock I was supposed to use. It turns out there are only 2 suitable stock tubes I could use and they were both the same length.

I marked the length required on the first tube and made the cut using the chop saw. Unfortunately I didn’t account for the width of the blade and cut the first tube too short. Grrr. Luckily I had a spare tube so I used that and made two good parts. The plans call for the parts to be precisely 1.4375″ long and I used the lathe to get a very nice flat face and a precise length.

In the end I had two identically sized aluminium tube spacers.

The next instruction was a surprise. Van’s asks for 4 solid wood blocks the exact same size as the spacers. Hmm, that was going to be a challenge as my woodworking skills have never been as accurate as that before. Luckily I had some hardwood stock lying around so I set up the chop saw to cut 1 7/16″ block. They were a touch oversized so I used the belt sander to bring them to the precise measurement.

After that I needed to drill a hole in the centre of the wooden spacers so I set up the pillar drill to get as straight a hole as possible.

After the most meticulous woodwork I’ve ever done, I’m really pleased with how they turned out.

To make sure that I’ve done it right Van’s instructions say to trial fit everything which I duly did.

That’s as much as I can do with the F-704 bulkhead for now. I will need to prime the parts before I can rivet everything together which I will do in one large batch with all the other parts.

8.5.7-9 F-704 Fit nutplates & prep cover support ribs

Carrying on with the F-704 bulkhead the next job on the list is to fit the nutplates to the top of the gold spars. To do that first I needed to enlarge the prepunched holes and then countersink all the holes that will be taking a rivet.

After that there are 4 ribs that need to have the prepunched holes enlarged enough to be able to fit grommets for plumbing and wiring. So I enlarged the holes and then cleco’d the ribs to the spar then match drilled all the holes. I then fabricated two stiffners as per the plans and match drilled that too.

That’s it for today.

8.5.1-5 Begin F-704 bulkhead

The F-704 bulkhead came with the wings and has been sat, safely, in my workshop for nearly 2 years. It was shipped with the wings because it is precision drilled with the wings. Today is the day I get to finally unwrap this puppy.

I carefully uwrapped the parts, they look fantastic with the gold anodisation. Once unwrapped I followed the instructions and drilled holes for the electrical wiring and rudder cables. I also located the control stick brackets and prepped those according to the instructions. Finally I match drilled the spacers and countersunk them as per the instructions.

It doesn’t sound much that was a serious session working on these parts. I really didn’t want to make a silly mistake with these so I took it slow all the way.

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