Justin's Raven

[justin.schoeman]

I have flown one Raven with mechanical brakes, and they were 'good enough'. Not great, but you can certainly land on any runway you can take off from.

The only problem is, there is no other place for such a long lever, than right in the middle, where it is at the moment. A smaller handle with a mechanical amplifier (pulleys) should do the trick though. Will lay out the system once the console is in, and calculate what cable force I can generate.

As for the engine, the machine work is done, and the spares are at Jeff Sharman and coming out on the next container. Amazingly enough, the entire exercise (2 new heads - complete with valves, springs, etc., 2 cylinder kits, all new bearings and seals) will come in at around R10k, and the engine is basically new. One of the big advantages of a VW engine.

[justin.schoeman]

And the results of today's efforts:

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Not a hell of a lot to show for the amount of time that went into it. It always amazes me how:
1) the smallest task snowballs into a million smaller ones, and
2) just how long it takes to prepare even a single piece of aluminium.

The centre console now weighs in at 230g, with a total of 12 individual pieces of aluminium...

Used up the last of my A4 rivets to tack it together. Must phone Avlock tomorrow, and see if I can convince them to Speed Services (is the strike over yet???) some to me. Tried to order from Placo, but they are just not responding to any calls or emails (just to add to the frustration).

[justin.schoeman]

Sometimes I wish I had one of those 'bells and whistles' workshops... Spent 1.5 hours just cutting out the hole for the transponder. Measure 3 times. Drill relief holes, drill starter holes, rough cut with a jig saw (I think I am deaf now), then finish off the last few mm with a file (and my arm is about to fall off).

BUT it does look good after all that effort. It is nice to see the transponder in the panel.

Anybody know if there are any rules/guidelines about placing radios next to transponders? They always seem to be next to each other in the stack, so I suppose it should be fine to put the radio below the transponder...

[justin.schoeman]

Just been experimenting with a home made rivnut tool. I decided to attach the non structural bits (mainly the instrument panel) with rivnuts. I don't particularly want to invest over R1000 in a tool to pull a handful of rivnuts, so I decided to make one...

I saw a picture on aircraftspruce.com showing a simple tool (that sells for USD10) to pull rivnuts with a standard hand riveter - so I tried to copy it:

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Basically took an M4 bolt, annealed it, then turned it down to a 3mm stem to fit a standard rivet mandrel. Pulls perfectly! I managed to pull the rivnut out later, but not without tearing the aluminium I set it in.

Two problems though:
1) I shouldn't have annealed the bolt - it is way to soft now. (It was the only sane way to turn it in a drill press though.)
2) I think I pulled a muscle in my shoulder setting the sucker. I need to modify the riveter to use a slightly shorter throw, so I can grip it in my hand, rather than squeezing with two hands.

Will have some fun later tonight completing and installing the centre console!

[Sukkelaar]

I have one you can borrow. With just about any size rivnuts you want also (these you can have) It is possible to get it to Pretorie every Monday.
Give me a shout

Regards

[Wallaby]

Hi Justin
I'm using rivnuts a lot and the other day I bought a new rivnut tool from Rivco in Cape Town. It have mandrels for 3mm, 4mm, 5mm and 6mm. The whole setup was only R495 rand. I have other rivnut tools that I bought a long time ago, but it is only for 6mm rivnuts. This one I spesifically bought to get the 3mm size and I couldn't find a 3mm mandrel for my other tools.

Better to invest in a proper tool for the job....believe me. And once you have a rivnut tool, you'll see how much you'll start using it for other applications.

[justin.schoeman]

Thanks guys. For now it seems my makeshift puller is working perfectly. Sets the rivnuts absolutely solid, and works as easily is a pop rivet :D . Wouldn't try to set anything bigger than an M4 rivnut though!

I did have to remake it without annealing the bolt though, as the first one sheered off after the 2nd pull!

Also made a stuff up measuring up the transponder bracket. Was going to rivet it in, but with all the holes skew, that wouldn't work. Used rivnuts instead, and it should be OK. I don't like it, but the extra holes will be covered anyway, and they don't affect the strength. And I really don't feel like remaking that panel!

Naturally, I didn't come anywhere near meeting my targets for the night, but here is a super bad photo of the almost complete centre console.

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[justin.schoeman]

Calling it an early day due to excessive blood loss . Working inside the cabin is a pain. Quite literally! Every time you drop something it roles to the most inaccessible possible spot, which inevitably results in a lot of skin and blood loss to retrieve.

Anyway, I have come to realise that the dual throttle setup isn't going to work. If anybody has any ideas for setups that may work on the Raven, please let me know.

The area inside the cowl, above the top crossmember has two reinforcing ribs on that the Zodiac does not, so putting a torque tube across there will be very difficult. The fuel tank is behind the panel (only a 10cm gap there, and it is pretty busy). I suppose the Jabiru 'crotch throttle' setup may work. Or a torque rod just below the panel, with some angled throttle arms? No idea.

[justin.schoeman]

Wasn't feeling that well this afternoon, so didn't get too much done.

The main panel, redone with rivnuts, cleaned up, and the centre console fitted. Also took out the fuel tank while I had the panel out. Need to replace the filler neck with a short one, and put a propper strainer on the outlet.

Trial fit a seat. If tomorrow is still hot, I will do the layups for the final seat backs.

[justin.schoeman]

Another slow day - needed to do some work around the much neglected house.

Only made one seat back today, and fixed the backup ASI (second hand - had a static leak).

Really boring photo of the seat back:

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Got the design on ch601.org. 2 layers of depron, and covered in 290g glass. Weighs in at 430g. Original zodiac design weighs 800g per seat. So much effort to save 740g... Was it worth it? I suppose time will tell.

[justin.schoeman]

Lazy night again.

Just as a matter of interest, I took some backlit photos of the type 1 and type 4 VW heads.

Type 4:

Type 1:

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This is why the type 4 can handle so much continuous power. Not only much bigger fins around the outside, but a large amount of finning on the inside - every part that doesn't have to be solid, is hollowed out and finned. All the valve guides, between the cylinders, around the ports - the works.

The type 1 has some finning around the exhaust port, and a huge hole through the middle. A tiny fraction of the fin area of the type 4.

[justin.schoeman]

Been playing with paper planes, or at least paper instruments:

I made a template of each of the instruments, indicating the maximum external dimensions of all of them, and stuck them to the panel, to confirm visibility, accessibility and spacing.

Aside from these requirements, the only other goal was to place the compass as far from the electrical systems as possible.

Any comments?

[justin.schoeman]

Antenna doubler:

Taped to the outside of the fuselage for match drilling. Will obviously be mounted inside, with all mark folds downwards. Hope I am not stuffing this up. Calculations say that the measurement difference between inside and outside is only 0.1%, and accessibility from outside is soooo much better...

[Scotsman]

Are you building on the weekend Justin? Would be keen on popping round for an hour to have a look.

j

[justin.schoeman]

Hi James.

I will be building Saturday and Sunday afternoon and evening. Just give me a call/drop me a PM, and we can make a time.

Justin

O eight too 78I 2O67