Timber Tourer - Spruce and Diesel

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Head in the clouds

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Folks,

I am posting this to help a new friend and new HBA member getting started with the site.

Kierie Pieterse is a retired commercial pilot from South Africa and has been having trouble with the site's log-in and 'vanishing posts' problem and had almost given up. I am interested in his project and was able to contact him and have had a look at some pictures of his neat craftsmanship.

It started out as a 3/4 scale C310 and has then evolved into an 'own design'. Kierie describes it as a 2-4 seater, the use of the rear seats will depend on flight testing results. It's a fixed gear taildragger and will use direct drive Subaru Diesel engines, a great choice in my mind since they are plentiful, reliable and very economical. And Kierie's configuration should carry the weight ok.

Anyway here are some pics of the early stage of the project to get the ball rolling and KP would love to hear from other timber builders to share tips and ideas.

Cheers all,

Alan

experimental ac.jpg DSCN0614R.jpg DSCN0567R.jpg
 

fly2kads

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So, am I seeing that the skin is not directly affixed to the longerons, but stands off through the formers? Fabric skins, of course, are done this way all the time. Just not used to seeing this with ply skins. What is the thinking there?

Interesting sounding engines. We don't have much in the way of diesels for passenger vehicles here in the US, so we don't have a lot to compare it to.

Very interesting project. I'm glad you've posted the pictures and description for Kierie. I hope he gets his forum access issues straightened out.
 

4trade

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Be careful and test those engine/prop combo very carefully before actual use in aircraft. I heard that here, in Finland, somebody test diesel Subaru with direct drive and metal prop. Just few minute idle run affect several crack at prop bolt pattern area.

Diesel engine have much more violent ignition pulse than gasoline engine. That´s why Thielert diesel engine PSRU don´t last.
 
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Hi fly2kads,
You are right, the skin does stand off from the longerons but only from the door to the nose. From about the glareshield the sqare shape slowly becomes more round untill it meets at the nose as a perfect bullet shape. From the cockpit rearwards the turtledeck will be round, and covered with 1.5 mm (1/16") Finnish ply, the sides and bottem flat. The covered nose section is spruce plank strips 1/8" X 3/4". I am still toying with my idea to "fill" (read close) the sqare box frame with a compact high density foam. When the epoxy cement is dry the outer edge of the foam will be cut with a hot wire knife flush with the wooden structure. I know this sounds very confusing, I will post a foto of a section where I have made some experiments, and also the power curves of Subaru diesel motors.
 

Head in the clouds

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...When the epoxy cement is dry the outer edge of the foam will be cut with a hot wire knife flush with the wooden structure.....
Kierie,
Welcome to YOUR thread :ban:, good to see you have been able to login etc.

This thing about epoxy foam etc has been a matter of discussion elsewhere on this site also, so your input will be very much valued. And by me particularly because I didn't know I could cut an epoxy based foam with a hot wire, or do I need a heated knife rather than a wire?

Anyway, you said you'd explain so I'm looking forward to more details, thanks, Alan

PS - I also heard about this power pulse thing with DD diesels, 4trade might have a good point, I think its not so much to do with the power curve but the individual power pulse of each piston stroke. Maybe a heavy flywheel could help? And I guess they are already in your plan since you mentioned 175kg per engine? I guess that's standard weights rather than lightened? If not then could a rubber drive coupling help the condition?

More help anyone please on this, 4trade? This will affect CG if engine rethink has to be considered so best to work it all out now?
 

Head in the clouds

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Hi folks,

Just getting Kierie up to speed on posting images into the thread, in the meantime he has asked me to put this up for him -

The foam that I am going to use is very dense and strong. With flat sole shoes you can stand on it and not make a mark. I think it is a polyester type foam, because epoxy glue does not erode or deform it. Glued to wood it is very strong. It is light blue in colour, 3-4" thick, comes in squares 4' X 4' and is used in the USA building trade for insulating dry wall wooden houses. Maybe one of our American friends can tell us more about it. I got it from an import co. that used it for packaging.


The one foto is of my experiments with butt joints and the other is of the actual joints in the airframe, what do you think ?

I am grateful for all your help. I will find somebody younger than myself to teach me all the tricks on a p/c.

Wish you many happy hours in your workshop.

Kierie

Butt joint exp..jpg actual fuselage joints.jpg foam inserts in lattice construction.jpg
 

topspeed100

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Be careful and test those engine/prop combo very carefully before actual use in aircraft. I heard that here, in Finland, somebody test diesel Subaru with direct drive and metal prop. Just few minute idle run affect several crack at prop bolt pattern area.

Diesel engine have much more violent ignition pulse than gasoline engine. That´s why Thielert diesel engine PSRU don´t last.
It is possible that wood works better as a structure with a diesel engine....I have experienced this with models...also have a deep scar from an old Frog diesel model engine on my right elbow.
 

Head in the clouds

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Timber Tourer - Progress

Hi all,

More pictures from Kierie that I should have posted for him ages ago, I expect things are a fair bit down the track from here by now.

The pictures show -


1 Annual rings in Douglass Fir
2 Direction of parallel grain
3 Method of bending strips
4 Curved strips kept their shape
5 Strips cut 100 mm, glued to roof formers
6 Curved strips used to form round shape between roof and screen

1 Annual rings  in Douglass Fir.jpg 2 Direction of parallel grain.jpg 3 Method of bending strips.jpg 4 Curved strips kept their shape.jpg 5 Strips cut 100 mm, glued  to roof formers.jpg6 Curved strips used to form round shape between roof and sreen.jpg
 

Head in the clouds

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Re: Timber Tourer - Progress

any more progress? It's such an interesting build.
In the last while Kierie has been to USA to visit his son who has designed, built and is test-flying a new plane which he hopes to produce as workhorses and medivac craft for remote areas in Africa. It is something like an overgrown Maule and is called the Mammoth. Back in SA Kierie built a mockup of the cockpit to design the control runs, double slotted flaps and so on. He has also completed the tailfeathers.

Just at the moment I can't find the photos he sent me but I'll keep looking.
 

Head in the clouds

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Just a quick update, Kierie's progress has been slow but steady, he also has kids, grandkids and home maintenance to keep up with.

Our latest good news is that we've been sharing regular correspondence with Kierie and Janette off-forum, and some while ago they kindly invited my wife and me to visit 'anytime we'd like to'. Since my wife hasn't been to Africa yet, and I haven't been back for many years, we decided to take next year's holidays in South Africa. We just got back from the travel agents with the tickets. We'll spend the first weekend as Kierie and Janette's guests in Pretoria and then the following week travel around with them in the Kruger National Park.

After that they'll return home and we'll head south to the Cape for next week or so. We may even get a chance to drop in on HBA member Lawotschkin (Daniel) and his wife Tina who moved two years ago from Berlin to run the Bush Rock guest lodge at Barberton Airfield near the Kruger National Park.

So there you go, HBA has created yet another international friendship :)
 

Jan Olieslagers

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I will be following with great interest, especially about using the Subaru Diesel (their EE20 model, I should think?). But that engine can run a good deal faster so I think reduction drive, either geared or belted, would be worth the added weight and complexity. Still, even the Centurion and Austro diesels use both reduction and a slipper clutch to control the vibration issue, so that might well be necessary here, too.

BTW the blue foam mentioned must be extruded polystyrene, known commercially (amongst others) as Styrofoam (Dow), Styrodur (BASF) &c. I was told it should be avoided because, if any condense water ever gets in, it can never get out again, causing cracks in the covering epoxy. Not sure how serious to take this.
 

Head in the clouds

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I will be following with great interest, especially about using the Subaru Diesel (their EE20 model, I should think?). But that engine can run a good deal faster so I think reduction drive, either geared or belted, would be worth the added weight and complexity. Still, even the Centurion and Austro diesels use both reduction and a slipper clutch to control the vibration issue, so that might well be necessary here, too.

BTW the blue foam mentioned must be extruded polystyrene, known commercially (amongst others) as Styrofoam (Dow), Styrodur (BASF) &c. I was told it should be avoided because, if any condense water ever gets in, it can never get out again, causing cracks in the covering epoxy. Not sure how serious to take this.
Any status with the Boxer diesel installation?

boxer diesels are now on sale in USA (boxeer.com)

I'm also curious about WVO/SVO conversion of the boxer diesel

PlantDrive™, WVO, SVO vegetable oil fuel system, gas alternative, biodiesel, Canada, US, International is a good resource for conversions.
I don't think there's much progress on the engine side of things yet, Kierie's spare time is quite limited and shared between his family, home and the plane project, so he's just concentrating on getting the cockpit mock-up and control system built at the moment, I expect the engines will be left until the rest is done. Thanks for the links though, I'll be sure to pass them on to Kierie and I'll have a lot more info and photos when I get back from my visit over there next March-April.

Regarding the blue Styrofoam - I don't keep up on the composite side of things these days, since I became allergic/sensitive to exposure to the resins, but I always thought the blue extruded Styrofoam was the one to use and that the white expanded Styrofoam was the one to avoid. Can someone shed more light on this please?
 

Saaymanp

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Hi pieter here from Cape Town, South Africa where can I get hold of kierie. Who sells the ee20 engine in South Africa? What a nice engine for the cozy mk4.
 

Jan Olieslagers

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What a nice engine
it would be - if it weren't for the warning by fellow 4trade higher up. There must be a reason why this nice engine is not seen in active aircraft use. Needing both rpm reduction and hefty damping, a belt drive seems indicated, but for such an amount of power that is not easy either.
 

Head in the clouds

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Hi pieter here from Cape Town, South Africa where can I get hold of kierie. Who sells the ee20 engine in South Africa? What a nice engine for the cozy mk4.
I correspond regularly with Kierie, if you send me a private message with your email (and phone if you like) I'll ask him to contact you.

it would be - if it weren't for the warning by fellow 4trade higher up. There must be a reason why this nice engine is not seen in active aircraft use. Needing both rpm reduction and hefty damping, a belt drive seems indicated, but for such an amount of power that is not easy either.
They use belt PSRUs on Chev V8s, Subaru V6s etc. I don't know much about them but the one on the Supermarine Spitfire seems to be fairly trouble free. There's also a planetary reduction drive which, I think, has a rubber coupling or slipper clutch which takes out the TVs. RV6EJguy on this forum uses one and would know much more ...
 

rv6ejguy

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The early EE20 engines had crankshaft breakage issues- hardly inspiring for aircraft use. Supposedly Subaru fixed the problem in 2010 MY but I saw a forum post with someone saying they had a crank failure with a 2011 car so maybe not.

I have been helping a friend in NZ on his direct drive EE20/ RV7 project. This will use a different turbo and injection system than the stock setup. We'll have to wait and see how that one works.
 

Jan Olieslagers

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For this particular engine, was the added weight/cost/complexity/hassle of a PSRU considered not worth the possible increase in rpm? What were the figures?
 

rv6ejguy

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For this particular engine, was the added weight/cost/complexity/hassle of a PSRU considered not worth the possible increase in rpm? What were the figures?
Weight with PSRU is a big concern. PSRU reliability with the diesel is unknown. The engine will be fitted with a custom prop/ crank support bearing setup.

I'll have to check my email at work on the stripped engine weight. The target here is about 135hp at 2700 rpm, sustained to about 8000 feet. Specialist Components in the UK will be supplying the ECU. We are matching a new Garrett turbo currently.
 
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