Thread: How do I make this part?

Originally Posted by ian

Briney

would it be too much of a departure to install a variable pitch prop for flight?

if my very vague recollections from 30+ years ago are correct variable pitch props were developed to get around the high torque requirements of fixed pitch props.



ian

Close - the main reason is that you can vary the prop's pitch depending on whether you want to climb or cruise. Before their invention you had to optimize the fixed pitch prop for one or the other or somewhere in between (meaning you didn't climb OR cruise well!).

It would be a complication that I'd try to avoid - this is a fairly light airframe and variable pitch props add a bit of weight.

Originally Posted by jaguarrh

WOW!

and I thought I had seen pretty much every conceivable project on these boards...?

this is very interesting, will be watching the developments with interest.

Keep posting, would love to see the end result.

Thanks! It will be a slow project though - budget and time constraints mean it will be trickle fed over many years. However, I will try to post as much as I can. The main forum I post in for this sort of thing is at http://www.theaerodrome.com. On the replica aircraft forum you will see some amazing projects much more advanced than mine (try this one from Melbourne: http://www.theaerodrome.com/forum/re...e-project.html)

Once I have a few pics I'll set up my own web page.

Hi brinesharks, Great project! I'll be following this with much interest. I have a Homebuilt project in its absolute infancy..( planning stages) so your links were made to order, thanks.

I take it aircraft grade spruce is a pretty rare commodity these days, can you give any tips about its availability?.

most excellent... I'm clad I found this forum

If there are lots of custom parts, a CNC mill might be nice!

I was fascinated by the parts one can make on a CNC mini mill - see for example at the small extreme:
http://www.minitech.com/

Originally Posted by BrettG

Hi brinesharks, Great project! I'll be following this with much interest. I have a Homebuilt project in its absolute infancy..( planning stages) so your links were made to order, thanks.

I take it aircraft grade spruce is a pretty rare commodity these days, can you give any tips about its availability?.

most excellent... I'm clad I found this forum

Hi BrettG - what project are you looking to start? Aircraft grade spruce is still available out of the US and some parts of Europe. But if you are registering experimental you just need to use materials that are suitable. The term 'aircraft grade' doesn't really apply to timber though. Find a good reference you trust (try 'Wood in Aircraft Construction, 1936) which will give you the guidelines for choosing aircraft timber. Good ply is hard to find but really good quality marine grade can be used. Alternativley you can buy all your material from an aircraft supply place in the US and get it shipped out. I'm told you should count on a nearly 25% rate of timber that's unusuable in it's original role (eg. 25% of spar material will be unsuitable but you could cut it up into capstrips). In the end you must be happy with the material - so educating yourself is a good invetment in your own longevity!

Search for any forums that have posts by 'Spadmaker' - he has some invaluable advice on wood selection. If you can't find anything, let me know.

Originally Posted by blouis79

If there are lots of custom parts, a CNC mill might be nice!

I was fascinated by the parts one can make on a CNC mini mill - see for example at the small extreme:
http://www.minitech.com/

I get someone else to cut my parts but as he is an 'amateur' wooden boat builder he takes the time to understand what I want and to produce usable parts. I found some commercial firms just want to cut the part and take your money - no real interest in what you are doing. Try telling then it's for a flying aeroplane - many refuse to talk to you!

The CNC routing/milling of wood is a great way of cutting repetitious parts like the wing ribs. I have seen laser cutting used but I don't believe the glue joint is suitable - the laser burnishes the edge of the wood slightly making gluing a little dicey. This isn't a breadboard - it has to hold together under g-load at 200km/h...

brinesharks ~ my project is ( will be) a WAR P40E I'm determined to build the thing, although I have a few concerns. I've been unable to contact the designer of the P40 (Aussie) bit of a worry! At any rate I have LOT of skill building to do before I can start, and as you mentioned every little bit of info I can gather will be gold. Thanks for the clarification and info. I'll take every bit I can get ~ so I don't end up as a local headline.

Good luck with your project, I'll enjoy following its progress ( I suspect I'll be working in an even slower time frame .)

Originally Posted by brinesharks

Joe, the ends of the scallops are actually flared out a little more than my drawing. Your suggestion of the jig to bring the router in gradually would work nicely.

blouis79 - thanks for your suggestions! The music stand looks very nice.

I just realised I haven't mentioned what the project is - it's a Nieuport 17 aeroplane as per the original (1916) factory drawings - or as close as I can come to them! I figure I have at least 10 years of building ahead of me and a whole lot of learning! Not only does it need to look the part, it also has the be engineered to fly so any modifications to methods/materials need to be carefully considered. Here's a quick intro to the plane:

http://www.theaerodrome.com/aircraft...ieuport_17.php

ian - Making it in two halves is an option. The original design calls for a single piece, however the main wing spars (the main structural member of the wing that runs from the centre to the tip) are glued up from to spindled out pieces of Spruce with a ply I-beam let in to the centre. Externally they look solid but internally there is weeks of work - I plan to take a whole lot of photos to prove I actually did the work! The part I asked about in this thread is the Leading Edge of the wing which is not as critical structurally as the spars, so I guess I could make them in two halves. Might research this a bit more...

Was sent this link tonight to reproduction aircraft by a friend in the US .
I remembered your post so I though it was timely to post it here .
These guys are building brand new WW1 aircraft from original drawings by hand and actually flying them when completed .
Big task but great work.

http://thevintageaviator.co.nz/proje...ying-masterton

Kev.

Originally Posted by Woodlee

Was sent this link tonight to reproduction aircraft by a friend in the US .
I remembered your post so I though it was timely to post it here .
These guys are building brand new WW1 aircraft from original drawings by hand and actually flying them when completed .
Big task but great work.

http://thevintageaviator.co.nz/proje...ying-masterton

Kev.

Thanks Kev - these guys are really punching above their weight! It really shows you how tough it would have been to fight in these craft. I'm hoping mine will be comparable to these guys but I don't have the commercial backing! Apparently a lot of the NZ work is paid for by Peter Jackson of Lord of The Rings fame. He is a real military history enthusiast and a little bird tells me he has a whole bunch of WW1 uniforms and equipment too - I hope his next movie is a WW1 ANZAC epic!

Having a team of CAD designers to draw up modern plans must really speed things up. You know beforehand if the part will fit or not.

Wish I had an original engine. Just have to keep saving my pennies...

Can anyone suggest a place for timber. Some timbers I need are:

Ash (true European Ash): 20mm x 28mm and about 2m long x4
Ash: Lots of strips 30mm x 5mm x 1.2 (approx)
Maple: 8mm thick and large enough to make the fuselage formers on the turtledeck
Walnut: strips 9mmx13mm x 1.2m
Poplar: Need Poplar ply but I think I'll substitute Birch ply
Spruce: Lots and lots!

I was under the impression that Walnut is hard to come by these days in anything except veneer. If it's too difficult to source I could use a good quality Birch ply.

Any leads/suggestions are welcome. I can re-saw timber but not sure how to finish the thinner strips - ie. how does thin material go through a thicknesser?

Originally Posted by BrettG

brinesharks ~ my project is ( will be) a WAR P40E I'm determined to build the thing, although I have a few concerns. I've been unable to contact the designer of the P40 (Aussie) bit of a worry! At any rate I have LOT of skill building to do before I can start, and as you mentioned every little bit of info I can gather will be gold. Thanks for the clarification and info. I'll take every bit I can get ~ so I don't end up as a local headline.

Good luck with your project, I'll enjoy following its progress ( I suspect I'll be working in an even slower time frame .)

BrettG - the WAR designs were what first fired my interest in homebuilding. I love WWII fighters but knew I'd never afford one.The WAR designs are like big model aeroplanes - timber structure with foam shaped and glassed to make it look like the full-sized ones. I have an article from 1974 on the first FW190 prototype they made. I'll try to scan it and send it through. One thing though - the WAR replicas are pretty small. If you are above about 5'10" I don't think you'll fit. I sat in the P47 and couldn't close the canopy. If you are willing to go bigger (and more complex) try:

http://www.marcel-jurca.com/index.ph...tpage&Itemid=1

All wood - Marcel Jurca's designs come in 3/4 scale and full scale!!!! Feel free to build a Spitfire or ME109 if you like! A 1200hp V12 Allison would drink a bit of juice though...

I'd love to build the 3/4 Fw190 (maybe after my Nieuport!) and the 'Sperocco' looks great too.

Thanks for the link brinesharks, I'll certainly scope those designs out = A P40!! music to my ears my friend. [Sigh].. yeeesss.. the size of the WAR aircraft is definitely a concern = 5'10'' + Kg ++.. curse my parent's lofty stature and healthy appetite. I'd like to investigate rescaling them ( the WAR design, not my parents) I believe there's a 75% design in development based on the WAR construction. Plenty of research to do as yet.

Btw. Re your request for timbers. In the FEB 09 issue of Recreational Aviation Australia, Steve Bell ( technical editor ~ Wood and fabric man) offered a trailer load of Spruce to anyone that could get to Canberra and collect it. (If I was able to, I'd be on the road right now!!) Probably to late, although it may pay to contact him. ( sorry I don't have the mag handy right now ~ contact details?.. google the mag title..?)

Originally Posted by brinesharks

Can anyone suggest a place for timber. Some timbers I need are:

Ash (true European Ash): 20mm x 28mm and about 2m long x4
Ash: Lots of strips 30mm x 5mm x 1.2 (approx)
Maple: 8mm thick and large enough to make the fuselage formers on the turtledeck
Walnut: strips 9mmx13mm x 1.2m
Poplar: Need Poplar ply but I think I'll substitute Birch ply
Spruce: Lots and lots!

I was under the impression that Walnut is hard to come by these days in anything except veneer. If it's too difficult to source I could use a good quality Birch ply.

Any leads/suggestions are welcome. I can re-saw timber but not sure how to finish the thinner strips - ie. how does thin material go through a thicknesser?

Briney
what tools do you currently own?

If you saw the strips from larger stock with a table saw there'll be heaps of waste, so I suggest you use a band saw and plan on beaking down larger stock
I also suggest you use a drum sander to finish thickness the strips – I'm guessing that consistent thickness is critical for you, but because the strips are thin, you can accomodate a certain amount of twist – hence you may not need a jointer.



ian

Originally Posted by ian

Briney
what tools do you currently own?

If you saw the strips from larger stock with a table saw there'll be heaps of waste, so I suggest you use a band saw and plan on beaking down larger stock
I also suggest you use a drum sander to finish thickness the strips – I'm guessing that consistent thickness is critical for you, but because the strips are thin, you can accomodate a certain amount of twist – hence you may not need a jointer.



ian

I have a table saw but also have access to a large (enormous!) bandsaw that can re-saw old Jarrah posts! Also a jointer and thicknesser. I don't have a drum sander though.

I plan to pick up some Ash tomorrow and try cutting some cap strips. I think I might substitute Birch ply for the Maple formers (can't fathom why Maple was used in the first place). I could even face the ply with Maple veneer.