dave314459

Hi there fellow shop-dwellers.

After starting a great planes rapture 40 kit the building bug hit me again like it used to 10 years ago when i was new to this hobby (and before my 8 year break). Only now i have the tools to make even my wildest dreams come true.

Cut to the chase: I recently acquired a nice set of plans for a .40 size fokker D-V1 biplane, and was wondering if anyone else had ever tried using other woods besides balsa. The reason I ask, is because woods like spruce or WRC (western red cedar) are abundant at the local lumber suppliers, are light, are stiff, and are easily worked down to model sized strips and sheets using a bandsaw. But im not sure how suitable they would be for scratch building, or how well normal techniques (CA glue) will apply to them. My main motivating factor is that I could potentially build this crafts entire frame for 15 bucks worth of lumber and a few extra hours of resawing. Compared to probably $75-100 in balsa, before even considering the light ply (which is much cheaper in the form of 1/8th marine ply at your local specialty lumberyard... dont buy it from a hobby store).

So whats the general thoughts on woods other than balsa? I know I will probably have to overpower the model to make up for the extra weight, but I plan to run a 4 stroke .91 or so anyway. Any experiences shared will be very much appreciated

mogman

Cedar can be very oily. Some glues don't stick too well. Try some test pieces with different glues,(CA, Titebond etc.) and see how strong the joint is.

Laird SS

Spruce is used in full-scale homebuilts. It should be OK. I can agree with the post on the suitability of cedar. The natural oil is what makes it weather resistant. Something that one of our local kit manufacturers uses for wing ribs is corrugated cardboard with cap strips on the edges to stiffen it. It is light and very strong when used in this manner. He is building a 1/2 scale Pfalz D.3 this way and it has a 15-foot wingspan.

TFF

Stika spruce and Douglas fir and Western hemlock are used in full scale planes. Building with it is great as long as you use it where it is needed. Good for spars and stick type fuselages, but weight behind the CG will add fast. Many designs will use spruce at the front of the plane and splice balsa for the back, to keep the weight in check. At 1/4 scale using spruce really comes into its own. on a .40 you have to be picky where to use it and go with balsa in places like ribs. The Proctor VK WW1 planes use a mix of all. At smaller sizes balsa is hard to beat.

yojoelay

I regularly substitute 1/8" hardware store plywood for lite ply, particularly for formers. I have a 60 sized extra that calls for 1/8" balsa fuselage sides but I'm considering substituting hardware store ply with lightening holes for most of it.

I also use nice 1/4" huon plywood from a boat building store for firewalls and other high strength areas. I bought a 4x8 sheet (1220mm*2440mm) - it wasn't cheap but I've got enough to last for a long time and it is nice to work with. Overall it was much cheaper than hobby store prices though.

Highflight

My Feedback: (4)

Nope, that pretty much says it all.

The problem with what you want to do is that weight is a HUGE factor in airplanes up to .90 size displacement. So balsa is the only good choice for building them, including your .40 size Fokker.

But when you get into giant scale, lots of opportunities open up for types of wood, and for some applications, spruce and other straight grain woods are sometimes a decent choice.

For my part, I find that clear, straight-grain Basswood makes great spars in giant aircraft, but I still stick to balsa for the non load bearing surfaces because while big wing giants can handle a little extra weight without difficulty, weight still means something if you want the most friendly flight characteristics possible.

Lnewqban

For what it may help you decide, here is a link to article and plans for an old timer built with pine:

http://www.theplanpage.com/Months/2505/dfp.htm

Regards!

dave314459

Thank you everyone for your thoughts on this matter. I have already done some rough (very rough) calculations of weight and i do believe i will skip the idea to use something other than balsa for the majority of the shaped parts. maybe if this were a monoplane design, thin resaws of pine could be used for the ribs and formers, but you add that extra wing on top of everything and it gets heavy fast. i was also put off balsa by the insane prices at the LHS. i have never thought of ordering balsa online, but several sources ive seen linked from this forum have opened my eyes to the possibilities

i will continue experimenting and theorizing on this topic. i'll post further news when i decide to start this project (have 1 kit in progress and another i picked up cheap on ebay to finish first.)

shootnstarz

It might not be the lightest plane at the field but it will be the best smelling, and no termite problem either !!!

Rick

Yuu

Be aware that CA will not penitrate well into hard woods. And using carpenter's wood glue requires you soak the endgrain pieces in glue for a few minutes to allow the glue to penitrate, then apply a second coat and stick the pieces together and clamp them. Read the 'how-to' at the Elmer's glue site. It actually works.

zx32tt

My Feedback: (9)

Find a local source for 1/8" lite ply, sometimes called Italian poplar ply. A 4'x 8' sheet is usually less than $20.00. Basswood is often used for spars in gliders, and is easy to work with. You would need to rip your own, or buy from Balsa USA or a LHS. Balsa is the best for strength and lightness. You can use foam ribs, with balsa caps on a "40 size" plane with good success. Ribs can be cut from supermarked "meat trays". Use gorilla glue or pro-bond to build the wing if going this route. Good luck, and let us see your build.
zx32tt[sm=shades_smile.gif]

carlosponti

My Feedback: (1)

I would shy away from doing end grain to end grain joints as someone suggested. if you wish to lengthen a piece use a scarf joint it widens the gluing area for the bond to adhere to. you might look for WW1 designs to see how they would have been built since most of those were built from wood. the fokker D8 had a wing skinned in bending ply a foam wing covered in thin plywood could be another option for you. it did have a tubular steel frame for the fuselage. you could do alot of that with spruce or other such wood. where an end grain butts against a long grain i would add gussets of thin ply for strength.

neat reading
http://www.auf.asn.au/scratchbuilder/beams.html
http://www.sportair.org/articles/1Ai...art%20One.html

this site has some neat pictures of a wooden airplane going together
http://www.mywoodenairplane.com/Wing/20090915.aspx


ps you might look into the pink foam from the hardware store i have seen some people make ribs from it before.