Thanks for the link info Ron. I have a copy of the wood book (I think these 2 are called "building the custom aircraft in wood"), again early 70's vintage (all these old books came from a donation to the local clubs library, and as I work unicom at the field I have about unlimeted access) The ash/ poplar idea came from the old flying and glider manuals and what I have seen done with aircampers, coupled with knowing the wood market in the area. (I am one of these guys who dont mind paying a fair price for the materials, but hate like hell supporting the exchange banks and courier companies in the process. Last order from AS&S was about $40 US price, and nearly $150 CDN at my door) Might be time to join EAA Canada council again (nearest chapter is at Hamilton, couple hours away) but I always found them nicer people than RAA ;-) -----Original Message----- From: Ron Wanttaja <ikvamar@gte.net> To: FlyBaby <FlyBaby@listbot.com> Date: Tuesday, November 16, 1999 10:14 PM Subject: Re: Wood Substitutions (was New list member) >FlyBaby > >> Mike Lund wrote: >> >> FlyBaby >> Hi Guys >> >> Just a quick note to let ya know there is a new lurker here. >> >> I have been aware of the flybaby for a number of years, but untill >> today I had never seen the plans or the plane up close (all my wooden >> airplane experience is with Pietenpols). >> >> Then, I came upon a treasure at about 9:30 this morning... a 1971 >> issue of the complete EAA plans for the fly baby. I have had my nose >> burried in the book and on every flybaby site I could find all day. >> NEAT little plane, and after a Sky Scout and an Aircamper the >> construction would be a snap. AND I happen to have an EA-82 handy >> without an airframe behind it ;-) hmmmm grey cells are turning ;-) >> >> Have there been any major changes to the design since '71 (safety >> wise) ? > >Major change has been the addition of a steel strap reinforcing the rear >spar carry-through. There was a change page issued for the plans with a >batch of corrections on them; the change page is dated April 1970 so >your plans set probably includes the change page (page 9-1 in my copy). >The information on the spar carry-through mod is summarized on my Fly >Baby web page. > >> Also, being in Southern Ontario, aircraft spruce is hard to get, and >> worth more than gold when you get it...has anybody used a different >> wood for the plane (with appropriate sizings of course)? > >FAA Advisory Circular AC 43.13-1B has a chart denoting what woods can be >substituted. Jim Pratt has made this document available for downloading >at: > >http://www.moneypit.net/~pratt/ac43/ > >To summarize the table: > >Douglas Fir: Stronger than spruce, a bit difficult to work with hand >tools. > >Noble Fir: Slightly exceeds spruce, but 8% deficient in shear. >Slightly less hard than spruce. Can be used as a direct substitute, >except where shear is critical > >Western Hemlock: Slightly stronger than spruce, less uniform in >texture, but can be used as a direct substitute. > >White Pine: 85% as strong as spruce, low in hardness and >shock-absorbing capability. > >White Cedar: Stronger than spruce, but gluing difficult. > >Yellow Poplar: Slightly less strong than spruce > >Weight comparison: > >Spruce: 28 lbs/ft^3 >Red Pine: 33 lbs/ft^3 >Douglas fir: 33 lbs/ft^3 >Western Hemlock: 30 lbs/ft^3 >White Cedar: 29 lbs/ft^3 >Red Fir: 28 lbs/ft^3 > >Note that the most obvious replacements for spruce, hemlock and fir, are >quite a bit heavier (10% and 18%, respectively). > >However, keep in mind that there are definite standards for quality that >should be followed even if something other than spruce is used. AC >43-13 includes some of these standards. Dave Munday referred to the >EAA Wood publication; the title is "EAA Building Techniques: Wood." It >includes a chapter on evaluating wood. It's available from a fine >Experimental Aircraft Association near you.... :-) > >Ron Wanttaja > > >