Original Posted By: Borodent(at)aol.com
Just got a table saw and found a local supply of some very nice verticalgrain doublas fir. Was curious if any fir Air Camper builders changedthe dimensions of their fuselage and tail feather stock to compensatefor the increased strength and weight of the fir over spruce.Mike List________________________________________________________________________________
Pietenpol-List: Douglas Fir Piet's
Pietenpol-List: Re: Douglas Fir Piet's
Original Posted By: RdwdSgn(at)aol.com
Michael,Plenty of DF in our Corvair version Aircamper. S.O.P. was to dimension rough stock slightly below plan specs w/ Delta power planer. Most fuselage and tail group pieces were 1/16" smaller prior to assembly.Good building!CJ Beck / Wichita________________________________________________________________________________
Michael,Plenty of DF in our Corvair version Aircamper. S.O.P. was to dimension rough stock slightly below plan specs w/ Delta power planer. Most fuselage and tail group pieces were 1/16" smaller prior to assembly.Good building!CJ Beck / Wichita________________________________________________________________________________
Pietenpol-List: Re: Douglas Fir Piet's
Original Posted By: Michael Hinchman
Mike, I also have beautiful doug fir for my project. The way I understand it isthat the fir is 26% stronger than spruce, while being 23% heavier. To be onthe safe side, I was going to cut dimensions by 20% on some pieces. The onlyproblem I foresee is the "domino effect", where reducing dimensions willeffect dimensions down the line.Ron E.________________________________________________________________________________
Mike, I also have beautiful doug fir for my project. The way I understand it isthat the fir is 26% stronger than spruce, while being 23% heavier. To be onthe safe side, I was going to cut dimensions by 20% on some pieces. The onlyproblem I foresee is the "domino effect", where reducing dimensions willeffect dimensions down the line.Ron E.________________________________________________________________________________
Pietenpol-List: Re: Douglas Fir Piet's
Original Posted By: michael list
In a message dated 1/24/99 12:23:47 AM Central Standard Time, mclist(at)ptw.comwrites:> Mike,I'm using 3/4" X 4 3/4" Doug fir spars, instead of the 1" Spruce that is inthe plans. This seems to be an acceptable practice amoung builders. Mypartner built the longerons to original dimentions with fir, so the fittingpoints would come out right. He also used Doug Fir, to original dimentions,in the empenage. I just hope we don't end up too tail heavy.Chuck________________________________________________________________________________
In a message dated 1/24/99 12:23:47 AM Central Standard Time, mclist(at)ptw.comwrites:> Mike,I'm using 3/4" X 4 3/4" Doug fir spars, instead of the 1" Spruce that is inthe plans. This seems to be an acceptable practice amoung builders. Mypartner built the longerons to original dimentions with fir, so the fittingpoints would come out right. He also used Doug Fir, to original dimentions,in the empenage. I just hope we don't end up too tail heavy.Chuck________________________________________________________________________________
Pietenpol-List: Re: Douglas Fir Piet's
Original Posted By: Raffaele Bellissimo
>I'm using 3/4" X 4 3/4" Doug fir spars, instead of the 1" Spruce that is in>the plans. This seems to be an acceptable practice amoung builders. My>partner built the longerons to original dimentions with fir, so the fitting>points would come out right. He also used Doug Fir, to originaldimentions,>in the empenage. I just hope we don't end up too tail heavy.Probably depends on which engine you're using. One Piet builder herein New Hampshire used Doug fir throughout and found that he had tomove the wing (about three inches, I think) to get the c.g. where it neededto be. He built the tail feathers to the original dimensions and believedthat this is where he had gone wrong. When I first considered buildinga Piet, he suggested that I use fir in the heavily stressed members ofthe tail and compensate by using pine for the rest. However, he useda C-85. If he'd been carrying a Ford up front, I doubt that he would havehad much of a problem.Owen Davies________________________________________________________________________________
>I'm using 3/4" X 4 3/4" Doug fir spars, instead of the 1" Spruce that is in>the plans. This seems to be an acceptable practice amoung builders. My>partner built the longerons to original dimentions with fir, so the fitting>points would come out right. He also used Doug Fir, to originaldimentions,>in the empenage. I just hope we don't end up too tail heavy.Probably depends on which engine you're using. One Piet builder herein New Hampshire used Doug fir throughout and found that he had tomove the wing (about three inches, I think) to get the c.g. where it neededto be. He built the tail feathers to the original dimensions and believedthat this is where he had gone wrong. When I first considered buildinga Piet, he suggested that I use fir in the heavily stressed members ofthe tail and compensate by using pine for the rest. However, he useda C-85. If he'd been carrying a Ford up front, I doubt that he would havehad much of a problem.Owen Davies________________________________________________________________________________