Original Posted By: "Ben Charvet"
Ben wrote->I built an entire fuselage mock-up with some lumber yard douglas fir>that I bought before I really knew what the recommendations were>as far as grain slope, etc.I looked at Ben's construction photos and everything looks real nice to me. But beyond that, I am going to stick my neck waaaay out and ask why in the world build that nice fuselage mock-up only to discard it due to some of the wood grain slope being "out of spec"? It's fine to build a mock-up out of scrap for trying out different configurations of things, and it's fine to do it for the sheer practice and learning to build, but I don't believe I've every read anything that says the grain slope is critical for any reason other than to control twist/warpage due to changes in moisture content of the wood UNLESS we're talking about wing spars. For a truss structure like the fuselage, with short spans and everything cross-braced, grain slope as a factor leading to twist or warpage would not only be insignificant, it would have to all even itself out unless you intentionally aligned all the pieces with the grain in the same direction... not very likely with that many small pieces.There are differences in bending strength when comparing loading parallel or perpendicular to the grain, but for the fuselage structure where the loads are tension/compression, I don't see that it would make a bit of difference. If the stock is clear, knot-free, and has tight grain, I'd like to hear (for the purpose of my own education) why it wouldn't be suitable for the fuselage truss structure or even for the tail feathers (braced structures).I will say this about Douglas fir though... it's a pain to make holes in it when you're not drilling counter to the grain ("through the layers"). The layers of grain differ significantly in hardness and the "hard layers" grab your drill bit and offset the hole you're trying to drill if you don't use a guide or a short, stiff bit with the work held securely. Having built the entire structure of my "Flying Squirrel" out of 3/4" square stock fir, I've made my share of slightly offset holes!>There are three other Piets under construction within 40 miles of meI must have missed it in your post. Where are you located?Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________
Pietenpol-List: Ben Charvet's Piet/Douglas fir
Re: Pietenpol-List: Ben Charvet's Piet/Douglas fir
Original Posted By: "Oscar Zuniga"
Well, the mock-up looks real good in person too....and you're not the firstperson to ask why the wood wasn't good enough. The grain run-out problemswere within a foot of the end of the longerons on 2 or 3 of them. If it hadbeen in the middle I might have been willing to take the chance. I figuredI had a chance of breaking off the tail in a hard landing, or losing theengine and having a severe out of balance problem
. It probably wouldhave been fine, but at that stage of the project I wasn't sure if it waswise to make such a compromise. Also, I hadn't made many connections at EAA866 yet. Probably should have had one of the local builders look at it.Anyway, after I figured it was just a mockup, I used cheap plywood, andcarpenter's glue to put the thing together, so it really is just a mockupnow.I live in Mims, Fl, which is just north of Titusville (next to Kennedy SpaceCenter)I need to update the website. I made rib# 12 tonight and bought a corvairmotor for $100 today. My progress has been slowed by the illness and deathof my father Good Friday. He's the guy standing in my shop in one of thelast pictures on the website. That was the last time he was in my shop andhe will be sorely missed.Ben----- Original Message -----
Well, the mock-up looks real good in person too....and you're not the firstperson to ask why the wood wasn't good enough. The grain run-out problemswere within a foot of the end of the longerons on 2 or 3 of them. If it hadbeen in the middle I might have been willing to take the chance. I figuredI had a chance of breaking off the tail in a hard landing, or losing theengine and having a severe out of balance problem
. It probably wouldhave been fine, but at that stage of the project I wasn't sure if it waswise to make such a compromise. Also, I hadn't made many connections at EAA866 yet. Probably should have had one of the local builders look at it.Anyway, after I figured it was just a mockup, I used cheap plywood, andcarpenter's glue to put the thing together, so it really is just a mockupnow.I live in Mims, Fl, which is just north of Titusville (next to Kennedy SpaceCenter)I need to update the website. I made rib# 12 tonight and bought a corvairmotor for $100 today. My progress has been slowed by the illness and deathof my father Good Friday. He's the guy standing in my shop in one of thelast pictures on the website. That was the last time he was in my shop andhe will be sorely missed.Ben----- Original Message ----- Re: Pietenpol-List: Ben Charvet's Piet/Douglas fir
Original Posted By: Wizzard187(at)aol.com
Subject: Re: Pietenpol-List: Ben Charvet's Piet/Douglas firBen,meant to get in touch with you sooner re: local lumber sources in central Florida. I am still (9 years) plugging along on my Piet and I made it almostcompletely out of Doug Fir. I found that 84 Lumber has clear fir 2 x4'sup to 20 feet. Als ogt some clear fir 2 x 4's from local yards that cater to custom home builders; these were in Orlando and Winter Park.I live in the country South of Tavares. right now I am making a hoist frame so I can install my Ford 'A' in the airframe. I need to get the CG determined so I can proceed with the cowling sheet metal. The piet is coveredand the fabric is painted.I used fir for all of the structural members: laminated my spars (8 strips) out of 3/4" fir and made the longerons out of 15/16" pieces. I found that all fir is not created equal and its possible to find some that is no more than 10% heavier that the nominal spruce density. I found that I could get 8spar strips out of one 2 x 4. and the leading and trailing edge pieces all from a single 2 x 4.Did you know that the EAA Chapter in Merrit Island is building a Piet?Bear in mind that bernie made his design 'hell for stout' (somewhat over designed) so in my opinion the wood choice is not super critical except for keeping the weight down. After all Charley Rubeck has made and sold a ton of Piet ribs , made of red cedar and Larry Harrison made a whole Piet out Poplar.Good LuckLou Larsen ________________________________________________________________________________
Subject: Re: Pietenpol-List: Ben Charvet's Piet/Douglas firBen,meant to get in touch with you sooner re: local lumber sources in central Florida. I am still (9 years) plugging along on my Piet and I made it almostcompletely out of Doug Fir. I found that 84 Lumber has clear fir 2 x4'sup to 20 feet. Als ogt some clear fir 2 x 4's from local yards that cater to custom home builders; these were in Orlando and Winter Park.I live in the country South of Tavares. right now I am making a hoist frame so I can install my Ford 'A' in the airframe. I need to get the CG determined so I can proceed with the cowling sheet metal. The piet is coveredand the fabric is painted.I used fir for all of the structural members: laminated my spars (8 strips) out of 3/4" fir and made the longerons out of 15/16" pieces. I found that all fir is not created equal and its possible to find some that is no more than 10% heavier that the nominal spruce density. I found that I could get 8spar strips out of one 2 x 4. and the leading and trailing edge pieces all from a single 2 x 4.Did you know that the EAA Chapter in Merrit Island is building a Piet?Bear in mind that bernie made his design 'hell for stout' (somewhat over designed) so in my opinion the wood choice is not super critical except for keeping the weight down. After all Charley Rubeck has made and sold a ton of Piet ribs , made of red cedar and Larry Harrison made a whole Piet out Poplar.Good LuckLou Larsen ________________________________________________________________________________
Re: Pietenpol-List: Stromberg needles for Continental engines
Original Posted By: Rcaprd(at)aol.com
Subject: Re: Pietenpol-List: Stromberg needles for Continental enginesPieters, I just read the neat article on stromberg carbs and the seats used with auto gas and wonder if anyone has any info for Marvel Shebler withprobably the same neropreme needles. Thanks, Ken Conrad in nearly spring Iowa________________________________________________________________________________
Subject: Re: Pietenpol-List: Stromberg needles for Continental enginesPieters, I just read the neat article on stromberg carbs and the seats used with auto gas and wonder if anyone has any info for Marvel Shebler withprobably the same neropreme needles. Thanks, Ken Conrad in nearly spring Iowa________________________________________________________________________________