Original Posted By: PIETLARS29(at)wmconnect.com
All,A few weeks ago I posted a message wondering if there is a difference in weightsof the same size stick of DF. The consesnsus was if the moisture content wasthe same then each stick should be about the same. Today I weighed my rudderwhich is about 97% complete (no covering or metal fittings) and it came outto be 3lbs. Is does anyone think this is to heavy or just about right for DF.I would not even have questioned it but my DAD said he thought it was heavy.He was comparing it to a cub rudder though. I dont think you can compare tubingto wood. I am really getting into the project and think I could finish thewhole tail section by the end of Nov. If the weight is way out of line I needto make some changes now before I go onto the next part. What ever the caseI don't think I will scrap my parts I have finished (rudder, VS). I will justmake up for it somewhere else.Nick Harris________________________________________________________________________________
Pietenpol-List: rudder weight DF
Re: Pietenpol-List: rudder weight DF
Original Posted By: "Tom Stinemetze"
Subject: Re: Pietenpol-List: rudder weight DFNick,About the weight if your rudder; doesn't seem bad at all.Regarding wood in general and DF in particular, its all about density which depends on several things.The densities of wood from the same tree can vary considerably depending on the rate of growth. Its the proportion of the sections of the growth 'rings' like the darker, harder streaks vs the lighter, softer portions.My piet is almost completely DF and I found a big difference between the 'sticks' I selected. In fact I made it a point to 'heft' each of the piecesthat I found acceptable and bought the lightest ones. In building my laminatedspars, I used 14' 2x4s which I ripped into 8 strips. I could weigh each stripand I color coded the ends base on weight. Made about 6 different classes. Nominally spruce density is about 25 or 26 lbs/cu. ft. My strips weighed outbetween 26 and 30 lbs/cu ft.A good source of information on wood is the book: 'Understanding Wood' by R. Bruce HoadleyThis proved to me that you have to be as selective as is reasonable in getting your materials. Also noted that the heavier the stick the more brittleit is.Anyway thats what I learned.Good luck with your building.Lou LarsenPS Assembled the piet for the Chapter 'show and tell'ast week and also so I can get it weighed and do the W & B. ________________________________________________________________________________
Subject: Re: Pietenpol-List: rudder weight DFNick,About the weight if your rudder; doesn't seem bad at all.Regarding wood in general and DF in particular, its all about density which depends on several things.The densities of wood from the same tree can vary considerably depending on the rate of growth. Its the proportion of the sections of the growth 'rings' like the darker, harder streaks vs the lighter, softer portions.My piet is almost completely DF and I found a big difference between the 'sticks' I selected. In fact I made it a point to 'heft' each of the piecesthat I found acceptable and bought the lightest ones. In building my laminatedspars, I used 14' 2x4s which I ripped into 8 strips. I could weigh each stripand I color coded the ends base on weight. Made about 6 different classes. Nominally spruce density is about 25 or 26 lbs/cu. ft. My strips weighed outbetween 26 and 30 lbs/cu ft.A good source of information on wood is the book: 'Understanding Wood' by R. Bruce HoadleyThis proved to me that you have to be as selective as is reasonable in getting your materials. Also noted that the heavier the stick the more brittleit is.Anyway thats what I learned.Good luck with your building.Lou LarsenPS Assembled the piet for the Chapter 'show and tell'ast week and also so I can get it weighed and do the W & B. ________________________________________________________________________________
Re: Pietenpol-List: B-17 flight (video)
Original Posted By: "Graham Hansen"
Surly you jest! That was "way cool" as some generation a while backused to say. Sorry for the quality of the video, keep in mind this was my firsttime using the camera (I bought it the day before). It was also my first tryat editing video, and I was trying to do other "crew duties" while taking thevideo, so a lot of it didn't turn out great.Building and dreaming in McPherson.Tom____ | ____ 8/ / ________________________________________________________________________________
Surly you jest! That was "way cool" as some generation a while backused to say. Sorry for the quality of the video, keep in mind this was my firsttime using the camera (I bought it the day before). It was also my first tryat editing video, and I was trying to do other "crew duties" while taking thevideo, so a lot of it didn't turn out great.Building and dreaming in McPherson.Tom____ | ____ 8/ / ________________________________________________________________________________
Re: Pietenpol-List: rudder weight DF
Original Posted By: "Dick Navratil"
Nick,It sounds as if your rudder weight is "in the ball park" for an uncovered unit,less metal fittings.During the early 1970's, I helped a friend build a Pietenpol. The wood he usedwas Sitka Spruce and all plywood was Finnish Birch, aircraft quality. I don'thave the final empty weight handy, but still have the weights of various componentswhich we recorded. Hopefully, they will be of use to you and others forreference:COMPONENT UNCOVERED COVERED***************** **************** *************WING PANEL 50.5 lb 63.5 lbCENTER SECTION N/A 22.5 lbRUDDER 3.5 lb 4.5 lbVERTICAL FIN 1.5 lb 2.25 lbTAILPLANE 6.0 lb 8.75 lbELEVATOR 3.0 lb 4.5 lbAILERON 4.0 lb 5.5 lbNOTE: These figures are to the nearest quarter pound.The spruce spars were 1" x 4 3/4" along their entire length. Possibly, severalpounds per wing panel could have been saved by routing the spars as shown in theplans.The front lift struts were made from Aeronca front strut material which is heavierthan necessary (cost was a factor in choosing them). The rear lift strutswere made from Aeronca rear strut material, as were the center section (cabane)struts. The combined weight of lift struts and jury struts, strut bracing wires(1/8" a/c cable), tail bracing wires (3/32" a/c cable), hardware and fittingswas about 30 pounds.The covering material was 3.5 OZ. per sq. yard polyester fabric, which probablyis heavier than required for the light wing loading and slow speed of a Pietenpol.Nevertheless, the airplane is still flying with its original fabric cover30 years later. Butyrate dope was used. The total weight of the doped fabriccover for the above components is 36.5 pounds. The weight of the fuselage coverwas not recorded, but is likely less than 10 lb, so the total weight of thedoped fabric cover for the entire airplane should be about 45 pounds.By using a lighter grade of fabric and a minimum amount of finishing material (eg.dope, etc), some weight may be saved. But when the entire cover weighs only45 pounds, it won't be too significant in the big picture.With the exception of the larger wood pieces (spars and longerons, for example),substituting Douglas Fir for Sitka Spruce won't add much weight to a component.You can rather easily compensate for this added weight by using a minimumof instruments, lightweight seat cushions, a lightweight fire extinguisher, lightweight(eg. Slick) magnetos, a wooden propeller, and avoiding oversize tires.A single piece wing could save as much as 15 pounds (Ref. B.H. Pietenpol himself).When I recovered my Pietenpol some 20 years ago, I weighed the various componentsand their weights were comparable to the weights provided herein--with theexception of the wing panels. My wings have Douglas Fir spars built up to theI-Beam section in the plans by laminating, and this apparently added a few poundsto each panel. Yet the empty weight of my airplane is significantly less thanthe empty weight of the aircraft described above (which was built from thesame jigs!).I hope this helps.Graham Hansen (Pietenpol CF-AUN)________________________________________________________________________________
Nick,It sounds as if your rudder weight is "in the ball park" for an uncovered unit,less metal fittings.During the early 1970's, I helped a friend build a Pietenpol. The wood he usedwas Sitka Spruce and all plywood was Finnish Birch, aircraft quality. I don'thave the final empty weight handy, but still have the weights of various componentswhich we recorded. Hopefully, they will be of use to you and others forreference:COMPONENT UNCOVERED COVERED***************** **************** *************WING PANEL 50.5 lb 63.5 lbCENTER SECTION N/A 22.5 lbRUDDER 3.5 lb 4.5 lbVERTICAL FIN 1.5 lb 2.25 lbTAILPLANE 6.0 lb 8.75 lbELEVATOR 3.0 lb 4.5 lbAILERON 4.0 lb 5.5 lbNOTE: These figures are to the nearest quarter pound.The spruce spars were 1" x 4 3/4" along their entire length. Possibly, severalpounds per wing panel could have been saved by routing the spars as shown in theplans.The front lift struts were made from Aeronca front strut material which is heavierthan necessary (cost was a factor in choosing them). The rear lift strutswere made from Aeronca rear strut material, as were the center section (cabane)struts. The combined weight of lift struts and jury struts, strut bracing wires(1/8" a/c cable), tail bracing wires (3/32" a/c cable), hardware and fittingswas about 30 pounds.The covering material was 3.5 OZ. per sq. yard polyester fabric, which probablyis heavier than required for the light wing loading and slow speed of a Pietenpol.Nevertheless, the airplane is still flying with its original fabric cover30 years later. Butyrate dope was used. The total weight of the doped fabriccover for the above components is 36.5 pounds. The weight of the fuselage coverwas not recorded, but is likely less than 10 lb, so the total weight of thedoped fabric cover for the entire airplane should be about 45 pounds.By using a lighter grade of fabric and a minimum amount of finishing material (eg.dope, etc), some weight may be saved. But when the entire cover weighs only45 pounds, it won't be too significant in the big picture.With the exception of the larger wood pieces (spars and longerons, for example),substituting Douglas Fir for Sitka Spruce won't add much weight to a component.You can rather easily compensate for this added weight by using a minimumof instruments, lightweight seat cushions, a lightweight fire extinguisher, lightweight(eg. Slick) magnetos, a wooden propeller, and avoiding oversize tires.A single piece wing could save as much as 15 pounds (Ref. B.H. Pietenpol himself).When I recovered my Pietenpol some 20 years ago, I weighed the various componentsand their weights were comparable to the weights provided herein--with theexception of the wing panels. My wings have Douglas Fir spars built up to theI-Beam section in the plans by laminating, and this apparently added a few poundsto each panel. Yet the empty weight of my airplane is significantly less thanthe empty weight of the aircraft described above (which was built from thesame jigs!).I hope this helps.Graham Hansen (Pietenpol CF-AUN)________________________________________________________________________________
Re: Pietenpol-List: rudder weight DF
Original Posted By: Nick Harris
NickI just weighed mine at 2lb. 11oz. That is fully finished, 2 coats of varnish,West System epoxy on exposed edges and hinges installed. I used Sitka. Dontworry about small amounts like this. Some of the difference can be in our scales.Dick N. ----- Original Message -----
NickI just weighed mine at 2lb. 11oz. That is fully finished, 2 coats of varnish,West System epoxy on exposed edges and hinges installed. I used Sitka. Dontworry about small amounts like this. Some of the difference can be in our scales.Dick N. ----- Original Message -----
Pietenpol-List: rudder weight DF
Original Posted By: "w b evans"
Pietenpol-List: rudder weight DF
Original Posted By: "w b evans"