Original Posted By: steve(at)byu.edu
Subject: Pietenpol-List: Rib Jig building>I have started my rib jig (Tailwind) and I have realized that due to>shrinkage of the paper my full scale rib drawing, isn't. The spars are>supossed to be 24" apart and they are about 3/16" to short. My question is>how do I get an accurate lofting of the airfoil transfered to my jig?>>Steve E.>________________________________________________________________________________
Pietenpol-List: Rib Jig building
Pietenpol-List: Rib Jig building
Original Posted By: Ken Hannan
Subject: Pietenpol-List: Rib Jig building>I have started my rib jig (Tailwind) and I have realized that due to>shrinkage of the paper my full scale rib drawing, isn't. The spars are>supossed to be 24" apart and they are about 3/16" to short. My question is>how do I get an accurate lofting of the airfoil transfered to my jig?>>Steve E.>________________________________________________________________________________
Subject: Pietenpol-List: Rib Jig building>I have started my rib jig (Tailwind) and I have realized that due to>shrinkage of the paper my full scale rib drawing, isn't. The spars are>supossed to be 24" apart and they are about 3/16" to short. My question is>how do I get an accurate lofting of the airfoil transfered to my jig?>>Steve E.>________________________________________________________________________________
Pietenpol-List: Fw: Rib Jig building
Original Posted By: Ian Holland
Just a warning when copying your CAD drawings on a blueprint copy machine.I did that with my Piet. ribs and the copy was not the same as the plottedCAD drawing.Craig________________________________________________________________________________
Just a warning when copying your CAD drawings on a blueprint copy machine.I did that with my Piet. ribs and the copy was not the same as the plottedCAD drawing.Craig________________________________________________________________________________
Pietenpol-List: Rib Jig building
Original Posted By: Ken Hannan
I have started my rib jig (Tailwind) and I have realized that due toshrinkage of the paper my full scale rib drawing, isn't. The spars aresupossed to be 24" apart and they are about 3/16" to short. My question ishow do I get an accurate lofting of the airfoil transfered to my jig?Steve E.________________________________________________________________________________
I have started my rib jig (Tailwind) and I have realized that due toshrinkage of the paper my full scale rib drawing, isn't. The spars aresupossed to be 24" apart and they are about 3/16" to short. My question ishow do I get an accurate lofting of the airfoil transfered to my jig?Steve E.________________________________________________________________________________
Pietenpol-List: Re: Rib Jig building
Original Posted By: steve(at)byu.edu
Steve I can Draw it in cad and plot it out full sizeif you give me the coordinatesKen Hannan-----Original Message-----
Steve I can Draw it in cad and plot it out full sizeif you give me the coordinatesKen Hannan-----Original Message-----
Pietenpol-List: Re: Rib Jig building
Original Posted By: steve(at)byu.edu
Ken, What do you need for coordinates? Inches and stations? How would Iget that from the plans?Stevee-----Original Message-----HannanSent: Thursday, September 10, 1998 3:58 PMSubject: Pietenpol-List: Re: Rib Jig buildingSteve I can Draw it in cad and plot it out full sizeif you give me the coordinatesKen Hannan-----Original Message-----
Ken, What do you need for coordinates? Inches and stations? How would Iget that from the plans?Stevee-----Original Message-----HannanSent: Thursday, September 10, 1998 3:58 PMSubject: Pietenpol-List: Re: Rib Jig buildingSteve I can Draw it in cad and plot it out full sizeif you give me the coordinatesKen Hannan-----Original Message-----
Pietenpol-List: Re: Rib Jig building
Original Posted By: steve(at)byu.edu
Steve If you have a full size drawing and you what to make a copy see ifthere's a blueprint house near bythey can make 1 to 1 copy's. but if not then Inches and stations will work.or if you know what rib it is I my have it in my handy book of airfoilcoordinates.Please Call if not clear.Toll free 888-693-2496Ken Hannan-----Original Message-----
Steve If you have a full size drawing and you what to make a copy see ifthere's a blueprint house near bythey can make 1 to 1 copy's. but if not then Inches and stations will work.or if you know what rib it is I my have it in my handy book of airfoilcoordinates.Please Call if not clear.Toll free 888-693-2496Ken Hannan-----Original Message-----
Pietenpol-List: Re: Rib Jig building
Original Posted By: The Endicotts
steve(at)byu.edu wrote:> > I have started my rib jig (Tailwind) and I have realized that due to> shrinkage of the paper my full scale rib drawing, isn't. The spars are> supossed to be 24" apart and they are about 3/16" to short. My question is> how do I get an accurate lofting of the airfoil transfered to my jig?> > Steve E.Steve,You have probably already figured out a solution to your problem andhave 4 or 5 ribs built already, but if not here are a few ideas.Take your rib template sheet and play the steam from a humidifier overit for a few minutes, then lay it out flat and see what the dimension isbetween spars. It may expand enough and stay put long enough for you totransfer the countours to some plywood, especially if you work in asteamed up bathroom with the shower running full hot. The wife and kidswill look at you funny, but if it works... Or you could trace out thefwd and aft halves of the rib as they are but with the correct sparspacing and best fit a smooth short curve in the 3/16 gap somewhere inbetween where there isn't too much curvature. Your spar height probablydid not change enough with the plans shrinkage to worry about. Youcould also use the plans as they are since you lose less than a quartersquare foot of wing area, but then you have the domino affect of havingto move spar attach points on your fuselage, on and on.Mike________________________________________________________________________________
steve(at)byu.edu wrote:> > I have started my rib jig (Tailwind) and I have realized that due to> shrinkage of the paper my full scale rib drawing, isn't. The spars are> supossed to be 24" apart and they are about 3/16" to short. My question is> how do I get an accurate lofting of the airfoil transfered to my jig?> > Steve E.Steve,You have probably already figured out a solution to your problem andhave 4 or 5 ribs built already, but if not here are a few ideas.Take your rib template sheet and play the steam from a humidifier overit for a few minutes, then lay it out flat and see what the dimension isbetween spars. It may expand enough and stay put long enough for you totransfer the countours to some plywood, especially if you work in asteamed up bathroom with the shower running full hot. The wife and kidswill look at you funny, but if it works... Or you could trace out thefwd and aft halves of the rib as they are but with the correct sparspacing and best fit a smooth short curve in the 3/16 gap somewhere inbetween where there isn't too much curvature. Your spar height probablydid not change enough with the plans shrinkage to worry about. Youcould also use the plans as they are since you lose less than a quartersquare foot of wing area, but then you have the domino affect of havingto move spar attach points on your fuselage, on and on.Mike________________________________________________________________________________
Pietenpol-List: Re: Rib Jig building
Original Posted By: steve(at)byu.edu
Michael (and others)Thanks for your suggestions!I have choosen your suggestion #2 I came up with the same idea. I measuredand marked the spar locations and then traced the rib outline ahead andbehind the spars and then the middle. The gap I split between the two sparlocations and drew in the gaps. I have a flyin to go to this weekend, butribs should be forthcomming after that!Stevee-----Original Message-----michael listSent: Sunday, September 13, 1998 1:23 PMSubject: Pietenpol-List: Re: Rib Jig buildingsteve(at)byu.edu wrote:>> I have started my rib jig (Tailwind) and I have realized that due to> shrinkage of the paper my full scale rib drawing, isn't. The spars are> supossed to be 24" apart and they are about 3/16" to short. My questionis> how do I get an accurate lofting of the airfoil transfered to my jig?>> Steve E.Steve,You have probably already figured out a solution to your problem andhave 4 or 5 ribs built already, but if not here are a few ideas.Take your rib template sheet and play the steam from a humidifier overit for a few minutes, then lay it out flat and see what the dimension isbetween spars. It may expand enough and stay put long enough for you totransfer the countours to some plywood, especially if you work in asteamed up bathroom with the shower running full hot. The wife and kidswill look at you funny, but if it works... Or you could trace out thefwd and aft halves of the rib as they are but with the correct sparspacing and best fit a smooth short curve in the 3/16 gap somewhere inbetween where there isn't too much curvature. Your spar height probablydid not change enough with the plans shrinkage to worry about. Youcould also use the plans as they are since you lose less than a quartersquare foot of wing area, but then you have the domino affect of havingto move spar attach points on your fuselage, on and on.Mike________________________________________________________________________________
Michael (and others)Thanks for your suggestions!I have choosen your suggestion #2 I came up with the same idea. I measuredand marked the spar locations and then traced the rib outline ahead andbehind the spars and then the middle. The gap I split between the two sparlocations and drew in the gaps. I have a flyin to go to this weekend, butribs should be forthcomming after that!Stevee-----Original Message-----michael listSent: Sunday, September 13, 1998 1:23 PMSubject: Pietenpol-List: Re: Rib Jig buildingsteve(at)byu.edu wrote:>> I have started my rib jig (Tailwind) and I have realized that due to> shrinkage of the paper my full scale rib drawing, isn't. The spars are> supossed to be 24" apart and they are about 3/16" to short. My questionis> how do I get an accurate lofting of the airfoil transfered to my jig?>> Steve E.Steve,You have probably already figured out a solution to your problem andhave 4 or 5 ribs built already, but if not here are a few ideas.Take your rib template sheet and play the steam from a humidifier overit for a few minutes, then lay it out flat and see what the dimension isbetween spars. It may expand enough and stay put long enough for you totransfer the countours to some plywood, especially if you work in asteamed up bathroom with the shower running full hot. The wife and kidswill look at you funny, but if it works... Or you could trace out thefwd and aft halves of the rib as they are but with the correct sparspacing and best fit a smooth short curve in the 3/16 gap somewhere inbetween where there isn't too much curvature. Your spar height probablydid not change enough with the plans shrinkage to worry about. Youcould also use the plans as they are since you lose less than a quartersquare foot of wing area, but then you have the domino affect of havingto move spar attach points on your fuselage, on and on.Mike________________________________________________________________________________