Pietenpol-List: Wedgies, et al
Posted: Sun Aug 11, 2002 8:59 am
Original Posted By: "walter evans"
Here are some musings that come to me as I read the postings from the past severaldays...............What is the purpose of a wing rib? Assuming that it is built rigidly enough tohold it's intended form, isn't it's main function to hold two pieces of fabricapart in a particular shape that will allow flight? (Nod your head up and down)IF it is stabilized from shifting vertically and laterally it can do an admirablejob. So, what forces would act to shift it from it's planned position? Laterally..........notmuch. Vertically......sure, because of thepressure on the BOTTOM of the airfoil. The stabilization would appear to be handled very well in a vertical plane bythe top and bottom rib strips resting against the top and bottom of the spar.Shifting (if any) in a lateral plane is easily taken care of by a spot or twoof glue wherever a spar/rib junction can be found. Rib stitching probably doesas good a job at this, too even though that's not the intended purpose.Back now to the wedgies, er wedges (sorry). If you plan to stabilize your ribslaterally by putting a nail from the top and bottom of the rib into the spar (VERYbad idea) it would be well if you used a wedge to fill the space in the topso as not to smash the top rib cap when you drive thenail home. That's the reason for the wedgies, NOT because of any structural considerations,at least not in the Cherry Grove Missile design.Now can we please find something else to dwell on? I might be verbose but I'm humble.......and thick skinned. Blaze away!Larry"The Piet is slow but the sky is patient"(a great quote from a famed Piet pilot)________________________________________________________________________________
Here are some musings that come to me as I read the postings from the past severaldays...............What is the purpose of a wing rib? Assuming that it is built rigidly enough tohold it's intended form, isn't it's main function to hold two pieces of fabricapart in a particular shape that will allow flight? (Nod your head up and down)IF it is stabilized from shifting vertically and laterally it can do an admirablejob. So, what forces would act to shift it from it's planned position? Laterally..........notmuch. Vertically......sure, because of thepressure on the BOTTOM of the airfoil. The stabilization would appear to be handled very well in a vertical plane bythe top and bottom rib strips resting against the top and bottom of the spar.Shifting (if any) in a lateral plane is easily taken care of by a spot or twoof glue wherever a spar/rib junction can be found. Rib stitching probably doesas good a job at this, too even though that's not the intended purpose.Back now to the wedgies, er wedges (sorry). If you plan to stabilize your ribslaterally by putting a nail from the top and bottom of the rib into the spar (VERYbad idea) it would be well if you used a wedge to fill the space in the topso as not to smash the top rib cap when you drive thenail home. That's the reason for the wedgies, NOT because of any structural considerations,at least not in the Cherry Grove Missile design.Now can we please find something else to dwell on? I might be verbose but I'm humble.......and thick skinned. Blaze away!Larry"The Piet is slow but the sky is patient"(a great quote from a famed Piet pilot)________________________________________________________________________________