Pietenpol-List: Mods to Model A engine mount....
Posted: Mon Aug 22, 2005 9:19 pm
Original Posted By:
My fuse is 1" wider than plans and I have a Model A mount that is built to plans....sowhen I bolt on the 3/4" tubing braces, the holes that the ash sits onare spaced 1" too far apart.I considered adding a 1/2" piece of ash to each side of each of the bearers (tomove them toward each other 1/2" each tomake up the 1") but that adds a bit ofa moment arm.....probably not an issue but I would rather keep the engine asclose to the center line of the tubing holes as possible.I can notch the tubing per the attached picture and weld the gap shut. The bendworks out to approximately 3 degrees, which means I'll notch out a .04" gap(not much more than the width of my saw blade) and then weld that back together.(My preference is to do NO cutting and welding......)Since I only need a 3 degree bend over a 19" distance (for a change in the holelocation of 1/2" on each side of the engine mount) I'm considering heating thetubing up and bending it in 1/2". Maybe heating up a 12" length (rather thana short distance) would not compromise the strength of the tubing......wouldthat work?I'm obviously going to run this by my EAA Tech Counselor but these solutions seemmore than adequate....but I sure would like a sanity check from anyone whocares to help me out here.Suggestions? Notch/weld or heat/bend?I welcome all input!Thanks! Jim in Plano________________________________________________________________________________
My fuse is 1" wider than plans and I have a Model A mount that is built to plans....sowhen I bolt on the 3/4" tubing braces, the holes that the ash sits onare spaced 1" too far apart.I considered adding a 1/2" piece of ash to each side of each of the bearers (tomove them toward each other 1/2" each tomake up the 1") but that adds a bit ofa moment arm.....probably not an issue but I would rather keep the engine asclose to the center line of the tubing holes as possible.I can notch the tubing per the attached picture and weld the gap shut. The bendworks out to approximately 3 degrees, which means I'll notch out a .04" gap(not much more than the width of my saw blade) and then weld that back together.(My preference is to do NO cutting and welding......)Since I only need a 3 degree bend over a 19" distance (for a change in the holelocation of 1/2" on each side of the engine mount) I'm considering heating thetubing up and bending it in 1/2". Maybe heating up a 12" length (rather thana short distance) would not compromise the strength of the tubing......wouldthat work?I'm obviously going to run this by my EAA Tech Counselor but these solutions seemmore than adequate....but I sure would like a sanity check from anyone whocares to help me out here.Suggestions? Notch/weld or heat/bend?I welcome all input!Thanks! Jim in Plano________________________________________________________________________________