I was wondering if anyone had some tips for scratch building centering rings and just hand rolled/constructed motor mounts in general. are there any easily scavenged bits out there (akin to wiper blades for motor hooks) that you guys are using for low power motor mounts?
Below are a few of the different materials I've used for centering rings for just about all LPR and MPR's. Starting with the backs from Lined paper pads to file folder, Sho-card, Mat boards, Cardboard and even heavy posters. along with basswood and light ply. all can be cut with one of several compass or Beam compass style circle cutters.
Over the years I've found it most helpful to stack cut 10 to as many as 20-30 centering rings at a time using double faced masking tape, drill press and scroll or band saw to cut out and sand the stack OD then file and sand the ID. This doesn't take much longer to do then cutting rings in pairs but helps create a little on-hand stock for the next bird that needs that size centering rings. I've stack cut up a Max of 30 different pieces of various materials at the same time with this method including everything from .010" waferGlass to 3/32" basswood together. Just remember the higher the stack the more important it is to keep everything straight and level. Don't push it! let the saw or sanding drum do the work. This practice works well for Clustered motor mount rings as well but does take a good bit more time finishing
As seen in the second Photo below it also make sense cut stacks of OD diameter rings with a fine point center for future ID cutting of just one or two for a particular motor or tube size.
Hand rolling tubes really isn't that much trouble once you Gind, Gather, Buy mandrels that fit what you want to make. Brass and copper tubing, some PVC, even steel or wood rods or pipe can be used with either some form of "Mold Release" or wrapped with wax paper.
Spiral wrapping with heavy brown butcher paper or heavy weight white paper roll can be done on these mandrels using nothing more the watered down Elemer's white glue. Geneally a minimum of three layers are required alternating directions as you build up the tube wall thickness.
Straight seam tubes lay up the same way but are generally a bit heavier as they require an extra layer or two for rigidity. Personally I use spiral wraps for body tubes and straight seam tubes for external detailing, add-ons and surface features.
Those same 14ply Sho-Cards make pretty good LPR fins as well.
Keep your eyes open at the dollar stores, party stores and other places for anything that might be transformed into a nosecone. Candy containers, Plastic Wine Flutes, Old Legs Eggs were great! Easter eggs in a number of sizes. etc.
