Good to hear that foam cutting is being added, i will check out the current CVS and try it out once i get the machine complete (should be this weekend).
The filament winding applications I am looking at are for winding fiberglass and carbon fiber tubes. There are basically 3 different windings I am looking at. 1. Regular round tubing. Fibers will be laid in layers of 90 degrees to the axis of the tube (or as close as possible to it) to provide crush resistance. Then lengthwise down the tube (as close to 0 degrees as possible) to provide lengthwise stiffness. Then +-45 degrees to provide torsional rigidity and a nice finish. These seem pretty easy because the winding angle and pitch is constant down the whole length of the tube. Having extra material bunch up at the end of the tube is no problem, we can just make the mandrel longer than required and chop the ends of afterwords. 2. Axis symmetric tapered or contoured tubes. These would basically be round sections that are either evenly tapered or multiple sections that are of different tapers. ie tube diameter is 6" at the base, 6" at the half way point, and then tapered evenly down to 3" at the tip. The tricky part here would be calculating the decreasing velocity of the winding head in relation to the spindle speed as the diameter (and thus the surface speed) of the mandrel changes. But i assume I would just divide the length of the tapered section into multiple Gcode statements as the "pitch" is going to be changing constantly as the diameter of the mandrel changes in order to keep the same winding angle. I guess the key is that I want the angle to be maintained even as the diameter of the tube (and thus the pitch required) is changing. And in some cases we want a tapered tube, where the winding angle is varied down the length of the tube. ie fibers running near parallel to the axis of the tube at the base to make it stiff, and having the angle slowly change towards the tip of the tube to make it more bendy. 3. Axis asymmetric straight tubes. Basically this would be a straight tube with an elliptical or rounded foil section, with the base and tip being the same section. The winding head would have to speed up as the filament is being laid on the flatter part of the ellipse, and slow down as the filament is being laid on the more curved part of the ellipse to keep the same fiber angle. This would have to happen with each rotation of the mandrel. As for the basic winding procedure, the "tow" would be a ribbon of fiberglass or carbon fibers that is soaked in resin in the feed head, and then wrapped on the mandrel. On Wed, 2007-08-15 at 16:13 -0400, John Kasunich wrote: > Chris Radek wrote: > > On Wed, Aug 15, 2007 at 01:08:26PM -0400, John Kasunich wrote: > >> G33 threading passes are one way to sync "tool" motion with the spindle, > >> but maybe not what you want, since each G33 pass waits for an index > >> pulse - in a winding application you will still be winding fiber during > >> that wait. > > > > Not quite true - adjacent G33 moves maintain synchronization while > > direction of motion changes. If the wire is .020, it seems like you > > could get the required motion simply with G33 Z2 P.020, G33 Z0 P.020, > > etc etc. > > > > Cool, I didn't know that. > > Does G33 stay in sync even if you change the P value? I'm pretty sure > some filament winding applications want to vary the pitch. Low pitch > windings are strong against hoop stress, but much higher pitches are > used for axial and bending stress. I think I've seen fiber wound > pressure tanks with fibers at 45 degrees to the centerline. > > Another area where winding differs from threading is that you do NOT > want subsequent passes to repeat - you want them to be interleaved like > a multi-start thread with LOTS of starts. I bet you could do that by > making the length of each pass a non-integral multiple of the pitch: > > G0 Z0 > (pause to thread fiber) > S20 M3 (winding is a slow process) > G33 Z20.01 P0.2 (20.01" divided by 0.2" per rev = 100.05 revs) > G33 Z0 P0.2 (anther 100.05 revs, now at 200.1 revs) > G33 Z20.01 P0.2 (this pass is 1/10 of a rev offset from the first) > G33 Z0 P0.2 > (repeat for 8 more passes) > ... > (you now have one layer of 10 fibers at 0.2" pitch, 0.020 spacing) > G33 Z20.01 P2 (20.01" divided by 2" per rev = 10.005 revs) > G33 Z0 P2 (anther 10.005 revs, now at 20.01 revs) > G33 Z20.01 P2 (this pass is 1/100 of a rev offset from the first) > G33 Z0 P2 > (repeat for 98 more passes) > ... > (you now have a second layer of 100 fibers at 2" pitch and 0.020 spacing) Seems like this would work for symmetrical tubes, but how about tapered tubes and non symmetrical sections like ellipses? 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