You could also do the same thing with a hub with some holes drilled into the periphery of the hub. Release a spring loaded pin onto it and let it fall into the nearest hole. A flat disk that had holes in it could be used he same way. Same idea, different implementation. Gears are nice because they are off the shelf. Depending on volume, you may not want to have to make another component.
There are some clever mechanisms used in automatic transmissions to implement the "park" function. Think of a wrench slipping onto a nut. Attach the nut to the shaft and spring load the "wrench" so it slides onto the nut. I think my router spindle lock works that way. Actually I think I have a grinder that works that way also to lock the shaft so you can change the disk. You might want to search out that book set called ingenious mechanisms or something similar. I think that many libraries have them in their reference sections. Those books are loaded with ideas. http://www.amazon.com/Ingenious-Mechanisms-Designers-Inventors-Set/dp/0831110848 If nothing else they are fun to look at. ;-) Dave On 3/11/2010 10:30 PM, doug metzler wrote: > Today I played around with mounting a gear on the rear shaft and having a > simple spring-driven solenoid simply release a pin into the teeth of the > gear. That will work, but does have some complexity with regards the > surrounding extrusion. I like the string idea - it's ingenious in its > simplicity, I will play around with that as well. The only issue I see to > that is the manufacturing complexity, unless I could somehow package it into > an attachable unit. > > Keep 'em coming! > > Thanks, > > DougM > > On Thu, Mar 11, 2010 at 7:09 PM, cogoman<cogo...@verizon.net> wrote: > > >> I apologize. I just sent this one, but forgot to paste the proper >> subject in, so this time it's correct. >> >> If space is at a premium near the motor, and the torque requirement is >> light, you could use a string (some durable cord) tethered off to one >> side of the shaft, wrapped around the shaft once or twice, then draped >> over a pulley or two to get to someplace where you could mount a spring >> and a solenoid. The spring (or a weight) would provide tension to hold >> the shaft in place, and the solenoid would counteract that to release >> tension when the stepper was energized. If your Z axis doesn't move a >> lot (2d or 2.5d usage mostly) then good cord should last a long time. >> Could possibly be done with guitar string, and if more holding torque >> were needed, adding a disk to increase the diameter of the shaft where >> the string wraps around could make it lock better. >> >> Just my 2c. >> >> >> >> ------------------------------------------------------------------------------ >> Download Intel® Parallel Studio Eval >> Try the new software tools for yourself. Speed compiling, find bugs >> proactively, and fine-tune applications for parallel performance. >> See why Intel Parallel Studio got high marks during beta. >> http://p.sf.net/sfu/intel-sw-dev >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> > ------------------------------------------------------------------------------ > Download Intel® Parallel Studio Eval > Try the new software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
