In point form - lay the rod in a long V (angle iron will be fine) - rotate the rod at about 10RPM from the far end with a small reduction DC motor and a 3-jaw chuck - at the working end, support the rod with two large (80mm) overlapping rollers (like used for balancing) - have a third roller lightly pressing down - make a small X-Y table and mount a grinding wheel on it (axis of grinding wheel is parallel to rod)
- system is easy to load and unload - you can program the X-Y to any arc you like, and is easy to edit the code - have a sharp point nearby so you can dress the wheel automatically - since the X-Y is very light duty, you could use as small as 4mm threaded bar for the feedscrew. Light spring pre-load and brass nuts. - best to use rollers instead of slides for the axes. Regards Roland On 5 June 2015 at 22:19, Mark Johnsen <[email protected]> wrote: > I thought I'd throw this out here because some of the ideas passed around > are really good. I thought someone might have a helpful suggestion. > > I have an application where we need to grind a ball-end on the end of rod > that can be between 0.5 meters to 2 meters long and vary in diameter from > about 1.25mm to 8mm. Currently, it's done by hand on rotary disk sander. > The material is stainless steel or titanium. > > It seems like a solution might be a small cnc'd lathe and bar feeder type > application and it needs to be easy to use and quick. > > 1. How do I cut/grind the hemisphere? > I'm thinking a small CNC type lathe should do it? > I read on practicalmachinist.com that for manual lathes they often use a > custom tool at the radius they want to cut, but I have varying radii, so it > didn't seem like that would be a good solution. Using a CNC would solve > the varying radii problem. Either a sensor or operator manually enters > dia. > > 2. How do I hold and spin the rod? Especially, w/ differing diameters > that can show up at any time. Here were some ideas, but they don't handle > the differing diameters? > http://www.processwelding.com/standardLathes.php > http://www.4machining.com/4m-Tooling/Harig-All/Harig-Air-Collet-Closer > > What about a large rolling wheel driving against two idlers to rotate the > bar? > > 3. Lastly, controlling the whip while the stock is rotating? > I could see a barfeeder type application and then something to keep the rod > from whipping? > > Thanks, > Mark > > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
