On Wednesday 13 October 2021 00:02:12 John Dammeyer wrote: > > > Maybe a stub on the end held in a 4th axis? > > > > > > Any suggestions are welcome. > > > John > > > > What is it cranking? Maybe I could 3d print it. > > > > Cheers, Gene Heskett. > > Chrome plated pot metal and if that can crack and break a 3D printed > handle would definitely. > > What I could do of course is use epoxy to rebuilt the broken tang. > Grind off the rivet holding the knob. Then cast a replacement out of > bronze. > > I'll measure it up and do a drawing. It's been lying on my desk for a > few years now and since I have working CNC it seems appropriate to > finally get to it. And to use CNC because this is the type of > exercise that teaches. > > John > This is true. And if making it, alu is a lot easier to machine. Stronger than pot too.
Since I usually write my own gcode for such. I tend to use the raw stuff I have, and presently have several sq feet of 1/2" & 1" thick alu. After the gcode is written and maybe proved by making some sawdust, that would be perhaps an hour at the most to cut out of that 1/2" on my 6040 mill, using a 2 or 3 ounces of kool-mist mix to keep the tool cool and clean. The main gcode would be the tapered shank and the slot that straddles the shaft its turning, then a different clamp down to drill the two holes, probably all with the same 3mm carbide tool in one clamp up. I there is turning clearance such that the angle that broke it in the first place is only needed for looks, leave the angle out of the new one, it will be stronger. Drilling a 4mm rivet hole with a 3mm SC mill is a piece of cake to write using arcgenm18.py. So is the outer rounded end you will drill the hole in to remount the knob. The tapered shank, is an incremental depth loop, all done by tracing the outside, 25 thou deeper per trace around the shape. Leave the big end square, but write an arc at the knob end for that depth loop turnaround. Then the only clamp up change will be turning it on it on its side to drill the hole it swings on. If you do it right, it might be less than 80 lines of code. I needed some wrenches to fit the er12 chuck on the 6040's new motor and the double D-flated motor shaft. They fit very precisely and work better than anything I could buy. And the weight is much reduced. I also use a CBN disk about 30 thou thick and 2" in diameter in that 24k rev motor to sharpen HSS lathe tools, getting them many times sharper than an si-carbide green wheel in the bench grinder does since HSS and diamond wheels don't gee-haw at all, it just burns up the diamond. Leaves a face like a mirror but w/o any saw tooth edge burr to dull quickly. CBN is the best kept secret in abrasives. It can also resharpen a carbide tool about as fast as diamond can, making a cheap molded chip much sharper than it is coming out of the 10 pack shipper. But you won't find it at Lowes, TSC, or whatever the hardware store is called on your local dirt. Its also more expensive than diamond as I bought 3 from a maker in denver at 110$ each. And broke one of them with a crescent wrench that slipped before I got to use it. That is what prompted the wrench making, but that breakage sure ruined the air in the garage for a while. Take care John. Cheers, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
