On Wednesday, March 23, 2011 10:12:56 PM BRIAN GLACKIN did opine: > On Wed, Mar 23, 2011 at 12:49 AM, gene heskett <ghesk...@wdtv.com> wrote: > > On Wednesday, March 23, 2011 12:35:24 AM Igor Chudov did opine: > > > On Tue, Mar 22, 2011 at 10:28 PM, gene heskett <ghesk...@wdtv.com> > > > > wrote: > > > > Anyway, <http://gene.homelinux.net:85/gene/emc> > > > > new toy is left pix in next to the last row. > > > > > > Looks awesome. I still have not completed my high speed spindle. > > > > I put a slightly used Bosch solid carbide 1/4" upcut spiral bit in it > > to play with this evening, and swept it back & forth over the end of > > a short stick of white ash, a moderately hard and dense wood. If I > > only advance it about 1/4 of the diameter, the finish is so smooth I > > could plate it & use it for a mirror. Absolutely no tear out at the > > edges of the cut, it will do great for carving tenons in woodworking. > > > > I mounted a half inch router bit in my HF grinder and used it to face > > the > > sacraficial board on my table. It powered through it nicely.
MDF I presume. And you know how to sharpen cemented carbide bits I assume. ;) > I currently run my HF spindle using a 1/8" endmill 30-90 ipm at 0.1" > passes. Unforch, for this project I need to run at about 1.000" deep. I have not set it up to step the depth (yet, run time on the grinder for little gain is a concern) > > I will fault the on-off switch though, that puppy is stiff & not near > > enough of a finger purchase to slide it, I hope it breaks in before it > > breaks. > The switch is not one of the better points of this tool. I bought a > dual > relay board and one day I will hook it up to avoid having to fuss with > the switch. In the meantime, I can see a toggle switch where up is on mounted someplace handier than using both thumbs on that POS. > > No idea if its a PM field or plane universal motor, but I suspect the > > latter. If it was a PM field, I'd hook the mills speed controller to > > it, but that would need a 5 amp fuse then, currently the mills own > > motor is a 2 amp fuse limit. > > I would be interested in donating my spare HF grinder for > experimentation if you want to try and figure this out. > Nah. With a bit of imagination, I think I can rig a switch between the output of the mills controller, which goes to the reversing relays etc, and just feed the relays with std 127 VAC from a wall plug. That will take a 4pdt switch, but its doable. No reverse of course, but thats the breaks. ;-) > > But at 25k rpms, I'd ought to be able to carve at 15-20 ipm as long as > > its a climb cut. Pretty fast for that toy mill. > > > I have also run 1/4 inch up spiral endills at .75" in MDF due to > improper > gcoding on my part. Amazingly it powered through that at 20 ipm. I > would not recommend that too often. Neither would I, to start with, that MDF is full of glue, which is about 100x more abrasive to the bits edge than clean wood. Plywood also fits this category, its hell on bits & saw blades. But, your cut wasn't where the mill thought it was either, that loading is quite able to cause the bit to flex sideways at the bottom of the cut by at least .010", maybe more. Playing around tonight, working on some code to carve the tenon on the end of the stick, I found both bit runout, and bit flex issues. The run out made the tenon a couple thou smaller at the tip of the bit. The Bosch bit is hard pressed to have a full inch of sharp flute edges, plus the collet on this HF grinder seems to allow a smidgeon of run out at the end of the bit. I first cut the full inch length of the tenon, using about 1/3rd the bit diameter as the stepover, I found I had to slow the feed to about 7 ipm else it sounded like it was working too hard, and found the tenon was about .015" bigger in both directions compared to when it was only working on a .075" depth of cut. I wound up shrinking it about .015" both ways in the gcode, then ran it once at .5" depth to see if it would shave it to size, but even that left it tight, so I now run around the tenon one more finish pass at the same settings, so I can now drive it together by hand with more effort than I'd like. I think that when I dug the mortises, the same effect was in play, they were dug in 3 or 4 passes, getting deeper per pass, but at only 2500 rpms in the mills spindle, and the bottoms of the holes are smaller than the entrance size by about .010", so the last 1/4" of driving them together is pretty snug, not much room for glue. So all I can do is reduce the tenon size as I go, till I have a good fit that will still let the surplus glue out when a 1/2" Pony clamp says its going home regardless, so the glue is going to have to find an exit, through the pores of the wood if need be. In Oak, piece of cake, glue will bleed out 6" from the joint, but this ash is a lot more tightly sealed grain. > Thanks for sharing your photos. I would love to spend more time on my > projects too, but traveling to St. louis keeps me locked up in hotels > instead. The pix are my way of showing folks what keeps me out of the bars, most of the time. ;) Thanks for listening Brian. ;) -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) <http://tinyurl.com/ddg5bz> <http://www.cantrip.org/gatto.html> It's gonna be alright, It's almost midnight, And I've got two more bottles of wine. ------------------------------------------------------------------------------ Enable your software for Intel(R) Active Management Technology to meet the growing manageability and security demands of your customers. Businesses are taking advantage of Intel(R) vPro (TM) technology - will your software be a part of the solution? Download the Intel(R) Manageability Checker today! http://p.sf.net/sfu/intel-dev2devmar _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
