Greetings all; I may have found the source of some of my tool destroying chatter.
I pulled the compound off this POS last night, and discovered that it was not sitting solidly, flat cast iron to flat cast iron at the mating faces, but was rocking on the corners of that screwed onto one bolt-on on the left face that has the angle markings on it. Its attached with flathead screws, and its either take it off, or lap it off. I did the latter on a sheet of 600 wet-r-dry swimming in cutting oil on my granite flat. For me, since its function can be done by LCNC, it is nothing but a spacer 1.6" tall to hold the QC post. So I have considered replacing it with a round block of metal nominally 3" in diameter so it would sit solidly on the cross slider, be 1.6" thick so it would hold the QC post at a usable height. Having a massive weight there would make sense to me, so while I have a big block of aluminum, I haven't done it out of that as steel or cast iron would add mass which "should" reduce the chatter, plus alu will scratch and dent much easier from toolpost movements its not supposed to do but does. I also noted that the toolposts thru bolt, a 10mm stud, does not screw into the top of the compound slider more than about 3 turns because its not tapped deep enough, and having stripped that thread in one slider already from trying to tighten the tool post to keep it from turning when I am deepening a center drilled starter hole with a drill bit, not in a chuck in the tailstock, but in chuck screwed onto round rod in a boring bar tool carrier which can easily beat the socks off using the poorly aligned tailstocks limited barrel travel for that. As there is surplus stud above the nut, that will get extended about 3 turns of the tap, giving some much needed additional thread engagement so I can put a little more muscle on the wrench without stripping out the threads in the compound. But I want this compound gone as it limits the toolpost placement such that the tool tip is often beyond the puny footprint of the main carriage where cutting forces can and have on hundreds of occasions been more that sufficient to lift the right edge of the carriage off the bed by whatever clearance the gibs might allow, which tips the tool into the workpiece enough that the tool digs in and locks the spindle dead from several hundred revs in just 2 to 5 degrees of rotation. As you can imagine thats also broken drive parts up to and including a bent gear shaft in the backgear. Because of this, I intend to bore the bolt hole for the toolpost about 3/4" off-center so that I can displace the toolpost to the right, pulling the tool tip back into a position where it has carriage enough under it to prevent this tipping even if the gib might allow a couple thou's motion. But I want a plain metal block, and will goto the re-cyclers place today looking for a starter piece to make this from. If one of you had a choice of a block of cast iron this 3" diameter, 1.6" thick piece could be carved out of, or a piece of bar steel of unk additives but likely 1065, both in the iron pile, which would you use? 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) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
