On Wednesday 28 October 2009, Andy Pugh wrote: >2009/10/28 Gene Heskett <gene.hesk...@gmail.com>: >> I need to take the saddle off >> again and see if I can actually make it set level and solid on the ways, > >When I checked my (cheap, chinese) lathe I found that each part of the >saddle had been scraped-in to its bed way, but not so that they both >touched simultaneously. >It only took about an hour with blue and a scraper to get it sitting >down solidly on both bedways at the same time, and the improvement was >immense. (the brass tapered gibbs help a bit too). I can now >cheerfully part off 3.5" stainless, whereas previously I couldn't even >dream of parting 1" aluminium.
I'm having a hell of a time with 5/8" steel, chatter is breaking the edge off the knife. I lost an inch resharpening it while parting off the motor couplings for the mill, but that was old mine shafting and harder than hells hinge pins. I guess I'll have to do the same here. My bed is wider and thicker over the last 2" on the right end, enough that if I have it snugged down, I have to loosen the gibs to get it off. PIMA! Thanks for the encouragement to dig deeper. The first thing I fixed was the angle of the front v-cut in the bottom of the saddle, pulled down snug in front, it rocked the rear of the saddle up about 90 thou when it seated on the V. I fixed that on the milling machine as I have one of those 4" sears angle vises. And in trying to control the spaghetti of that QCTH, I pulled the threads out of the compound & the new one is about a thou too narrow, so its pretty solid. And a PITA to crank. I believe I am going to make a new square steel tool holder, with the slot bottom on 2 sides to hold 1/4" tools, the 3rd for 5/16" stuff (I have a Glanz kit. uses a Valenite chip, thats several bucks a chip), and the 4th side rigged for a cutoff knife as that would be hundreds of times stiffer than the QC POS. Why they cut that for 3/8" tools on a machine that small is beyond me. For that I just need to find a suitable block of steel & my round tuit. I seem to have miss-laid that puppy. The A axis adapter I made for the mill, I had to make a boring bar, used 3/4" rod about 10" long, milled a groove in the end to hold the teeny little Glanz bar & super glued it in, and made a clamp block out of a 2.5" sq block of steel, using the hold down bolt to close the clamp. In alu, it worked fairly well with a bunch of junk on the back end to keep the chatter down to a dull roar (most of the time). It took me about 3 days to do that bore though cuz the biggest starter hole I could bore was 5/8 and the little bar kit from LMS was all used up from broken tips by the time I could get that big bar started into the hole. I ran out of carbide resharpening them. :) Using the QCTH, the tools are so far off center on the whole rig, its difficult to keep the cross slide from rocking up half a thou, and that is enough to get the chatter started I believe. Cutting with the compound pulled way back reduces it, a lot. As does bigger chucks. I put the old 3" it came with on the A axis table for the mill, more fun getting that centered than a barrel of monkeys. And because the scroll is miss-cut, center is defined by how big the part being held is, as the table itself has no provision for a morse taper center. Things such as this have discouraged me from trying to cnc it, I'd be time ahead to drop the card for one of grizzly's bigger ones as I really need a larger bore in the headstock, and 26+" between centers. Then I'd probably need an FFL too. :-) -- 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) The NRA is offering FREE Associate memberships to anyone who wants them. <https://www.nrahq.org/nrabonus/accept-membership.asp> If you're carrying a torch, put it down. The Olympics are over. ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
