On Sunday 21 April 2019 22:19:15 Gregg Eshelman via Emc-users wrote: > With the post and spindle a degree off, that's a likely contributor to > various issues. It would definitely increase forces on the tooling > when rigid tapping. Rather than messing about with shims I'd be taking > the thing apart and finding a shop where I could borrow the use of a > bigger mill to ensure the areas of column and base meet are flat and > parallel to the spindle on the column, flat and perpendicular to the > table ways on the base. When I owned the 30th lathe off the Logan > production line, one thing I did to it was to borrow use of a > Bridgeport to mill the tops and bottoms of the cast iron feet flat, > parallel and to the same height. Lordy be! The lathe worked better > when the bed wasn't being tweaked out of shape from being bolted to a > crooked base. > > All those clever fixes you've wrote about at radio stations and other > places, can't be bothered to fix something right in front of you today > that's causing you trouble. Sheesh. ;)
As that thing weighs right around 400 lbs, walking it and its base cabinet from the garage door where I unpacked it and wrestled it onto its base cabinet, then into its hopefully final position is a good share of whats wrong with my back today, crushing the first 2 disks above my pelvis & pinching my sciatic nerves on both sides down to tissue paper as the xrays show. And the surgeons are reluctant to try a disk replacement because the rejection rate is still quite high. So I'm stuck with the pains and legs that don't want to do as they are told from time to time. The thought of moving 2 tons of other stuff just to get an engine hoist to it to take it apart brings back the memories of the months of pain that caused and still is at times stops me from embarking on that project. Yes, its hell to get old. I have some trackage with trolleys that I might use, but that would take hanging the one to the garage door, after bringing the post out about 4 feet just to get a shot at the door would be a weeks project as the garage door when up, blocks the access to the ceiling to install the needed skyhooks. I'd estimate the post at 100 lbs or a little more, striped. 75 or more for the base. And TBT, I think any such regrind should also be done to the face of the sled and its mating rear of the head casting. I think theres at least as much error there, allowing the head to sag. If the head moved with the sled would likely fix 99% of that. But its not, readily proveable by mounting a 12" piece of A2, adjusting it for zip runout, and dialing the front or back as its run up and down the post, it only takes a couple inches to use up the 15 thou range of a .0001" dial. I have considered removing the head, drilling and tapping it for some 10 or 12mm bolts whose faces have been ground flat, then adjusted to hold a teeny gap at the bottom when the other 3 nuts are tight. then maybe once the gap needed was determined, fill around it with moglice & file it back till the bolts shine thru. But that too tall for the 6040 so I'd have to make a mount to put a die grinder on the sled, shim it till the piece of A2 was zeroed to a dial on the sled. That I could do. Then the sled is low enough the 6040 could grind it if I could figure out how far off the bed of the 6040 was. I have a cheap probe, so I could map it I suppose and sanding sponge the high spots. Or even mill them if I could afford the tools to level that acreage of alu. Even .001 accuracy is better than that bed is right now. If there is height, a sheet of 3/4" mdf, shaved with the 6040 should be accurate enough, although it should be propped up with parallels inside the v-way pocket so it references the face of the post. Then I could just scan the top, bringing the stone down .0002" at a time till it was clean, same with the head on the g0704's tables. IOW, I don't think the post off level is the biggest problem, the round seat that allows the head to be rotated to horizontal is the larger problem. If the head was plumb with the post, it would help a lot, but its not and there is not currently any way to adjust that except grinding the mating surfaces. But I do have one of the chicago die grinders, and a bag of stones that will handle its 20k rpms. They can also be used in the 6040's spindle. I use a silicon carbide dressing stone to hollow them out a bit since they grind best on the edges of the face. Dammit Gregg, you are making me think, so this just might be the summers project after I drag the air conditioner out and replace the stuck relay that leaves the compressor running full time. Next thing I know I've a 75 lb block of ice where the evaporater coils were. But I'll start with the shimming bolts idea first to see if it can be done. I can still just barely handle the head by hand, a lot easier with the motor removed first, then its only 40 lbs or so. [...] Thanks Gregg. 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> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
