A regular asked me if I've even laid our 4th axis down flat on it's back to machine something. I said no.
So my questions IS: Is there anything you can do with a part in a 4th axis laying flat on it's back that you can't do by putting your part directly on the mill table?
Turn the outside of the material round by spinning the rotary while moving x,y, and z to get it rubbing just right on the corner of the spindle housing? Maybe clamp a threading tool to the housing and single-point a thread on the outside of something too big to fit in the lathe? Beginning to sound like a vertical turning machine.
I don't think you're understanding or answering my question. If you turn the rotary 90 degrees and lay it flat on the table, what have you gained in operational ability for the VMC? I'm not talking about angling the rotary, that OBVIOUSLY allows the machining of MANY different features that are unable to be done in a VMC with a part laying flat on the table. The only advantage I've seen so far is if like what I think Charlie was suggesting, doing a part larger than the travels of the machine.
I've done keyway shaping with a part sitting flat, but your spline & gear shaping actually IS an answer to the question. Although, I don't know if I'd want to be doing much shaping on a VMC, unless I had a bin full of spare spindle bearings.
"A regular asked me if I've even laid our 4th axis down flat on it's back to machine something. I said no."
What you can do, and I'm and inch away from violating my security clearance here (Check your board Monday) is put very accurate features in this part.
ftp.machiningsolution.com/IMG_0171.JPG
BTW, your rotary is accurate to 30 arc seconds and that might have been problematic. It isn't the .001 degree you thought.
This is a $9,000.00 piece of material that will be on and SNK Sunday with yours truly having set it up, written the program and pushing the button. It's not a set up part. There will be exactly one of these and if it's not right, I'll have to have All Metals and Forge send me another open die forged piece of Nickel 200 at nearly a C note per pound. The blank weighs
I was kidding Juan and John K. when they were turning the Nickel 200 part (each at different times), by pointing to it and saying: *EIGHT THOUSAND DOLLARS* every time I walked by. No pressure there. LOL
Well, the readout on the control is in .001 of a degree. I've never put an indicator on it to see if the readout transfers to actual movement of the rotary.
77 Kelvin. Why the hell would anyone brand a cryogenic process as cold? The only thing colder is helium and I can't fit the equipment into my garage or I'd be doing that instead. You can even WELD the stuff and it doesn't move! I have the "coolest" garage in the south bay. I guarantee!
OK. But 30 arc seconds is like .0083 of a degree. And at 5" comes out to 5 X sin .0083 or .00073. Do your holes have to be more accurate than that?
Also, if you rotate in the same direction the repeatability is supposedly 10 arc seconds or .00024. So someone could program an arc type "positive approach" for all their holes, and "theoretically" be within a few tenths, at least on a new Haas HRT210 rotary.
Compressor scrolls. A lot of people will do these using 3 axis but the best process is using the 4th axis. This was one of the niche markets that Bostomatic controlled.
ISTR reading a paper back in ~1982 touting the process in order to machine ti, seemed like nothing ever became of it so far as becoming anything close to mainstream.
============== Not to put too fine a point on this, but how do you measure the "actual" hole location? Tell me its *NOT* gauge pins, a pair of "verynear" calipers, and a scientific calculator....
Given the type of work, more than likely you are using true position dimensioning, but then factors such as hole squareness, straightness, temperature, etc. start to interact at those tolerances. 2-tenths over 5 inches?
Unka' George [George McDuffee]
------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?
Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).
Probably not what you're looking for, but I'll lay the Haas indexer down and mill out the jaws using the 4th axis. This is a simple way to cut the jaws concentric to the indexer spindle centerline.
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