John, without in any way being patronising, you are a classic and judging by your off beat sense of humour, damn good at what you do, but you are wrong about curves. A curved shape is stronger and more rigid than a box of equivalent size, uses less material and the pattern maker only has to do his job once, so a curve is better from in engineering and economic terms. You see, form and function really does work :-).
The only reason they went to squared off machines was for fashion. to make them look more "modern". Nothing to do with engineering and the worst possible reason, imho...
The right place being either in a bikini on a sandy beach in summer or wrapped in a wyncette tarpaulin and tucked up in bed on a cold winters night.
Again the yardstick is where do you stand you bottle of Newkie Brown ? Even bedside tables are flat and square.
So why do modern machine tool makers still stick with square when their products are the most expensive they have ever been. A VMC can cost over 1/2 a mill smackers and they don't pull any punches at what goes in them, bearing chillers, linear slides not scraped but precision ground to a hairsbreadth of a gnats c*ck [ that's fine limits BTW ] and the latest electronics that man has devised.
If they could tweak the last bit out considering they are using state of the art design, simulation and stress software to design these, don't you think they would ?
It would be interesting to see some of the earlier designs run thru a FET software package [ or whatever they call them.]
Upside is they still look pleasing and you now have nice surfaces to bolt tool changers, DRO's or stand your beer.....
Have you ever personally had to bolt a DRO arm to a Bridgeport base casting ? It's like playing snooker on roller skates and without crafty use of packing the completed job looks like a photo of Janet Street-Porter
Isn't that for the Colchester and a special ?. Perhaps not typical, but you can always vote with feet and not buy such a machine if they are trying it on.
Can't argue withat at all, other than the wynciette, which I always thought was decidedly dodgy. Silk yes, or cotton, but never wynciette :-).
Maybe the difference in strength or material cost is not worth the added design effort to make it pleasing to the eye, or it could be that the cad designers of these machines have no imagination and haven't worked out enough about the software to make it draw curves. I guess it makes it easier when you have shafts and control levers at all angles as well, but a belt drive headstock only needs the back gear lever, so there's no excuse.
My guess would be very grossly overengineered in places and marginal in others, because they didn't know any better, or have the tools to do a proper analysis. 50 years ago, remember. Being real engineers, they looked at it and said "this needs a bit more there" and threw a bit more metal at it, or sculpted a bit away until it looked about right. Have always thought that engineering is as much about instinct as doing the sums. Both are important, however much the modern world of cad would say different. Judging by some of the so called designs around these days, you sometimes wonder if the designers ever really thought about the product at all in terms of the big picture, or who or how it would be used. Total lack of imagination, but I digress.
No, never, but I would probably mill a proper flat on the base to take the dro. Of course, this becomes a bit chicken and egg if the milling machine itself is in bits ^). As for JSP, who could criticise anyone with that much attitude :-)...
LOL, In this day and age you're really concerned about aesthetics in a belt drive lathe? Anyone contemplating purchasing one new is more concerned with the price rather than looks. As a consequence most of the lathe makers who sold to your father or grandfather have gone, mainly because noone or very few wish to pay in real terms what they paid in their time.
Why waste time? Obviously as they still survive, those ill-informed "engineers" who designed them, did their job well.
Your guess? Fortunately for the real world, real engineers don't rely on guesswork. As for engineering 50 years ago, I suggest you have a look at an airport someday and observe some of the aircraft over 50 years old and commercially viable. The US, leader of the world technology still using bombers made on the 50s.
How the heck would I know ? though I might take more notice if I were about to buy such a lathe. Someone already said earlier that they had replaced the bearings on their cva for 200 quid, so at least some of them can't be that exotic.
Single source vendors are invariably uncompetitive on price. Theres no incentive to be anything else if you have the customer by the S&C.
No, too old and what's football anyway ?. (ducks :-) My 14 year old lad could probably quote chapter and verse, but I make no apologies for being not in the slightest bit interested, though I have been known to sit down and watch a game from time to time. The way I see it, it's just another branch of show business these days. Too much money involved for it to be anything else, imho.
Getting back to engineering, do you have an inspectors report or certificate for your Monarch ?. Managed to find one for a Boxford, but am still trying to get a feel for how much better the top end stuff was. For example, the Boxford spindle external diameter and centre point eccentricity were found to be within 2/10ths and a test bar was 3 to
5/10ths over he first 12". Would assume top end stuff was far better. Any data ?...
No, what you are saying is that *you* are more concerned with the bottom line than anything else. Others may disagree.
Because it's interesting to some. There really doesn't have to be a logical reason for everything in life.
ROFL - "Leader of the World Technology". Bow to the master etc. You cannot be serious :-). Agreed, US engineering prowess can be breathtaking, but with their resources, it damn well should be and it's not exactly absent eleswhere in the world either. As for guess work, read what I actually said. The sums are necessary, but it's design flair that produces true world class product.
Anyway, what's up Tom, coffee disagree with you this morning ?...
Yes but a Boxford is only a 40 year old South Bend anyway, all good things mellow with time
Those figure don't sound all that great to me and that's from new. What happens 10 years down the line when the wind is in the wrong direction.
Centre point eccentricity on a new lathe should be nil or close to. To read 2 tenths on a standards sheet must have been a Friday afternoon grinding session.
Tom, get the Slichinger standards out and tell us what's acceptable for eccentricity and run out at 12".
Fuck me I've seen duals fought to higher standards at 30 paces.
Depends what you mean by 'standard' and 'off the shelf'
I expect lots of them use 'standard' bearings inasmuch as the bearings have a number which a knowledgeable supplier will understand. My DSG uses 'standard' Timken bearings, in that sense, but to actually find any in the precision form might need a generous combination of money and good fortune. The CVA bearings are much easier, and I was lucky in that my supplier was owed a favour by a stockist who happened to have some, so I got them at a good price. OK they were a Japanese brand, but a reputable one and theoretically the same precision level as the originals. There should be no problem getting them from a good supplier at any time, though the price might not be so favourable. The Monarch 10EE uses essentially the same bearings but with a locating flange on the outer race, which makes supply a bit more restricted and expensive. AFAIR the Boxford uses Timken bearings, so probably someone somewhere has them 'on the shelf'.
Peter I've seen those figures quoted as well but can't reconcile them with the figures for the Schaublin 125 we were going to buy (well I wasn't but you know what I mean) a fair few years ago. They would only guarantee accuracy of concentricity of 0.005mm (.0002") or better with their most expensive collet set. We should have gone to Boxford or SB perhaps? This machine was for a job that couldn't be ground afterwards but I can't remember any other manual lathe promising better. In the end we had to waste production time on our Huron 6 axis CNC (a prototype and best part of =A31m). To rub salt into the wound, 10 years later the little Mikron 3 axis machines that cost us less than =A350K a copy were out performing it daily.
Apart from being bored with this piss*** contest I'm out of date but IIRC DIN 8605 states lathes of this type will be below 0.01 mm (.
0004") for most geometric properties, and below 0.005 mm (.0002") for some. That of course is for finished assemblies.
In the 40 years that I have been involved in Aerospace the accuracy of a lathe to these limits was a little irrelevant as in my experience the accuracy of the finished article was the responsibility of the grinding section not the turning department. The exception to this of course was if the job couldn't be finish ground for some reason.
Having said all of that, the spindle on my own Boxford (obviously a good one and I will be selling it shortly) shows absolutely no runout on the spindle outer surface; but then again - what was the resolution of the DTI? I won't repeat the story again but when the lads in the metrology lab tried to take the piss out of a well used Taiwanese lathe I had by running the CMM over it, they were stunned by the accuracy of the grinding. Didn't make it a nice machine to use though.
I'm keen to get up to date with the modern world so perhaps someone will be able to dig out what the current bread of machining centres are good for.
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