Lathe evolution

[Zee]

Years ago I read an article that said that if you use a lathe to make another lathe, the second generation lathe will be better/more precise than the original lathe. When I mentioned this "factoid" to a tool maker friend of mine, he gave me a skeptical look. Comments? Published references?

[Skew ChiDAMN!!]

Hmmm... :think: personally I think that's a fallacious concept, although there is a grain of truth in it.

For example, give me a Vicmarc or a Oneway lathe (drool, drool) and I could probably knock together a wooden lathe... but it definitely wouldn't be "better" than the original. Quite the contrary, by a long way!

Or give me even a mediocre metal lathe and the resulting lathe would still be of lesser quality. (Unless you also gave me access to a milling machine and a well-populated workshop... :rolleyes:)


But there is that little "grain of truth" - give me a bit of string, a skew chisel, a suitable tree and enough felled timber and I could make a very basic pole lathe. From that I could make a better pole lathe, and work my way up to a reasonably acceptable treadle lathe. Without a single skerrick of metal, apart from the skew chisel! (Mind you, any nearby cows would be pretty wary of blokes armed with skew chisels by the time I'd finished. After all, leather belts don't grow on trees! :doh:)

It'd be a lot of time 'n effort though... and for the same time 'n effort I could work for Joe Blow down the road for a few days and earn enough to go buy something far more substantial. :U

[arose62]

I'd think that if you made your first metal lathe without any facility for rotating any of the parts, then it would probably be fairly mediocre.

Using that lathe to make another would certainly give you the possibility of making a better lathe, as you now have the capacity to machine rotating metal.

However, beyond this first generational step, I can't see how you'd get additional accuracy, and I don't believe that even the move from lathe_1 to lathe_2 would *guarantee* an improvement.

There is a book called something like "Precision in machine tools" which I've heard is The Bible when it comes to making accurate stuff. Haven't found it in the real or online worlds yet, but would be interested in finding it.

Cheers,
Andrew

[TTIT]

This 'theory' held fast in the development of screw cutting on lathes at least. Apparently around the beginning of the industrial revolution, the evolution from handcut threads through to accurate threads that would auto feed the next generation took quite a while. Seems the bumps and blemishes of the handcut jobs persisted for some time :shrug:

...........and welcome to the forum Zee:U

[hughie]

Years ago I read an article that said that if you use a lathe to make another lathe, the second generation lathe will be better/more precise than the original lathe. When I mentioned this "factoid" to a tool maker friend of mine, he gave me a skeptical look. Comments? Published references


Zee, welcome to the forum.

It would a challenge to make a better lathe with another one. Because the accuracy of the second would be dependant on the first.
Secondly and perhaps more importantly it would take more than a lathe to build lathe. ie additional tooling would be a universal mill,radial drill to name the basics.

The only machine shop 'bible' I know is Machinerys Handbook, used to retail in Sydney around $150. PM me if your desperate for a copy.
http://machinerys-handbook.com/index.html

[Wood Butcher]

I think that this is true but not so much nowadys. If you go back to the time of the Industrial Revolution than yes it was very true. Take James Naysmyth (http://en.wikipedia.org/wiki/James_Nasmyth) for example. He used his fathers treadle lathe to make himself a lathe, which in turn he used to make other lathes and machines.

This to a degree can be realated to modern days. Really if you couldn't use a machine to produce a better machine, than we would all still be in the stone age:p

[arose62]

It would a challenge to make a better lathe with another one. Because the accuracy of the second would be dependant on the first.


Ahhh, that's what the still un-named book was about; how to use machine A to build a machine B, which was significantly more accurate than A.

Obviously it's do-able, otherwise humans wouldn't have got to dealing with things in thousandths of an inch.

Cheers,
Andrew

[hughie]

Obviously it's do-able, otherwise humans wouldn't have got to dealing with things in thousandths of an inch.


Andrew,
Its do-able under specific conditons, you most likely would go through a evolution of design and building your machine tool. We are talking perhaps several generations of design etc.

But to build a better lathe in the strict sense is not so do-able due the complexities of lathes today. Flat line machining, gear cutting would a be couple of hurdles to over come...bit tricky on a lathe..:U

But your point is well made, improvement must achieveable other wise we would be in still riding horses or thumping each other with clubs etc

[arose62]

Agree entirely!

Going back to the OP, looks like consensus is that if you use a lathe (or other machine tool) to build another lathe (or machine tool), it is possible for the second machine tool to be better than the first, but not guaranteed (just by virtue of it being "2nd generation").

Also, it was probably easier to make bigger progress earlier in history, but now some sort of limit(s) [human, design, technological] are being approached, and it's simpler just to duck down to Hare and Forbes and grab a C3.

Cheers,
Andrew

[Hickory]

Would be just the opposite, Similar to teaching, I learned half what my teacher knew so my students learn half of what I knew then they learned 1/4 of what my teacher knew... And so on, Dumbing down of society....

Same with machinery, the imperfections in the original would not allow it to make a piece superior to itself because the same imperfections woud transfer to the product. Similar to using a tracing bit on a router. the final results would be only as smooth or accurate as the pattern piece. any dips or nibs would be transferred to the finished piece as the bearing road over the lumps and dips.

[Zoinker]

If you can find any part on a lathe that cant be made with a lathe id be impressed. Of course this excludes the initial casting of raw materils. As for increase in accuracy, i would say it depends on the skill of the opperator, but entirely possable. for example get a piece of wood, like a branch or something, and cut a board using that piece of wood as a guide, now use that freshly cut piece as a guide and repeat over and over again and you will end up with dead straight board

Boring and threads with basic tooling, gears and face milling with a modified fly cutter, even surface grinding with the addition of simple shaft to attach a gringing wheel, with half a days work you could make all the jigs you need to manufacture a lathe, prity much any metal removing tool in your workshop is a more refined version of a lathe, hence the reason your first piece of machinery for metal forming should always be a lathe

Links
Gears http://www.lulu.com/content/250712 (average book)

Random google search (covers almost everything) http://images.google.com.au/imgres?imgurl=http://www.g7khf.com/lathe%2520010.jpg&imgrefurl=http://www.g7khf.com/pic.htm&h=1200&w=1600&sz=289&hl=en&start=1&um=1&tbnid=rAT0VzGftwTdyM:&tbnh=113&tbnw=150&prev=/images%3Fq%3D%2522fly%2Bcutting%2522%2Blathe%26svnum%3D10%26um%3D1%26hl%3Den%26sa%3DN

[weisyboy]

If you can find any part on a lathe that cant be made with a lathe

prepare to be impresed:2tsup:

lets see

spindle
pulleys
bed
handles and nobs
toolrest
you could also make a round headstock and tailstock.

[Wood Butcher]

Weisy, all those parts can be made with a lathe??

Zoinker is talking about parts that can't be made with a lathe

[MrFixIt]

Hi


Zee, welcome to the forum.

It would a challenge to make a better lathe with another one. Because the accuracy of the second would be dependant on the first.

NOT necessarily!

Secondly and perhaps more importantly it would take more than a lathe to build lathe. ie additional tooling would be a universal mill,radial drill to name the basics.

NO it DOES NOT

Raising a point that has been raised before, A LATHE is the ONLY MACHINE tool that CAN MAKE ITSELF! :2tsup:

Other tools like those you mention ONLY make the task easier. :U

[weisyboy]

Weisy, all those parts can be made with a lathe??

Zoinker is talking about parts that can't be made with a lathe

sorry about that i left out the last line.

<TABLE cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER- 1px inset; BORDER- 1px inset; BORDER-BOTTOM: 1px inset">If you can find any part on a lathe that cant be made with a lathe </TD></TR></TBODY></TABLE>prepare to be impresed:2tsup:

lets see

spindle
pulleys
bed
handles and nobs
toolrest
you could also make a round headstock and tailstock

damit maby not:(

[MrFixIt]

Hi

Would be just the opposite, Similar to teaching, I learned half what my teacher knew so my students learn half of what I knew then they learned 1/4 of what my teacher knew... And so on, Dumbing down of society....

That SHOULD NOT be the case!

You should have learned all that the teacher could provide, PLUS you should have gained knowledge from OTHER sources OR teachers, therefore YOU SHOULD have a GREATER knowledge. Any lessening in the level of knowledge is not relevant to what the teacher knows but the ability of the student.

As has been proposed elsewhere in this thread if we did NOT progress we would still be in the stone age.


Same with machinery, the imperfections in the original would not allow it to make a piece superior to itself

NOT so.


because the same imperfections woud transfer to the product.


Maybe so, BUT think of it this way...

Similar to using a tracing bit on a router. the final results would be only as smooth or accurate as the pattern piece. any dips or nibs would be transferred to the finished piece as the bearing road over the lumps and dips.

... if you make the first item BIGGER and as accurate as possible the errors within an item produced by the first item would be reduced by the factor of the size difference.

So if you create a lathe that is 20 foot long, (nothing unusual about that in the industrial revolution era), and make it accurate to one thousandth of an inch - not too hard to do by hand, just slow and tedious.

The SECOND lathe 10 foot long made by the first lathe would have any error reduced by a half so the second lathe would be accurate to HALF a thou'