Metric lathes in the US

[gweloboy]

Do any of the importers of Chinese lathes bring in metric lathes?
I prefer metric(I grew up in Rhodesia and did an appie-ship after it became Zimbabwe). Our cars and a lot of equipment were Imperial but metric is just easier.

I called Big Dog once and got a very definite 'no' when I asked about them bringing in a metric model.

Right now I have a South Bend which, at $450 was a lot more lathe than a new Sieg or Big Dog. I am going use a digital DTI as a DRO on it.

 

[kvom]

DROs typically will read in both metric and imperial. The only thing missing would be metric threading, and some lathes that use change gears can do that.

 

[Blogwitch]

Now I have DRO's on everything I never look at my dials at all.

As far as metric threading goes, I used to use an old Atlas Imperial lathe, and never using the drop in dial for any threads, just a permanently engaged leadscrew, I could cut any metric or imperial thread I ever wanted with no problems at all, it was all to do with swapping change gears.

John

 

[Henry]

Sherline has metric lathes and mills. Don't talk about the imperial or metric system :fan: it is too dangerous in an American forum. I think that the metric system is far superior and easy to handle. USA Army, NIH, NASA, etc anyone that need serious measures use it. LMAO :hDe:

 

[XD351]

<Don't talk about the imperial or metric system :fan: it is too dangerous in an American forum. >


Surely they cant resist forever - powerful is the dark side of the force !
Maybe trump can build a wall - keep all those metricans out !
Funny thing though is when i go to my local hardware store here in ( unfortunately ) metricated Australia they stock more inch size bolts than metric and i recently had to buy some 10 mm bolts ,nuts and washers but they only sold 3/8 washers , they even had these fantastic looking " high tensile " flat washers - looked the same as the standard zinc plated ones to me just twice the price !
I know there is little difference between a 10 mm and 3/8 washer for general usage but it really confuses the average person with little or no mechanical or engineering knowledge !

 

[Wizard69]

You could always try importing yourself.

As for metric being easy, in some cases yes. However once you understand the USA based system you will see some advantages. For one it appears that bolt and screw threads where designed with lathes in mind.

In any event I've spent years working in the optics industry which has been mostly metric since forever. After a while working with both simultaneously is a cake walk. Well most of the time, you will want to strangle engineers that designed in M5 and 10-32 screws into the same part.

In the end though you are just working with numbers.

 

[lohring]

I am designing and building an engine with a nearly all metric design. It's a lot easier to avoid design mistakes with the mostly 2 digit integer dimensions a model size engine will use. All my equipment is used American including a K&E drafting machine, a Monarch 10EE, and a Bridgeport mjll. My best measuring equipment is also imperial. However, the DROs and my caliper can easily read in metric. My cell phone has a calculator for when I need to use my precision imperial measuring equipment. The quick conversions are 25 mm per inch or .040 inches per mm. If you need better accuracy, there are 25.400 mm per inch. Divide mm by this to get inches or multiply inches to get mm. Number and letter drills are often close enough to metric dimensions for drilled hole tolerances. Screw threads are still Imperial because grade 8 socket head cap screws are available at any hardware store. Also the common small metric threads are too fine for strength in aluminum compared to number size NC threads.

Lohring Miller

 

[Cogsy]

Also the common small metric threads are too fine for strength in aluminum compared to number size NC threads.

I've never tested the strength but I use M3x0.5 in aluminium all the time and haven't had a failure (yet). I've even tightened them a bit tighter than I was comfortable with at times and so far haven't stripped a thread, though I do like to have lots of engagement. It's tough to get imperial fasteners down here, especially in small sizes so I mostly use metric for all my engines.
For my Peewee engine I've imported fasteners and I do like the 4-40, 2-56 and 0-80 sizes, but they cost me a small fortune...

 

[Blogwitch]

During my working life I have worked for two US companies here in the UK.

The first was a subsidiary of Maxtor, the hard drive people, where everything was those weird US screw sizes. Eventually we started to make our own designed hard drives and computer peripherals.
Of course, on the changeover we moved over to metric fasteners, which saved the company a fortune in costs because with metric being a standard here the nuts and bolts were a fraction of the price.

The next company was a small family concern, which had their machinery made in the US, and although built like tanks, they were absolutely crap for what they were designed to do.
I was given free reign to get the factory up and running, and over the coarse of about two years, I managed to swap over all fasteners to metric because US threads were just not stocked by my local supplier, so saving a lot of time when we had a breakdown. If we needed to use US threads, it would take a couple of days to get them in whereas metric was available off the shelf.
My shop is basically both Imperial and metric, but the Imperial are just UK threads, BSF and BSW and the metric based BA. But I do have a full set of UNF and UNC taps and dies just in case I have to make something for someone else.

John

 

[Niels Abildgaard]

I've never tested the strength but I use M3x0.5 in aluminium all the time and haven't had a failure (yet). I've even tightened them a bit tighter than I was comfortable with at times and so far haven't stripped a thread, though I do like to have lots of engagement. It's tough to get imperial fasteners down here, especially in small sizes so I mostly use metric for all my engines.
For my Peewee engine I've imported fasteners and I do like the 4-40, 2-56 and 0-80 sizes, but they cost me a small fortune...

I make tangential toolholders and have tried a lot of different threads for the clamping screws.My best bet yet is shown on picture.It was standard M8 12.9
screw made into a rather special one with M8 0.5 thread as shown.
As a first test it was tested ,compared to normal M8,some rather smart differential arrangements and a 3/8 UNF .It feels very much nicer but needs a lot of turning key.
I do not believe,based on my test that fine thread will strip before corse but industry will hate to pay humans for more screwing.Fine threaded screws have larger core diameters than corse ones.

 

[james_III]

You could always try importing yourself.

Or import just the important part from UK. Over here (Europe) you can buy metric or imperial lead screw to Chinese lathes. If need is only for threading there should be odd size change gear to compensate wrong lead screw, I have metric lathe and I can cut imperial threads.

 

[lohring]

I don;t have anything against metric threads and have taps and dies for many small sizes. They, along with UNF threads, are great in steel or cast iron. However, it's common to strip head bolts in model engines. That includes #4-40 UNC and smaller threads. The metric ones are a little smaller than #6-32 so retapping them is an easy fix.

I've also come to appreciate US hardware stores. I was reassembling a Chinese built 3.5 cc engine and twisted the head off a socket head cap screw. I've stripped the socket before anything like that happens with US screws. Some of the larger engines are using Torx heads. I have yet to strip their 5 mm bolts in aluminum crankcases. It's the smaller sizes that give more problems.

Lohring Miller