Why 30mm x 3.5 Spindle thread size in Australia?

[Optimark]

My current lathe has a 1¼" x 8 TPI thread on the spindle, which is alright as long as I don't visit my brother and wish to use my chuck or accessories on his lathe. Also, as far as I can work out, most lathes bought in the last 10 years in this country have 30mm x 3.5 as the spindle thread size, so I cannot take anything anywhere to anyone with a current lathe.

I am at the moment looking to upgrade my lathe, mostly, everything I see is 30 x 3.5, however today I received the Record Power 2018 catalogue. The lathes in their catalogue that I looked at as possibilities, are all supplied with 33 x 3.5 spindle threads.

Looking on the Vicmarc website I see that depending upon where a lathe is being sent you will get a default size of 33 x 3.5 everywhere in the world, except Australia; where the default size is the smallest spindle thread size of anything listed. My current lathe with the 1¼" thread size which is 31.75mm is also bigger.

As I have been into wood turning only a short few years, I was wondering how we in the so called lucky country, are saddled with what may eventually be the odd size out, anyone know how we have ended up with this odd size?

Mick.

[artme]

This is a perpetual problem. Different counties have different standards and none seem willing to budge.

When Australia went metric it took some time for the switch to metic standards. With lathes the standard
for Australia is set at 30x3.5 for spindles I have a small Jet Lathe and or that I had to purchase an adaptor
which was not a great impost.

My larger lathe has a 30x3.5 spindle thread as standard.

More interesting and is the case with Morse tapers. In Aus the standard is MT2. Record Lathes have an MT1
and that is a right PITA!! I talked to Hare and Forbes about this ( they are Aus agents for Record lathes) and they
have brought these differences up with Record but to no avail.

The best answer seem to be get withe the Aus. standards and buy equipment to suit.

[Mobyturns]

As my Mum would say - "because!"

Vermec make an excellent range of spindle adaptors and will also make custom inserts for chucks. Cheaper than purchasing a new lathe.

Unless of course you are justifying a reason to - then disregard the last comment.

[rtyuiop]

It's not us vs. the world - M33 seems to pop up frequently in Europe but the US folks have their own whacky imperial sizes (of course!).

[Optimark]

This is a perpetual problem. Different counties have different standards and none seem willing to budge.

When Australia went metric it took some time for the switch to metric standards. With lathes the standard
for Australia is set at 30x3.5 for spindles I have a small Jet Lathe and or that I had to purchase an adaptor
which was not a great impost.

My larger lathe has a 30x3.5 spindle thread as standard.

More interesting and is the case with Morse tapers. In Aus the standard is MT2. Record Lathes have an MT1
and that is a right PITA!! I talked to Hare and Forbes about this ( they are Aus agents for Record lathes) and they
have brought these differences up with Record but to no avail.

The best answer seem to be get withe the Aus. standards and buy equipment to suit.

Well different countries do have differing standards and as you say they mainly stick to them, but, it is interesting to note that the European countries I have visited in the last few years are, within reason and with bigger lathes, standardising on 33 x 3.5 and a No. 2 Morse taper (MT). Record in their new 2018 catalogue, with their two bigger lathes, both lathes are new to Record, are running 33 x 3.5 with No. 2 MT. So they seem to be standardising with the rest of the world.

It would seem to me that the Australian standard of 30 x 3.5 may eventually be the odd one out, just thinking out loud here.

You mention that Australia eventually set their standard to 30 x 3.5, do you know who did this and why they did this?

I do know that when we went metric the building industry was consulted, from 1967 when they went metric using millimetres, not centimetres, the reason is that computers don't like fractions, with millimetres there are no fractions. Apparently saved the building industry a motza as a result, Australia saved squillions when other industries came on board using at first millimetres and metres. Ever wondered why our road signs show 900m or 1200m to the next turn-off instead of .9km or 1.2km, computers and their inherent fraction problem is why. These days things have changed, but computers still don't like fractions, hence the decimal inch in the USA.

Mick.

[Optimark]

It's not us vs. the world - M33 seems to pop up frequently in Europe but the US folks have their own whacky imperial sizes (of course!).

According to Vicmarc, they supply lathes to the world with 33 x 3.5. The USA market has two sizes, 33 x 3.5 and 1¼" x 8 TPI. I have noted quite a few offerings in the USA have both of these sizes, but the 1¼" x 9 TPI does seem to be losing over there.

Mick.

[Optimark]

As my Mum would say - "because!"

Vermec make an excellent range of spindle adaptors and will also make custom inserts for chucks. Cheaper than purchasing a new lathe.

Unless of course you are justifying a reason to - then disregard the last comment.

My mum must have been a cousin of your mum, only she normally said "Coz, that's why".

I am going to upgrade my lathe and will be arranging for new inserts for my equipment, hadn't thought of this as an excuse though.

Mick.

[Old Croc]

According to Vicmarc, they supply lathes to the world with 33 x 3.5. The USA market has two sizes, 33 x 3.5 and 1¼" x 8 TPI. I have noted quite a few offerings in the USA have both of these sizes, but the 1¼" x 9 TPI does seem to be losing over there.

Mick.

Mick there is no real answer to this question. 22 Million people here, 322 million in the US so it was quite easy for us to convert to metric but they have not. In the US you can buy, Woodfast, Jet, Laguna, Robust, Technatool, Grizzly, Powematic, Oneway and more. A lot were made in the US, so the UN8 1 1/4 8 tpi thread was their own standard. As manufacturing moved to China, more metric options became available as well as the swag of chucks made in China now with metric threads supplied into the US.
I think our local guys just used the closest thread to the UN8, which was 30X3.5 but from looking at the websites for the above listed lathes, most come with either UN8 or the optional 33X3.5.
Rgds,
Crocy.

[Dalboy]

As already stated here the norm is now becoming 33X3.5mm. When I can aford a new lathe I will be upgrading not only for the spindle size but also capacity and the extras that I would be able to use on it.

[BobL]

Ever wondered why our road signs show 900m or 1200m to the next turn-off instead of .9km or 1.2km, computers and their inherent fraction problem is why. These days things have changed, but computers still don't like fractions, .

I think this has more to do with lowest common denominator ignorance of folks who don't know what a decimal point is. My GPS shows distance to next turn off as X km until that distance is less than 10km and then it switches to X.X km until it reaches under a km and then it shifts to meters which is the true base unit for the metric system anyway.

The main reason Australia went metric had more to do with standardisation of global trade and industry and less to do with fractions. Existing metric countries were already using millimetres so to go with cm would have been dumb with European equipment and materials being already marked in mm. - didn't seem to stop the garment industry though.

BTW computers have been able to handle fractions just as easily as decimal points for about 40 years. I remember going to a conference in 1980 and seeing a maths software package called Mathematica operating completely in fractional mode with infinite numbers of decimal places. ie 1/3 +1/3 shows as 2/3 and not 0.666666666666667. These programs take advantage of the fact that computers are really good and VERY fast at integer maths, much faster than decimal point maths which requires the maths be handed to a floating point processing unit in the microprocessor. The 2/3 is not stored in the computer as a single decimal number, but as two separate integers and the divide operation.

Not just basic X+X but you can write down more complex statement like a/b*(c+d/e) - f*g etc and it would give you the result as a fraction, or a number a residual fraction.
These programs can also do algebra / trigonometry and calculus and even more complex maths. A friend of mine in the US did his PhD in the 1960s in an obscure branch of maths and some of the equations he needed to solve were many meters long so he used rolls of butchers paper to write them out and then he laid the pieces of paper out on trestle tables in a large room and spent a lot of time dashing back and forth between the tables. This process took about a year. In 1980 when Mathematica came out he was able to solve these long equations in just a couple of hours.

If you asked the computer to convert the fraction to a decimal it could print the number out to as many decimal places as you wanted and had time for - I remember asking it to print Pi to 1000 places, back then it took about 3 minutes, these days it would be done almost as fast as the display could print out the numbers. At uni we used these programs extensively to teach other maths and other subjects.

I'm surprised there is not an App for fractional only work, maybe there is and I have not looked hard enough.

[Dalboy]

and other subjects.

I'm surprised there is not an App for fractional only work, maybe there is and I have not looked hard enough.

There is an app for adding subtractin multiplying and deviding in imperial and not to decimal points. I did have it on my phone but no longer

[Optimark]

Crocy, I think your explanation of why the Australian standard is 30 x 3.5 sounds better than anything else mentioned.

Mick.

[Mobyturns]

I'm not a fan of the "nearest size" in practice though in theory it may have a purpose i.e. similar strength, shear performance etc specifications.

It is amazing however just how many people manage to fit / or at least get several turns on a thread and then jamb it with brute force. I often wonder if their brain ever comes to the brilliant thought "hang on something is just not right here."

[Paul39]

I'm not a fan of the "nearest size" in practice though in theory it may have a purpose i.e. similar strength, shear performance etc specifications.

It is amazing however just how many people manage to fit / or at least get several turns on a thread and then jamb it with brute force. I often wonder if their brain ever comes to the brilliant thought "hang on something is just not right here."

There are bunches of folks who go by, "if it doesn't fit get a bigger hammer".

Here is a pretty good list of spindle sizes available:

https://www.toolpost.co.uk/pages/Chu...ndle_data.html

I have a South Bend Heavy 10 metal lathe with a 2 1/4 X 8 TPI thread, and a shop made 28 inch swing lathe that the maker put on a 1 X 8 thread spindle. WHY, WHY!! I bought it anyway, $250 with a brand new 1.5 HP motor.

I started down the garden path with a 7 inch swing Chinese metal lathe, then a free sheet metal bed Delta with 1 X 8, then bought a Hegner with 33 X 3.5, then the 20 inch swing short bed Woodfast with 1 1/4 X 8. The most common of the older medium size lathes in the US is 1 X 8.

[woodPixel]

Mick there is no real answer to this question. 22 Million people here, 322 million in the US so it was quite easy for us to convert to metric but they have not.

Pirates.

The USA missed out due to pirates: https://www.npr.org/sections/thetwo-...-metric-system