Lathe performance testing

[Niels Abildgaard]

What is the 'my' unit you mention? I'm not familiar with it.

0.001mm

 

[Cogsy]

0.001mm

Ah, so it's microns. I've never seen the 'my' designation before, I'm much more familiar with 'μm'.

 

[Niels Abildgaard]

Thank You for clarifying.
When I was apprentice more than fifty years ago they were my`s here in Denmark.
Microns are 0.001mm and mills 0.0254mm?

 

[goldstar31]

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N

 

[Cogsy]

Mills I'm not familiar with at all. In my work I only deal in SI units and their derivatives, if anything else comes along it gets converted to SI. Of course model making is different and I can (and do sometimes) work in inches. I envy your measuring equipment - there's no way I can accurately measure 1/10th of a mm at home.

 

[goldstar31]

deleted

 

[Asm109]

a mil is 1/1000 of an inch. ie 0.001 inches. Or .0254 mm or 25.4 microns.

 

[bazmak]

Not heard of mil,always refered to as thous in the UK in the OLDEN days

 

[redhunter350]

Well my on board computer was programmed in imperial so still use thous and tenths ! Plus all my kit is imperial. However I have a close friend in the gunmaking industry in Italy and asked him to clarify the metric terms , the list is below:-
Metric Micron 0.001mm
0.001
1 millimetre = 0.03937"
0.1 decimo = 0.00397"
0.01 centesimo = 0.00039"
0.001 micron = 0.000039"
I keep it handy for reference and the conversion to imperial gives it meaning- to me and my computer!

 

[Cogsy]

Those terms may be specific to Italian gunsmiths, but they're not correct terms for general usage. For example, the centi- designates a division of 100, as in 100 cents in a dollar or 100 centimetres in a metre, yet the milli- designates 1000 units, as in 1000 millilitres in a litre or 1000 millimetres in a metre. Realistically, for our usage, tenths of a mm is all we can possibly hope to measure, and even then the surface finish is likely rougher than that unless it's polished or ground.

 

[Niels Abildgaard]

My new WM250 cheap chinese lathe is getting more and more adorable.
It sits on a piece og granite and runout and straigthness can hardly be improved.
What can be improved are those stupid EMCO designed/copied compound arrangements.

My toolmaker friend with more than 50 years expirience bougth an identical lathe himself.
He likes to keep his AlfaRomeos original and un-modified and I hope he does not improve his sister lathe before some tests.
It will be possible to compare my gifts to humanity :

Lathe on rock
Better compound
Worlds best tangential carbide tool

with more mundane solutions.
What do readers think will be most beneficial?

 

[Jasonb]

What do readers think will be most beneficial?

Leave as is and get on making something rather than do "improvements" that in most cases are not needed.

In 11 years of using the slightly larger 280 and 25years with an Emcomat 8.6 before that I found it did all I wanted

 

[goldstar31]

This gifts to humanity thing? I hope that you are not being serious.

Norm

 

[Niels Abildgaard]

This gifts to humanity thing? I hope that you are not being serious.

Norm

They are the best I can offer.

 

[moerman]

What is your problem with the compound on this lathe? I have a simple SIEG C2 which probably has about the same design. It could have been made better, but that's a problem in manufacturing and not in design. What am I missing?

 

[Niels Abildgaard]

What is your problem with the compound on this lathe? I have a simple SIEG C2 which probably has about the same design. It could have been made better, but that's a problem in manufacturing and not in design. What am I missing?

The toolposts are very different in design I think but send us a picture and correct me.
I think the SC2 hs a compound system where you have to wind the slide very ,very far aft before You get acces to two screws

This system can be improved by drilling two holes

And another picture

When cutting the SC2 system is very rigid and OK but a pest to angle shift.
On my WM250 lathe the EMCO system is flexible when cutting but easy to angle shift.
My new system(or rather a variation of the good old Southbend 9 system) is faster to angle shift than my old EMCO system and almost as rigid as the SC2 system while cutting.

 

[Niels Abildgaard]

First two pictures of the EMCO style system from a WM280.The made in millions 918 types have more or less the same and my present WM250 had as well.
last two pictures show my much stiffer system.

 

[goldstar31]

I don't wish to seem controversial but I recall several respected people who would only use a swivelling top slide when it was necessary.

I'm talking about people like 'Martin Cleeve' with 'Turrets without Milling',
'Tubal Cain', the English variety and his Gibraltar tool post- still available from
Hemingwaykits
John Stevenson- who was controversial about everything- and often right

I was re-reading Cleeve and his Turrets without Milling and noted that all that was needed was 4 chunks of steel for the front turret and 3 for the latter. Not surprising- but I have a rear one-- for umpteen years.
I noted that in my scrap box, the necessary 4 lumps which only require bolting together.

Makes me wonder why people buy these fancy QCTP's and ratchet turrets- at enormous expense.

I made a George Thomas affair with its hardened ratchet -- and wondered what kept my ears apart!

Oh, and I have Martin Cleeve swing tool holder- for boring.


Just a simple soul

Norm

 

[Wizard69]

On my 9x20 I actually remove the compound for a quick change tool post mounted on a block. The support block bolts to the cross slide.

Obviously tapers can not be done with this approach. But a bit of planning and a selection of cutters will solve that problem.

 

[Niels Abildgaard]

On my 9x20 I actually remove the compound for a quick change tool post mounted on a block. The support block bolts to the cross slide.

Did turning improve measurably and can we have pictures?