tramming a mini mill

I don't know what type of mill you have, but when I had RF round column mill, I used shims underneath the column. I never did get it right (the thing had a twist in it that no amount of mount tweaking would cure), but I got it better.

Regards,

Peter

For us Brits, what is tramming?

Just Brits? Heck, for us Americans, what is tramming?

The 'art' of adjusting the spindle truly square with the X/Y axis of the table. Ken.

I'm not certain of the origin of the word but it probably comes from "trammel" . In this sense it means to align the spindle of the machine so it is normal or perpendicular to the plane of the table movement.

Richard Coke

It's the art of adjusting most anything "truly square, or parallel, or properly spaced, etc" as called for by the application at hand. Tools used to obtain this include surface plates, gage blocks, levels, squares, plumb lines, etc., and today, lasers. The degree of accuray needed to obtain a good 'tram' depends on the application.

One use of the word is in setting up a steam locomotive suspension ... getting all the driving axles parallel and spaced the same as the holes in the siderods, and everything centered in the frame so the rods will all line up with the crossheads and cylinder/valve bores, etc. When it's properly 'trammed' everything will work smoothly.

Dan Mitchell ==========

Ken Davey wrote:

John,

You're question is valid, not only in the UK, but here in the States as well. Tramming, as far as I know, is an archaic term that was applied to the application of a tramming tool to time motion on steam locomotives and other steam engines. How in hell it became the term for truing machinery is a mystery to me. I've worked in the shop (commercially) since 1957 and had never heard the term used. Only when I got online, talking with a huge number of people that run machines for pleasure, did I hear the term used. Everywhere I worked, dialing in, or sweeping, was the term used. I guess it doesn't really matter what terminology is used so long as everyone is on the same page. It appears in this instance that is not the case.

Sort of reminds me of how the word " swarf" is being used. If you buy a new machine, if it's CNC and produces a lot of chips, they sell you a chip removal system, not a swarf removal system. A lathe comes with a CHIP pan, not a swarf pan. Swarf, by definition, is fine residue created by abrasion or machining. Grinding machines create swarf, lathes and mills create chips.

Harold

A few years ago, a designer of a special machine was said to have made the remark during testing that a few 'shims' would correct a minor problem. The VP of that division overheard him and said ".... no shims!" So the designer immediately rephrased and said "Okay, a couple of spacers..."

But seriously, what's wrong with using shims? Shim stock is sold in a variety of materials ,thicknesses, and shapes.

Shims are all you have unless you want to remachine the column mount or base casting, or both. Unless the head is out of parallel with the column, which could very well be also.

The use of shims for machine tools is sort of bush league. One of the problems of shims is if you dismantle the object, there's no guarantee the shim will be replaced, nor that it will be replaced where needed. In machine tools, you pay for precision, which can include scraping or precision grinding. Shims are a dodge to avoid doing so. That's not to say that a shim doesn't work. Of course it does. You just don't have as much control over the end result that you might have by doing it "right".

Harold

One definition of the word trammel is: tram|mel «TRAM uhl», noun, verb, -meled, -mel|ing or -melled, -mel|ling. ?n. a gauge used in adjusting and aligning mechanical parts.

So, "tramming" probably came into common usage as a corruption of "trammelling". That's my story and I'm sticking to it.

Richard Coke

I generally agree with your statements. The term is somewhat, but not totally, archaic; and did indeed apply to steam locomotives. It may have originated there, since an early term for railways was 'tram', and THAT usage seems to have originated in Britian. The word 'tram' evolved, becomming a widely used term for electric streetcars, both in Europe and the USA. The word is still often used today as regards underground mining and tunneling railroads.

However, it also appears frequently in MANY, especially older, machine operating manuals, machine shop instruction manuals, etc.. These are not at all just those involved in railroad practice. The word may well have 'migrated' from RR shops, among the earlier heavy industries, to more general use. It still appears in such publications today, especially as regards squaring and aligning various machine axes in mills, drill presses, and the like.

And, it's still MUCH in use in the steam loco fraternity, both with model locomotives and the preserved full sized ones.

Personally, I've encountered the word MANY times in many places, but I will admit that I hang around with 'steam loco folks' a lot! :-)

A 'Google' search turned up MANY hits, in various contexts.

The word is certainly specialized, but it's FAR from 'dead'.

Dan Mitchell ==========

Harold & Susan Vordos wrote:

But it sounds so cool to say, "swarf".

And the strings, corkscrews, and needles are not properly "chips".

Harold & Susan Vordos wrote: Swarf, by definition, is fine residue created by

About a thousand years ago, when I used to cut records, the acetate gouged out by the stylus in the record lathe was refered to as "swarf". The vacuum system and jar that sucked up the cuttings was the "swarf collector". The other night I had to explain to my daughter what a "45" was. Damn I'm old.

Kevin "Red Label" Gallimore

It's more than just 'not right.'

In this case the issue is an angular mis-alignment of the column with respect to the table. Placing a shim under *one* side of the column base means that the contact area between the two parts has been drastically reduced.

That's the whole idea with fitting parts by hand-scraping, to obtain large, uniform contact areas to enhance stability and rigidity.

And yes, I've personally seen asian mill-drills with just such shims installed - right from the factory! The interesting thing was, they were made of copper, and taped in place under the column!! How's that for stability?

Jim

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That term has a great deal of varied use, depending on where one is from. The instructor at the voc-tech school used it all the time to describe machined chips. He was from the UK and I think that was standard use there.

It is also a general term for any particulate by-product, for example the fine debris that results from flint arrowhead manufacture is indeed described as 'swarf.'

Jim

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I'll add a little here, Harold. With the particular mill in question, the column tilts for angle milling, and there's no guarantee that the shim will be correct for any other position other than with the column square to the table. I just bought one similar but smaller, but haven't had time to lay the base and column out to see if there's a problem there, or where the head mounts to the column dovetails. I have to say, I'm impressed that such a small machine has an R-8 spindle taper, and it seems to be quite rigid for it's size. For something like model building, and with it's $279 price, it seems to be a pretty good value at first glance. Time will tell the full story.

Ok - I'll bite - can you describe the method -

Mart> Tramming is done with a co-axial indicator. It is common that many