Moving the Head on a Round Column Type Mill

I took John McNamara's advice and watched Marc L'ecuyer's videos and they are, indeed, excellent. Everything John described.

In the ones I saw Mr L'ecuyer describes at some length setting the head on a column type 'mill' then trying not to move it again. I have a Warco Economy machine with which I'm very pleased and use a lot. As members will know, this is a round column design (not like a Bridgeport with a 'knee' where you raise and lower the table) and I wind the head up and down fairly frequently to accommodate different tools and jobs.

What I'm now wondering is whether this is bad practice.

Mr L'ecuyer tells us to use the 'long tool method'. That is, fit your longest tool to the quill as accurately as you can - in my case that would probably be a collet arbor and about a 20mm end mill - tighten the head with it in position then leave it alone and only use the quill thereafter.

Makes sense?

However, I guess if you don't adhere to what Mr L'ecuyer advises you might swing the head around the column to some extent to access some jobs. But if you do follow his rule couldn't you normally reach the work by winding the table on the X or Y axis or both?

Martyn

The reason for trying to avoid moving the head during one machining setup is that there is some play and you could loose your reference point.

For example if drilling several large holes, you may start with a spotting drill, go up through several sizes of drill bit and then find to fit say a 1/2" drill that you then need to raise the head more. It now becomes a problem to get the raised head exactly where it originally was.

Hi Martin,

For a round column type mill, a simple idea for keeping the mill head aligned in the same plane if you have to move it up or down is to attach a laser pointer to the side of the moving head and point the laser at a vertical line which is painted on a wall or object in front of the mill. Align the head with the vertical line as you move the head.

The target line should be as far away from the laser as possible. The greater the distance, the greater will be the accuracy.

Paul

Use an edge finder. Drill the holes as large as you can and then use the edge finder again when you have raised the head.  Also extension holders could be used so everything is about the same length.

Edited By David Clark 1 on 14/11/2015 08:51:27

There was an article in Model Engineer a few years back for a guide for the column of round column mills, I keep on thinking I should fit one on my Rexon vertical mill as the head can swing about 1/4" as it is.

Ian S C

I know that David Clark is wary of Laser Finders, (and his suggestions DO work) but like Paul Lousick, I use a small Laser. Apparently, from what he has said, Stan Bray also uses this method.

It is a cheap unit, bought from a DIY store, and fits into a slot machined in a piece of steel plate, fixed to a bracket on the head of my Warco Economy Mill/Drill. The laser projects a line onto the furthest point of the shop, (roughly 3 metres away). Less than ideally, this is a white painted door carrying a long pencil line (drawn to the line projected by the laser). Probably OK until the hinges wear!

Howard

I also use a cheap DIY laser, but instead of using a pencil line I put up a strip of black tape on the wall of the workshop, put in a nail at the top of the strip, hung a piece of white string with a weight (big nut) at the bottom. Before moving the head up or down bring the laser light onto the sting when the light appears to floorese (sp?). Anyway, when you move the head, bring the head round to bring the light back onto the string and I think I'm near enough for farm work. We had a fair old discussion at the York Club about this, and although we never came to a definite answer to the degree of accuracy I could expect over the 12 feet or so of separation, it was thought that only changing for a knee type machine (which I couldn't afford) would affect any improvement.

Alan.

Gentlemen,

I have a round column Mill and I think i've just had an idea, if I drilled a series of holes up the column that were reamed to take a dowel pin and I had a fixed stop attached to the mill head I could hold its position when I wound the head up and down. Obviously the holes would have to be reasonably accurately placed.

Martin P

First thing is to see if you can set the head at a height which will cope with a spotting drill, and the biggest drill you need for the operation. 80% of the time I need to move the head, its because I forgot to think through the full series of ops first. I've got one of the old Chester Eagles/ Warco Minor type and it's usually got enough travel if set up right in the first place.

Steve

If I could ask some of the advocates of laser devices, could you point to a device as such that you use please? ( no pun intended..😆  )

Martin, sounds doable and probably more repetative than the laser idea?

Edited By John Rudd on 14/11/2015 21:59:14

Thanks for all that. Both the laser and edge finder seem 'doable'. But I reckon for my purposes Steve Withnell's approach will suffice and, of course, comples with Marc L'ecuyer's advice - move the head as little as possible.

Martyn

John Rudd:

Mine came from Axminster.

The mod I referred to above mounts a guide on the crank housing that bears against the rack, the bearing points could be a pair of ball races, I think the ones in the article were metal(?cast iron) pads.

I quite like the idea of the Laser pointer. To get a good vertical you could use a Plumb Bob.

Ian S C

Your milling machine column will also have to be as vertical as your reference line otherwise your movements will not be in line with the column as it raises/lowers.

Alan

Alan, true, And my mill is on a wooden bench, so that can change from day to day depending on the humidity./ I first found that problem when I built a circular saw bench from wood, every time I use it I have to adjust the blade square, I'll rebuild it in steel, I really will, perhaps one day.

Ian S C