How to use a round column mill

I have a Rexon, also known as Naerok in UK, it has a round column that goes down through the base, it is located by the rack. You must lock the column, and the way that you are not using, also the quill. It serves me ok(could do better), I bought the machine before I took up model engineering, I was into wood turning, and wanted a drill press, and the mill was cheaper at the time.

Ian S C

Here are a few more additions I have made for the FB 2,

Regards

Gray,

Mixed results today, I tightened up column hex bolts and gib to the point it was getting hard to move the head and the 2 flute cutter still caused the head to vibrate sideways. Checked all over and I am sure it is due to flexing of the column. I ended up with a hole 8.2mm x 8.07mm

I also needed to cut some 10mm slots. Using a 2 flute I get exactly the same vibration on a plunge. However I also have a good quality 4 flute center cutting endmill. Using that It works perfectly, no vibration and lovely curls coming off.

So either the mill does not like 2 flute cutters, or the cutters I have bought from RDG are a problem.

Adrian

I'd place a small bet on the latter.

Andrew

Edited By Andrew Johnston on 02/07/2019 19:00:35

I have been using a Warco Economy Mill/Drill for about 20 years. Yes, it is not ABSLUTELY rigid, and the head needs to be clamped to the column quite hard. If it is not, a cutter will dig in and shift everything.

It sounds as if your machine has play in it, possibly in more than one place. (I am assuming that your cutters are sharp; and that you are not climb milling )

My advice is to go through the machine check for clearances and eliminate them. The alignment strip is only an approximation, from what you say.

Is the column firmly fixed to the base?

Are the X and Y gibs correctly adjusted?

Is there a lot of play between the quill and the head?

Are the quill bearings, in the head in good condition, and correctly adjusted. They may be taper roller bearings. The manual should show you, and possibly advise on how tom preload them.

In any case, the head needs to be clamped firmly to the column

As you eliminate unnecessary clearances, things should improve.

HTH

Howard

Edited By Howard Lewis on 02/07/2019 20:23:28

It looks like a game of 'snap' with regards to your milling machine. Your mill is the 1st one I've seen identical to mine, see this previous thread Link

The symptoms you describe are exactly the same as my machine and I get around it by drilling a hole 1st as described by others. Also in another of your threads you made a new oil lift screw and mine also broke! My solution wasn't as elegant as yours, I just drilled and tapped the end for a cap screw and cross drilled the end and attached to the motor with a split pin.

Dave

Machine issues aside, it's great to see such clear photographs chaps.

OH for a workshop Gray!

Sam

Gray

Regarding your modifications to the Emco, is the 3rd picture down an extended slitting saw arbor? What do you use it for? Also in the 4th picture is the slot for the stops on the Y axis something you have fitted or is it standard on the Emco as it's not present on my copy.

Dave

iNf

I’m guessing that as horizontal mills have an arbor support, he has done much the same for the vertical arbor. Smallish slitting saw, gear cutters or anything else that might be used on an arbor and benefit from a little (or more) support. Rigidity is the ideal characteristic for most metal cutting machines and every little extra helps towards that goal.

Hi Dave,

The Over arm support is used mainly for gear cutting, the additional support improves the finish.

I have also added an bracing system when using very large DP or Module cutters.

Lastly the Y-Axis stops are another of my designs,and are not fitted to the machine as standard.

Regards

Gray,

Gray,

In your first picture, is that a quill lock?

Trying to get to the bottom of why the ZX-16 is more flexible and looking at your pictures, I am getting the feeling the column may be a larger diameter than the ZX-16, I have measured mine at 3". What is it on the FB2

Thanks

Adrian

Hi Adrian,

Yes the first picture is a quill lock. What a lot of Emco owners do not realise is that there is a Tufnol gear in the input train from the motor to the gearbox. These have been broken in the past where owners use bottom gear to lock the quill.

This little unit ensures there is no strain through the gearbox.

My column is 78 mm diameter. One of the posts above mentioned checking the condition of the slides on the table. I once had a problem with the finish on the end of any bar when cleaning up the face with the side of an end mill or slot drill. Of course initial thoughts turn to play in the spindle, but as this was ruled out I looked at the slides. Sure enough both were a little on the loose side.

Tightening the slides made a world of difference, but, and it is a big BUT do not over do the tightening. To adjust any slide way you need to take off the feedscrew and push the slide by hand. If it is that tight, that you cannot then this will cause premature wear. The only correct way to adjust the head to column slide is with the head off and feedscrew removed. The Gib strip on the guide key wants to be loose so that you can set the adjustable clamping bolts to get the slideway sorted, once these are set then adjust the Gib.

Get this wrong and you can get to a stage where the slide will stick, then suddenly drop to take up the play in the feedscrew.

Regards

Gray,

Not being a precision engineer, after moving the head up or down the column,to align the head, a cheap laser is temporarily placed on a custom made bracket, on the head, and used to shine a line of red light onto a pencil mark on the most distant part of the shop. At a range of ten feet, (3 metres ) or so, an error of the width of the pencil line only approximates to a good old English thou (25 microns for those who are metricated )

HTH

Howard

Hi Gray,

Yes I have tightened it to the point where you get the sudden drop, decided it was not good and loosened it off.

Well 78mm = 3" so it must be either the tube wall is thinner or the steel is not such good quality. I am now 99% sure the vibration is coming from the spring in the tube and castings. I have tightened every thing up to almost jamming solid point and it still does it. Plus Inf also says he has the same issue.

Just some thing I have to live with or buy another mill.

If i really must cut blind slots I just need to by 4 flute center cut end mills as they work perfectly. Or maybe i should just invest in a good quality 2 flute to see if that works. I am tempted to try making a D bit to see if that works.

Adrian

Howard,

Yes the laser is a good idea, your article in MEW inspired me to look further. Did you know that on ebay you can get just the laser diode line module and a psu plug. It is a lot smaller than the laser line unit you used in your article.

Adrian

Adrian

You have a PM

Dave

iNf

Latest news about slot cutting on the ZX-16

I have found that of the 5 new milling cutters I inherited, I have a Maydown Triplicut 3/8" long series cutter. It is centre cutting and will do a perfect plunge cut. I also tried a rather large and blunt 2 flute Osborn cutter, same head wobbling problem.

I am also learning how diffrent cutters can be. I have Maydown, Franken and Osborn that cut perfectly and the £85 set of 20 are terrible. They seem to be sharp and do cut but the finish is all torn and very rough.

Any sugestions for reputable supliers of HSS cutters that dont cost an arm and a leg?

I am unable to use my mill at the moment As I had to take it apart to move it. The reason for moving it is that the builders are coming this weekend to start on the garage extension (Yay!) Maybe then I won't have to dance around my bike to use it or the ml7!

When I eventually get it in it's preferred position I will take on board Joe and Gray's advice regarding adjustments

Has anyone ever filled the column on a round column mill with concrete or similar to improve the stiffness or is it not a good idea?

Dave

iNf

That's an important lesson to learn, and one that is not always understood.

I don't buy many new small HSS cutters (I use carbide as standard), but when I do I use Drill Service in Horley.

Andrew

Edited By Andrew Johnston on 04/07/2019 15:15:37

Some of the HSS cutters I have are Dormer, they work very well but are expensive. I have also bought HSS cutters from Tracy Tools and ArcEurotrade and they have worked OK for me. I also have cheap cutters that I regrind and use for roughing.

Thor