Guidance on turning in a vertical mill

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Guidance on turning in a vertical mill

This topic has 43 replies, 15 voices, and was last updated 9 January 2011 at 09:36 by RJKflyer.

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19 May 2010 at 11:25 #51831
RJKflyer
Participant
@rjkflyer
Hi All,

Shortly to receive my vertical mill, having got good advice from these columns…

Am contemplating how best to do some simple turning in the mill, and would like some guidance as how best to do this – in terms of tool holding etc. Would much appreciate any links to suitable equipment.

Thoughts folks?

Thanks!
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19 May 2010 at 11:25 #5070
RJKflyer
Participant
@rjkflyer
19 May 2010 at 11:47 #51832
JasonB
Moderator
@jasonb
Are you talking about rotating the work against a cutting tool, if so a lathe would really be the better option. I suppose small dia work held in a collet could be rotated against a lathe tool held in the machine vice but not ideal.

If you are working on parts that are too large to turn in your lathe then they are best fixed to the largest rotary table you can obtain and the work rotated against a milling cutter.

Jason

Edited By JasonB on 19/05/2010 11:48:48
19 May 2010 at 12:13 #51835
Terryd
Participant
@terryd72465
Do You have a lathe? If not that would have been a better buy as it is a much more versatile machine. A lathe can act as a miller, especially with a vertical slide attachment and as a horizontal borer with the work fastened to the cross slide, as well as complex turning of irregularly shaped materials and components.

That is besides it’s normal turning operations. But as Jason says there is only a very limited amount of turning as such, possible on a milling machine. Setting up even simplest of cutting tools will be difficult given the necessity for ensuring rigidity and the correct cutting angles.

Have you considered how you will hold your components/materials, let alone the tool.

Sorry to sound negative but turning in a milling machine is not a process normally carried out or encouraged. Of course it depends on the actual components to be made, if accuracy is not necessary and components small, I have heard of light turning in a 3 jaw Jacobs chuck using a file, in a drilling machine.

Regards

Terry
19 May 2010 at 15:09 #51841
RJKflyer
Participant
@rjkflyer
I’ve got a toolmaker’s quality 2hp vertical mill which should more than capable of undertaking reasonable turning tasks. 90% of my work is drilling/cutting/milling/shaping hence the choice of this not a lathe.

I’m only looking to turn things 12mm or less in diameter, and will use the collets. Anything larger – unlikely for me – but i’d use a boring bar.
19 May 2010 at 15:37 #51844
Terryd
Participant
@terryd72465
Hi,

Your machine sounds like a smaller version of my old Bridgeport, a very powerful and accurate machine, but the problem with ‘turning’ on the Milling machine is the positioning and support of the tooling and the accuracy with which you are able to manipulate the tool in relation to the component you wish to ‘turn’.

It is of course possible and I for one would be very interested to hear your experiences, I am always willing to learn new ideas and skills even after a lifetime in the game. I look forward to hearing of your experiments, keep us informed.

Best regards

Terry
19 May 2010 at 15:41 #51845
JasonB
Moderator
@jasonb
If the head tilts 90deg then turn it on its side so the axis is parallel to the mills table. You can make a simple toolpost from a block of steel that bolts to the table, you can then use the x & y axis of the mill like a cross & top slide.

Not so easy when it comes to drilling the end of the work, probably have to resort to removing it from the collet, setting up true in the machine vice, clocking the centre and then drilling.

Think I would be looking for a cheap mini lathe very soon.

J

Edited By JasonB on 19/05/2010 15:43:21
19 May 2010 at 15:53 #51846
RJKflyer
Participant
@rjkflyer
JasonB – i’ve seen quite a few videos of folks drilling using a drill in a proper 3-jaw chuck bolted to the table and with the workpiece (smallish pieces – up to 20mm) in a collet.

Seem to work fine and also by coax centering the chuck with a dowel in it first, it’s absolutely 100% on centre. Certainly no less so than in a lathe.

Terryd – agree that i’ll be limited to what can be practically done, but seeing the pretty negative posts here i think i ought to do a set of YouTube videos when i’ve cracked this!
19 May 2010 at 15:54 #51848
RJKflyer
Participant
@rjkflyer
Should have added I’d be inclined to set the workpiece in the 3-jaw and the drill in a collet in the mill, as opposed to the way i described i saw in a video – i think they’re doing that the less optimal way around…
19 May 2010 at 20:49 #51859
Terryd
Participant
@terryd72465
Hi There,

Could you point me to the you tube video I’d really like to see what is happening.

Jason, even if you clock the workpiece, if it is round how would you ensure real concentricity if that is important. At least in a lathe you can turn the diameter and drill on the same setting to ensure concentricity (at least if your lathe is set up correctly) how would you manage that on a milling Machine?

I really would like to know as it may come in useful some time.

Best regards

Terry
19 May 2010 at 20:57 #51861
JasonB
Moderator
@jasonb
Thats the point I was trying to make terry it would take forever to try and set up 100%. Even with a DRO and decent edgefinder its unlikely to be a good as a lathe and certainly not faster.

You will also be limited to the length of the workpiece as there is no tailstock support or the drawbar will get in the way.

I know I would rather mill in the lathe than turn on the mill, the Minnie in my avitar was all done on the lathe but now having a mill I would never go back.

I would like to see those videos as well, just because you have seen it on you-tube does not make it right

J
19 May 2010 at 21:25 #51864
JasonB
Moderator
@jasonb
Well with the addition of CNC it may be worth doing but to set that all up manually would not be so easy

Edited By JasonB on 19/05/2010 21:34:24
20 May 2010 at 05:38 #51873
Terryd
Participant
@terryd72465
As you say Jason,

With cnc it’s a very different ‘kettle of fish’. However if you are producing one offs it would still be a chore writing all that code – unless you are using a graphic system, even then I would have made several components on the manual lathe by the time I had the code completed.

The tool holding system also looked home made if I’m not mistaken but it’s difficult to see that much detail on the video. The thread of course would be impossible on a manual milling machine as there is no way of providing the necessary coordination between the tool and the component.

However from the op’s last posting, from what I can see he is describing using the machine as a drilling machine rather than ‘turning’ a component. Even so it’s still a lot of setting up to accurately drill a round bar. Of course you could use some kind of drilling jig or fixture but you would need to be making quite a few of the part to make it worth the effort.

Interesting exercise

Terry
20 May 2010 at 07:16 #51874
RJKflyer
Participant
@rjkflyer
Take a look at these.

Not actually the ones I originally saw, but thought i’d post these having spotted the CNC comments here…

http://www.milltolathe.com/video.php

Needless to say, the concept of the kit at milltolathe is something most of us could probably replicate ourselves for the occasional use we might wish to make.

My biggest learning from my foray into this whole area is just how innovative we can all be.

I’m a novice here, and i can appreciate entirely the line of commentary that says a lathe is for turning and a mill is for milling, but for someone like me who has a really decent mill now, does not really have space for a lathe, and does only occasional ‘turning’ this looks like a very plausible way to make more the mill more versatile.
20 May 2010 at 08:17 #51875
Terryd
Participant
@terryd72465
Hi there,

As you say you are a novice and I’m not quite sure that you understand the concepts here. Excuse me if I speak out of turn but I am trying to be positive. These videos show a computer controlled milling machine being used, not a ‘good quality’ manual one. These cnc machines are very different to a normal manual milling machine. A basic small cnc milling machine will set you back 2 to 3 thousand pounds. See the example KX1 cnc here and check out the size:

http://www.arceurotrade.co.uk/Additional-Departments/Special-Offers/Sieg-KX1-Hobby-CNC-Mill

A manual machine can be converted to cnc but it will cost. Probably several hundred pounds upwards and then there is the computer and software. You need three ballscrews (about £150 each) a stepper motor for each (say £30 each) and a control board as a minimum, a pc and software (£100 to £300 say). And then some expertise to set it all up and program it. See here for some sample prices:

http://www.arceurotrade.co.uk/Catalogue/Ball-Screws

Of course you then need to buy the tool holding device shown on the video and the necessary tooling. A small to medium sized lathe would cost much less, and if you’re only going to turn small components a mini lathe which is very small, take up little space and is inexpensive (probably less than the tooling shown on the video and not much more than the cost of one ball screw), would be ideal. See here:

http://www.arceurotrade.co.uk/Catalogue/Machines-Accessories/Lathes/C0-Baby-Lathe

I’m sorry if I sound negative but a manual Milling machine is just not equipped for accurate turning, you are making a rod for your own back. I’ve shown Arc Euro trade stuff simply as an example but these components and this equipment are available all over the internet.

Best regards and good luck,

Terry
20 May 2010 at 09:10 #51877
JasonB
Moderator
@jasonb
If you do want to explore this route then the tool holders in the shereline video would be a simpler way to go. You would really only need one tool to be able to face and turn a simple shape. and an inverted drill chuck or collet fixture for drill bits, better to keep the work in the mill for concentricity. Or maybe make something up like a capstan head.

What these videos don’t show is the time it takes to set up this tooling as each cutter will have to have its co-ordinates set exactly. Does your mill have any form of digital scales or a proper DRO? if not its going to take a long time to set up each time you want to turn something and you will have to record the handwheel positions, which will likely be lost as soon as you revert to milling. If you had a DRO it would be possible to leave one of these tooling clusters at one end of the mill table so that you could reasonably easily go from milling to turning/drilling

It also depends on what you call occasional turning, is that once a month or once a week?

J
20 May 2010 at 11:33 #51883
Ian S C
Participant
@iansc
A good many years ago I damaged the pin that locks the back gear on my lathe,with the mandrel out of the lathe I turned the new pin by clamping the steel in the jacobs chuck on the mill, and put the tool in the machine vice, it worked OK but I would not say its a thing I would recomend as a regular method-OK in emergency.Ian S C
20 May 2010 at 12:13 #51888
Terryd
Participant
@terryd72465
I agree Ian, in emergency we try all sorts of approaches, but not necessarily recommend such jury rigs as a norm.

Years ago i used to do a lot of recreational sailing and often heard of people jury rigging sails after accidents, bad weather etc, but you wouldn’t use that rigging for everyday use.

Horses for courses.

Terry
20 May 2010 at 12:43 #51891
Circlip
Participant
@circlip
That’s a new shaped wheel, Mill to lathe, wonder if a toolholder is cheaper than a vertical slide?? Spose it falls into the modern way of thinking, family first and THEN get married.

Regards Ian.

Edited By Circlip on 20/05/2010 12:46:06
20 May 2010 at 12:52 #51892
Terryd
Participant
@terryd72465
This site has some comments on using a milling machine for turning with some useful comments.

http://newsgroups.derkeiler.com/Archive/Alt/alt.machines.cnc/2009-10/msg00078.html

Terry
20 May 2010 at 20:43 #51913
david lockwood
Participant
@davidlockwood10028
Before trying any of this please keep in mind that I am not an expert in the matter these are just some ideas. I am quite happy to accept may be wrong

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Not long ago i had a job set up in the lathe that I did not want to disturb and found that the boring bar I had was not going to do the job so I made another on the mill. The only problem was that I would have to turn a taper on the front so I could cross drill the bar at the angle I wanted. It was a very simple job to put a large lathe tool in the mill vice set at an angle (as a form tool) and turn the short taper by advancing the work with the quill.

A longer taper would have to be set by setting the mill head over and taking trial and error cuts possibly with a test piece but you have to advance to tool by raising the knee of the mill if it has one. Or turn the head right over near ninety degrees. I have read about some one doing something similar to fix a morse taper in the mill spindle. It may have been in model engineers workshop?

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I have as it happens made some holders for holding round work in the mill vice with ER collets.

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These could be used as drill holders as in the Youtube video. I think that they could be set very easy

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1        by holding a piece of nice straight stock on both ends one in the mill collet and one in the drill holder then lowering the quill until the holder is on the mill table then clamping in place

2        clamping the holder down first then holding the drill in a mill collet and aligning it until the drill will just drop in and out of the close fitting holder.

>>

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On my mill I can loosen the column that holds the head and it is then easy to set a a piece of stock tuned to a close fitting diameter in a slot or pre drille
20 May 2010 at 20:46 #51914
david lockwood
Participant
@davidlockwood10028
On my mill I can loosen the column that holds the head and it is then easy to set a a piece of stock tuned to a close fitting diameter in a slot or pre drilled hole as in the second method for the purpose of setting the spindle accurately in the centre.

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This all being said I would look for a cheap small lathe. I expect you would use it more then you think

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Here is a link to a youtube video of a mill converted to a lathe but I think you would need a lathe to make it as you could only turn short work in the mill due to not having tail stock support and the spindle would be to long to make. http://www.youtube.com/watch?v=b2-Kdud7eiA

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Good luck all the same no harm in trying whether it works or not.

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20 May 2010 at 21:19 #51915
Terryd
Participant
@terryd72465
Dear David,

That is a cnc milling machine, not a manual one, fitted with what looks to be a homemade equivalent of a lathe headstock.

What is the point?

How much cost for the motor, bearings, time for manufacture etc. That doesn’t take into account the setting up time etc etc. Again, what is the point when a lathe is so cheap and versatile? Just because you can doesn’t mean you should as someone said earlier. I’m just flabbergasted at the wasted effort.
21 May 2010 at 16:33 #51940
david lockwood
Participant
@davidlockwood10028
As I mentioned I would look for a cheap small lathe. I think the reason for making the attachment was for the pleasure of making it as it is for everything I make.

The fact that it is cnc I think is not important apart from threading you could do every thing manually

I would go the lathe root every time and consider turning in the mill as a little eccentric but if that is what someone wants to do as a hobby then its not a wast of time if they enjoy it

Respectfully David

Ps sorry for all those face things in my ealier post i don’t know why they are there

Edited By david lockwood on 21/05/2010 16:36:02
30 June 2010 at 18:45 #53024
RJKflyer
Participant
@rjkflyer
Well, I have now done what i’m afraid many here seem to consider the unachievable, or perhaps plain stupid.

I’ve more than successfully turned material accurately in my mill.

I made a toolholder from a piece of (scrap) 3″ long 2″ dia EN1A bar which i:

1. milled square,

2 milled out a 12mm square slot about one quarter way down and along one side,

3. fitted 4 M5 socket head cap screws (to hold the tool),

4. relieved the edge above the tool by 10 thou to allow for the torsion opening the slot slightly when the tool bit is clamped (and thus pushing it out of square), so making sure the tool holder was clamped only by the absolutely parallel material below the tool.

Clamped 8mm carbide tool into the tool holder, obviously on its ‘side’, and then tool holder in mill vice.

Used laser finder to set tool cutting point to the centre. Locked y axis.

Held the workpiece in a appropriately-sized collet.

Turned away… Perfectly satisfactory on both z-axis (along the workpiece) and x-axis (across the dia) cuts.

So, am i missing something? Yes yes i am sure that parting off might be more troublesome, and knurling will be impossible (maybe…), but i have acheived what i set out to do – use a very high quality mill to turn the occasional smallish item.
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