Using a pillar drill for milling?

[Chris VParticipant @chrisv]

Good evening, I'm pretty new to model engineering and still working at getting my Myford ML1 up and running to learn on. I also have a Startrite Mercury bench top pillar drill. Just wondering if its feasible to use this for light milling work with suitable milling vice? As far as I can see the only(?) issue might be cutters slipping in the Jacobs chuck, but would it be ok for as I say light work?

Thanks in hopeful advance….

Chris.

[Chris VParticipant @chrisv]

Using a pillar drill for milling?

[John HaineParticipant @johnhaine32865]

NO! The Jacobs chuck will probably come off its taper in short order.

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[ChrisBParticipant @chrisb35596]

Not a good idea I think…spindle bearings on a pillar drill are not meant to be side loaded.

[Chris VParticipant @chrisv]

Thank you John, Bill & ChrisB for your prompt replies. Obviously I hadn't thought about the chuck coming adrift!

In anticipation of getting the lathe working eventually I did buy a set of collets with 1MT holder for the lathe. Presumably this would then be preferable for any light milling, but the issue might still be the collet holder coming loose in the morse taper? Would it be a reasonable (if/or necessary?) to adapt it with a bolt through the head-stock bore, I think this would be a draw bar?

The thread on the spindle nose is 7/8" x 9 tpi so guess I'm unlikely to get a collet holder to fit direct onto that?

Chris.

[John ReeseParticipant @johnreese12848]

It is possible remove a lot of metal by chain drilling. Using an endmill instead of a drill will allow a little overlap of the holes. If you can get rid of nearly all the excess metal by chain drilling you might be able to get away with very light milling passes to clean up. Note my emphasis.

[Steve King 5Participant @steveking5]

I tried it on my startrite drill it didn't end well. Lesson learned

[RobCoxParticipant @robcox]

If you want to find out how good a drill will mill, try searching youtube for AvE – turning a drill press into a s__tty mill. He does exactly that.

[Robin GrahamParticipant @robingraham42208]

I too tried milling with a drill before a got a milling machine. The problem I had was, as John Haine said, that intermittent loading on the cutter just 'vibrated' the chuck arbor out of the quill.

Your plan to make a drawbar for your collet holder for milling on the lathe is entirely sensible and in fact necessary. You don't say what collet system you've bought, but if ER or finger collets should find that there is a female thread in the back end for precisely this purpose. Likely M6 or 1/4" for MT1. All you need is a length of studding, a washer and a nut.

Robin.

[Chris VParticipant @chrisv]

Thank you John R 'chain drilling' will be something to bear in mind but the consensus seems don't try to mill with the pillar drill. Thank you also Steve & Rob for your replies.

Also thank you Robin. I just checked and it is an ER (?)set of collets and it does indeed I now see have a tapped hole in the arbor end, I hadn't noticed that before, though its barely been out of its box. So that should be simple enough to sort.

I did in fact get hold of a Myford vertical milling slide, its not the earliest single stud version but the later two stud version which I figured was a design improvement. I think it has a tee nut to secure it to the cross slide along with two alignment pins. Guess what, it dosent quite fit. Think I will have to file a small flat on the two pins, its only about 0.5mm out, rather that modify the cross slide tee nut groove.

[DuncParticipant @dunc]

I have not personally tried any of these approaches.

Have a look at Popular Mechanics July 1954 & Jan 1969; Popular Science Jan 1952; and, MEW Jan-Feb 1996.

Google for a link to the archives of (USA) Popular Mechanics & Popular Science magazines

A few other thoughts I have gleaned from the 'net (afraid that I lack any links)

Suitable, perhaps, for light surfacing of small aluminum or brass parts with a small end mill and maybe some slotting

Do NOT buy an Albrecht chuck, it will not be up to the task.

If the chuck is held in place by a morse taper anywhere you risk it coming loose under side load. The friction retention force only works if the load is axial. (Some of the above articles detail the construction of a chuck support to resist lateral forces.)

End mills are very hard. They are harder than the jaws on a drill chuck, so the jaws will not grip them the way they grip the soft drill shanks. This means the axial retention force for an end mill is poor, it will be drawn out by the helix angle on the end mill.

Drill chucks only support the tool at three points around its periphery. This allows the tool to move sideways to some degree – a lack of rigidity.

If doing this I would purchase the largest Jacobs ball bearing superchuck that would fit the machine. When installing it I would aggressively clean the taper socket and the arbor with clean solvent, and heat the socket and cool the taper before installing.

[Chris VParticipant @chrisv]

Thank you Dunc, I certainly did not realize that about hardness of cutters not holding well in a drill chuck.

I presume I would be safe enough held in a collet chuck, though I notice some milling cutters have a threaded end I think?

For my perceived limited milling though I will stick to trying it on my lathe, first I need to get that up and running.

Appreciate your input,

cheers Chris.

[thaiguzziParticipant @thaiguzzi]

Two words.

Just don't.

[not done it yetParticipant @notdoneityet]

Another few words to add to thaiguzzi: It ain’t worth it.

[Chris VParticipant @chrisv]

Thank you both, I won't!!

Cheers

Chris.

[old martParticipant @oldmart]

Is there any way to drill a 10mm hole for a drawbar in the drill spindle? MT2 milling collets use a 10mm thread, unless they are old when a 3/8" W is the nom. Even in a mill with a drawbar, drill chucks have their own short taper which makes them unsuitable for holding milling cutters. I have occasionally held milling cutters in a drill chuck to plunge cut like a twist drill, but never to cut sideways.

[Chris VParticipant @chrisv]

Thanks Old Mart, that interesting. As others have said also, if the sideways movement is out due to the bearing not being designed for sideways load it seems best to stick to milling on the lathe…and maybe upgrade that in due course if/when the need arises.

Cheers

Chris.

[AlanWParticipant @alanw96569]

Hi Chris,

I successfully adapted a Pollard bench drill for milling. Although it was a vast improvement on milling in the lathe I had at that time (Hobbymat MD65), it has never been capable of other than light milling. I got around the drill chuck problem by making a ER32 collet chuck to fit the Jacobs taper, retained by a c/s screw into the end of the spindle; the spindle drilled quite readily incidentally. Unfortunately this also increased the overhang from the bearing, which compromised rigidity. I managed to replace the existing ball races with tapered roller bearings for the reason stated by ChrisB. There are plenty of other hurdles to overcome, like fine feed, quill lock and, of course the x-y table. If you are really that interested, I wrote an article on the adaptation for MEW, around 2010/11. If I had known how much work was involved at the outset, for the limited performance, I wouldn't have wasted all that precious retirement time. Hindsight is a wonderful thing!

Enjoy the hobby, it is addictive.

Alan

[Nigel Graham 2Participant @nigelgraham2]

As others say… DON'T. With ANY type of drilling-machine and drill-chuck.

Regarding chain-drilling prior to milling, I would strongly advise filing the worst of the resulting "teeth" down before milling. That's because the milling-cutters will catch on the sharp edges and could cut inaccurately or even shatter. They prefer a smooth, continuous cut you will certainly not achieve on a drilling-machine. And if they shatter I hope you are wearing eye-protection.

'

Dunc's paragraphs:

" Drill chucks only support the tool at three points around its periphery. This allows the tool to move sideways to some degree – a lack of rigidity. "

Really? Line not point contact actually, but I don't recognise that lack of rigidity in a good-quality drill-chuck in good condition; used for drilling not milling.

'.

" If doing this I would purchase the largest Jacobs ball bearing superchuck that would fit the machine. When installing it I would aggressively clean the taper socket and the arbor with clean solvent, and heat the socket and cool the taper before installing. "

Clean the tapers yes, when fitting any chuck on any machine, though I don't know what you mean by "aggressively". It doesn't need degreasing, just any swarf and other particles removing.

Otherwise…. "if doing this…" (Milling) I wouldn't be doing "this".

And shrink-fitting? Not on my machines, you would not!

It's not clear whether you mean the Jacobs taper in the chuck itself, or the spindle taper. If the latter you do not want to shrink-fit anything in there, and anyway, to what temperature would you risk heating such equipment evenly, without harming any part of it?

'

Chris –

The threaded ends you refer to are common on most milling-cutters, to fit special chucks such as the Clarkson Autolock. The cutter screws into a collet ground accurately to hold the cutter shank, while the centre-drilled hole in the end of the cutter engages a pip inside the collet-chuck body fractionally before the collet-holder reaches its thread-end, to give axial support. A special ring-spanner is made to fit the flats on the chuck body.

NB: the cutter shank diameter and collet diameter must match. A 1/4" dia shank won't fit a 6mmm collet for example. However, although vice-versa will, you can't expect the collet to grip, and even if forcing it does not break the collet, the cutter could slip or jam and snap.

The collet chuck in turn has a Morse or other standard taper shank to fit a correspondingly tapered lathe or milling-machine spindle, with a draw-bar to hold the chuck back in the spindle. Collet sets of various patterns are available for standard tapers such as those in Myford lathes, and you can use these for holding milling-cutters.

There are two forms of ER collet then, if yours have a draw-bar thread. The ones I know use a dedicated chuck that fits the spindle nose, and holds the collet by a particular assembly / disassembly technique. This allows holding work-pieces that project backwards into the lathe spindle.

Myfords used to sell a neat version of its own, but sadly now they are as common as poultry-dentures and at avian-dentistry prices. I don't know if anyone stocks a copy of them, and if so, what they are like.

Again, the cutter must be the right diameter for the cutter or work-piece.

If you are milling in the lathe you can hold the cutter in the chuck if you must, but not preferably. It will only be as accurate as the chuck, and insecure if the jaws are worn. And being hard it won't do even hardened jaws much good if it slips round. A collet is far better.

'

The vertical slide locating-pins. Yes, modify them, not the lathe itself! And yes, the stud holding the vertical slide to the cross-slide will need a T-nut, but a good fit and generous length.

Be Aware that the stud or bolt should NOT pass through the T-nut, as that can load the T-slot shoulders very unfairly, and even break them. That's certainly the advice I have always known, and my clamping-sets' T-nuts all have the lower ends of their threads peened over to prevent it.

[Chris VParticipant @chrisv]

Hi Alan, Thank you for that. so its interesting to know that it could be done but as you say life is too short, I will focus on getting the lathe up and running and how to use that, then tackle milling later on.

Cheers

Chris.

[Chris VParticipant @chrisv]

Hi NigelG2, wow thank you, just shows me how little i do know (-: This is most helpful.

Appreciate the insight into the milling cutters. So to clarify the threaded end ones are the bees knees as the cutter cannot come out and they have the end pin for extra rigidity.. But plain shank cutters of the correct diameter are fine to use in the collett system you describe ER20 with a draw bar, that I will in time need to make. With this holding technique just like a wood router under heavy load the cutter can slip outwards into the work, but the key will be to take it easy. My mid 1930's Myford ML1 is not exactly built for rigidity so I would not expect it to handle anything too heavy anyway.

Thank you I had not thought about the length of tee nut helping with stability, I will consider that when looking at purchasing one.

When you say the stud should not pass through the nut, I understand that to mean into the nut, but not protruding out the other side so it grounds in the bottom of the tee slot ? Just check I fully understand…

You happen to mention hardened chuck jaws, Ive noticed with some chucks for sale they come with hard and soft jaws….er..lost on me?

Many thanks

Cheers

Chris.

[Nigel Graham 2Participant @nigelgraham2]

The wretched log-in system on this site…]

'

A pleasure!

You can use the threaded-end cutters in plain collets as long as it's the shank that's gripped and not the thread.

Lathes are not really milling-machines laying on their backs, and a vertical-slide on the cross-slide is not ever so rigid, so you can only take light cuts at gentle feeds.

The length of the T-nut is more to spread the load than add stability, though it will do that. My smallest lathe is a 2.5" centre-height EW Stringer, and I made not T-nuts as such but T-strips to hold the home-made vice on its vertical slide. These are bars of T-section the length of the slot, with two tapped holes in each.

Yes – that's right- the stud shouldn't ground on the floor of the slot.

Lathe chucks normally have hardened, or at least toughened, jaws; but the "soft jaws" are unhardened so you can modify for special purposes, for example by cutting shallow rebates in their top surfaces to grip thin discs.

'

It will be worth as I have done, building up a library of reference books written for model-engineers, on workshop techniques. The "Workshop Practice" series is a good start – I've about 10 of them, each dedicated to a particular machine-tool or metalworking method, selected to suit my own needs. Have a look on TEE Publishing's web-site. As well as mail order they usually have comprehensive stands at the major model-engineering exhibitions.

Note that some reference books appear to be mainly handbooks on making tools and machine-tool accessories, leading to a somewhat unfair reputation of making tools to make tools – but they are still full of valuable information. Harold Hall's books are project-led but in a progressive way, so if you follow them you create genuinely useful tooling as well as gaining experience; without being submerged in cutting-tool theory deeper than strictly necessary to start obtaining decent-quality results .

The older books, by such writers as Stan Bray and L Sparey, are a bit more general and if you own old machine- tool like your Myford, a handbook closer to its era will be more attuned to its capacities and likely to cover the subject of milling in the lathe.

[Chris VParticipant @chrisv]

Hi Nigel many thanks again. Of course I had to look up to see what an EW Stringer lathe ls like…looks fab!

I'm quite sure if I had the room and funds I could collect old British lathes.

That's good to know about soft jaws, is this a recent thing ie offering both hard & soft jaws? I would presume the jaws on my vintage lathe would be considered hard.

Regarding books yes I got The Amateurs Lathe by L Sparey, read most of it but skipped the milling section as back when I read it a few months ago I was not considering milling..so now I will read it, and in time add to my engineering library.

Yes building tools,… no doubt like sharpening them in the wood trades, one can get bogged down in this (the latter). That said the sensitive pillar drill project looks like a very useful bit of kit, cannot decide right now if I want to spend the time building one or buy one ready made if it turned up. I know how useful they are for tapping as i have a horrible Ali, chromed metal and plastic affair which whilst looking orrible/ offending my eyes is a real help keeping things straight….but its not great!

I found some parts I needed for my Myford ML1 on eBay but I'm still looking for a Bull wheel gear Guard which has the single point fixing rather than two bolt holes on the later models.

Cheers

Chris.

[Nigel Graham 2Participant @nigelgraham2]

Thank you!

That EW lathe needs refurbishing, but it is probably as old as me and yes, I do have a Bus Pass. My parents bought it for my 18th birthday present, from one of Dad's work colleagues. By Tony Griffith's Lathes web -site, it has all the optional extras except one – the change-wheel guard.

I think the oddest task it's done was screw-cutting a spare, special adaptor for connecting a keg CO2 cartridge to a heat-exchanger forming the core of a warm-air breathing kit owned by a cave rescue organisation. It's used to ward off hypothermia. The thread to be cut was metric but also completely non-standard (a common commercial dodge); the lathe is all-Imperial with an 8tpi lead-screw and change-wheels in 5-tooth steps from 25 to 65 teeth, so calculating the combination for the closest match was entertaining to say the least!

=

The concept of soft jaws is nothing new at all but finding ones for a particular, old make of chuck is another matter. Normally chuck jaws are hard, otherwise they would wear rapidly.

'

A neat aid for using a drilling-machine as a tapping-guide is a "Sprung Centre". It's simply a rod 2 or 3 inches long that slides smoothly inside a blind hole drilled deep into the end of larger-diameter shank, with a light compression-spring at the base of the hole, between them. The inner rod has a pointed end or a shallow centre-drilled hole to engage the centre-hole or point as the case may be, in the upper end of the tap.

The tap-wrench is on the tap's square as normal, the spring keeps the guide in contact with the tap. In use the outer rod is held in the chuck with the drilling-machine quill locked at appropriate height, the inner rod locates on the tap's upper end, so holding the tap vertical.

You'd probably find a design in one or another of those various books. Make the sliding rod bi-ended: hollow one end, pointed the other, so you can swap it round to suit the particular tap.

Another refinement is a screw and slot or other arrangement to keep the device together when you lift it clear of the tap.

===

It is satisfying putting an old machine back into service but be aware that vital spares for what might have once been a very common make, may now be totally unavailable so you'd have to make them.

If it's a lathe with an incomplete change-wheel set you've the added difficulty of finding replacement wheels simply to fill the gaps, because although you can buy stock gears easily enough, you need to know not only the tooth-pitch etc, but also the pressure angle of the originals. I don't know what happens if they are different, but I'd imagine at the least, one set would rapidly wear out the other..

[Author]

Posts