Amolco Mill

[Chris VParticipant @chrisv]

Hi all,

I am now the owner of a dedicated Amolco mill complete with its base and compound table.

The mill came with a selection of metric & imperial Myford collets and a collection of allsorted sized milling cutters. All the cutters have a threaded end to their shank.

If I just use the cutters in the collets I know I'm likely to get the cutters creeping downwards during use. So what arrangement would originally have been used to hold threaded shank cutters to prevent this?

Also how useful are the collet closing tubes?

Any idea when exactly these Mills first came onto the market?

I'm new to milling so have ordered Harold Halls book on the subject.

[Chris VParticipant @chrisv]

How to hold threaded shank cutters?

[Michael GilliganParticipant @michaelgilligan61133]

I bought my drilling machine in the mid 70s … direct from N. Mole & Co. [in Watford].

The milling machine is of very similar construction, and I believe contemporaneous.

MichaelG.

.

https://www.companysearchesmadesimple.com/company/uk/01035615/n-mole-co-machine-tools-limited/

Edited By Michael Gilligan on 03/01/2020 19:47:49

[noel shelleyParticipant @noelshelley55608]

Hi Cris, I know it's greedy but I have 2, both as attachments to fit Myford Etc. The spindle is 2MT and whilst you could use 2mt collets and the spindle nose holder I would look to use an auto lock type holder that will make sure that the cutters can't run out. There are 2 sets of collets, metric as 6mm,10mm,12mm and 16mm and imperial 1/4", 3/8".1/2" and 5/8". The auto lock chuck will/should have a drawbar, I think3/8" BSF this is easy to make. It does take the cutting edge well down from the bearing, but the cutter will be secure. I do realise this will cost a bit, chuck and 8 collets £100 or so but for screwed shank cutters it's bombproof. The current vouge for ER collets is fine but not as secure as an auto lock. Noel.

[MeunierParticipant @meunier]

Yes, MichaelG, I can confirm your comments. I was in Mole's emporium around that period and there was an AMOLCO mill attachment on display. My chum from the MES curbed my enthusiasm and talked me out of buying it but I did buy a Tripan 111 QCTP and several tool-holders on the recommendation of Bert? in the shop which together with a Myford Hoybide tip-holder and a Tripan parting tool have given good service since
DaveD

[Chris VParticipant @chrisv]

Thank you Michael and Noel. Actually I think having two is wise, one might break down after all! Mind you three would in my book be a collection, something to aim for perhaps!!

Seriously thought, autolock sounds interesting, the cutters screw in I take it? Did Myford make them?

Cheers

Chris.

[John HaineParticipant @johnhaine32865]

An Amolco was my first mill, made of one of the original heads and a base made by a company in Baldock that bought the designs from Mole later on. The base was a nice bit of engineering, the head not so good, the vertical key combined with the split casting wasn't clever at maintaining alignment when you applied downfeed. Its other big problem was the limited daylight between spindle and work, especially when you fitted a vice.

I did buy a Posilock chuck for it at considerable expense and in retrospect wish I'd just bought MT2 finger collets for use with a drawbar, because of that lack of daylight. The machine is also not all that rigid, having a lot of overhang and having to have the head a couple of inches higher because of the chuck doesn't help.

I don't know why you assume the cutters will move in the Myford collets, they shouldn't if properly tightened and you don't get too ambitious with cuts (which on a machine with limited power and rigidity isn't advisable anyway). Sharp cutters help too.

If you have the Myford collets that have a closer nut then treasure them. The collet closer tube is vital – it allows you to close down the collet so the nut will locate in the groove just behind the nose, so that as well as tightening the collet it will also extract it. If this isn't obvious then say and I'll post some photos. Before you spend money on a posiloc type chuck I suggest you try using the collets you have, possibly with some new sharp cutters. If you do decide to get a collet chuck then most people on here seem to find ER types very satisfactory and much cheaper.

Going back to that keyed column, it's very important that when you apply some down feed you then re-tighten the clamp otherwise the head gets deflected sideways by cutting force.

I made a significant modification to my column to get more daylight. This involved three things.

1. I fitted a new, longer key (a piece of key steel IIRC) to allow more travel.
2. Also then needed a longer leadscrew, which I wanted anyway as I'd bought a metric base and wanted metric downfeed. Also needed of course a new feednut.
3. I made a new fitting for the top of the column which added 50mm or so to its height and held a plate for the feedscrew bearings. The head didn't actually run on the extension, it just allowed the head to make use of all the existing column.

Had I kept the mill I think I would have changed the motor to 3-phase with a VFD, but I was finding it a bit too small for what I needed at the time.

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by Chris Vickers on 03/01/2020 19:26:53:

If I just use the cutters in the collets I know I'm likely to get the cutters creeping downwards during use. So what arrangement would originally have been used to hold threaded shank cutters to prevent this?

Also how useful are the collet closing tubes?

Chris,

I would be inclined to wait and see if I actually had a problem with the Myford collets. Many people are happy with finger collets which are very similar in action to the Myford collets – just pulled instead of pushed. Threaded milling cutters are old technology. Does any body make them now? As far as I am aware carbide cutters are only available in plain shank. Most hobby users are happy with ER collets if you do have problem but remember that any additional chuck will compromise your headroom which is not great on an Amolco.

The collet closing tubes are pretty much essential to allow you to mount the closing nut on the collet.

HTH,

Rod

[Mike PooleParticipant @mikepoole82104]

The classic chuck for screwed shank cutters was the Autolock by Clarkson, a number of others were compatible like the Osborn and Dormer versions and others like Posilock. If you are going to buy a chuck then the ER type has largely superseded the Autolock type. These will hold the screwed shank and plain shank cutters, properly tightened the ferocious grip of the collet should not have any concerns of the cutter moving. The ER is available on morse shanks and also the Myford nose fitting. The Myford collets are expensive and only effective on the size they are made for, a quarter inch collet will not be effective on a 6mm cutter. New ones are hard to find as I think they are pretty much obsolete. Most people seem to have migrated to the ER system typically ER25 orER32 for the Myford nose fitting. The Autolock chucks come in a couple of sizes and the small one up to 5/8 or 16mm would be most appropriate. The collets are only for one size of shank and metric and imperial sizes were available. ER collets typically have a 1mm range but are most effective at their maximum size, metric and imperial collet are available.

Mike

[noel shelleyParticipant @noelshelley55608]

Yes, the cutter screws in and the collet is tightened, if the cutter tries to slip it just gets tighter. very clever, and simple. Not made by myford , clarkson, as the auto lock, though many have copied it( mines a fake)

I lied, One of the amolco heads is now married to the base of an old zyto mill, this gives me a HUGE daylight, as I have both the amolco vertical plus the zyto vertical as well, over a FOOT. OH what fun !!! Then there's the bridgeport !!! That make 3. A collection ? Noel.

[Clive FosterParticipant @clivefoster55965]

Given the limited daylight between spindle nose and chuck "Weldon" style side screw locking holders could be a good choice for holding cutters. These are rather shorter than any collet chuck and pretty much as secure as a Clarkson style chuck taking threaded shank cutters.

Aurc Eurotrade do such holders on MT2 shanks for around £15 each in metric sizes and a littel cheaper in imperial **LINK**. Only four metric or imperial sizes needed to cover the milling cutter shank diameters normally used by Model Engineers so cost is comparable to Clarkson or ER sets unless you want bot metric and imperial. Objectively only sensible reason for that is lucking into a stash of milling cutters in both breeds. So the saving should cover the extra cost.

Not that hard to make from a blank end arbor given suitable care in getting things concentric. Were I to make some for a small milling machine I'd make an effort to get the tool shank further up inside the taper reducing the length.

Disadvantage of side locking screw holders is that you need to fit your own flat for the screw if using common cutters. Not hard to do free hand but I jig might be nice. I got some from Arc on R8 shanks many years ago and have found them effective, although I usually use a Posilock (Clarkson copy) chuck. I did have to trim the noses of the 6 mm and 1/4" holders to use Clarkson style throw-away cutters. Maybe the design has changed.

Clive

[John HaineParticipant @johnhaine32865]

There are a couple of problems with the Weldon style holders. For one, they still have quite a long projection from the nose. The other is that though the imperial sizes have a 3/8 BSW drawbar the metric ones have M10, and IIRC I found that the spindle bore didn't accommodate the larger size (I may misremember). I did make some holders myself, using some very short MT2 centres I picked up surplus that weren't hardened. Faced off the end so there was just enough meat for a grub screw, drilled and tapped a 3/8 BSW hole in the small end, drilled and bored for the cutter.

Given that screwed shank end mills seem to be a thing of the past (neither Arc nor MSC list them as far as I can see), and the ones that came with the mill are probably blunt, I would suggest that you do not invest in an an Auto/Posi-loc chuck. Do try the collets you have, making sure they are really tightened, and buy some new cutters, maybe just 3 or 4 sizes to start. You will see a lot of postings here about MT2 tapers getting stuck, but a benefit of the Myford style collet is that the closer nut extracts the collet when it is loosened, as long as the collet is properly fitted into the closer using the tube. So they don't get stuck. If you decide to buy a collet chuck, ER is the way to go these days, and get a ball bearing nut so you can really tighten it.

I replaced my Amolco with a VMB with an R8 spindle. Almost always for milling I use R8 collets direct in the spindle, so get maximum daylight and rigidity. As long as you tighten the Myford collets properly you should find the same.

[Chris VParticipant @chrisv]

Good morning all, and thank you all so much for this very helpful and interesting info. As a trained woodworker I'm well used to using collets in wood routers and find the cutters can slip. I figured the forces cutting metal would be greater and therefore the likely-hood of cutters creeping would be increased. Plus I was aware of cutters with threaded ends and had also noted the side lock holders in the Arc catalogue. I have ER20 & ER32 collets but was not aware you can get a Myford nose ER32 collet holder. I just looked that up and its most interesting. But it will still decrease my head height (and costs £80). Like-wise the the Autolock system and even the Arc type of side fix holders. So taking all this on board I will invest in a collet closing tube and try out the Myford collets I have and see what occurs.

Thank you ALL again, this is most helpful and appreciated.

Cheers

Chris.

[Clive FosterParticipant @clivefoster55965]

When it comes to cutter holding you have to accept that there is no perfect system. The art is to get best value for money when initially choosing a system that does well enough for most of your work.  The either supplement with something more suitable or figuring a work around when dealing with any specific things it doesn't do so well.

I suspect a lot of folk are tempted to overbuy on tool holding equipment to deal with things they might have to do later or because a set is cheaper than one size. Which tends not to work out so well when it turns out you only use two out of 8? I have certainly overbought over the years. But I'm a serious toolaholic with perfectionist tendencies! Hopefully most folk area little more sane. Thirty years from purchase to first use might be considered excessive. I've used my ER 32 collet set about 10 times in 35 years and once was a try out to see how it all fitted together.

As you have concluded by far the best answer, for now at least, is to use what you have and get some experience. Then figure out what you need for your work. One often overlooked issue with collets is the need for high standards of cleanliness in both collet bore and on the tool shank. Especially if you use cutting fluids. Morse taper collets are, by their very nature, high friction in the taper bore so they don't get as much grip per unit of drawbar pull or nose closer push as an R8 or other milling cutter specific taper.

John makes a good point about Weldon holder lengths. Most of the excess length in the 6 mm and 1/4" ArcEuro R8 taper ones I have is below the screw so can be lopped of with impunity. The screw is about as close to the end of the spindle bore as is practical. The 3/4" Arc one I have is significantly, maybe an inch, over-long when compared to professional versions which all have the screw well up towards the spindle. That one has a very long bore so no reason why it couldn't be cut down. But I drive a Bridgeport and the extra stick out is welcome as giving me a bit more vertical room before the big spindle interferes with visibility in a deep recess. But Weldon holders aren't hard to make if need be. I like to keep blank end arbor or two on hand for field expedient modifications just in case I need something right now. Whether for a cutter holder or other purposes.

Clive

Edited By Clive Foster on 04/01/2020 11:05:15

[noel shelleyParticipant @noelshelley55608]

Hi Chris, IF you want the dimensions of the closing tube and extractor to make your own, let me know! With the use of a lathe it's easy. Noel.

[noel shelleyParticipant @noelshelley55608]

Hi Chris, IF you want the dimensions of the closing tube and extractor to make your own, let me know! With the use of a lathe it's easy. Noel.

[Chris VParticipant @chrisv]

Thank you Clive, yes this makes a lot of sense and is the way forward for me.

Thank you Noel, I need to get out of the habit of buying because I don't have a lathe, I ordered one this morning, never occured to me to make one…plus I have some of Clives tendancies to collect tools! But appreciate the offer all the same.

PS in my book all the mills have to be the same make if you are to call it a collection, but you get an extra mark for trying (-;

Cheers

Chris.

[Chris VParticipant @chrisv]

The Mill also came with this vice, how do you fix properly to the table please?

Cheers

Chris.

[Clive FosterParticipant @clivefoster55965]

Either with flat bars on suitable parts of the side ledge or via rods in the round holes. Obviously avoiding parts of the ledge that the moving jaw will cover and the hole used by the tapped rod that holds the tightening screw.

Mix and match clamping as appropriate to the job using whatever is to hand or what you can make if you have nothing suitable. I'd use bars and step blocks 'cos I have some that should be suitable. I don't use that sort of vice but if I had to make something I might well do some small blocks with around stub to fit the holes. As ever whatever works for you.

If its a good example of the breed all the sides will be accurately squared up and at right angles to each other. Which can be a gread help when settling into position either by running a dial gauge down the side or by pushing up against a previously set fence.

Clive

PS

Video here showing how blocks with round projections can be used.  Those are general purpose ones, if you make your own you can make them exact to size with a fixed lip opposite the round stub rather than the adjustable plate shown.

https://www.youtube.com/watch?v=7Wuhm8qzkOU

Edited By Clive Foster on 04/01/2020 19:19:02

Edited By Clive Foster on 04/01/2020 19:20:08

[Chris VParticipant @chrisv]

Thanks very much Clive, that's most helpful, something else for my to do list!

Cheers

Chris.

[not done it yetParticipant @notdoneityet]

Some sizes of that type of vise have been found to contact the mill table at times, when tightening the jaws with the tightening bolt at a steep angle. It is worth checking that there is clearance between bolt and bed to avoid possible surface damage.

[Chris VParticipant @chrisv]

Thanks not done it yet, it appears mine has enough clearance, but I would not of thought of checking that?

Cheers

Chris.

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