Help recommend a milling machine?

[DiogenesParticipant @diogenes]

Such injustice 😁

I actually recommended MT because the opening post mentioned “a forging workshop” and a Bridgeport having been considered but being too big for the space – so the ability to use taper-shank drills and other tooling seemed to fit the bill, for the situation as I perceived it – all of the forges I have ever been into are distinctly ‘Archdale’ territory..

Nonetheless..

I’m sure we both recognise that the commonplace availability of R8 in the hobby-mill market is a relatively recent innovation and I certainly wouldn’t exclude a number of very good machines just because they employed a self-holding taper – I’ve certainly never felt any need to change just because of the taper.

[John MC]

On John MC Said:

On old mart Said:

I always recommend a mill with an R8 spindle size rather than any Morse taper if you have a choice when buying a machine. There are many more R8 tooling choices and it is a proper milling taper fit, wheras all Morse tapers were designed for drilling and so many people get the tooling stuck in the spindle.

I would not dismiss a Morse taper as just a method of holding drills in a drilling machine.

 

A good alternative is the Morse taper, again plenty of contact area and accurate location.   Plenty of low cost tooling is available.  The disadvantage that I am sure will be pointed out is that the taper is “self locking” and needs a tap on the drawbar to release its grip.  I’ve seen it suggested that striking the drawbar to release the taper will damage the spindle bearings or some other feature of the machine, it will not.  If it bothers the owner then fit a self ejecting arrangement.

The problem with the R8 is one of location.  A very short taper and an equally short parallel length.  These are known to wear in heavy use and lose accuracy.   Then there is the key, best described as the bain of the machinists life.  I’ve used Bridgeport type machines that have had the key fail and not replaced, just hope the short taper can transmit the drive to the cutter!

Going back to the previous comment I have quoted, if Morse tapers are for drills, what about the other tooling we use in the tailstocks of our lathes?

I’ve not experienced any issues with either of my MT3 mills, my first was an Elliott Omnill – an industrial machine. I have though made a small modification to my VMC to make it self ejecting. 

I too have heard lots of negative comments about R8, it’s not a proper taper according to some. Like the Morse Taper, for new machines it’s mainly found on hobby mills these days.

[PeteParticipant @pete41194]

Probably the largest 2 reasons for fewer manual machines using the R8 spindle taper today is the lack of repeatable Z axis tool positioning when pre setting tools, and a limit on just how hard you can drive the cutting tools since there’s no drive keys. Obviously the various 30,40 & 50 tapers are superior, but the R8 has been around for roughly 70 years now and is still used or offered as an an optional spindle taper by at least some industrial sized vertical mills today including Bridgeport. I’d suggest that’s not doing too bad for something that’s supposedly not a proper tool taper. My own Bridgeport clone has a 2 hp 3 ph motor and I’ve not found it’s R8 to be a problem yet. More limiting as far as how hard you can push most vertical mills is the head, knuckle and ram rigidity than the R8 spindle taper.

[Author]

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