MT2 or ISO30

Hello!

I am going to buy a small milling machine. I have a choice between MT2 and ISO30 taper in the spindle.

The ISO30 will cost me around 7% more. Not a very big diference. However, collet chucks, arbors etc. are also slightly more expensive than MT2.

What do you think? Is it worth it to get the machine with ISO30? (As i understand, it is slightly easier to change tools with ISO30 and less chance of it getting stuck).

Are there any advantages of MT2 (other than price / availability)?

If I ever were to add CNC capabilities to the mill, ISO30 would meke it easier to add some kind of automatic tool change system?

Any help would be much appreciated!

Thanks

There are indeed lots of cheap Morse Taper tooling around but I’d personally go for the ISO30. I suppose you can get ISO30 to Morse adapters if required?

ISO 30

Tony

30 is going to be a lot better choice than MT2. The option was more likely MT3 and there is some small advantage in having things compatible between lathe and mill head but in practice that is not often used. Arc do adaptors.

ISO 30 is a proper milling spindle size, Morse tapers were designed for drilling machines.

If the option was MT2, there is no comparison whatsoever, MT2 is very flexible when side loads are involved MT3 is better, but still not in the same league. Any of the Morse tapers are difficult to remove after being held in by a drawbar. All can slip if not held in enough in milling duty.

The ISO/NMBT 30 taper cannot slip, due to having drive dogs.

Thank you all very much. I think I will be going with ISO30, then!

Ben

Welcome to the forum.

I am rather ‘locked in’ to 2MT - both my lathe and mills are such. Cost difference and availability in the UK is likely different than for you (you are one of very few who have their location in the profile).

Clearly ISO30 is the better option mechanically (more favoured by commercial operators). Morse Taper has always been the cheaper option. R8 is the modern alternative to Morse fittings and might be worth investigating.

To answer your question simply: None. But those advantages are a considerable incentive for many of us!

I would say Morse is adequate but ISO is far better.

I have just gone to a lot of work modifying a Tom Senior light vertical from MT2 to R8, which is a superior fitting. I would prefer ISO 30, but the conversion is much more difficult, and I already have lots of R8 tooling.

ISO 30 is great but you are then locked in to using either end mill holders or a collet chuck, e.g. ER type, on an ISO shank. Both of those, but especially the latter, project probably 40 to 50 mm below the spindle. I have ISO 30 on my little Novamill and this is a pain for some jobs.

For a small milling machine, if you have the option, a better choice is R8 because you can then use R8 collets direct in the spindle - they are cheap, have hardly any projection beyond the spindle, and grip like b****y. ISO is more adaptable to auto tool change, but the benefits of that for amateur use are probably marginal. On my manual mill, a VMB, I have R8 and I wish the Novamill had the same.

If I had to use a morse milling spindle the I would want a positive ejection method rather than a mallet on the drawbar, if you don’t have an ejection method then you will need to develop the Goldilocks touch for tightening the drawbar, not enough and you risk it coming loose and possible damage to spindle cutter and job, too tight and the taper will need a good hit to remove and this force goes through the bearings which is always bad practice. I wouldn’t hesitate to go ISO 30 even if I had to buy some adaptors to use any morse gear.

Mike

I don't know about ISO 30, but knocking out MT's from their socket does put undue strain on the bearings unless you have a pneumatic / hydraulic extractor on the quill shaft.

When I carried out the R8 conversion, I had to put spanner flats on the bottom of the spindle as there was no way of holding the spindle when the drawbar was tightened and released. Holding both ends securely enables better tightening, and at the same time, I made the drawbar captive which is also a great advantage. No hammering to break the taper, and I also elected to run without the locating pin in the spindle. The only downside of a captive drawbar is that a few MT tools in R8 adaptors used a different drawbar size, which would mean removing the 7/16" one if I use them.

I agree that the R8 collets give you more Z axis space, but they don't get used very often, unless I put a 20mm shank tool up.

I was surprised that the op's choice was between MT2 and ISO30, the R8 comes in between them usually.

When I bought my Lux mill, many moons ago, I had a choice between R8 and MT.

I went for the MT model, should have bought the R8,,price was the same at the time [open day at Chester ]

Can always go from R8 to MT if required, not so easy the other way around, so, I think SO30 might be the best way to go.

At the time ,I had no experience of other systems, only MT. All part of the learning curve.

ISO 30 will be easier to remove, than 2MT or 3 MT, and will be stronger than 2 MT; but there will probably be a smaller range of accessories available.

That said, I use 3 MT so that tooling can be used on either the Lathe or the Mill.

To ease breaking the Morse Taper's grip, I made up and extractor to reduce the need to use a mallet on the drawbar.

Howard

Hi John,

I have a full set of these NT/ISO30 Collets

They have come in handy a few times on my Syil X5

Neat! Never seen those before.

Once again, thank you all for your very helpful advice!

Ben