Personally I'd say yes. but I am biased as both my vertical and CNC mills are R8 taper. There is an argument that with MT in the mill you can share tooling with the lathe. But you'll need to have a fairly large large to have a MT3 tailstock. And I've never felt the need to swap tooling. For a start the lathe tailstock doesn't need a drawbar, the mill definitely will. You might get away with drill chucks in the mill without a drawbar, but I prefer to have drill chucks dedicated to the specific machine tool.

Andrew

Andrew J makes good points. However I have lots of MT tooling going back years. Too expensive (and too late regarding my advanced years) to change to R8 tooling.

Perhaps Andrew is a little harsh, as there really isn't a right or wrong answer to your question, simply a matter of choice. Andrew works on "big stuff", usually with industrial machines. So R8 is a no brainer for him. For hobby sized kit then the answer is not so clear cut.

Andrew

I suspect it will depend on what you plan to do with the mill.

R8 ( and MT) collets are designed to hold specific diameters of material, so If you only ever use a small number of sizes of cutters then R8 ( self releasing) would be better. If however you will be using lots of smaller cutters, then you might want to consider an ER collet system where the collets hold a range of sizes ( and are cheaper than R8 or MT collets).

If you go the ER route, then once the MT3 shanked ER collet holder is installed, you will only rarely need to get it out, and probably will not really notice the difference.

On my small (MT2) mill I usually hold drills in the ER collets unless I am planning a significant drilling session with multiple sizes.

I haven't yet.

I bought MT because at the time MT tooling was more common than R8, and because it allows some tools to be shared between lathe and mill.

In practice most of my milling is done with ER collets so I rarely change between MT tools.

Main problems with MT, I think, are:

1. The need to undo a drawbar means it's not as quick change as later systems (I don't care)
2. Failing to tighten the drawbar means the tapers might spin and be damaged (not a problem for me yet)
3. Over-tightening the drawbar, especially if a cold tool is inserted into a hot spindle, can jamb it in place. The tapers can also stick if left in place for a long time, perhaps due to very slight corrosion or oil gumming up. Removing a badly stuck taper is difficult!
4. Tapping the drawbar sharply with a dead hammer to unstick the taper causes many to assume bearings must be damaged. Actually, although MT has been in wide use for about 150 years, there's very little evidence of this. Nonetheless people believe it. My mill is 7 or 8 years old, bearings are OK.
5. MT relies on a friction grip, which is very strong, but other systems provide positive locking. These allow more power to be put into the cutter, probably more than a hobby lathe can cope with, but accidental breakages of tools and holders become more likely.

Of these only the possibility a seriously stuck taper worries me. So far I've avoided it by not leaving MT tapers screwed tight for long periods – I undo them every six weeks or so and give them a wipe.

I think the main advantage of R8 in amateur hands they don't jamb. Plenty of tooling available for R8 now, so one of my original reasons for choosing MT has gone. Nor is it common for me to swap MT tools between mill and lathe.

For what I do MT is fine, R8 avoids a potential problem but in practice MT vs R8 makes no difference in my workshop. Be aware that not everyone thinks R8 is the best of all possible systems! I'm happy when tools do the job, and don't upgrade them unless there's a specific benefit.

Dave

The morse taper is designed as a self holding taper but still requires a drawbar for milling applications. I find the self releasing property of all tapers designed for milling to be a good idea. I think the Morse taper was designed for drilling and lathe tailstocks are frequently used for drilling so a morse tailstock became common. With an adapter sleeve morse tapers can be used with an R8 spindle. One thing I really hate is hitting spindles to release tapers so if a morse taper spindle is not fitted with an ejector system I would seriously consider adding one.

Mike

A few extra notes:

The R8 taper is common because of it's use on Bridgeport mills. There seems to be a rule of thumb that it struggles with transmitting much more than 2hp. Above that the INT series, and variants, are much more common as they are positively driven via dogs. My horizontal mill is INT40, but has a 5hp motor, so R8 wouldn't be much use. Knowing what I know now I wouldn't go for INT30 as tooling is rare; INT40 and INT50 are far more common.

I use the TTS tooling system on the Bridgeport and CNC mill, so I rarely swap R8 collets. I only have three, the special 3/4" one for the TTS sustem, a 5/15" one bought for a one off commercial job and a 1/2" collet. The 1/2" collet gets used with the right angle and Quillmaster heads for the Bridgeport, not for tool holding.

Most of my manual milling is done with 6mm and 10mm side holders. I rarely use ER collets for tool holding on the manual miil.They do get used more on the CNC mill. For other cutters on the manual mill I have large sidelock holders and Clarkson Autolock chuck copies.

The R8 taper rarely sticks, if it does a sharp tap is all that is needed. I've noticed that the taper sticks more on the CNC mill than on the Bridgeport. I suspect that is partly down to inaccuracies in manufacture on the CNC mill and also that it gets far less use than the manual mill. I try and leave the R8 collet loose on the CNC mill if I am not going to be using for a while.

As has been said there is no right or wrong answer.

Andrew

MT3 is perfectly adequate for 99.9% of model engineering needs. Real men use Int30 at least anyway. Putting R8 in a smaller mill than a BP is just like putting a supercharger on a Fiesta.

If it is this one then I can't see any mention of brushless which would tend to say it comes with a brushed DC Motor.

The knob on the right side of the head will be the Hi/Low gear change which can actually have advantages over a direct drive brushless as the gears give a bit more mechanical advantage to the motor and it does not have to run as slowly where they can start l lack guts. This is why the brushless option tend to need a more powerful motor.

At low speeds say when using an HSS slitting saw I can stall the SX2.7 with it's 750w brushless motor far easier than the X3 which only has 600W but Hi low range. Gears make a bit more noise but if it's your only mill I would rather have a bit more low down grunt. Different on the CNC when it's doing 5000rpm but I only tend to use small cutters on that.

Edited By JasonB on 23/06/2023 15:56:51

Now you have got the MT3 just be careful to not overtighten the drawbar. I expect the same price offer did not include the R8 model, so there should be more funds available for tooling. Many people keep an er32 collet chuck permanently attached and use it for drills as well as milling cutters. You can buy MT3 socket cleaners which will keep the taper pristine and tooling should be wiped with a clean, but very slightly oily tissue or cloth prior to fitting. There may be recommended drawbar torque figures available, and small torque wrenches are not expensive.