[Newbie] MT3 vs R8

[DavidR8]

Thee RF40 mill I was looking at turned out to have an MT3 spindle. I got the seller down on price but he pulled the vise from the deal. When I found out it had an MT3 spindle I walked away.

Ironically he alerted me to a Taiwanese RF 30 selling for $1500 LESS than what he was asking for has RF40.
I don’t know the spindle type but in case this mill is amazing but I need to know the inherent drawbacks to MT3 over R8.

One thing I 'think' I know is that MT3 doesn’t use a drawbar.



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[stupoty]

The mills should have a drawbar for the mt3 ,they come in metric thread and imperial just to make it simpler.

morse is ok for tool holding but less good for work holding as far as I understand.

Stu

 

[DavidR8]

Thanks @stupoty, that's also what I gather.
I'm trying to figure out what limitations I might be getting into with MT3.

 

[coherent]

Morse are fairly common but R-8 is more so. You'll likely find a larger selection of collets and tooling for R-8. In the normal scheme of things the greater the selection, the better the prices in my experience. I've never had an R-8 loosen while I was using it, but have had a Morse come loose. Overall if I had to buy and had an option, I'd go with an R8. You obviously can't just mix and match but there are sleeves and adapters that allow you to do so and may work ok for a given task depending on your purpose.

 

[DavidR8]

Morse are fairly common but R-8 is more so. You'll likely find a larger selection of collets and tooling for R-8. In the normal scheme of things the greater the selection, the better the prices in my experience. I've never had an R-8 loosen while I was using it, but have had a Morse come loose. Overall if I had to buy and had an option, I'd go with an R8.

Thanks, I'm a bit stuck on machine choices where I live so I may not have an option.
I'll see what the machine is like but given that it's an older Taiwan RF I suspect it's MT3.

 

[stupoty]

I have morse on my mill and the biggest issue I have is occasionally the draw bar requires quite a few taps to eject which I understand r-8 doesn't do as it's taper is much sharper than the morse. most stuff in the UK is morse taper .

I use an ER collet chuck as their clamping range alows me to use either metric or imperial shanked tools.

 

[DavidR8]

I have morse on my mill and the biggest issue I have is occasionally the draw bar requires quite a few taps to eject which I understand r-8 doesn't do as it's taper is much sharper than the morse. most stuff in the UK is morse taper .

I use an ER collet chuck as their clamping range alows me to use either metric or imperial shanked tools.

That's kind of where my thinking is at. I would expect at my early stages in milling I'd only be using tooling that fit in an ER collet chuck. And I could likely make any odd ball tool holder as an MT isn't impossible to turn.

 

[Superburban]

While you can likely use any MT#, you would want to stick to the ones threaded for the drawbar, which can be a bit harder to find. If the mill comes with a full set of collets, then you have enough to get you started. Drill chucks and other accessories can be hard to fine with a threaded MT3 end, but you can get it all with a 1/2" straight shank, and chuck it up in a 1/2" collet. Having both setups, I really cannot see any advantage of one over the other. I have boring heads and drill chucks with the 1/2" shank, so they can easily be used in either machine.

 

[middle.road]

If you end up with an MT3 then what I would do is find an MT3 to ER32 Collet chuck. (Unless of course the machine you end up with has tooling.)
Would to have to match the threads for the drawbar, else make a new drawbar which should not be too difficult.
Then you're covered with the wide range of selection in ER32 collets.

 

[C-Bag]

It's interesting you found a RF40 with MT3. I guess you could order them with either but down here all the RF30/31/40 I've seen were all R8. I think that might have been a deal breaker for me too. R8 is easy to find new and used MT not so much.