Milling in the lathe

[John McCullaParticipant @johnmcculla]

I've just got a vertical milling slide for my Warco WM250 lathe. I need to make an adapter to mount it on the lathe, but in the mean time, I was wondering what is the best way to hold milling cutters in the lathe? It has MT4 taper at the headstock, so presumably I could buy a collet holder with a MT4 end, but would I need a drawbar extending through the headstock to hold it in? Or is that not necessary? I take it milling cutters are too hard to hold in the chuck jaws?

[John McCullaParticipant @johnmcculla]

Tips for holding milling cutters

[Nick WheelerParticipant @nickwheeler]

Get a bolt-on ER collet chuck and a full set of collets. That will hold any type of milling cutter and be useful for small round stock.

[Chris CrewParticipant @chriscrew66644]

When I had to mill in the lathe I used the three jaw chuck to hold the end mills and slot drills, to prevent them creeping out simply wrap a sliver of newspaper around them, it works a treat,

[Tony Pratt 1Participant @tonypratt1]

If you buy a MT 4 milling adaptor you must use a draw bar through the spindle to secure it in place.

Tony

[JourneymanParticipant @journeyman]

As suggested by Nick above a good solution would be to fit a collet chuck. This avoids the need for a drawbar and gives the additional benefit of extra work holding capabilities.

This is an ER25 collet chuck fitted to my WM250. ER32 is another option which will afford wider work holding range. More info at *** Journeymans Workshop***

The lathe 3-jaw is not designed to hold milling cutters and will likely work it's way loose during milling operations damaging work, chuck or both.

John

Edited By Journeyman on 04/04/2023 14:03:42

[SillyOldDufferModerator @sillyoldduffer]

Another vote for an ER32 collet chuck and collet set. The collets will come in useful when you decide to buy a milling machine!

Don't expect much from milling in a lathe. The work envelope is tiny and lathes lack rigidity because they're designed to resist turning forces, not multi-directional milling forces. In consequence lathe operators can only take light milling cuts and have to organise lots of ingenious work-holding.

Lathe milling was once very common, but I found it immensely frustrating. I agree impatience is one of my defects! However, jobs that are an absolute doddle on a real milling machine become challenging projects on a lathe, especially small ones.

If it doesn't go well at first, reduce expectations and practice, practice, practice! I found milling on a lathe needs more skill than most other lathe work.

Dave

Edited By SillyOldDuffer on 04/04/2023 16:04:50

[Harry WilkesParticipant @harrywilkes58467]

I mill on my Myford as I dont have room for a milling machine I have used used the sliver of paper as suggested by Chris also I have some Myford collets but again as suggested invested in a set of ER25

H

[Mick B1Participant @mickb1]

Posted by Chris Crew on 04/04/2023 13:44:25:

When I had to mill in the lathe I used the three jaw chuck to hold the end mills and slot drills, to prevent them creeping out simply wrap a sliver of newspaper around them, it works a treat,

Me too, 'cept I never thought of the newspaper, and it doesn't seem to matter much if you don't get greedy.

You can get away with weird stuff, like chucking a boring bar with a long (carefully-set) toolbit to cut the internal radius on a ring-reinforce for a hypocycloidal engine…

[Paul LousickParticipant @paullousick59116]

Most ER collet/Morse taper adaptors have a threaded end and a draw bar can simply be a piece of threaded rod. (and needed for milling operations)

My lathe, mill and rotary table all have the same size morse taper, allowing me to transfer the job from one machine to the other without upsetting the set up in the collet.

[Andy_GParticipant @andy_g]

Posted by John McCulla on 04/04/2023 13:21:12:

I was wondering what is the best way to hold milling cutters in the lathe? It has MT4 taper at the headstock, so presumably I could buy a collet holder with a MT4 end, but would I need a drawbar extending through the headstock to hold it in?

FInger collets are probably the cheapest option, but they don't seem to be readily available in MT4 as compared to MT2 or 3.

So maybe a MT4-MT3 adapter (open type) and a few MT3 finger collets? Most of my end mills have 6mm or 10mm shanks, so that's only 2 finger collets – they're <£10 each from Arc.

A drawbar is easy to make with a long bolt (or even threaded rod) and a turned collar to suit the rear of the spindle.

Beware that the drawbar thread is usually different between metric and imperial collets (e.g. M12 vs 3/8 Whit).

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