lathe milling attachment - good? bad?
I am considering either buying or making a lathe milling attachment. I would like to mill some shafts for keyways and the like. The shafts are no larger than 1" in diameter. It is a waste of time and money or something reasonable? Ideally a small mill would be preferred, but I am really hurting for shop space.
They work fine. Be aware that you will be taking much lighter cuts, at a slower
pace, than with a milling machine. If you're willing to trade your time that way,
this really is what the milling attachment is designed for.
It also matters what kind of lathe they are attached to. Bigger = better.
9" southbend is sort of the minium entry level.
keyways they work OK for.
if you wanted to hog out any real material, you'd be there forever with steel. Aluminum I have actually done some serious milling on using the Palmgren
The S-B / Atlas type is probably much better than the Palmgren. I have the latter, and if you get one, I'd advise immediately putting in a removable taper-pin hole to hold the tilt adjustment perfectly horizontal......
Otherwise it may let go from the inevitable vibration. That is "highly undesirable".... Don't ask me how I know that.
If you can avoid it don't hold the bit in the chuck...get a collet closer - it'll make a big difference.
The only thing I used the milling attachment for was to hold a piece of aluminum bar stock to taper the end and then drill three holes on the face equally spaced and perpendicular to the tapered face. Worked fine, but can't imagine doing any milling with one (though I have a mill/drill for that).
Milling in the lathe
The attachments work fine as long as you take light cuts.
Single biggest item is how you hold the mill cutter. Never use a drill chuck as these are not designed for side loads. Get one of the many morse tape end mill holders with a threaded shank. You will most likely also need a reducer for the spindle to end mill adapter as these typically come in #2 or #3 morse taper and the spindle tapers are bigger. Use a piece of all thread with a big washer for the draw bar.
Most mill supply will carry but for examples see
You will most likely need to cut off the end of the morse taper reducer.
for example see
This makes changing end mills quick. You can also hold in a 4 jaw chuck or fabricate a holder to mount to your face plate but these take time to install and changing endmills can be a pain.
Note that you will need end mills with the "Weldon" flat for the setscrew [you can grind your self]
Save yourself a bunch of time and wasted effort/money and buy "Milling operations in the lathe" by Tubal Cain ISBN 0-85242-840-5 c20$US.
Several US sources but see
Let the group know how you make out.
Actually some milling attachments can take pretty heavy cuts. The US Government Test for a VersaMil REQUIRES it to take a 3/4 inch wide, by 3/8ths deep cut in a shaft in a lathe, cutting twenty inches of keyway in twenty mintues. Using a stagger tooth mill it's NO PROBLEM.
For the occasional user, a VersaMil may not be in the cards, but VersaMils and Master Milling heads are used throughout the world for cutting keys, flats and doing all sorts of milling jobs in a lathe. LOTS of shipyards mill shafts in their lathes simply because it's easier than trying to set up a shaft in a mill. With the VersaMil or Master LAthe Convertor, your end mill is held in a real milling head. www.versamil.com
If you only need the milling attachment for cutting straight keyways, you can instead make a compound mounted v block with the v at the lathe center line (>). Very easy to set up since you only need to align the shaft (when clamped in the >) perpendicular to the lathe bed.
2 points......both of which you are aware of
1) The Versa-mil is the REVERSE of the ones we refer to, having the CUTTER traveling on the carriage.......instead of the WORK.
2) The minimum size machine to use a Versa-Mil is quite a bit larger (and so more rigid) than the typical size S-B that would have a milling attachment..... Those are mostly 10" at most, and I doubt that the Versa-mil will really usefully go onto a machine smaller than maybe 14" or so, even if it "fits on" a smaller one. Not so?
HSM magazine had a construction article over three or so issues in the 90's on building a milling attachment. I believe the foundry that cast the base may still have the pattern. They were charging about $75 for a casting years back. Also, HSM had an article over several issues in the same timeframe about improvements to the Palmgren milling attachment.
Although this thread turned into a discussion on milling attachments used by placing the cutter in the spindle of the lathe, the original post just asked about whether milling attachments were good or bad. A VersaMil IS a milling attachment for a lathe. The Smallest VersaMil milling head, uses #2 Morse taper tooling, and is suitable for use in a small lathe. HOWEVER, you can't do high quality work with low quality machines. If the lathe is not very robust, you won't have luck milling with it- with a VersaMil OR a milling attachment.
The real problem with milling in a lathe, is the saddle is not designed to have loads applied to it that can LIFT the saddle up. Because of the cutting forces in a lathe, the saddle is ALWAYS being forced down into the bed of the machine. Milling doesn't always force the saddle down, so you get chatter and lousy finishes. SOME lathes like Monarch 10EE's actually have bearings on the bottom of the saddle that keep the saddle from lifting. These lathes are MUCH more suitable for use with a milling attachment. So unfortunately, in the hobby homeowner variety of lathes, milling can be a frustrating task.
I realize that buying a new Versamil is out of the question for most hobby machinists. HOWEVER, there is a plethora of USED VersaMils available, that are well within the price range of a serious home shop machinist. It's just another option available to get a job done in a minimum amount of space. I regularly get reports of the small VersaMil sets being available for well less than $1000.00. The Army used literally thousands of these sets over the last fifty years, and the majority of their surplus sets, are the smaller #31 number two morse taper size. Considering all the attachments, this is some real bang for the buck for a small shop.
What size swing will the small unit "usefully" fit?
The couple I have seen were seriously large units.....
And, while a small S_B or Logan etc is likely not a candidate, a 10" Sheldon or 11" Rockwell is sturdy enough for most anything...... So machines are available in smaller sizes that are solid enough, if the attachment would fit.
The #31 Versamil has a four inch square base, weighs around 60 pounds complete with motor. It would work fine on a 10 inch and larger swing lathe. Again, the heavier lathes of this size would work better than a GRIZZLY. Logans, Sheldon, the Rockwell, are all quantum leaps better candidates for milling than an Atlas. Fact is I would say milling on an Atlas would be a lesson in frustration. The #32 with a Morse #3 spindle works great on my Monarch 10EE's. They're only a twelve inch swing, but at 3500 pounds, pretty darn robust!
I have a seriously large unit in stock right now, with a fifteen inch square base, 10 horsepower motor, driving a fifty taper spindle. Weighs more than most small lathes, at fifteen hundred pounds. I don't know if I'd even use it on my 32 inch swing 20,000 pound Axelson!
I think a Versamill is out of the question. While I consider myself a serious hobbyist, I am not THAT serious.
I have a Palmgren and a Globe milling attachment. The UK site shows the Globe I believe. It has a "Heavy for lathe size" vertical slide that mates with the lathe bed to give you a Z(?) axis. It was better than the Palmgren on the 10" Logan we had. We have a SB Heavy ten at work that is in very good condition and it does much better with the Palmgren than the Atlas(12" Craftsman) or 10" Logan I had. Although these attachments opened new horizons for me, I am very thankful to have a milling machine, albeit less than desirable. Actually, these attachments made me want a milling machine even worse! That said, you can mill successfully on the lathe by being patient.
No offense,to Versamill,but the cost really puts me off. By the time you buy the attachment,and a few extras,you could have bought a full size mill. I am sure they have their place on places like ships,etc.,where space is at a premium. The original units I have seen usually have chunks missing out of their round "T" slots. Haven't seen a new one yet.
Originally Posted by Unka' George
Could I use a collet to hold the endmill instead of the MT mill holder?
That's how I used to run them, end mills in a collet (3C). Remember you won't
be shifting a lot of stock with those attachments, you will be pushing it hard if
you take a ten thou deep cut, half inch wide.
End mills can suck out of collets in principle, but you'll blow the milling attachment
off the cross slide before that happens.
take a look here:
All cast iron. I would kill for it, but that stuff is too heavy to drag it home to Germany...