A milling attachment for the 9" lathe

[Galaxie]

In the last few days, there's been talk of posting more projects, as well as milling on the lathe, so I thought I'd finally take the time to post this milling attachment (a.k.a. vertical slide). I don't have a mill yet, so this comes in handy for things I can't do on the shaper.

First, I saw our own Paul Alciatore's milling table and I knew I had to copy it. Photo #1 shows it in action. The drawback of course is you have to shim the workpiece to the correct height. The upside is it's quite rigid.

However, needing more versatility, I was intrigued by these two milling attachments: Photo #2 is from Popular Science Nov. 1941. Photo #3 is from Popular Mechanics Nov. 1951. (If anyone wants the links, let me know.) Now, I was pretty skeptical that these would work as intended, but I had some suitable material in the scrap bin and I needed an excuse to practice lapping a ~2" bore. With the exception of the table, these can be made entirely on the lathe, but I cheated and used the shaper to cut the keyway and square up the block that holds the vise.

Continued in next post...

[nickel-city-fab]

Yes, please-- I would *love* to have links to those articles!

[Galaxie]

Photos #4, 5, and 6 show the completed milling attachment. Unfortunately, I did not take photos of the machining! Photo #7 is a cross section view.

The main pillar is mystery steel ~2" in diameter (probably cold rolled). Care was taken to get this as straight and true as possible, which meant the final skim cut was done without tailstock support and a very sharp cutter. Material was left at one end to hold this in the chuck and was removed later. The top end is tapped 1/2-20 for about 1", and the bottom end was machined with the South Bend spigot. As I said, the keyway was cut on the shaper and great care was taken to get this parallel with the pillar's axis.

The sliding tube is 2" schedule 80 pipe bored and lapped to fit the pillar. A steady rest had to be used, but I still fought chatter/ringing most of the time. Ear plugs were required! In retrospect, I would not bother using flat head screws to hold on the cap; the vise block never needs to slide up that high on the sliding tube. Lapping was done with a homemade "Duplex-style" lap and Timesaver compound. I had to be mindful of temperature as I almost got the tube stuck on the pillar during the first test fit!

The key is a piece of bearing bronze. To machine the radius on it, I temporarily superglued it to the pillar (with a shim under it) and held both in the lathe, turning it down it until it could slip inside the sliding tube.

The cap piece fits on top of the sliding tube and has four tapped holes for #10-32 flat head screws. The center is tapped 3/4-10 for a sleeve that holds two Delrin bushings.

The leadscrew, sleeve, bushings, and spacer are straightforward. The handle was purchased from JW WInco. The spacer could be graduated with divisions for .050" if desired. If the spacer is carefully machined to length, and one sneaks up on the leadscrew thread depth, one can achieve very little backlash.

The vise block was made from a chunk of cast-iron ~1" thick from a scrapped arbor press table. It was carefully bored to fit the sleeve and then split with a 1/8" slotting saw on the lathe using the milling table from Photo #1.

Overall, this milling attachment works pretty well and is usually rigid enough for what I do. The vise block is actually easy to adjust up and down and I have not had it move during cuts yet. Squaring everything up with the lathe take some time however. A future improvement will be a means to attach the secondary spindle shown in Photo #8. I already have the spindle (used for toolpost grinding), but I have to make the motor mount brackets. The spindle was actually made a couple years ago with this future use in mind.

[Galaxie]

Yes, please-- I would *love* to have links to those articles!

Here you go:

https://books.google.com/books?id=nCcDAAAAMBAJ&pg=PA188&dq=popular+science+lathe+milling&hl=en&sa=X&ved=0ahUKEwjRu4X4vODYAhVEXawKHYAtB2EQ6AEIOTAE#v=onepage&q=popular%20science%20lathe%20milling&f=false

https://books.google.com/books?id=wdgDAAAAMBAJ&pg=PA211&dq=lathe+vertical&hl=en&sa=X&ved=0ahUKEwiW_fXFuOrYAhVLI6wKHf1DBHEQ6AEINTAD#v=onepage&q=lathe%20vertical&f=false

[Galaxie]

Forgot some stuff:

1. To determine the final length of the spacer (the conical shaped piece with a shoulder), an adjustable parallel works well. I slid the parallel between the handle and upper bushing so there was some drag and measured.
2. I did not have to put a key or set screw in the handle. The friction from the #10-32 screw on the end of the leadscrew is enough. The handle was JW WInco #GN_10-101-B8-F.
3. The vise can be cumbersome, so an aluminum "tooling plate" attached directly to the vise block is handy.
4. South Bend made an offset bracket for their milling attachment, and I can see why. Without it, one can easily run out of travel when moving toward the lathe center line.

[wmgeorge]

I have this milling attachment for the mini lathe I would like to use.

https://littlemachineshop.com/produc...ory=1963256899

I think I have enough material to build a plate to fit my 9x19 Grizzly lathe but can you purchase the T nuts to fit the slide?

[Gary Paine]

Very well done Galaxie. I've a set of old Popular Mechanics Enclylopedias and have found a lot of interesting shop tips in it like this one over the years. I have done some milling in the lathe in years past and got the job done. Getting my mill drill, though was like a breath of fresh air compared to the challenges of doing it on the lathe.

[mattthemuppet]

that's really cool! Just so I get my head straight on it - the vise is attached to an outer cylinder (via the cast iron clamp) that can be raised or lowered on an inner pillar that's attached to the cross slide, with a key preventing rotation? That's a neat way of doing it.

Only thing I'd suggest changing would be to make another cast iron clamp and then make a small tapped plate to attach to both clamps. Then you can clamp work directly to it or make a little 2 piece vice to attach to it. that would both make it a bit more versatile and also reduce the lever arm (how much force the cutter can exert on the pillar through the work) = more rigid and less chatter. But that's just an idea, no reflection on the lovely work you've done.

[wmgeorge]

Trying to understand, but it looks like the only thing to keep that clamp holding the vise from moving on the round cylinder is the clamp pressure? No key way to hold it from twisting. Kind of like a round column mill - drill.

[Galaxie]

that's really cool! Just so I get my head straight on it - the vise is attached to an outer cylinder (via the cast iron clamp) that can be raised or lowered on an inner pillar that's attached to the cross slide, with a key preventing rotation? That's a neat way of doing it.

Yes, that is correct. The most challenging processes in this design are cutting the keyway and boring the sliding tube.

Only thing I'd suggest changing would be to make another cast iron clamp and then make a small tapped plate to attach to both clamps. Then you can clamp work directly to it or make a little 2 piece vice to attach to it. that would both make it a bit more versatile and also reduce the lever arm (how much force the cutter can exert on the pillar through the work) = more rigid and less chatter...

Agreed! In post #5 I mentioned a tooling plate would have less stick-out compared to the rather clumsy vise. In the photo where I'm machining a part, I don't know why I didn't just bolt the aluminum fixture plate right to the clamp.

[Galaxie]

Trying to understand, but it looks like the only thing to keep that clamp holding the vise from moving on the round cylinder is the clamp pressure? No key way to hold it from twisting. Kind of like a round column mill - drill.

Yes, that's right. I was skeptical that the clamp ring would stay put during a cut, but surprisingly, it is very solid. It should be noted that the surface area in contact with the sliding tube is, in theory, much greater than the South Bend spigot/clamp screw interface on the cross slide. That is where rotation is most likely to happen in my opinion.

I will say, I was afraid that the clamp ring would distort the sliding tube and lock it up, but it does not. In fact, there is another older Popular Mechanics design for a toolpost grinder mount that uses an even thinner tube and the same clamp ring idea.

[nickel-city-fab]

To what Galaxie says, IMHO the SB spigot design is it's single greatest weakness compared to (say) having 2 bolts or studs coming up into the compound base.

[Galaxie]

To what Galaxie says, IMHO the SB spigot design is it's single greatest weakness compared to (say) having 2 bolts or studs coming up into the compound base.

I believe when the 9A/B/C came out, South Bend added the second clamp screw on the left side, and even later, they put in two tapped holes to the cross slide, but those only work with the factory milling attachment as far as I know.

Mine is a 405 so I just have one clamp screw on the right side. 🙄

[old mart]

As many of the milling attachments for lathes, that one looks about as stiff as a wet noodle.

[wmgeorge]

As many of the milling attachments for lathes, that one looks about as stiff as a wet noodle.

There has been an amazing amount of work done for years and years on milling attachments, some just like this. The OP did a excellent job on his build.