Learning to lathe [things]

[modamag]

Fred anymore update, it have been two weeks since you're back from vacation now.

[PhotonFanatic]

Fred anymore update, it have been two weeks since you're back from vacation now.

Yeah, I know, I'm a slacker. However, it did take a week just to get through all the mail, e-mails, orders, etc., so that's my excuse.

Not to mention that the weather has been terrific here, so running and biking seem to be taking preference at times.

[modamag]

Fred, I was reading over your comments regarding your ball-endmill fluting technique

In regards to your post #147.

I still don't get which direction are you feeding the part to get the proper cut. Is it -Z, moving the part toward the cutter? Another word from deep to shallow?
I didn't notice this much during fluting but I guess w/o flood coolant or misting there is remaining debris that cause this artificial galling. What RPM were you doing with that 1/8" ball em?

[McGizmo]

Cool stuff Fred! I don't visit this thread as I should and I think it has to do with a hang up I have with the thread title, of all things!

Beyond CPF and I think started by Roth(?!?!), I have never encountered the word lathe as a verb. Is it just me?!? A lathe is a tool and not an action. I realize that a mill can be both a tool and an action in machining.

Lathe is not even consistent across disciplines. In a machine shop, to my understanding, a lathe is a tool that spins the part and the cutting tool is rigid while drawn in a controlled path, across the surface of the spinning part. A Jeweler's lathe is a bench motor like a grinder and it holds rotating cutting burrs and buffers while the part is brought to the tool by hand.

When I am working on a lathe, I am turning (or cutting) parts, not lathing.

OK, back to topic, I have made a similar "unibody" pak to the one Fred is working on as well with the McClickie. In my iteration, I considered it a tail cap switch housing that also held the battery and mounted directly to the head. I feel guilty with how easy the Hardinge allows you to thread, deep into a bore!

Nice drive tool for the McClickie!!

[KC2IXE]

...snip...A Jeweler's lathe is a bench motor like a grinder and it holds rotating cutting burrs and buffers while the part is brought to the tool by hand.

Nope - a jewelers lathe spins the part, but you work more like a wood lathe, there is a rest, and you work with gravers, although some have compounds and the like

[will]

I had to look this up - my new word for the day

Main Entry: 1lathe
Pronunciation: 'lA[th]
Function: noun
Etymology: probably from Middle English lath supporting stand
: a machine in which work is rotated about a horizontal axis and shaped by a fixed tool

Main Entry: 2lathe
Function: transitive verb
Inflected Form(s): lathed; lath•ing
: to cut or shape with a lathe

[PhotonFanatic]

Fred, I was reading over your comments regarding your ball-endmill fluting technique

In regards to your post #147.

I still don't get which direction are you feeding the part to get the proper cut. Is it -Z, moving the part toward the cutter? Another word from deep to shallow?
I didn't notice this much during fluting but I guess w/o flood coolant or misting there is remaining debris that cause this artificial galling. What RPM were you doing with that 1/8" ball em?

Jonathan,

The part was held in a indexing collet holder, which was on top of a rotating plate, and both were on the cross slide. So the collet was actually tilted just over one degree, or so. To achieve the taper, the cross slide is moved toward the end mill making the widest part of the taper. Then the cross slide was moved perpendicular to the end mill, basically cutting the taper since the piece was tilted out of perpendicular.

I believe that the milling was done at 2200 RPM, perhaps up to 3000 RPM max.

[modamag]

Thanx Fred, I C now (Post #132). Nice looking attachment.

The reason why I ask is because I'm gonna be doing some slot on my mill w/o coolant so tapping into your wisdom will save me a whole lot of headache.

[PhotonFanatic]

Cool stuff Fred! I don't visit this thread as I should and I think it has to do with a hang up I have with the thread title, of all things!
. .

When I am working on a lathe, I am turning (or cutting) parts, not lathing.

. . .

Nice drive tool for the McClickie!!

While I remain confident that the syntax of this thread's title is correct, I could have also, in retrospect, titled it, "Learning to Mangle (things)".

[PhotonFanatic]

Thanx Fred, I C now (Post #132). Nice looking attachment.

The reason why I ask is because I'm gonna be doing some slot on my mill w/o coolant so tapping into your wisdom will save me a whole lot of headache.

Jonathan,

For some really good machining advice, I usually turn to Practical Machinist. You might want to review this thread where I inquired about end mills--lots of good advice on techniques there.

[McGizmo]

While I remain confident that the syntax of this thread's title is correct, I could have also, in retrospect, titled it, "Learning to Mangle (things)".

From the definition shared above, I believe you are correct in the syntax and I learned something new. Something I might even be able to remember!

As for learning to mangle, can relate to that!! Also launch and explode, melt and ignite!

As to the dental lathe, I have a similar version of one of THESE that I picked up in surplus and I'll be damned if I know where to chuck the part?!?! I have also have one of the Baldor polishing lathes that has the tapered point on each end for polishing wheels. This tool does not hold the part!! I don't doubt that jewlers do use lathes as well but I don't understand why these "buffers" are considered lathes?!?! I wonder if one can lathe with them?!?

While you guys discuss an action you are learning to do, in additon to that, I am also learning what I am learning to do is called.

In my last attempt at defense, I believe I was instructed by the high school shop teacher that one mills on a mill and turns on a lathe. Can I blame him??? I sold precision gaging to machine shops for a while and have never heard the word lathe used as a verb. I stand corrected and will now go hide and lick my wounds of embarrasment.......

[PhotonFanatic]

There have been numerous posts about knurling, but most of them involve aluminum, not titanium; although TB had a separate thread recently showing his knurling on some Ti.

TB used a scissor-style knurler, and if you take a close look at the depth of the knurl, you can see that it isn't very deep, due, of course, to the hardness of the Ti.

However, ArsMachina, had mentioned that perhaps a cut knurler might have better results.

Well, I had tried that before, with disastrous results. However, one has to remember that I'm learning to lathe, so it was entirely possible that I did something wrong before.

Today, I decided to give it another try. What follows are some pics of the piece, complete with errors made in the beginning of the knurl, but still demonstrating that, yes, it is possible to cut knurl Ti.



With the flash on:







Overall, I'm pleased to see that it is possible to knurl TI, now I want to learn how I did it.

Certainly opens up some more design possibilities, too.

[jch79]

Very nice work, Fred! I bet that thing is GRIPPY!

Can you show a photograph of the device used to cut the threads?

john

[TranquillityBase]

Nice job Fred

TB used a scissor-style knurler, and if you take a close look at the depth of the knurl, you can see that it isn't very deep, due, of course, to the hardness of the Ti.

Pressure/Forge/Force knurling will raise to a higher peak/crest, I just prefer a lighter knurl, with corners that have just started to curl...This gives the perfect grip, for a flashlight body IMHO, and it's not sharp enough hook on clothing. The reason Ti is more difficult to forge knurl, is because of its tendency to work harden.

However, ArsMachina, had mentioned that perhaps a cut knurler might have better results.

Your cut knurling tool is probably the best choice for sharp crested knurling, with the least amount of strain to your machine, and more than likely the only tool for traverse knurling Ti.

Looks like you're addicted to your lathe, glad I don't have that problem

[PhotonFanatic]

Pressure/Forge/Force knurling will raise to a higher peak/crest, I just prefer a lighter knurl, with corners that have just started to curl...This gives the perfect grip, for a flashlight body IMHO, and it's not sharp enough hook on clothing. The reason Ti is more difficult to forge knurl, is because of its tendency to work harden.


Looks like you're addicted to your lathe, glad I don't have that problem

Scott,

True, theoretically one can form crests on the pyramids using form knurling, but I haven't seen anyone do it yet on Ti, at least not from one of the home shop guys. ArsMachina did post a piece that he did with a scissors knurler and by turning the lathe by hand; certainly not too conducive to producing more than one light though, as the cutter style that he used is only for plunging, not traversing.

While I'm addicted to my lathe, from time to time, I'm definitely not as over the edge as you are--at least I'm not sleeping with it.

[PhotonFanatic]

Very nice work, Fred! I bet that thing is GRIPPY!

Can you show a photograph of the device used to cut the threads?

john

John,

Grippy, but not abrasive as I touch it up with some buffing compound.

Here are a couple of shots of the knurler--it is a Dorian cut knurler:





That piece of AL was just stuck in the chuck, and untightened, just to show the direction of travel toward the headstock.

[HarryN]

Hi Fred - I am sure glad you have that lathe - Thanks for boring out the custom cnc-123 for me, as well as the rest of the build.

Harry

[PhotonFanatic]

Cut Knurling + CP Ti = a CR123 Twisty

Well a female friend of mine just described this body as 'sexy', so I take that as a compliment.

It really does feel terrific in the hand, since I polished the sharp edges of the knurling away; still plenty of grip though.







Going to have a McR-17 reflector and a Seoul P4 emitter with a NG750 driver once completed.

[ICUDoc]

Very very nice, as usual Fred.
Love the knurling- those cutters make it look great.
And twisties can be nice and short....

[PhotonFanatic]

Been a while, but I needed to revisit knurling for a special custom light that I'm building, which is a twisty. The length of the completed light will be 64mm (2.56") and it will be 20mm in diameter. Since you need to knurl more than the finished length in order to be sure that you will have enough to play with, should there be any blemishes, etc., I decided to shoot for 100mm.

While I could make two separate shorter pieces, which are, indeed, easier to do since there isn't as much overhang (distance from the spindle to the end of the piece), the whole process of knurling is time consuming and nerve racking--it requires a fastidious attention to details, proper height, proper infeed, proper speed, etc.--so I wanted to make one piece and then cut it down as needed.

So, that meant using a center, which I normally don't use, since my pieces are fairly short. But knurling, even cut knurling, puts a lot of side pressure on the piece, so the center was the way to go. To be honest, I'm still a noob when it comes to machining, such that I wasn't sure if it was cricket to use a center when the piece was being held in a collet. Evidently, it is, as I saw a recommendation on Practical Machinist, that a center should be used when making long threads.

So, I dusted off the tailstock, found a live center and proceeded to turn down some 1" stock to 20mm (.78"). Note to self: buy some 7/8" stock.



Once that was done, the knurling tool was set up so that it was perfectly perpendicular to the piece:



The height of the knurling tool needs to be set also. The Dorian cut knurler has a self-centering mechanism--you loosen a set screw at the side of the piece, push the toolholder into the piece until the cutting wheels are centered and then tighten the screw. The tool also has another height adjustment feature--a screw on top of the tool than can raise or lower the knurls by very small increments, but I use that only for adjustments while the knurling is being cut (machine off though).

When the time comes to make the first cut, I put my machine in a very low RPM, about 125-150, which is about the speed one might use when threading. Then I press the knurlers into the piece using the cross slide. Experimentation had shown that to achieve proper tracking, that I need to infeed at least .2mm, so that's how far I penetrate the workpiece with the knurlers, then I let it spin for a few seconds before engaging the leadscrew, which moves the crossslide toward the spindle--just as one does while threading.

Since cut-knurling actually produces chips, I use kerosene to wash the swarf away:



That's the first pass along the length of the piece. Some people probably cut the entire depth with one pass, and that may work just fine, but I prefer to cut one pass, stop the spindle while the knurling cutters are still in place, and check out the look of the knurl. If one cutter is too high, then I adjust the setting using the height adjustment on the knurling tool. Then I reverse the leadscrew and go back to the start. Again, I stop the spindle and see how the knurl is looking, make any further height adjustment, and then infeed the cutters to the final depth before making the second pass:



And this is what it looked like after the second pass; this shows the full length that was knurled:



Taken on the lathe:



Taken off the lathe later:



Overall, I was pleased with the result. The piece will now be made into a light and the knurling will be softened by polishing later.

[jch79]

It's funny how something that resembles a modified can opener can do that!

Very cool, Fred!

john

[PhotonFanatic]

As part of learning to lathe things, one often tries new tools and materials, just to see what you can do with them.

As I learned a bit about knurling, I bought more and more knurling wheels, and, of course, made some trial knurls with them.

And I never throw any of those pieces away, even if they aren't perfect. Everything goes into a little box near my lathe, along with cut-off scraps, etc. From time to time, I rummage through there looking for something that is already cut down to the right size, or something that might work on another light.

And lo, and behold, I needed a knurled knob for a light that will be used in a microscope to replace the current fiber optic/halogen set-up. The light that enters the microscope is only 13mm in diameter, so the knob just need to be at least 15mm or larger. And I found a nice little leftover, which I bored out, threaded, etc., to work with the light:





Good enough for government work, or in this case, a dentist.

[gadget_lover]

Real purdy, that is!

I like the nicely polished edges as they contrast with the brushed finish on the end.

Daniel

[jch79]

Dig the square knurling there, Mr. Fred! Will there be a completed photo of the light mounted on the microscope?
Nice!
john

[PhotonFanatic]

John,

Yeah, the square knurling is nice--too bad it is only made by plunging the wheel into the piece--would be great to have a long length of the light knurled that way.

Most of the light, which is actually the matte appearing tube shown in the photo, is inserted into the interior of the microscope, so there wouldn't be much to see, other than the knurled knob.

[PhotonFanatic]

Many folks have four-jaw chucks, and occasionally one needs to take them apart, clean them out and relubricate things.

But, getting the four jaws back into the chuck can sometimes be a challenge--seems like an extra set of arms would help a bit when you try to reinsert all four jaws at once.

What I tried the other day, and it worked beautifully, was to place each numbered jaw set into its starting position, and then I took a bicycle tube and stretched it around the four jaws many times. That put a good amount of pressure to pull the jaws into the chuck when the key was turned. And, as I did so, each jaw moved into position as it should. Funny how such simple things can make life so much easier.

[cmacclel]

Many folks have four-jaw chucks, and occasionally one needs to take them apart, clean them out and relubricate things.

But, getting the four jaws back into the chuck can sometimes be a challenge--seems like an extra set of arms would help a bit when you try to reinsert all four jaws at once.

What I tried the other day, and it worked beautifully, was to place each numbered jaw set into its starting position, and then I took a bicycle tube and stretched it around the four jaws many times. That put a good amount of pressure to pull the jaws into the chuck when the key was turned. And, as I did so, each jaw moved into position as it should. Funny how such simple things can make life so much easier.

Hmm strange

If it's a scroll chuck which it sounds like it is to me since the jaws are numbered, I thought you had to put one jaw in at a time??

With all my scroll chucks I just take the jaws out...clean em up..then insert jaw number one and rotate the chuck handle as to loosen until I feel a bump on the jaw. I then turn it as to tighten slightly until the scroll grabbs jaw number one. I then insert jaw number 2 and keenp slight pressure on it as I again rotate the scroll until it grabs. The repeat this for the last 2 jaws.

Mac

[PhotonFanatic]

Mac, the Swiss are different--didn't you know that??

[PhotonFanatic]

I swear that I should have taken meditation classes at some point in time--they would have helped with this:



That will be the head--it took almost all day to complete. One mis-turn of the rotary indexer and you can ruin a day's work in the blink of an eye.

This is just the first cutting of the grooves. Next up will be some anodizing of the Ti, then it gets machined once again, with the grooves being cut deeper, partly to outline the blocks a bit more, but also to clean up the anodizing that will have sneaked into the grooves.

[EricMack]

That's hawt, Fred!!