before the chips fly

[DavidR8]

Hey David,
What material have you tried machining with the Korloy inserts? Are you roughing and finishing with those inserts ?
Do you re-call the previous inserts and holder you have tried that didn't work out with the types of material you were machining?

All steel, from 1080 to 4141HT, both roughing and finishing.
The imports are from Bangood I think so nothing to write home about. Used on 1080 and aluminum.

 

[little ol' e]

All steel, from 1080 to 4141HT, both roughing and finishing.
The imports are from Bangood I thing so nothing to write home about. Used on 1080 and aluminum

Sounds good, I never heard of Bangood. Although, I do like to get bangood once in a while on weekends...

I can see the Korloy inserts working in 1018 and such with that coating. The .015r isn't optimum for roughing... but in mild steel they will hold up for a bit. Higher RPM's will kill the coating and wear those inserts quickly thou even in Mild steel.
I like a minimum .03rad for roughing and leave the .015r inserts for finishing.


I'm thinking you meant PH4140/4140HT rather than 4141HT?
I think you will find, those inserts with that type of coating won't survive long in 4140/PH4140 even at lower RPM's. Even trying to get through the first pass on HRS will be a task with those inserts with a .015r
If your happy with them and feel your getting your $'s worth out of them, then that's all that matters for now.
Just my .02

 

[Proxule]

Doubleboost has recently made a series of lathe tutorials on his channel for beginners.

LOVE this guy

 

[DavidR8]

Sounds good, I never heard of Bangood. Although, I do like to get bangood once in a while on weekends...

I can see the Korloy inserts working in 1018 and such with that coating. The .015r isn't optimum for roughing... but in mild steel they will hold up for a bit. Higher RPM's will kill the coating and wear those inserts quickly thou even in Mild steel.
I like a minimum .03rad for roughing and leave the .015r inserts for finishing.


I'm thinking you meant PH4140/4140HT rather than 4141HT?
I think you will find, those inserts with that type of coating won't survive long in 4140/PH4140 even at lower RPM's.
If your happy with them and feel your getting your $'s worth out of them, then that's all that matters for now.
Just my .02

Yes typo on the 4140

 

[Former Member]

Not here to disagree with anyone here, but, IMHO
If some guys are just getting into indexable tooling over HSS, I would have to disagree and steer them away from any-all uncoated inserts.
Especially, if they are new to the hobby. Not knowing the different materials grades, speeds, feeds, depth of cuts or stepovers will certainly turn anything uncoated into a mess quickly along with a work piece...
Stick with coatings and find the coating that works best for the materials you plan to machine. The different grades of Carbide/coatings will then be much easier to work with once some experience has been established. The things to figure out is how to control premature wear, heat, and surface finish quality.
Micrograin carbide with Tialn coatings are a good starting point IMHO.

Really gotta disagree here, a little lube is good, always applied even with HSS, however if you use TIALN coatings with aluminum you are going to have binding on the insert or mill cutter for that matter.

Think what TIALN stands for....Titanium Aluminum Nitrate.

I have been advised by a tooling supplier no coating in better for all purpose, coatings for purpose specific applications.

Second old brazed Carbide tooling did not have coatings (and still don't) and had no issues.

Use a lubricant and coolant as heat is generated and this is what causes the binding.

Don't over complicate things for those new to this side of the field.

 

[little ol' e]

Really gotta disagree here, a little lube is good, always applied even with HSS, however if you use TIALN coatings with aluminum you are going to have binding on the insert or mill cutter for that matter.

Think what TIALN stands for....Titanium Aluminum Nitrate.

I have been advised by a tooling supplier no coating in better for all purpose, coatings for purpose specific applications.

Second old brazed Carbide tooling did not have coatings (and still don't) and had no issues.

Use a lubricant and coolant as heat is generated and this is what causes the binding.

Don't over complicate things for those new to this side of the field.

@Degen- Don't over complicate things for those new to this side of the field.

Fair nuff...
I haven't experienced binding inserts or loading up milling cutters with Tialn coatings. However, at higher RPM's with low feed rates without air or any flavor of coolant chosen, it is a good possibility.
I will keep quiet here now and won't over complicate things that don't make sense here.

 

[little ol' e]

Three simple things to remember.

1. I find with inserts you have flexibility of speeds and feeds.

2. Not sure on what material you are cutting or don't want to have too many options always go uncoated. Simple guide: Coated ones are generally for steels only.

3. Each Insert holder comes with a number, this specially tells you size and shape of the insert. Stick with that number lets you select for the application.

FYI some of the tool holders that KBC carries come from the same source as Accusize. That said, the holders are good (and match standard spec's) so no worries there. Inserts can be purchased from any source as long as they match spec of the holder you are good. Now you can match whatever insert your budget/quality requires.

That sums things up. The KISS system works in your case.

 

[Susquatch]

Sounds good, I never heard of Bangood. Although, I do like to get bangood once in a while on weekends...

Bangood is like Ali Express. Both a PIA, but hard to beat the pricing. There are apps for both on Android and maybe iPhone too.

Can't help with your weekends. Sometimes I get weekends off when the boss is busy with Grandkids.......

 

[DPittman]

LOVE this guy

Ya I just wish he spoke English.

 

[curmudgeon]

and then there were chips....

As I mentioned before, I'm making a plywood bench top with aluminium legs. The legs came from the corner posts of our old deck railing. I'll cut them down, and turn them upside down to screw the surface mounts to the bottom of the benchtop. The posts had cast aluminum pyramid caps that will now be inset in the bottom of the legs and get drilled to mount the levelling casters. I could have used a bench grinder and handheld drill, but I have a metal lathe now.

It was interesting centering the work in the 4 jaw chuck; I wasted a good amount of time adjusting it in the wrong direction. With more practice I expect it will become more intuitive.

I just used the tools and compound angle that the PO last used, so if you see something wrong, please shout.

 

[ShawnR]

It was interesting centering the work in the 4 jaw chuck; I wasted a good amount of time adjusting it in the wrong direction. With more practice I expect it will become more intuitive.

I just used the tools and compound angle that the PO last used, so if you see something wrong, please shout.

That looks like it would be a PITA to center. I have not done a lot with a 4 jaw but have progressed a bit with it. Not afraid of it anymore. I think a ways back, I would have referenced off of each edge of the square base. But my first impression looking at your set up, I wonder if this would work....? (more a request for input rather than giving advice)
That particular project is not super critical that the piece be centered, although a good opportunity for practice. Would it be acceptable to center punch the center of the piece after scribing diagonal lines, then use the tailstock as a pointer? Put it very close and visually, you could see what jaw actions are doing to the piece alignment. I would think that you would get within a few thousands and since the purpose is to flatten the bottoms, not drill an exact center hole, would that be a suitable set up procedure?

Otherwise, how does one center a square sided piece with cast edges like that? I think I saw someone on Youtube pull the pointer of a dial gauge back, rotate the piece, check, pull the pointer back, etc. And those edges are cast edges so bumps here and there?

Or should one reference off of the back of the jaws?

Any suggestions?

 

[phaxtris]

Measure, scribe, center punch like you said...then the trick is to put a center in your tailstock, and then another center between your tailstock and into the center punch, you can then indicate off the second center as it wobbles when you spin the chuck

But it is a casting, you can only be so accurate

 

[ShawnR]

Measure, scribe, center punch like you said...then the trick is to put a center in your tailstock, and then another center between your tailstock and into the center punch, you can then indicate off the second center as it wobbles when you spin the chuck

But it is a casting, you can only be so accurate

Right.....that sounds familiar. Thanks. I will need to play with the center on center and then maybe it will stick in my mind. I have read that here before. Sounds like a very useful method.

Thanks!

 

[ShawnR]

I wasted a good amount of time adjusting it in the wrong direction.

Nope....just studied in depth....

 

[phaxtris]

Right.....that sounds familiar. Thanks. I will need to play with the center on center and then maybe it will stick in my mind. I have read that here before. Sounds like a very useful method.

Thanks!

After you have done it once you won't forget, the trick is figuring out method works best for you dialing in a 4j

my technique is get it close by eye, withen 100 tho or so, and only work 2 jaws at a time, 180 apart, indicator in line with the jaw, take note, spin 180, try to move the indicator half what you noted...rinse and repeat and until that set is close and move on to the next set, once they are both close you can snug the jaws until it's perfect

Once you get the hang of it only takes a minute or two

 

[YYCHM]

Centering Work in a 4-Jaw Chuck

I've always struggled with centering work in a 4J. Some times it would take me over an hour in order to get something even remotely close. These instructions work, and work great. https://littlemachineshop.com/images/gallery/PDF/centering4-jawchuck.pdf Now if I could only find something...

canadianhobbymetalworkers.com

 

[Susquatch]

@curmudgeon & @ShawnR.

This problem too will be simple when solved.....

Try centering AND aligning axially. Now that is wicked FUN!

You guys are doing great in my view. A few more tips.

Always try to mount the part so that as many jaws as possible have a fairly good grip. But you will find that if you have at least two opposite jaws with good grip, you can usually get away with it. The other two will mostly act as guidance for centering the part. The last thing you want is the part coming loose from the Jaws.

Also, moving a jaw half the offset distance will center it. So if you measure a 30 thou runout, just move the Jaws 15 thou. If you are measuring from a center, then move the Jaws the full amount. Always back off the jaw that is low and tighten the one that is high - in that order. It's a good idea to know how much one turn of the T-Wrench moves your jaws. It's much faster to dial the part in if you do.

 

[curmudgeon]

Centering Work in a 4-Jaw Chuck

I've always struggled with centering work in a 4J. Some times it would take me over an hour in order to get something even remotely close. These instructions work, and work great. https://littlemachineshop.com/images/gallery/PDF/centering4-jawchuck.pdf Now if I could only find something...

canadianhobbymetalworkers.com

Thanks for the link Craig.

I'm relieved that I followed the correct process (dial indicator referencing off the stock on opposing jaws). I just struggled with keeping the relative directions and reactions straight in my head. I think I have it now, and a mantra to help me remember, "push the big numbers down". Meaning that the dial indicator will register a higher number on the side that it too close, so I need to move that side away by tightening the jaw (after loosening the one on the other side).

Another good takeaway for me was the mention of using a pop can or other shim stock to protect the workpiece when sliding it past the side jaws. Didn't matter in this case, but good to know for when it does matter.

This was my first experience with a 4 jaw chuck, and first use of a dial indicator, so it was double the fun for me. A question about dial indicator best practices: Does it matter which range of the dial indicator you use? Almost fully extended? Almost fully compressed? In the middle? Thanks!

Although a fat, sloppy, almost round hole is good enough for my purpose here, I might as well play with the boring bar too.

 

[curmudgeon]

It's a good idea to know how much one turn of the T-Wrench moves your jaws. It's much faster to dial the part in if you do.

Yes!!! I need to measure that, and write it down.

 

[curmudgeon]

then the trick is to put a center in your tailstock, and then another center between your tailstock and into the center punch, you can then indicate off the second center as it wobbles when you spin the chuck

I like this trick. I like this trick a lot. I will save this trick in my book of tricks.