# Tips Of Lathe Tool Bits Rolling Up.



## BarnyardEngineering (Apr 7, 2016)

After owning my Logan 815 lathe for almost a year I finally got to the steel yard for some 6061 aluminum round stock. Got a nice 3' long piece of 2-1/2" round.

My first project was a simple 3/8" thick "donut" to use as a motor mount spacer on the front of a model airplane.

Now I don't have much for tooling, mostly some Harbor Freight carbide bits and what little came with the lathe. I did purchase an Aloris-clone QCTP. 

Far as I could tell the tool was dead nuts on center on the work, but I kept rolling up the tips. Ruined half a dozen tools the same way.

So what am I doing wrong? I watch many of the youtube makers religiously, and thought I understood the basics.


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## Bob Korves (Apr 7, 2016)

BarnyardEngineering said:


> After owning my Logan 815 lathe for almost a year I finally got to the steel yard for some 6061 aluminum round stock. Got a nice 3' long piece of 2-1/2" round.
> 
> My first project was a simple 3/8" thick "donut" to use as a motor mount spacer on the front of a model airplane.
> 
> ...


What do you mean by "rolling up the tips?"  An easy way to see if you are on center for outside turning is to pinch your 6" scale gently and vertically between the cutting edge and the work.  If the scale is standing vertical, you are on center, if the top is tilted toward you, the tool is too low, if tilted away, the tool is too high.  If you are speaking of aluminum getting welded to the cutting edge and building it up with aluminum, WD-40 or kerosene used as a cutting fluid will help with that.  Some of the Chinese brazed carbide tools are ground with poor geometry and the side of the tool will rub on the work.  Check for that as well.  If the steel below the carbide is rubbing it can be ground off on a normal bench grinder.  You need diamond or silicon carbide wheels to grind the carbide.  You say it is 6061.  Is it factory stamped as 6061, and what is the temper (6061-T6, 6061-T651, 6061-T0, or whatever)?


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## seasicksteve (Apr 7, 2016)

Im not sure what rolling up means. The above post covers some potential issues.I dont think your going to ruin a brazed carbide cutter on aluminum.I wonder if what your experiencing is the workpiece is not properly supported and its moving. If the work shifts it can cause tool chipping or breaking


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## Wreck™Wreck (Apr 7, 2016)

seasicksteve said:


> Im not sure what rolling up means. The above post covers some potential issues.I dont think your going to ruin a brazed carbide cutter on aluminum.I wonder if what your experiencing is the workpiece is not properly supported and its moving. If the work shifts it can cause tool chipping or breaking


Try running the spindle in the wrong direction for the tool being used, this never works well.
Two weeks ago I set up a CNC lathe job to be run by an operator, not a machinist. 1000 parts with simple OD's on one end only, 3/8" crs turned to .220 diameter X .350  length.

Four easy steps.
Place part in chuck firmly against stop
Close door, turn on spindle and push start button
When cycle ends stop spindle, remove part
Chuck next part, if you encounter problems ask me for help.

I ran maybe 10 parts with him watching so that he had it down, after about 25 parts he tells me that the insert broke, a 55° screw down.
Sure enough it was broken in half at the hole, he had run the spindle in reverse.


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## Andre (Apr 7, 2016)

Wreck™Wreck said:


> Sure enough it was broken in half at the hole, he had run the spindle in reverse.



Nope, never done that before.....not once.....promise


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## tomh (Apr 7, 2016)

By chance are you using the tool bit to cut the inside of the hole?  If so then you need to raise the bit above the center so the it doesn't rub on the bottom.   Can you post some photos?


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## Paul in OKC (Apr 8, 2016)

If "rolled up" is material on the tool tip, that can be common with aluminum. Need to use some sort or cutting fluid. WD-40 as suggested above is one. Those HF carbide tools leave a bit to be desired, especially right out of the box, and you do need a 'green' (silicon carbide is what it is called) wheel to grind them on.


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## BarnyardEngineering (Apr 8, 2016)

By "rolled up" I mean the sharp tip of the bit is bent upwards.

I just don't understand how it can bend UP when the force of the cut is DOWN.

This happened while facing and while boring. Spindle is turning in the correct direction. It does not even have reverse.


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## Paul in OKC (Apr 8, 2016)

I am still gonna bet it is material build up. Take a scale, or small piece of metal or aluminum and carefully put it against the end of the tool, and or side matching the angle of the cutter. Then "roll" it on the cutting edge with a little pressure and the lip should pop off.  At least that works for me when that happens. YMMV.


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## JimDawson (Apr 8, 2016)

BarnyardEngineering said:


> By "rolled up" I mean the sharp tip of the bit is bent upwards.
> 
> I just don't understand how it can bend UP when the force of the cut is DOWN.
> 
> This happened while facing and while boring. Spindle is turning in the correct direction. It does not even have reverse.



Is it possible your tool is set too high?  Maybe try lowering it a bit?


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## T Bredehoft (Apr 8, 2016)

BarnyardEngineering said:


> By "rolled up" I mean the sharp tip of the bit is bent upwards.





Paul in OKC said:


> I am still gonna bet it is material build up.



I think Paul has it. Often aluminum will 'build up' on the tip of the cutting tool instead of shearing away. Remove the build up by pushing (with a loose piece of aluminum) against the buildup, parallel the top  surface of the tool, until the build up pops off. 
Avoid buildup by using a lubricant. Some suggest WD40, which is a water displacement material, I use A-9 cutting fluid, just  a drop or two on the work. High cutting speed will encourage buildup of both metal and heat. Keep the work and the tool bit cool by using lower speeds.


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## NightWing (Apr 8, 2016)

T Bredehoft said:


> I think Paul has it. Often aluminum will 'build up' on the tip of the cutting tool instead of shearing away. Remove the build up by pushing (with a loose piece of aluminum) against the buildup, parallel the top  surface of the tool, until the build up pops off.
> Avoid buildup by using a lubricant. Some suggest WD40, which is a water displacement material, I use A-9 cutting fluid, just  a drop or two on the work. High cutting speed will encourage buildup of both metal and heat. Keep the work and the tool bit cool by using lower speeds.



What does the finish on the workpiece look like?


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## BarnyardEngineering (Apr 12, 2016)

No, the tip of the tool is actually bent upwards. There's no material to pop off, and when I try to force it the bent-up tip breaks off.


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## Jim1946 SB9" (Apr 12, 2016)

Can you send a pic of your setup. And some close ups of the cutting tool also.


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## Paul in OKC (Apr 12, 2016)

Don't say if you wee just facing, or turning as well. If just facing, I would say your tools are below center a hair too much. When you face past center your tool tip is on the 'up'side of the rotation of the part, which can crack the tip a bit and force it up.


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## kvt (Apr 12, 2016)

Agree post a pic of your setup, and with the tool up against the material.  also a pic or two of what you said is a ruined tool may help.   What I was thinking of is if you were working to on the metal to far out from the chuck and it is flexing up to ride over the tool.   Often those HF tools are not really sharp, thus you need a diamond stone or something so you can sharpen them.   Prior to having problems what do your chips look like.


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## CluelessNewB (Apr 12, 2016)

Assuming you are using a chuck to hold the work, how much material to you have sticking out past the jaws of the chuck?  What size is the HF tooling that you are using?   How much of the tooling do you have sticking out beyond the tool holder?  Generally the less tooling and work you have sticking out the better.  Using the largest tooling you can get away with also helps.


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## eeler1 (Apr 12, 2016)

Sorry, I have no clue what you are talking about,  can't offer any suggestions if the problem is not well understood.  I'd be interested just to see what the heck a rolled up tool bit is.


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## EmilioG (Apr 13, 2016)

It sounds like the cutting edge of the lathe tool is too "thin".  Did you grind these tool bits?
Mikey on the Machinists Blog has a nice write up on grinding lathe tools bits.
Also, using good quality lathe tools may help; RexAAA or Cleveland MoMax.


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## GK1918 (Apr 13, 2016)

Just about everybody including myself tempted buying HF for cheap.  And all of those I had to tweek.
So I don't use those .   I suggest grinding your own HSS blank with a end radius. I just find HF 's
seem not to have relief and rub and have square shanks so other than grinding your stuck with it.
We don't have diamond wheels,  so a die grinder & cut off wheel is used (need steady hands for that)
Good thing about HSS you dress up as needed over and over.  
Harbor Freight stuff is dull out of the box.


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## ericc (Apr 13, 2016)

A photo would really help.  The tip should not deform at all.  Something like this happened to me once when I was just starting out.  The tool was from a garage sale lot.  I reground it, and it cut just fine, for one inch.  I paid more attention to the grinding sparks, noting that it matched the A-2 coupon in my spark test standards.  Not HSS.  It turned out to be a brazed carbide bit minus the little piece of carbide.  I posted a photo, and it was confirmed.


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## crazypj (Oct 1, 2017)

HF brazed carbide isn't worth the effort in my opinion, particularly when the HSS is so much easier to use (and grind to various profiles). I do a lot with 6061 and some with 7075 plus a little with various cast aluminium parts. The only time I've used solid carbide is the ball end milling cutter. Alu-alloy doesn't stick as easily to carbide tools but it will stick if your trying to use recommended speeds and feeds without flood coolant (or, usually, much slower than recommended rpm/feed)
If your in a production shop were 'time is money' go with the charts, if your in a garage or basement (etc) start slow and speed up to where machine is happy. It's way cheaper and less frustrating in the long run
BTW, carbide won't (can't) roll the edges, way too brittle


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## rzbill (Oct 3, 2017)

Maybe the brazed HF cutters are NFG but I have been delighted with the set of 1/4" insert cutters I bought from them.  The largest depth of cut I have tried so far is 0.040" on cold rolled mystery steel at approx 125 FPM.  Cut like butter and made a 4' long swarf coil. Thats about as far as I plan to go because the chip breaker groove is about that size and it doesn't seem right to go deeper than that.  Maybe I will try it just to see.  I've honestly been amazed at how well these things cut.  With the performance so far, it may be a long time before I have to buy some name brand inserts.


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## Tozguy (Oct 3, 2017)

BarnyardEngineering said:


> By "rolled up" I mean the sharp tip of the bit is bent upwards.
> 
> I just don't understand how it can bend UP when the force of the cut is DOWN.
> 
> This happened while facing and while boring. Spindle is turning in the correct direction. It does not even have reverse.



Carbide tips don't bend. If you have been turning for a year now and the problem started with aluminum, my bet is build up of aluminum on the  tool. Very common since some al alloys are very gummy. How has your turning of steel been going? Photos would been a boon to help us help you.


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## mikey (Oct 3, 2017)

Ummm, guys, have you noticed the date when this thread was active?


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## crazypj (Oct 3, 2017)

Yep, over a year old. I did look for post date but didn't see it, too small and too faint. I prefer post dates to be easily seen to prevent this sort of thing


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## mikey (Oct 3, 2017)

Happens a lot when new members join up and wish to share their knowledge. They eventually figure out where the dates are. Just didn't want you to think the OP was being unresponsive.


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## Tozguy (Oct 4, 2017)

mikey said:


> Happens a lot when new members join up and wish to share their knowledge. They eventually figure out where the dates are. Just didn't want you to think the OP was being unresponsive.



Barnyard hasn't been back since April 2017, I hope all is well with him. Still am curious about how the problem was solved.


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## BarnyardEngineering (Oct 17, 2017)

Well, the problem was never solved. I got so frustrated with the lathe I quit trying. It's been sitting in my garage gathering dust ever since. I've been considering kicking the whole thing to the curb.

I know the HF stuff isn't great but it was all I could lay my hands on at the time. I had no clue about grinding tool bits and all I could find on the subject was "you gotta try different angles and feeds and speeds until you find out what works for you." When you don't even have a good starting point, such advice is WORTHLESS, hence my frustration.

The best luck I had was after watching a This Old Tony video on grinding tool bits. I was able to have a modicum of success with a crude bit I ground from a chunk of HSS that came with the lathe. But my enthusiasm was already beaten down pretty badly.


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## Tozguy (Oct 17, 2017)

Yikes, sorry to read that. The only utter and persistent frustration I have had was with some gummy aluminum. Seems like I tried everything to prevent it building on the tool tip but to no avail. It sure felt good when I turned some free machining steel and got excellent results. Was your success with turning steel not encouraging?


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## mikey (Oct 17, 2017)

BarnyardEngineering said:


> Well, the problem was never solved. I got so frustrated with the lathe I quit trying. It's been sitting in my garage gathering dust ever since. I've been considering kicking the whole thing to the curb.
> 
> I know the HF stuff isn't great but it was all I could lay my hands on at the time. I had no clue about grinding tool bits and all I could find on the subject was "you gotta try different angles and feeds and speeds until you find out what works for you." When you don't even have a good starting point, such advice is WORTHLESS, hence my frustration.
> 
> The best luck I had was after watching a This Old Tony video on grinding tool bits. I was able to have a modicum of success with a crude bit I ground from a chunk of HSS that came with the lathe. But my enthusiasm was already beaten down pretty badly.



Hey BE, why not join us on the model tools thread: http://www.hobby-machinist.com/threads/models-for-grinding-hss-lathe-tools.62111/

It makes me sad to think that you quit trying just because of tooling. If you're willing to try your hand at tool grinding I bet we can turn this around.


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## tweinke (Oct 17, 2017)

Give Mikey's offer a try, I'll bet you will be surprised how well your lathe can work. Actually having a sample tool in hand gave me the ah ha moment I needed to succeed.


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## BarnyardEngineering (Oct 18, 2017)

If it's any consolation I am having an absolute blast with my too-small round-column mill. 

I'll check out the model tool thread. I wouldn't even need the models in hand, just measured drawings. I can work off drawings. I am an engineer after all.


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## mikey (Oct 18, 2017)

Nothing so complicated that we need drawings. If you can grind to a line then you can grind a tool. Oh yeah, you have to be able to move your hand in a straight line so you can hone the tool. Now that I think about it, you might be over-qualified.


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## SemoBill (Oct 21, 2017)

BarnyardEngineering said:


> Well, the problem was never solved. I got so frustrated with the lathe I quit trying. It's been sitting in my garage gathering dust ever since. I've been considering kicking the whole thing to the curb.
> 
> I know the HF stuff isn't great but it was all I could lay my hands on at the time. I had no clue about grinding tool bits and all I could find on the subject was "you gotta try different angles and feeds and speeds until you find out what works for you." When you don't even have a good starting point, such advice is WORTHLESS, hence my frustration.
> 
> The best luck I had was after watching a This Old Tony video on grinding tool bits. I was able to have a modicum of success with a crude bit I ground from a chunk of HSS that came with the lathe. But my enthusiasm was already beaten down pretty badly.


O


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## SemoBill (Oct 21, 2017)

Please order a 12“ piece of 12L14 free machining steel rod (1/2 ", 5/8" or 3/4 ", doesn't matter). Play with it. Turn it, face it, drill it, bore it. Try light cuts and heavier ones. Experiment with your slowest spindle speeds, fast speeds and those in the between. Grind a few cutting tools. Regrind and try again.
I have walked away from my lathe many times. Sometimes, it is the right thing to do. I I have learned a great deal more from "playing with" the lathe than I ever did making It a part for a project. 
Hang in there. We all struggle to get it right.


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## earthbound (Oct 22, 2017)

Barnyard, don't give up on this. I've been in your boat and wanted so badly to just throw in the towel. When you get past that point it's the greatest feeling. I've seen this mentioned already in the thread, but I'll rehash the point that carbide does not bend. It just doesn't. It will crack before it bends. You've mentioned using HSS bits and having bad luck with those too. I've thrown out more HSS tools than I've actually ground properly and that's ok! I just have two questions for you about turning your aluminum because I believe your setup is fine and with aluminum, the tool doesn't have to be perfect. 
1) are you turning and facing with the power feed or by hand?
2) are you taking a substantial cut such that a chip is coming off, or are you taking light skimming cuts?


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