# First lathe, tool bits



## Jmanb13

I finally got my 1946 15" Leblond lathe cleaned up and running. I have added a CXA QCTP with holders.

I'm planning to buy a set of HSS bits to grind to shape. How many and what size would you recommend as a starting amount for the different profiles.

I was thinking of 3/8 by 3/8 Grade M2 bits.

What would be a good starting set of bit profiles to have on hand?


----------



## wawoodman

Right and left-hand cutting, R & L facing, single point threading.


----------



## ghostdncr

I'd also add a parting/cutoff tool of some sort.


----------



## Wreck™Wreck

Think about what work you are planning on doing, OD turn ,ID turn, face, chamfer and part are the most common, that is 3 or 4 tools. Internal thread, External thread, Internal grooving, External grooving and Face grooving both square and with a substantial radius, you are now at 9 tools. OD and ID back cutting adds a few more as does profile work. Buy or make the tools when needed not before you need them as they may never be used.

A single tool that holds many different insert profiles is useful, Kennametal Top Notch tools use square groove, full radius groove and many different thread profiles such as 60 Deg., 55Deg., Acme, metric trapizoidal and buttress in the same holder, very slick. Kaiser Thinbit has an excellent line of internal, external and face grooving tools including those pesky dovetail O-Ring groove tools, I can not even begin to communicate how much I dislike dovetail grooves.


----------



## intjonmiller

This is the basic, standard set. It would be reasonable to grind these ahead of time if you feel so inclined, but other shapes beside these would make more sense when you need them. Starting with a dozen or more blanks would be a good idea, as you typically save money by buying larger quantities. 




If you look on eBay you can typically find old HSS tooling lots for sale. Sometimes blanks, sometimes ground, sometimes mixed. Vintage Rex AAA, MoMax, and Firth Sterling tend to be better quality than the majority that you'll find today. May be others as well, those are just the ones I've dealt with. 

Also note that T15, M36, and M42 (the latter two having roughly 5% and 10% cobalt added) are "better" (in roughest terms) grades than M2, but M2 is certainly good enough for most work. There are other grades as well, but they're less commonly available as tool blanks.


http://tomstechniques.com/ has a lot of good info about tool geometry, grinding, and use. His YouTube channel is good, but he generally advises people to start on his website because the information is better organized there.


----------



## Bob Korves

A 15" lathe can certainly use 3/8" blanks for bits, but can also usually handle larger ones, typically up to 5/8 or 3/4".  They are more rigid, and more expensive.  HSS tools can be had for very cheap prices used.  I have several times bought fairly large amounts at about a dollar a pound, already ground into tools, just touch up or regrind as desired...


----------



## mikey

The line between reasonable and expensive seems to lie at about 1/2" tooling - go bigger and the cost goes up really fast. The same is true for grinding times - above 1/2" takes much longer. Unless you are going for really heavy cuts most of the time, I would just go for 1/2" HSS and/or cobalt bits.

The best cobalt bits, in my opinion, are Cleveland Mo-max bits (5% cobalt) or Super Mo-max (8% cobalt) but standard their HSS is fine for most work. I personally avoid Chinese bits when I can. Other names to watch for are Crucible, Rex (made by Crucible), Chicago Latrobe and Morse. ETM makes very high quality HSS tooling as well. 

As for shapes, most hobby guys use a general purpose tool that can face and turn in RH and LH. A good facing tool is a knife tool, also in RH and LH. A zero-rake general purpose tool and a round nose tool for brass is handy, as is a good 60 degree HSS threading tool for external threads. I suggest you research and buy a blade-type parting tool instead of grinding one. Boring and internal threading tools are another discussion with many options.


----------



## Bob Korves

Watch out for grinding lathe bits.  Even the regular HSS tools contain cobalt.  The "cobalt" tools have even more, and so do most inserts.  Wear a dust mask and don't blow the dust around the shop.  It is not high risk stuff, but still, why take a chance on making yourself ill. 
----------------------
Wikipedia:
*Precautions*
Main article: Cobalt poisoning
Cobalt is an essential element for life in minute amounts. The LD50 value for soluble cobalt salts has been estimated to be between 150 and 500 mg/kg.[91] In the US, the Occupational Safety and Health Administration (OSHA) has designated a permissible exposure limit (PEL) in the workplace as a time-weighted average (TWA) of 0.1 mg/m3. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 0.05 mg/m3, time-weighted average. The IDLH (immediately dangerous to life and health) value is 20 mg/m3.[92]

However, chronic cobalt ingestion has caused serious health problems at doses far less than the lethal dose. In 1966, the addition of cobalt compounds to stabilize beer foam in Canada led to a peculiar form of toxin-induced cardiomyopathy, which came to be known as _beer drinker's cardiomyopathy_.[93][94]

After nickel and chromium, cobalt is a major cause of contact dermatitis.[95]

Cobalt can be effectively absorbed by charred pigs' bones; however, this process is inhibited by copper and zinc, which have greater affinities to bone char.[96]
---------------------
I have some old school Stellite 5/8" tool bit blanks that are around 60% cobalt, and some others with somewhat less than that, but still way more cobalt than tools have today.  I am not excited about trying them out.  Their scrap value is probably quite high.


----------



## gheumann

I will go out on a limb here. I tried this with my first lathe. It was a mistake. I really didn't know enough, even after reading up on it a bit. Grinding your own tool bits is a skill and an art. Are you sure you want to try to learn that before you know how to machine with a lathe in the 1st place? If something doesn't go right, how will you know if it is the tool or one of countless other variables you might not be familiar with? Me? I really wanted to learn to make things FIRST. It really helps to have actually experienced using various tools to understand why this angle is that, and that angle is this, and so on. You say this is your first lathe. If I were you, I'd buy a tool holder set with indexable inserts. They work great and even to this day I do 95% of my work with them. They last long, they're a time saver, they're not expensive - and they just WORK so you can get to the business of learning how to make things. About the only cutting tool I take to the grinder on a regular basis are my parting blades.
A set like http://www.grizzly.com/products/7-pc-Deluxe-Tool-Holder-Set/G8787.

If you really want to grind your own, this looks like a nice compromise. Seeing a properly ground tool will really help! https://www.littlemachineshop.com/products/product_view.php?ProductID=4516&category=

I know the old timers all say "learn to grind your own tools". THEIR teachers HAD TO. I don't think it is a bad idea if it interests you in and of itself. It just isn't necessary to learn RIGHT AWAY to start really enjoying your new lathe. Old timers used to tell me I should learn to use a slide rule - but I grew up in the calculator age. The analogy applies. They were tied to the way THEY were taught but they were wrong. I've never, ever needed a slide rule.


----------



## Jmanb13

I'll keep an eye out on ebay for used bits.

My lathe came with a box of misc lathe bits that I could use. They are all pretty rusty, but with some grinding that should go away. I probably have about 10 or so 3/8 and 1/2, with a few 3/4 bits. However, looking at all the profiles, I couldn't find a single one that remotely resembled any of the standard profiles. If I were to use them it seems it would require a TON of grinding or somehow cutting off the existing profiles and starting over. 

I tried using my bandsaw with a bi-metal blade to cut off the strange tips and start over, but it did not seem to be doing much and was probably ruining the blade. 

Unless someone knows an easier/better way of getting rid of the existing profiles, I figured I would just grab half a dozen name brand bits from MSC and grind both ends to give me a dozen or so different profiles.


----------



## intjonmiller

Don't get rid of them until you are certain you understand them! They may be very useful forms. Post pictures so we can help identify if you like.

Best case scenario your bimetal bandsaw blade's teeth are only very slightly harder than what you're cutting. That's not going to happen. Abrasive, plasma, torch, waterjet, or wire EDM are the usual methods for cutting tool steel like this, as this is the steel that is used to cut other steel.


----------



## Glenn Brooks

I'd like to encourage you  to learn to grind your own tooling.  Sure, carbide inserts are swell and easy to use.  However they have two significant draw backs.  They break and shatter in no time with interrupted cuts.  Also they require high lathe speeds (RPM) to operate properly.  Most old lathes are not made with the kind of high RPM's that carbide inserts are designed to work with. OK, Three drawbacks - they are also expensive to buy.  As a rule of thumb HSS works at RPMs ranging from 36 to 250.  Generally, carbide inserts work at speeds from 400 RPM to 2000rpm, depending on the diameter of your work. Another way to think about it is:  HSS speeds should be slow enuf to produce yellowish - straw colored chips. Carbide bits should work at higher speeds that produce hot blue chips.  So a lot depends on what your lathe can turn for RPM's.  A 1947 15" Leblond is definitely  a HSS machine -super slow and powerful.  

OK!  So also,  It's just not that difficult to learn to grind HSS tool bits. Plenty of examples on YOu tube. Plus your local live  steam (miniature railroad) club will have someone , or many someone's, who would likely be happy to help you learn how.   After a few tries, you will be touching them up all the time.  Sometimes just a few seconds on the grinder to apply a keen edge,  makes  all the difference in the world for producing fine finishes.  

Second the advice from Bob and others to use 1/2" bits.  Cheap on eBay, particularity the used ones, and more rigid than 1/4" or 3/8".  

Good luck and have fun!

Glenn


----------



## gheumann

Glenn I respectfully disagree. That may be what the book says. I turn wood, aluminum, brass, delrin and steel almost exclusively with carbide inserts. I DO increase my speed over the recommended IPS for HSS, but unless you're turning really tiny diameters material you won't have any trouble getting these tools to perform, even on a lathe that maxes out at 1200RPM. I get great surface finishes. I've never broken a tool bit. I don't do a lot of interrupted-cut work, particularly on steel, but I do do it occasionally.
I am not against learning to grind your own tools. I'm against doing it before you've learned how to use your lathe. I am proof you don't have to.


----------



## mikey

gheumann said:


> I know the old timers all say "learn to grind your own tools". THEIR teachers HAD TO. I don't think it is a bad idea if it interests you in and of itself. It just isn't necessary to learn RIGHT AWAY to start really enjoying your new lathe. Old timers used to tell me I should learn to use a slide rule - but I grew up in the calculator age. The analogy applies. They were tied to the way THEY were taught but they were wrong. I've never, ever needed a slide rule.



Hey, who you calling an old timer?  

It's good to have a choice. Many guys *cannot* grind a good HSS tool and there is a difference between choosing and not being able to choose. One day you'll be turning a piece that has a lot of work already in it and you'll have to take 0.0005" off the diameter. That's about the time you learn about nose radii, deflection, cutting forces and the benefits of predictability. 

In my opinion, the best idea is to learn to grind good tools and also try some carbide. Then compare them on your lathe, doing the kind of work YOU do, and make your own choices.


----------



## mikey

gheumann said:


> I am not against learning to grind your own tools. I'm against doing it before you've learned how to use your lathe. I am proof you don't have to.



I agree with you, Greg, to a point. If I understand your position, you're saying that you don't have to learn to grind tools just so you can use your lathe and its true, you don't. But what if the OP chooses to do so? Is that not okay, too? Many of us have a lot of experience with *both* carbide and HSS and many of us choose HSS because it works better for us, not because someone told us to do it or because its the party line.


----------



## AGCB97

I got a 1/2 gallon pail of tool bits of all shapes and sizes, some new with my lathe. I might be able to put together an assortment for you very cheap if your interested. 75% are cemented carbide, balance HSS.
Aaron
PM me


----------



## AGCB97

Or something like this will last you forever
http://www.ebay.com/itm/20PC-1-2-CA...496441?hash=item46334e8c39:g:lIoAAOxy-8pSZzP6

With a 15" lathe I wouldn't go less on average that 1/2". I've learned to make my own insertable carbide tools and use the biggest bar that will fit in the CXA. Only occasionally does one need a smaller bit


----------



## gheumann

mikey said:


> Hey, who you calling an old timer?
> 
> It's good to have a choice. Many guys *cannot* grind a good HSS tool and there is a difference between choosing and not being able to choose. One day you'll be turning a piece that has a lot of work already in it and you'll have to take 0.0005" off the diameter. That's about the time you learn about nose radii, deflection, cutting forces and the benefits of predictability.
> 
> In my opinion, the best idea is to learn to grind good tools and also try some carbide. Then compare them on your lathe, doing the kind of work YOU do, and make your own choices.



Can't argue with that!


----------



## Bob Korves

If I had to choose between a socket set or a combination wrench set, I would definitely choose "both."  Yes, they both turn fasteners...


----------



## willthedancer

Go with hi speed. Half inch bits are fine, but you'll use the 3/8 too. Less grinding with smaller bits. Make your inevitable mistakes with tools that you can fix.

Indexable carbide is great stuff, and I use it to save time or machine things that hss won't cut, but the inserts are expensive and unforgiving. The tool holders are also easily damaged, insert seats are hard to come by, and expensive too.

Grinding advice...

A slower grinder is better. Use a quart container of cold water to dip tool bits in. If the tool is getting temper colors, you're spoiling it. Keep it cool. Keep your grinding wheels dressed flat and free of metal embeds.

The tool isn't finished when you're done grinding. The little burr that's left will break off and blunt the edge. This leads to metal buildup on top of the tool and early failure. Take a fine stone and rub the faces carefully. It will more than double the life of the edge.

In common steels, your chips should not have temper colors darker than straw yellow. (You won't see temper colors in stainless unless you are cutting with ceramic tools).

Sent from my Moto G Play using Tapatalk


----------



## JPMacG

My thought is that smaller HSS bits are less time consuming to grind and less expensive to purchase.  Maybe you could start with 3/8 and move up to 1/2 later, when you have more experience with grinding.  You might even start with 5/16 or 1/4 if your tool post will accommodate those sizes. 

I think that grinding my own has become fun and satisfying, although I admit that I started with some pre-ground bits that came with my lathe.


----------



## Jmanb13

Thanks for all the suggestions!

I would like to learn to grind my own bits. I enjoy the learning process as much as actually making stuff, its kind of in my DNA. Also, I'm pretty sure old my lathe tops out at 500rpm in the top gear with the motor at 60hz. Even if I run the motor faster than rated i'm still barely breaking into carbide speeds. I think this really limits me to HSS. 

I dug out all the bits in the box of stuff I got with the lathe. Here is what I currently have to work with that came with the lathe. Most of the bits look like they were either ground for a specific profile or were broken in use. The labels I can read on them suggest that some of them branded REX.

The majority of the bits are 3/4" or 1/2". The tool holder I have can hold up to 3/4 bits.

Most of the 1/2" bits are generally between 1.5" and 2" long as is. The 3/4" bits are similar lengths as you can see. I'm not sure what the usable length of the bits needs to be, but to be held by 2 set screws on the tool holder they need to be at least 1" long plus whatever stick out amount is needed. I would think that leaves me very little wiggle room on regrinding the profiles.

I have close up pictures of each size of bit if it helps.


----------



## mikey

I love looking at old tool bits. Some of them have some really esoteric shapes and I wonder what the guy was thinking when he ground it. I have seen some bits that were ground by a skilled machinist, complete with cleanly formed shapes and angles, but such is not the case here, Jmanb. Don't mean to seem snobby or anything but I honestly don't see anything in the pic that I would choose to reproduce. 

If it were me, I would start from scratch. I would buy some cheap Chinese 1/2" HSS tool bits from ebay and while I'm waiting for them to arrive, I would go to the hardware store and buy some 1/2" square keystock. I would cut the keystock into bit-sized pieces and learn to grind tool bits on that; it grinds easily and is cheap. It will also take light cuts, although the edge won't hold up for too long. 

There is a lot of info on tool grinding on the net and this site - search, ask questions and someone will help guide you. On a big 15" lathe, you are less worried about cutting forces, power or rigidity than some of us with smaller lathes so the angles in the typical lathe tool angle table will work fine for you. As for shapes, intjonmiller illustrated the shapes that were typically used on older machines with older style tool posts and they work fine. Nowadays, with the QCTP, we can also use a more generalized shape that works for most cuts we make. Again, search because I don't want to bog down your thread with too much detail here. 

I would also agree with you that if your lathe can only run at very low speeds then HSS or possibly brazed carbide might be your best bet. Regardless of which you use, I agree with Willthedancer and would hone the cutting edges with a stone, either synthetic or diamond.


----------



## Bob Korves

Carbide insert tooling will certainly cut at lower speeds. but it will not be at it's best, especially regarding surface finish.


----------



## Reeltor

Everybody has an opinion, it reminds me of the Ford/Chevy/mopar discussions.

If you want to go carbide, I would stay away from this type of brazed on carbide:






I am no expert by any stretch of the word!  But I find that I can do very well with HSS hand ground bits and then tried some of the cheap brazed carbide ones similar to the photo from HF.  I wasn't happy at all with how they cut and the finish they produced.  You can dress them with diamond sharpening stones to make them a little better.  Then I found some NOS carbide insert tooling and tried it.  The difference between the insert carbide and the brazed carbide is like night and day.  Several name brand HSS tooling was already mentioned, try to find some of those rather than eBay ones of mystery HSS.
Just my .02

Jnamb13, shoot me your name and address in a pm, I think I have a new old stock HSS  MoMax in 3/8" i can drop in an envelop to you, if you'd like to try grinding  your own.

Mike


----------



## Bob Korves

Brazed carbide tools are just fine if you get good quality ones, and grind them properly as they need it.  You can make them sharper than how most inserts come, which cuts nicely, leaves a good finish, but also needs grinding more often.  Depending on the grade and quality, they can be very good for interrupted cuts as well.  I have had some luck with grinding cheap Asian brazed carbide tools to a form that actually might cut something and getting good work out of them.  Others have been poor in just about every respect.


----------



## Reeltor

Bob Korves said:


> Brazed carbide tools are just fine if you get good quality ones, and grind them properly as they need it.  You can make them sharper than how most inserts come, which cuts nicely, leaves a good finish, but also needs grinding more often.  Depending on the grade and quality, they can be very good for interrupted cuts as well.  I have had some luck with grinding cheap Asian brazed carbide tools to a form that actually might cut something and getting good work out of them.  Others have been poor in just about every respect.



Bob,

can you explain what a "good quality" brazed carbide tool is?  Brand?  Price seems a crap shoot.  I know not to expect too much from HF, what about buying on eBay?  What is there to look for?


----------



## mikey

I'll let Bob give you the real answer but I like and use Micro 100 brazed carbide tools on occasion. In my opinion, they are the best of their kind.


----------



## Bob Korves

Reeltor said:


> Bob,
> can you explain what a "good quality" brazed carbide tool is?  Brand?  Price seems a crap shoot.  I know not to expect too much from HF, what about buying on eBay?  What is there to look for?


I went out in the shop and dug into the top layer of the brazed carbide.  Lots of Kennametal, Carboloy, Morse, Firthite, and Lake.  Also some Armstrong, Super Tool, and Modco, and some unbranded.  To make it simple, all the brand names ended in USA, and the majority of these tools might be older than half the people on this forum, from back when these tools were what was used in production and job shops, before inserts took ahold.  Nearly all are new, unused, in beautiful condition after some Evapo-Rust, some elbow grease and some ATF.  I have at least a hundred of them, 1/4" to 3/4", 20 pounds or more, in various configurations, and not more than $10-15 cost in the whole stack, Craigslist tool lot purchases.  They work really well.  Don't pay retail!  Try not to buy junk!


----------



## Jmanb13

Since I want to get started quickly I ended up picking up a lot of vintage bits off ebay. Its a combination of Mo-Max, Firth, and Empire bits. Not the "best" price. But at around $1.30 per bit it sure beats the $15+ per bit that MSC wants for new 1/2 USA bits.

I'll be keeping a lookout for really good deals in the future, but I wanted to get started ASAP, and this auction seemed to be a decent enough deal for what was there.

http://www.ebay.com/itm/30-Vntg-HS-...gKfUL0TRpk7CkVVYQ%2B8%3D&orig_cvip=true&rt=nc


----------



## Bob Korves

I like the older HSS and brazed carbide bits better than the new ones.  They seem to be higher quality.  In HSS I like the MoMax best, and the Rex (Crucible), Morse, and Ludlum as well.


----------



## Glenn Brooks

looks like a good price for a bunch of bits.  Actually, with your original collection of bits, Polish them up with a wire wheel  in your grinder if you have one to remove the oxidation  on the surface. Then you will know better which you might be able to use. The short 1"-2" bits can be mounted back to back in one tool holder.  One end does facing cuts, switch around, the other end does turning cuts.  Very efficient  use of short cutters.

Any of the long bits you can't use because of shape, just grind the ends off into a right or left handed turning bit, or whatever you need.  Really doesn't take much time to do, and gives them a new life.  Same with the thread turning bits.(60* angle, pointy end in the center of the bit).  Looks like you have several.  Probably you will only ever really use one of them.   Convert the long ones into roughing and finishing tools- they each have different shapes- and see what you can do to tweak finishes etc...  that's more or less what I have been doing to learn how to use the various types of HSS geometries, and develop a feel for proper cutting edges and shapes.

BTW, I mounted a small 3" diameter grinder on the bench beside my smaller bench lathe, where I store the bits I use.  At the slightest sign of not cutting properly, I can just reach over and  put a fresh edge on the bit - sometimes without removing it from the tool holder.

Good luck.
Glenn


----------



## ThunderDog

I agree with Reeltor in post #25.  Those import mystery meat a.k.a. brazed carbide are terrible.  I bought a small set when I first got started.  On the very first cut it broke the tip right off.  So, I put in another one and thought it was operator/beginner error and backed off on my depth of cut only to see the same thing.  Mind you, I had a bunch of HSS bits that I bought at a yard sale for $10.  It was then that I decided to force myself to learn how to grind.  I took a methodical approach and actually did what worked for me.  I made a very basic jig out of wood and learned with a 1"x 30" belt sander.  I know what you're thinking, "This Thunderdog guy must be dumb!!".  It worked, it was slow, I didn't own a bench grinder at the time, and I made some decent chips with that first knife edge bit.  Over time I kept revisiting the topic through my L.H. Sparey book(my favorite to this point); knowing that I wanted to learn and should learn how to make proper HSS bits on a bench grinder.  I bought a grinder and started learning and made mistakes along the way.  Only now have I just started to get into carbide inserts. I agree with BOTH sides of the table when it comes to just making stuff vs. learn to grind first.  I can see the validity for both camps of thinking.
Regardless, have fun and get out there with that machine!!  Just don't be tempted to purchase those horrible *import* brazed carbide things.  Let it be known that I'm not against brazed carbide bits of higher quality.


----------



## Eremius

Jmanb13 said:


> Also, I'm pretty sure old my lathe tops out at 500rpm in the top gear with the motor at 60hz. Even if I run the motor faster than rated i'm still barely breaking into carbide speeds. I think this really limits me to HSS.



It really depends on how big what you're turning is.  SFPM is king.  It doesn't take much diameter to make up for your lack of RPM.


----------



## Jmanb13

Eremius said:


> It really depends on how big what you're turning is.  SFPM is king.  It doesn't take much diameter to make up for your lack of RPM.



That is a good point. I looked up recommended SFM specs for different materials. At 500 RPM It looks like anything above around 2.5" gets me in the carbide range for steel, but i'd have to be in the 6 or 7" range for aluminum.


----------



## whitmore

Jmanb13 said:


> Thanks for all the suggestions!
> 
> I would like to learn to grind my own bits....
> 
> I dug out all the bits in the box of stuff I got with the lathe. Here is what I currently have...



Well, that's LOTS of tool steel, you won't have to buy blanks for a while.   It's
a good thing you want to do the grinding.

If you don't have a project in mind yet, this would be a good time to wire-brush the bits
you have, and examine the edges.   Chuck up some scrap and see how they
cut, make a few washers, wedges, or widgets.

And, try truing up and sharpening bits that don't cut well.   I find that
a stereo microscope is a great help in edge examination, but even a jeweler's loupe is good.

Tuning up the lathe was good, now for sharpening you'll want to tune up the grinder, too.
A flat stone, or (better) a selection of hones, does the fine tuning on a ground tip.


----------



## Downunder Bob

Jmanb13 said:


> I finally got my 1946 15" Leblond lathe cleaned up and running. I have added a CXA QCTP with holders.
> 
> I'm planning to buy a set of HSS bits to grind to shape. How many and what size would you recommend as a starting amount for the different profiles.
> 
> I was thinking of 3/8 by 3/8 Grade M2 bits.
> 
> What would be a good starting set of bit profiles to have on hand?





Jmanb13 said:


> I finally got my 1946 15" Leblond lathe cleaned up and running. I have added a CXA QCTP with holders.
> 
> I'm planning to buy a set of HSS bits to grind to shape. How many and what size would you recommend as a starting amount for the different profiles.
> 
> I was thinking of 3/8 by 3/8 Grade M2 bits.
> 
> What would be a good starting set of bit profiles to have on hand?



Congratulations on getting the lathe cleaned up and running. I'm not sure how much previous experience you've had, but your question suggests not much. I'm not familiar with the Leblond brand of machines, but the age 1946, that's getting old, and "the size 15", getting big,  would suggest to me that it would not be a very high speed machine, and therefore carbide inserts would not be very useful at the smaller diameters. By all means use them on larger dia's, and very hard materials, they are very good. 

Back to your own thinking of 3/8 HSS, probably the most universal size for medium to large machines and certainly the right size for a 15" lathe, unless you're going to only be doing fairly small work. you might want to get a couple of 1/2"bits for the heavier jobs, but otherwise I'd stay with 3/8. 

Certainly learning to grind your own tools is quite a challenge, although not as difficult as drills, although all the same rules apply. But it is well worth the effort, and skill to b e proud of. There are plenty of discussions on angles on this site as well as others, so I won't get into that, other than to say there is no absolutely correct way to grind a tool as long as your relief angles are reasonable, and it works, remember that not enough relief will not cut, and too much weakens the bit and reduces the ability to get the heat away, it also takes longer to grind. If the tool you grind works well then it is near enough to correct.

I would start by enquiring at what quantity of bits do you get a good price break, for instance a packet of 10 or 12 , then buy that quantity. If there is no advantage then buy 5 or 6. I'd start with a general purpose turning, facing bit, 1 for RH and 1 for LH, I'd add a 60deg thread cutting tool, regular right hand threads only, I'd leave the LH tool until you need it, maybe never. I'd also leave the 55 deg thread tool until you need it. For parting off I'd go with a specialised parting tool with holder I prefer the wedge type. 

A couple of boring bars with holders will get you started. Remember save all your broken drill bits, including center drills  and tool bit stubs the are very useful for making boring bars.

Have fun,

Bob.


----------



## intjonmiller

bobshobby said:


> Remember save all your broken drill bits, including center drills  and tool bit stubs the are very useful for making boring bars.


Yes! I have a box labeled "dull/broken bits" where I toss anything carbon steel or better. Even an old spade style wood drill bit can become a useful tool of some other kind down the road. If you have family or friends in woodworking, construction, manufacturing, etc. you can ask them to save their "junk" bits as well. SDS-type hammer drill bits are particularly good as the shanks are very tough and the tips are often carbide. Once they round off that carbide a little they often get tossed. I've picked up several off of the ground at job sites (when I used to work in construction) so I can sharpen them into something else when needed. Tiny drill bits can become the knives in a shop-made wire stripper or the tip of a new scribe.


----------



## Highsider

You don't mention if you have a good coolant system on your 15", but if you do and your set up is rigid, you will be missing a bet if you don't learn how to grind lipped cutting tools from HSS.  For brute metal removal rates with the RPM range you state, they can't be beat, and they produce an acceptable finish with coolant.  They are all we used before carbide and high RPM gigahorsepower lathes were common.   The difference is that the removed metal comes off as a tightly coiled ribbon rather than as a chip that's breaking up and coolant flow is essential.   The depth of cut can be 3/8" to 1/2" per pass depending on horsepower.


----------



## Al 1

Go for the E-b-- lots.  You can get a pile  for a good price.  Practice your sharpening with different types of cutters.
(HHS and carbide).  I got into metalworking in 2010 and have many cutting tools, probably  more than I will ever use.
None were purchased at new product prices. 
    Al.


----------



## mikey

Highsider said:


> You don't mention if you have a good coolant system on your 15", but if you do and your set up is rigid, you will be missing a bet if you don't learn how to grind lipped cutting tools from HSS.  For brute metal removal rates with the RPM range you state, they can't be beat, and they produce an acceptable finish with coolant.  They are all we used before carbide and high RPM gigahorsepower lathes were common.   The difference is that the removed metal comes off as a tightly coiled ribbon rather than as a chip that's breaking up and coolant flow is essential.   The depth of cut can be 3/8" to 1/2" per pass depending on horsepower.



Can I ask what kind of lathe you used to take those depths of cut?


----------



## Highsider

mikey said:


> Can I ask what kind of lathe you used to take those depths of cut?


Industrial lathes ranging from 13" to 32" ( Colchester Clausing, Monarch, and Le Blonde.


----------



## mikey

Highsider said:


> Industrial lathes ranging from 13" to 32" ( Colchester Clausing, Monarch, and Le Blonde.



Thanks, Highsider. Them is some mighty cuts, that's for sure!


----------



## Rustrp

Jmanb13 said:


> Thanks for all the suggestions!
> 
> I would like to learn to grind my own bits. I enjoy the learning process as much as actually making stuff, its kind of in my DNA. Also, I'm pretty sure old my lathe tops out at 500rpm in the top gear with the motor at 60hz. Even if I run the motor faster than rated i'm still barely breaking into carbide speeds. I think this really limits me to HSS.
> 
> I dug out all the bits in the box of stuff I got with the lathe. Here is what I currently have to work with that came with the lathe. Most of the bits look like they were either ground for a specific profile or were broken in use. The labels I can read on them suggest that some of them branded REX.
> 
> The majority of the bits are 3/4" or 1/2". The tool holder I have can hold up to 3/4 bits.
> 
> Most of the 1/2" bits are generally between 1.5" and 2" long as is. The 3/4" bits are similar lengths as you can see. I'm not sure what the usable length of the bits needs to be, but to be held by 2 set screws on the tool holder they need to be at least 1" long plus whatever stick out amount is needed. I would think that leaves me very little wiggle room on regrinding the profiles.
> 
> I have close up pictures of each size of bit if it helps.
> 
> View attachment 228706


I didn't see any recommendations or I read over them. Watch the Tubalcain lathe tool grinding video(s) and you can use the old HSS for practice.  I'm not sure what's on the tools you have shown so a quick cleanup would make a big difference along with being able to see if they have any markings as to what you have.


gheumann said:


> I will go out on a limb here. I tried this with my first lathe. It was a mistake. I really didn't know enough, even after reading up on it a bit. Grinding your own tool bits is a skill and an art. Are you sure you want to try to learn that before you know how to machine with a lathe in the 1st place? If something doesn't go right, how will you know if it is the tool or one of countless other variables you might not be familiar with? Me? I really wanted to learn to make things FIRST. It really helps to have actually experienced using various tools to understand why this angle is that, and that angle is this, and so on. You say this is your first lathe. If I were you, I'd buy a tool holder set with indexable inserts. They work great and even to this day I do 95% of my work with them. They last long, they're a time saver, they're not expensive - and they just WORK so you can get to the business of learning how to make things. About the only cutting tool I take to the grinder on a regular basis are my parting blades.
> A set like http://www.grizzly.com/products/7-pc-Deluxe-Tool-Holder-Set/G8787.
> 
> If you really want to grind your own, this looks like a nice compromise. Seeing a properly ground tool will really help! https://www.littlemachineshop.com/products/product_view.php?ProductID=4516&category=
> 
> I know the old timers all say "learn to grind your own tools". THEIR teachers HAD TO. I don't think it is a bad idea if it interests you in and of itself. It just isn't necessary to learn RIGHT AWAY to start really enjoying your new lathe. Old timers used to tell me I should learn to use a slide rule - but I grew up in the calculator age. The analogy applies. They were tied to the way THEY were taught but they were wrong. I've never, ever needed a slide rule.


.....and then your battery died. Were they really wrong? Learning how to do something isn't the same as saying you must always use the old way. Not learning how to grind and taking the shortcut is good up to a point, as long as your supplier keeps the inserts coming. Knowledge and the educational process to attain is something that can't be taken away. Bottom line; Do you want to be a machinist or a machine operator? 

From the position of an apprentice in training, there's a lot more being taught when you grind a 60 deg. tool to cut a thread, or a Lt. & Rt. hand cutting tool.


----------



## Rustrp

Eremius said:


> It really depends on how big what you're turning is.  SFPM is king.  It doesn't take much diameter to make up for your lack of RPM.


True, but then horsepower comes into play.


----------



## Rustrp

Highsider said:


> You don't mention if you have a good coolant system on your 15", but if you do and your set up is rigid, you will be missing a bet if you don't learn how to grind lipped cutting tools from HSS.  For brute metal removal rates with the RPM range you state, they can't be beat, and they produce an acceptable finish with coolant.  They are all we used before carbide and high RPM gigahorsepower lathes were common.   The difference is that the removed metal comes off as a tightly coiled ribbon rather than as a chip that's breaking up and coolant flow is essential.   The depth of cut can be 3/8" to 1/2" per pass depending on horsepower.


That's why a chip breaker was ground into the tool which is something someone doesn't learn if they never grind a cutting tool. Okay, they may learn why inserts are designed to break chips and they may even learn to look for color if that's the shop environment they work in.


----------



## Rustrp

mikey said:


> Thanks, Highsider. Them is some mighty cuts, that's for sure!


I was fascinated by the process. I just happened to walk into a shop looking for someone to repair the die on my punch press. The owner felt the need to show me why they didn't do work that size. They were turning a shaft that was in the 12" x 20'+ range and they were breaking the spiraled cuts (serious weapons) at 5'-6' and collecting them in a trough/bin that followed the cutter.


----------



## dontrinko

Buy a few but also buy some blank HHS and grind your own. It is amazing how ugly a bit can look and still work fine! All IMO; Don


----------



## Eremius

Rustrp said:


> True, but then horsepower comes into play.


I'm guessing with a 15" LeBlonde it's not going to be an issue.


----------



## Rustrp

Eremius said:


> I'm guessing with a 15" LeBlond it's not going to be an issue.


A 1946 LeBlond wasn't really designed for carbide so the high speed and the horsepower rating is for HSS, and back then, they were using CS. The high speeds devolped would be on tall gears so pushing a carbide cutter into the work surface would be based on HP. Working in reverse, the SFPM would slow and the quality of cut would go downhill also. Without knowing what horsepower the lathe has or the SFPM it can maintain, I was simply stating that HP comes into play. 

I have a vintage Lodge & Shipley that I don't as yet know the age so I've spent a lot of time looking at the old machines. My father-in-law who gave me the lathe, purchased it sometime in the early 1950's. His 40+ year machinist career started in the early 1930's. When he gave me the 2-gal. can of misc. HSS and carbide cutters he explained the pros and cons. The cons for the carbide cutters are primarily the speed and feed rates required. At slow speeds the heat isn't transfered to the chip so it builds up in the work. The carbide inserts work better than the brazed tooling because they have a smaller surface and a built in chip breaker. 

I'm not comparing my lathe to the LeBlonde because they are two diffrent machines with decades between their production. I think you know everything is relative, especially in the machinist trade. In regards to may comment, we can start with the quality of the carbide cutter. In 1946 the LeBlond operators manual was mentioning carbide as a cutter with minimum instructions on material-speed-feed etc. -Russ


----------



## Eremius

Rustrp said:


> I think you know everything is relative, especially in the machinist trade.



Actually the best description I've heard is the only thing two machinists can agree on is the third one is an idiot.


----------



## Reeltor

MrPete222 aka Tubal Cain does have some great videos on tool bit grinding, when to use what/when etc.  Adam Booth (ABomb79) and Tom Lipton (OxToolCo) did a series on how big a cut they could take on their respective lathes.  I thought that they both had some real gems of information on different approaches to HSS lathe bits and grinding them.  Don't hold me to it but I think it was Adam Booth who would rough out the bit by clamping it in a vise and using his 4-1/2" angle grinder.  He made it look easy and fast, then he moved on to the bench grinder to finish it off.  They call this series Chip Control.





This Old Tony recently published a video on his take on grinding HSS bits





Tubal Cain uses the tried and true oversized wood mock-ups of HSS tool bits to show the relief angles.  The same visual aids that shop teachers used for decades (when schools had shops).  I don't remember who it was who used a new approach to the visual aids on relief angles etc, might have been Dale with Metal Tips and Tricks.


----------



## Jmanb13

Highsider said:


> You don't mention if you have a good coolant system on your 15", but if you do and your set up is rigid, you will be missing a bet if you don't learn how to grind lipped cutting tools from HSS.  For brute metal removal rates with the RPM range you state, they can't be beat, and they produce an acceptable finish with coolant.  They are all we used before carbide and high RPM gigahorsepower lathes were common.   The difference is that the removed metal comes off as a tightly coiled ribbon rather than as a chip that's breaking up and coolant flow is essential.   The depth of cut can be 3/8" to 1/2" per pass depending on horsepower.



I do not have a coolant system. Definitely have thought about adding one at some point.




Rustrp said:


> A 1946 LeBlond wasn't really designed for carbide so the high speed and the horsepower rating is for HSS, and back then, they were using CS. The high speeds devolped would be on tall gears so pushing a carbide cutter into the work surface would be based on HP. Working in reverse, the SFPM would slow and the quality of cut would go downhill also. Without knowing what horsepower the lathe has or the SFPM it can maintain, I was simply stating that HP comes into play.
> 
> I have a vintage Lodge & Shipley that I don't as yet know the age so I've spent a lot of time looking at the old machines. My father-in-law who gave me the lathe, purchased it sometime in the early 1950's. His 40+ year machinist career started in the early 1930's. When he gave me the 2-gal. can of misc. HSS and carbide cutters he explained the pros and cons. The cons for the carbide cutters are primarily the speed and feed rates required. At slow speeds the heat isn't transfered to the chip so it builds up in the work. The carbide inserts work better than the brazed tooling because they have a smaller surface and a built in chip breaker.
> 
> I'm not comparing my lathe to the LeBlonde because they are two diffrent machines with decades between their production. I think you know everything is relative, especially in the machinist trade. In regards to may comment, we can start with the quality of the carbide cutter. In 1946 the LeBlond operators manual was mentioning carbide as a cutter with minimum instructions on material-speed-feed etc. -Russ



This thing still has the original 1hp 203 frame 3 phase motor and it still works  However the seals on it are bad and it leaks oil/grease like crazy. I'd like to get a new motor on it eventually, but I can't find any motor frame adapters for that frame. Not sure if it would be advisable to get a higher HP motor or not.


----------



## Rustrp

Eremius said:


> Actually the best description I've heard is the only thing two machinists can agree on is the third one is an idiot.


There's no need to deflect and bring the plumber into this.  I'll add, I'm a novice machinist or less than. I have 40+ years working with metal but very little using machine tools unless my 4 1/2" grinder qualifies as a hand held surface grinder. My sheetmetal layout experience and training along with my welding experience gives me some depth into geometry, trigonometry and metalurgy, which are easily applied to machining. The question asked specific to the topic was on HSS cutting tools along with grinding and shaping. If my apprentice is working through the steps on making a simple pan, it would be futile for me to interject how I go about laying out a square to round transition with a compound offset. Maybe it's the hobbist aspect here that seems to take the threads onto many paths. 

We can agree to disagree and I always stand by **I don't have to be wrong for you to be correct**. I agree with you on the large diameter being suited for the carbide cutter, but is the operator and the machine suited for the task. An underpowered machine with only carbide cutters to draw from could create the potential where a beginner never wants anything to do with machining again. The same could be true with HSS but not likely. When I ask the apprentice; Why are you doing that? Sometimes the response is; That's what you were doing! I saw you do it this way! I know I need to tune up my training or they have inserted a shortcut they don't have the experience to handle.


----------



## Rustrp

Jmanb13 said:


> I do not have a coolant system. Definitely have thought about adding one at some point.
> 
> 
> 
> 
> This thing still has the original 1hp 203 frame 3 phase motor and it still works  However the seals on it are bad and it leaks oil/grease like crazy. I'd like to get a new motor on it eventually, but I can't find any motor frame adapters for that frame. Not sure if it would be advisable to get a higher HP motor or not.


In regards to more HP, I would lean that direction if there is protection for for the head. i.e. shear pins etc. Some HP ratings have changed. I would suggest taking the motor to a shop or see if they are willing to part with expertise at to the direction you take. What type of lubrication does the motor use, oil, grease, and what type of seals. Are the windings, armature open or enclosed. Replacing the seals may be an easy and inexpensive fix.


----------



## Dinosaur Engineer

I find that you can sometimes get real bargains in buying the larger HSS bits. Sizes above 1/2" are not used so much in industry as they used to be as most industrial M/cs are now equipped with carbide insert tools to get the improved speed/efficiency required. It is a bit of chore to grind the larger sizes but once ground they hold their edges reasonably well due to their increased heat conducting capacity.


----------



## Reeltor

Maybe you can find a manual or sales brochure at Vintage Machinery . org to see what hp motors were originally available for your lathe.


----------



## 4GSR

Jmanb13 said:


> This thing still has the original 1hp 203 frame 3 phase motor and it still works  However the seals on it are bad and it leaks oil/grease like crazy. I'd like to get a new motor on it eventually, but I can't find any motor frame adapters for that frame. Not sure if it would be advisable to get a higher HP motor or not.


I've replaced many old motors with newer ones on machine tools over the years.  You have to forget the old frame sizes and adapt the old motor base to accept the new motor.  I just did one the other day on my 15" Sheldon lathe.  Don't remember the original frame size, but had to mount a couple of pieces of 1/2 x 2 flat bar to the old base with new holes in place to mount the newer 182/184T frame motor.  (Just realized this is off topic. Sorry!)


----------



## Jmanb13

Reeltor said:


> Maybe you can find a manual or sales brochure at Vintage Machinery . org to see what hp motors were originally available for your lathe.



I have the "Running a Regal" from the model years of my lathe, but I did not see any motor ratings anywhere in the manual.



Rustrp said:


> In regards to more HP, I would lean that direction if there is protection for for the head. i.e. shear pins etc. Some HP ratings have changed. I would suggest taking the motor to a shop or see if they are willing to part with expertise at to the direction you take. What type of lubrication does the motor use, oil, grease, and what type of seals. Are the windings, armature open or enclosed. Replacing the seals may be an easy and inexpensive fix.



It has grease zerks so i'm assuming its grease lubrication. Motor plate picture is attached.



4gsr said:


> I've replaced many old motors with newer ones on machine tools over the years.  You have to forget the old frame sizes and adapt the old motor base to accept the new motor.  I just did one the other day on my 15" Sheldon lathe.  Don't remember the original frame size, but had to mount a couple of pieces of 1/2 x 2 flat bar to the old base with new holes in place to mount the newer 182/184T frame motor.  (Just realized this is off topic. Sorry!)



I will probably have to do something similar. I have found a few places that list a part number for a readily made adapter from 203 to 143T, but nowhere that sells them. This did get slightly off topic, but only because the use of Carbide inserts leads to discussions on RPM and cutting speeds which leads to how fast/powerful is my lathe


----------



## Bob Korves

Jmanb13 said:


> I have the "Running a Regal" from the model years of my lathe, but I did not see any motor ratings anywhere in the manual.


A book on how to run a lathe will often cover many different models, and so will not show the details for them all.  Do you have a parts or operation manual for your lathe?  Do you know the model number of it?


----------



## Rustrp

Jmanb13 said:


> It has grease zerks so i'm assuming its grease lubrication. Motor plate picture is attached.



If the motor is still in good condition; bearings/bushings/windings etc, I would suggest replacing the seals. If you have an ammeter check to see if it's within the rated amps when running under load. There are some features of older motors that are better than the newer ones today, even when you step into the industrial quality. Without knowing how many hours or the conditions in which the motor operated you're guessing. A good motor repair shop could help evaluate what's needed. If the varmish on the windings is breaking down they may be able to recondition those too. Take photos into a motor shop and see if they will give you a ballpark estimate.

PS. New grease seals don't tolerate over greasing and old ones are worse.


----------



## Rustrp

Your location gives you lots of resources for the motor repair and I'm pushing the repair angle for a couple of reasons, cost and keeping the machine close to original if possible.


----------



## 4GSR

Rustrp said:


> If the motor is still in good condition; bearings/bushings/windings etc, I would suggest replacing the seals. ............Take photos into a motor shop and see if they will give you a ballpark estimate.
> 
> PS. New grease seals don't tolerate over greasing and old ones are worse.


Old motors do not have seals.  They are open bearing with dust caps that are designed to keep trash out.
Replace bearings with modern sealed bearings for motor application. 
Take pictures to the motor shop??? Never heard of doing that.  Pull the motor and take it to the shop and have them do a general cleaning, inspection, and replace the bearings.  If the windings need help, they will suggest what to do.  Other than that, for less $100 maybe even $50, you can get a cleaned up ready to go motor.  
Nothing wrong with older motors, most will produce a bit more HP than the nameplate rating says, especially with the bigger name brands, without over heating and burning out a motor if not continuously run at a over rated condition.  Ken


----------



## Rustrp

4gsr said:


> Old motors do not have seals. They are open bearing with dust caps that are designed to keep trash out.


My comment was a general description. My old lathe motor has oil sumps with bronze bushing and slinger rings, yes rings, not sleeves. I wasn't referring to a sealed bearing and the comment was inclusive. It's common for the ball bearing to be outside the rotor, stator winding area of the case with a seal/sheild/flange to keep the oil/grease out of the winding area. If the motor is leaking oil/grease then the shield/seal is probaly worn out or the wrong type of grease was used.





4gsr said:


> Take pictures to the motor shop??? Never heard of doing that.



It's easier than taking the motor out and driving a 40 mile RT into OK City.


----------



## Reeltor

4gsr said:


> Old motors do not have seals.  They are open bearing with dust caps that are designed to keep trash out.
> Replace bearings with modern sealed bearings for motor application.
> Take pictures to the motor shop??? Never heard of doing that.  Pull the motor and take it to the shop and have them do a general cleaning, inspection, and replace the bearings.  If the windings need help, they will suggest what to do.  Other than that, for less $100 maybe even $50, you can get a cleaned up ready to go motor.
> Nothing wrong with older motors, most will produce a bit more HP than the nameplate rating says, especially with the bigger name brands, without over heating and burning out a motor if not continuously run at a over rated condition.  Ken



I have never taken a motor to a shop for evaluation.  I am surprised to hear how reasonable an inspection and general cleaning costs.  Good to know.

Many motors have a plug 180 degrees from the grease zerk, be sure to remove the plug when greasing.  Allow the old grease to come out the plug-hole.  Whoever serviced my VanNorman didn't know to do this and grease is everywhere.  If I can get a professional cleaning for $50-$100-I think that would be a deal.


----------



## Jmanb13

Rustrp said:


> If the motor is still in good condition; bearings/bushings/windings etc, I would suggest replacing the seals. If you have an ammeter check to see if it's within the rated amps when running under load. There are some features of older motors that are better than the newer ones today, even when you step into the industrial quality. Without knowing how many hours or the conditions in which the motor operated you're guessing. A good motor repair shop could help evaluate what's needed. If the varmish on the windings is breaking down they may be able to recondition those too. Take photos into a motor shop and see if they will give you a ballpark estimate.
> 
> PS. New grease seals don't tolerate over greasing and old ones are worse.





Rustrp said:


> Your location gives you lots of resources for the motor repair and I'm pushing the repair angle for a couple of reasons, cost and keeping the machine close to original if possible.





4gsr said:


> Old motors do not have seals.  They are open bearing with dust caps that are designed to keep trash out.
> Replace bearings with modern sealed bearings for motor application.
> Take pictures to the motor shop??? Never heard of doing that.  Pull the motor and take it to the shop and have them do a general cleaning, inspection, and replace the bearings.  If the windings need help, they will suggest what to do.  Other than that, for less $100 maybe even $50, you can get a cleaned up ready to go motor.
> Nothing wrong with older motors, most will produce a bit more HP than the nameplate rating says, especially with the bigger name brands, without over heating and burning out a motor if not continuously run at a over rated condition.  Ken



Thanks all!

I've never had an electric motor repaired. What type of shop would I look for? Any specific keywords to look for in the local google search?


----------



## Rustrp

Jmanb13 said:


> Thanks all!
> 
> I've never had an electric motor repaired. What type of shop would I look for? Any specific keywords to look for in the local google search?



"electric motor repair" should do it. My experience is that most shops will give you a free estimate. Call around. I like the shops that have been around for a few decades.


----------



## 4GSR

Rustrp said:


> "electric motor repair" should do it. My experience is that most shops will give you a free estimate. Call around. I like the shops that have been around for a few decades.


I don't recall any that have not been around a few decades....


----------



## Rex Walters

[My first post in a long, long, while. It may be lathe envy (I've been hankering for a bigger, heavier lathe). I'm still on my first: a very nice but pretty light 10" Logan.]

I'm still a comically incompetent beginner, but there are a few things I wish I'd known when I first got my lathe. Top of the list is all about tool bits and grinding: nothing will detract from fun on a lathe faster than a poorly ground tool.

The most useful (and most used) lathe tool accessory is a bench grinder. [The second most useful lathe tool, IMHO, is a vertical mill, but good ones aren't cheap and while you're hunting for a bargain you can get an awful lot done with a four-jaw chuck, faceplates, and centers. Work-holding and tool-holding creativity is the second most useful skill after grinding, and nothing teaches you the former better than the lack of a mill!]

Grinding an HSS lathe tool properly is *not* hard (usually). It *can *be done freehand (with practice). A few degrees difference in rake or clearance angles *won't *make a difference (except when it does). Experienced grinders know the reasons behind all the angles and can troubleshoot and correct troublesome tool bits. Unfortunately,  a clueless newbie has about a 0% chance of offhand grinding a tool bit correctly to begin with, and only a minuscule chance of correctly diagnosing problems. Problems are exacerbated on a light lathe with any flex in the machine (ask me how I know).

Apprenticing with someone would get you over the hump, but I suspect most of us hobbyists are alone in our shops, so the best options forward are one of the following:

1. You can forego some of the pain (or at least exchange it for *much* more pain in your wallet) with carbide inserts and tool holders. Perhaps surprisingly, though, carbide inserts will never be as sharp as a well honed HSS tool (meaning you can't take as fine a cut with them) and you still need to know an awful lot about cutter geometry to select appropriate inserts (there are a *lot *of choices). You guessed it: the best way to learn about those geometries is by grinding your own HSS bits.

2. You can take my route and begin a "YouTube apprenticeship." If you accompany watching videos and reading forums/blog-posts with *actually grinding bits and making chips*, you'll eventually become reasonably competent. I took the longer route of always grinding freehand, but if I had it to do over again I know it would have gone a lot faster if I'd taken the time to build a decent jig or grinding rest. It's a lot easier to figure out which changes help when results are repeatable and exact rather than random (and once you can grind a decent RH turning tool for mild steel you can pretty much just lock down the jig settings as that's all you'll need 90% of the time). I've just started building the Acute tool sharpening table from Eccentric Engineering. I'd also considered building Harold Hall's sharpening rest. I can also highly recommend the advice from Conrad Hoffman though I've not tried building his jig for honing.

Unfortunately, you'll need decently ground tools and modest skill to build any of these, which can be a bit of a chicken and egg problem for an absolute beginner. If you've got deep pockets, you can go the buy vs. build route with a tool and cutter grinder like this one. That would be an awesome investment for the shop. Even a rank beginner could grind perfect HSS lathe tools from the start (buy two while you're at it, and send one to me!). A used Deckel T&C grinder off of eBay might be a better choice, but probably won't cost any less.

3. You could build or buy a tangential tool holder and grinding jig like the Diamond Tool Holder from Eccentric Engineering. Like most people, I initially thought the diamond tool was just a gimmick, but if there was *just one thing *I could go back and tell myself right after acquiring my lathe it would be to go out and buy one of these to get started. Sharpening a bit could not be easier: just insert a tool bit into the grinding fixture and push it into the grinding wheel. You only need to grind a single face! Once you set the height on center in your toolpost, you're immediate set up for all turning and facing tasks (*without* needing to swing the toolpost around to switch between turning and facing). While it won't completely eliminate the need to grind your own HSS tools for special tasks, it will satisfy the all important need of *demonstrating how a properly ground tool behaves on your lathe*. Seriously, I now use a tangential tool for almost all of my lathe work — it rarely comes off my toolpost.

I suspect many beginners go through these options roughly in this order (1, then 2, perhaps never getting to 3). I know starting out, I just wanted to start making chips, so insert tooling seemed attractive. The sheer number of insert options was intimidating, though, so I started learning how to grind my own HSS tools freehand. The experience gained was incredibly useful, but it was definitely tedious and frustrating — I went a long, long time before I could reliably produce a reasonably performing result.

So my advice is to keep all those tool bits you acquired (never throw away any bits of decent HSS) and learn how to grind them, but *start* by acquiring a tangential tool and use that to build the parts for a grinding jig/rest/fixture as an early project. That is, 3, then 2, and perhaps eventually 1 as required. Treat those rusty old bits you have as a source of HSS stock. Often the trickiest part of machining is figuring out how to get a cutting edge where it needs to be (clever work holding and tool holding). Some of those weird offhand grinds make a lot more sense when you see them applied to their specific situation. Don't be surprised if you eventually find yourself rooting around in that pile of bits looking for something close to what you need, then taking one to the grinder for just a light touch up.

Have fun.


----------



## mikey

Really enjoyed your post, Rex. Well written and based on experience. 

Thanks!


----------



## Jmanb13

Thanks! Lots of good info there.


----------



## Rex Walters

mikey said:


> Really enjoyed your post, Rex. Well written and based on experience.



Thanks. Doubtless it was overly verbose, but if I'd just said "go get a diamond tool holder" nobody would have believed me!

Reminds me of my favorite expression: "There's no such thing as bad experience." (Assuming you survive!)


----------



## Bob Korves

I thought tangential tool bits were pretty much just for shallow cut finishing work.  I have never actually used one, but have watched a few in use, trying for average (and less) depth cuts on light lathes and not succeeding.  The only success I saw was with a very light depth of cut and a very slow feed rate, which worked well.


----------



## EmilioG

What is T15 and is it commonly used in cutters today? I'm curious because I came across a NOS Niagra T15 4 flute end mill with Weldon shank and a curious
ring around the end of the shank. Is T15 better than cobalt for lathe bits and other cutters? (sorry, not trying to hi jack, just saw a mention to T15 earlier in this great thread.)


----------



## Rex Walters

Bob Korves said:


> I thought tangential tool bits were pretty much just for shallow cut finishing work.



Are you confusing a shear tool with a tangential tool holder?

The former is definitely for very shallow cuts (a few tenths to about one or two thou) but leaves a fantastic finish. A shear tool is also very easy to grind, but is still plunged into the work with the tool held normally (radially). Works great for final finishing passes when precision turning. See Conrad Hoffman's article for a description of the sheer tool (about halfway down the page). The chips (shavings) really do look like very fine steel wool.

A tangential tool holder holds the entire bit at a tangent to the work. See the Diamond Tool Holder from Eccentric Engineering. [FWIW, I have no financial interest in the company, but I did have the pleasure of meeting Gary recently — great guy.]

I usually take about 0.040" to 0.060" off the diameter of mild steel with my tangential tool during a roughing pass on my light lathe, but I could probably take a bit more. Some might consider that a shallow cut but I think they've got *much* heavier direct drive lathes. My belt between the motor and the drive shaft is fairly loose and tends to slip if I attempt a cut much heavier than that.

Here's a video of someone taking what I consider to be reasonably heavy cuts in a variety of material with a tangential tool: 




Regards,
--
Rex


----------



## Bob Korves

EmilioG said:


> What is T15 and is it commonly used in cutters today? I'm curious because I came across a NOS Niagra T15 4 flute end mill with Weldon shank and a curious
> ring around the end of the shank. Is T15 better than cobalt for lathe bits and other cutters? (sorry, not trying to hi jack, just saw a mention to T15 earlier in this great thread.)


T15 is a Tungsten high speed steel that mostly uses tungsten for the hot hardness ability.  It is an older design of HSS that is not often seen anymore, but I have some.  M series HSS uses molybdenum for part of the tungsten amount for hot hardness ability.  Molybdenum is cheaper than tungsten, so they moved in that direction.  I have zero experience with using my T15 tool bits, but I assume that they perform pretty well.  If you can get the end mill cheap, go for it...
http://www.asminternational.org/doc...yNow.pdf/b8f2e317-5089-44bc-a14d-af31f80e33a5


----------



## Bob Korves

Rex Walters said:


> Are you confusing a shear tool with a tangential tool holder?


Yes, I certainly was confused on that.  I will look at your sources and educate myself.  Thanks!


----------



## mikey

I gotta' admit, that tangential tool is pretty slick. I think Tozguy also uses and likes that tool. The only thing I can't wrap my head around is the fact that the geometry is fixed ... no tool bit works for everything. Seems to me that for smaller lathes, you would want the flexibility to reduce cutting forces, no? To do that, you need to alter tool angles and this tool holder/concept will not allow for that. On the upside, grinding the tool bit can't get much easier and that's a big positive.


----------



## Rex Walters

mikey said:


> Seems to me that for smaller lathes, you would want the flexibility to reduce cutting forces, no? To do that, you need to alter tool angles and this tool holder/concept will not allow for that.



The angles are fixed, but I use mine for both soft aluminum and fairly hard steel without issue. I'd probably use a different tool for turning a bunch of Delrin or really gnarly stainless, though. The amazing thing is you can even use it for threading. (The grinding jig lets you grind a 60º angle as well.)

It's not the only tool you'll ever need (you can't grind chip breakers, for example) but it suffices for about 90% of the turning and facing I do. It does tend to generate long chips, but then so do most of the well-ground tools I've made. I never grind chip breakers myself, anyway: speeds and feeds (and a pair of long nosed pliers) suffice for my needs.


----------



## mikey

Rex Walters said:


> The angles are fixed, but I use mine for both soft aluminum and fairly hard steel without issue. I'd probably use a different tool for turning a bunch of Delrin or really gnarly stainless, though. The amazing thing is you can even use it for threading. (The grinding jig lets you grind a 60º angle as well.)
> 
> It's not the only tool you'll ever need (you can't grind chip breakers, for example) but it suffices for about 90% of the turning and facing I do. It does tend to generate long chips, but then so do most of the well-ground tools I've made. I never grind chip breakers myself, anyway: speeds and feeds (and a pair of long nosed pliers) suffice for my needs.



What I meant by my statement is that a good tool can enable your lathe to take cuts that a normal HSS tool and probably that tangential tool won't allow. My Sherline lathe is tiny in comparison to a 10" Logan but it will take a 0.050" deep cut in mild steel with the right tool. Your lathe, with the same tool, could easily double that cut. 

On the other hand, if it works good enough for your needs then that is really all that matters.


----------



## Randall Marx

I have and use a tangential tool on my Atlas 12" lathe. It works pretty well and is DEAD SIMPLE to sharpen. I have it set so that when the tip of the tool bit is level with the top of the toolholder, it is at center height in my lathe. That way, I can remove the toolbit, sharpen it, hone it, switch to a different bit (like a round one for finishing), and easily set it to center with a blank held on top of the toolholder. I have also found that I can vary the geometry by varying the grinder rest angle and how the sharpening jig/toolbit is presented to the grinding wheel. That way, I have different bits for different applications and different workpiece materials. I figured that part out after reading some of Mikey's postings about toolbit grinding.  I'm still planning to figure out how to grind a REAL toolbit, but this works well for work that is general-purpose. If I need to reach into a tight area, the tangential tool is a no-go. Other than that, it is pretty good for me and has opened my eyes to grinding variations.


----------



## mikey

Randall Marx said:


> I have and use a tangential tool on my Atlas 12" lathe. It works pretty well and is DEAD SIMPLE to sharpen. I have it set so that when the tip of the tool bit is level with the top of the toolholder, it is at center height in my lathe. That way, I can remove the toolbit, sharpen it, hone it, switch to a different bit (like a round one for finishing), and easily set it to center with a blank held on top of the toolholder. I have also found that I can vary the geometry by varying the grinder rest angle and how the sharpening jig/toolbit is presented to the grinding wheel. That way, I have different bits for different applications and different workpiece materials. I figured that part out after reading some of Mikey's postings about toolbit grinding.  I'm still planning to figure out how to grind a REAL toolbit, but this works well for work that is general-purpose. If I need to reach into a tight area, the tangential tool is a no-go. Other than that, it is pretty good for me and has opened my eyes to grinding variations.



Thanks, Randall. I'm glad that someone has sought to alter the standard grind on a tangential tool because it seems to me that it would be necessary at some point. If I had this tool, I would definitely try to figure out how to incorporate more side rake into the geometry because that would reduce cutting forces and temperatures a lot. You don't think it matters until you work harden a piece of 1144 and try to do a fine finish cut; then you wonder how the heck you cannot come in on size.


----------



## Rex Walters

Randall Marx said:


> If I need to reach into a tight area, the tangential tool is a no-go.



Yup. That's probably (for me) the most common reason for me to use a normal tool. For most common facing and turning, though, the extra size isn't a problem.

Easy enough to make different grinding fixtures to adjust the rake angles, but the default works well for most of the materials I work with (mostly mild steel and aluminum). As I mentioned: not the last tool you'll ever need, and it's still incredibly useful to learn how to grind a normal tool, but it's great as a standard tool to have on the lathe most of the time (and to give a beginner an example of all the angles to shoot for when grinding your own tools).

Good tip about keeping the tip at the top of the tool holder so you don't need to readjust tool height. I did something similar (scribed a line on my grinding fixture).


----------



## markba633csi

As far as grinding tool bits, I don't think about it I just close my eyes and grind.  Usually works pretty good.  My shop teacher is probably rolling in his grave to see my pathetic efforts LOL  Oh well nobody has to use them but me 
Mark S.


----------



## Silverbullet

Ill give you one extra tip I didn't read where anybody said to hone your tool edges . As far as grinding 3/8 or 1/2" or 5/8" . Most all of the shapes will cut , some will cut cleaner and quicker , easier. Others will work good on steel but not brass or aluminum. I have even made and used contour bits . Made to fit a profile those are a different game as to speeds and feeds. Even using other bits to hog out spots. Many times you will need to grind chip breakers in the tool. Clearance angles needed then stoned with an India stone. You will need a couple half round , square 3/8  Or 1/2" , usually there about 4" long. I even have a green set for carbide. Honest it helps to hone the edges the tool cuts better and last longer , at times you can touch them up in the holder . I've found rounded tools work well in cold rolled and brass. When making corners on tooling I leave the inner edge rounded , to many times I've seen sharp corners just snap.


----------



## bfd

your picture shows good hss bits with a little regrinding they can all still be used over and over again you don't need to completely remove the old grinding just make the tool you need at the time bill


----------

