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Sportandmiah
03-13-2009, 01:57 AM
I've seen hundreds of ways to mill on a lathe, but little mention of lathing on a mill. I read a few bits here where people have done so...anyone have any pictures of a setup they might use to mount the tool holder? Also, which direction would the mill have to turn? Foward or Reverse?

Thanks
SAM

b2u44
03-13-2009, 02:07 AM
I've not done this personally, but there are quite a lot of videos on Youtube that show these kinds of operations. A few good ones are at the following links:

http://www.youtube.com/watch?v=n0rBt8WLXho
http://www.youtube.com/watch?v=S34fe7JHkSo

J Tiers
03-13-2009, 09:58 AM
How to "lathe"?

I suppose that gets a bit more on-topic responses than "How to turn on a mill?" ! :D

Table/knee is carriage / crosslide.....with an extra movement (which one is extra depends on V vs H mill) Go from there.

A.K. Boomer
03-13-2009, 11:07 AM
The next time I have my mill in that "mode" I will take a full picture of it in all its matching ensemble's --- but for now you have to use imagination and the pic below, imagine the angle block/quick change is where the rotary table is --- then the head of the mill is off to the left and laid down (mimmick a lathe - motor off to the left and when you do this forward is still forward) -- My mill is a turret mill so the turret is already dialed in for this, it is pre-aligned perfectly with the table --- this is something to consider when mill/lathing as normally this really is of no concern when milling totally upright --- start to throw the head down and now your jacking with stuff, Now imagine a little R/8 5" three jaw and you have the makings of a makeshift lathe for small hub work or even smaller very accurate work on tiny items by just using the R/8 collets like a 5/C work holding ----- no you cant work on long stuff - no you can't thread (cnc'ers could prove me wrong)--- but you can do most stuff or at least I can for what I need a lathe for,
I jam the quill nut up against the stop, I also lock the quill cinch down -- I am VERY surprised at the amount of metal I can remove and how stable it is -- I can also utilize my turret and X-axis for tapers and can use the quills fine feed for finish cuts, If the quill is used it automatically eliminates taper errors - but cannot be used if trying to create one.
For about $250 bucks Iv created a system that can keep me going late at night when I can't get to my friends shop where the real lathes live:)


http://i146.photobucket.com/albums/r249/AK_Boomer/DSC00375.jpg

Carld
03-13-2009, 12:41 PM
That question comes up often and I always cringe. If you can afford to buy a mill and are now needing a lathe just buy a lathe. To do lathe work on a mill is rediculous to me.

First it is not designed to do that and second it is not rigid enough to do it.

You will spend more time, effort and money to make the mill do something it can't really do than it is worth.

shawnspeed
03-13-2009, 01:45 PM
yep , I used to use my bridgeport far a lathe before I got a lathe....just put a piece of HSS in the vice and chucked up a piece of stock in the collet...the parts were pretty simple....made some pretty cool tapered pins for a die that way once...Shawn (neccessity is the mother of invention)

Jpfalt
03-13-2009, 04:53 PM
The only reason I can see for turning on a mill is if you need a swing well beyond that of your lathe. I've done this on guide shoes with a 24 inch radius. I was cuting 16 shoes at a time and ran the mill, a Cincinnatti horizontal at it's lowest rpm to get the needed SFM.

The shoes were mounted on a fixture of generally face plate geometry with blocks added to mount the shoes with socket head capscrews.

It worked like a charm and really kicked up the job productivity.

CLARKMAG
03-13-2009, 05:27 PM
I have done lathe work in the mill when the lathe cannot do the job.

The mill rotates the tool, with the work in the vise.
The lathe rotates the work, with the tool in the vise.

To use the mill as a lathe, rotate the work in a collet and hold the tool in the vise.

Oldbrock
03-13-2009, 07:35 PM
http://i273.photobucket.com/albums/jj232/brockley1_bucket/Millerintolathe002.jpg I made a chuck mount for the horizontal spindle and machined various items too large for my lathe.
http://i273.photobucket.com/albums/jj232/brockley1_bucket/th_Millerintolathe001.jpg (http://s273.photobucket.com/albums/jj232/brockley1_bucket/?action=view&current=Millerintolathe001.jpg) Don't see pics here, hope they come through. Peter ( didn't cost me anything, only time)

Evan
03-13-2009, 07:40 PM
If you have a mill then making it into a lathe is only a matter of a headstock and a tailstock. When I built the 4th axis headstock for my CNC mill I included a secondary motor that can run the spindle at a around 1000 rpm. The exact same setup can be used on a manual mill to do turning.

This is my setup:

The 4th axis headstock

http://metalshopborealis.ca/pics3/4axis1.jpg

This is turning an 8" metal mirror.

http://metalshopborealis.ca/pics3/8inch1.jpg

This is the tailstock

http://metalshopborealis.ca/pics3/tailstock1.jpg

JCHannum
03-13-2009, 10:49 PM
Lathes and milling machines are both metal working machines. There is no reason they must be used in the "traditional" configurations. There are times that it is more convenient to mill on a lathe or turn on a mill. If you only have one machine, your imagination will be the limitation of what you can accomplish.

As CNC becomes more common, the machining centers of the future will more closely resemble milling machines than lathes.

Michael Moore
03-13-2009, 11:10 PM
Instead of making a ball-turning attachment for my manual lathe, why not do it in my CNC mill? Seems like I can do a much wider range of radii

Yes, I'm unlikely to turn a 10" OD ball on the mill. But then I've got no intention of doing that on the lathe either.

For small stuff the mill (which I already have) seems cheaper than buying/making more lathe tooling.

cheers,
Michael

Mcruff
03-13-2009, 11:39 PM
That question comes up often and I always cringe. If you can afford to buy a mill and are now needing a lathe just buy a lathe. To do lathe work on a mill is rediculous to me.

First it is not designed to do that and second it is not rigid enough to do it.

You will spend more time, effort and money to make the mill do something it can't really do than it is worth.
Boy you are wrong on every count. there are certain things from time to time that are far easier to do this way. If you are lucky enough to have a CNC this opens up tons of things.
I have been doing this for more than 25 years now and my father showed me and my grandfather showed him.

CLARKMAG
03-13-2009, 11:51 PM
If you have a mill then making it into a lathe is only a matter of a headstock and a tailstock.

http://metalshopborealis.ca/pics3/tailstock1.jpg

Amazing work.

How do you align the tail stock with the headstock on a mill table?

A.K. Boomer
03-14-2009, 12:17 AM
That question comes up often and I always cringe. If you can afford to buy a mill and are now needing a lathe just buy a lathe.

That statement does not make sense to me, Just because i could afford to buy a mill doesn't mean I can afford to buy a lathe --- in fact - your less apt to be able to buy the lathe due to just buying the mill because nobody pays you to buy the mill - you have to buy it and that takes money - and money is what you need to buy the lathe with:confused:
To do lathe work on a mill is rediculous to me.

First it is not designed to do that and second it is not rigid enough to do it.

It depends what your using it for - like I stated I was very surprised at the amount of metal (steel) I can remove and how stable it is with no chatter - my mill is by far rigid enough for all of the things I turn and its only a 2/3rds scale mill and does not have mehanite castings. My experience is actually quite the opposite that what I thought it was going to be --- I thought Id have to "baby" things along -- and although I know im limited with a small size chuck iv had it maxed out with steel and the cuts i was taking were fair, the shock was there wasnt any chatter and I would swear to the point that in some ways it seamed better at certain things than my friends heavy engine lathe, maybe its the stability of my mills massive table in comparison to the lathes very small carriage.


You will spend more time, effort and money to make the mill do something it can't really do than it is worth.

Its not the way it worked out for me --- I spent about $250 bucks and it does everything and more of what I thought it would, it makes my little shop extremely versatile and saved me much money in not having to buy a lathe,
The biggest drawback is its a pain in the butt to change over for every little item so I make a list and organize my projects procedures to shift back and forth as little as possible, If I didnt have access to "real" lathes I would probably want one - but - I cant afford one anyhow (due to buying the mill:p) so I think Id be doing the same thing I am right now.


Something else to consider -- if i ever do get a lathe it will most likely be semi-entry level -- meaning it wont have a quick change tool post -- so, $100 bucks of the 250 can still be used in the future, also - the angle block (although modified now) I would have bought for the mill anyways ($50 bucks) and the 3 jaw R8 is just plain handy for the mill as it adds great versatility ($100) as its chuck also couples to my Rotary table so now that I own one I wouldnt want to give that up regardless of whether I had a lathe or not.

Very practical and cost effective compromise - for me anyway.

Fasttrack
03-14-2009, 12:17 AM
Amazing work.

How do you align the tail stock with the headstock on a mill table?

Same way you align the tail stock with the headstock on lathe, I expect :D
The T-slots get you close and then use a DTI in the headstock and sweep the taper of the tailstock 'till it's "dead nuts". Evan may have a quicker or more interesting way to do it, though.

lakeside53
03-14-2009, 12:59 AM
if you have a horizontal mill, or a right angle adapter on a vertical mill, bolting a compound to the table would let it be very "lathe like".

oldtiffie
03-14-2009, 01:24 AM
Originally Posted by CLARKMAG
Amazing work.

How do you align the tail stock with the headstock on a mill table?


Same way you align the tail stock with the headstock on lathe, I expect :D
The T-slots get you close and then use a DTI in the headstock and sweep the taper of the tail-stock 'till it's "dead nuts". Evan may have a quicker or more interesting way to do it, though.

I'd use fasttrack's initial method, then put the centre in my head-stock or rotary table (vertical position). I have a couple of 20mm (~0.080") precision-ground shafts with a centre bored in the ends (to be very true to the OD). Put one of those shafts between the centres and put your dial indicator on the front/side and then top of the shaft and run the shaft under the indicator. Adjust the tail-stock until the required "run-out" along the front/side and top of the shaft is as you require it.

Note that many tail-stocks on mills don't have a removable centre and hence no "bore" to "true up to".

There is a hazard and risk in using a dial indicator on a head-stock or diving-head or rotary table etc. to "true-up" (to?) a "tail-stock bore" as noting is 100% rigid as most stuff we use is "flexible/elastic" to an unknown degree. That is usually not a practical problem in most every-day use of a dial indicator as the indicator general remains in the same orientation. It is a risk where the indicator is revolved in a vertical plane about a horizontal axis where its orientation changes up to and through 180 degrees. The effect of the "back and forth" elasticity can be quite considerable.

I have seen Forrest Addy warn about it on several occasions - and its true. It was one of the first lessons I learned with indicators - a long time ago.

And no, my caution should not apply to "tramming" a mill spindle as even thought the indicator is revolves it remains in the same orientation.

Fasttrack
03-14-2009, 01:42 AM
There is a hazard and risk in using a dial indicator on a head-stock or diving-head or rotary table etc. to "true-up" (to?) a "tail-stock bore" as noting is 100% rigid as most stuff we use is "flexible/elastic" to an unknown degree. That is usually not a practical problem in most every-day use of a dial indicator as the indicator general remains in the same orientation. It is a risk where the indicator is revolved in a vertical plane about a horizontal axis where its orientation changes up to and through 180 degrees. The effect of the "back and forth" elasticity can be quite considerable.



Evan's looks to have a "bore" like a lathe's tailstock does. Like you said, everything is elastic to some degree. I'm willing to be that 9 times out of 10, sweeping the tailstock bore with a DTI will get it lined up to a degree of accuracy that is more than sufficient. Most jobs, if you get it lined up to .001" you'd be doing good. Think about the kind of work that usually gets mounted like this - seems like gear cutting is a big one. Even if the gear blank was an 1 or more across, it's a pretty short distance. It's not like trying to turn an 18" shaft to .001 taper or something. The arbor for the gear blank will have a good bit of flex in it anyway, so trying to get very precise is silly.

Point well taken, though. It definitely pays to be careful and I'm not arguing that sweeping in the horizontal posistion can't have unfortunate effects on one's attempt to "dial something in". But for most stuff, sweeping with a DTI seems much faster than indicating along a test blank. Of course, that's the only way to do it if the tailstock has to be set away from the headstock any considerable distance.

Evan
03-14-2009, 03:40 AM
The front edge of the tailstock and the front edge of the headstock are parallel with the centerline. All it takes to align the two is to place a straight edge along the front of both with a purpose made spacer between the rule and the tailstock and lock them down.

Sparky_NY
03-14-2009, 09:22 AM
Boy you are wrong on every count. there are certain things from time to time that are far easier to do this way. If you are lucky enough to have a CNC this opens up tons of things.
I have been doing this for more than 25 years now and my father showed me and my grandfather showed him.

I have a bridgeport I retrofitted to cnc running under mach 3 control with a vfd on the spindle motor and a rotary table as a 4th axis. The idea of using it as a small lathe has been on my to-do list for a while. It has a kwik switch 200 spindle and I have been looking at how to mount a 3 jaw chuck. Right now the best option seems to be a MT2 (or MT3) 3 jaw chuck, 4inch mounted in a mt holder WITH a bolt through the rear to make sure the chuck does not loosen. I have a collet system for small parts.
(a scary thought)

Anyone using mach 3 for their mill knows it comes with "mach lathe" also. It is a simple matter to configure the setup for mach lathe to the existing hardware on the bridgeport and I will have a cnc lathe. It will be limited in capacity due to the 4 inch chuck and limited Z travel on the quill (also no tailstock) BUT should be extremely usefull and VERY cheap to set up.

I have not yet worked out how I am going to do tool holding but am inclined to use the aloris holders from my lathe and make up the holder so the center height is the same as the lathe, no height adjustments between the two machines will be needed that way.

I am building the D&E gatling gun which has a few balls that need turning, that is what got me interested in this project.

Oh yea, if playing with a cnc lathe is anywhere as much fun as a cnc mill, that alone justifies the project. I have had a ball! (non-cnc)

Sparky_NY
03-14-2009, 09:27 AM
Deleted double post

fdew
03-14-2009, 12:09 PM
I was touring a shop once and sported a steel plate welded to a building upright post. Bolted to the plate was a Bridgeport head with the quill horizontal.
I stopped and stared at it and asked what are you doing here? The shop owner smiled and said "A customer needed a bunch of parts 5 ft diameter turned. We took the job. When it was clear I was amazed he said "A Bridgeport doesn't know anything. If you tell it that it is a lathe it will be a lathe.

Great shop.

Frank

Sportandmiah
03-19-2009, 01:41 AM
Wow a lot of replies. I'll eventually purchase a lathe, but might dabble turning on a mill for right now.

Forrest Addy
03-19-2009, 04:08 AM
In days of yoke I scounged up an old 24" 4 jaw chuck and adapted it to fit on the spindle of a G&L HBM. Came in handy. You always need a bushing or a flange faced for an HBM but there's never a lathe handy. I've han 12" gate valves chucked up when the TV:'s were all busy. I can't coun't the little dial indicator and tooling gimmicks I've milled on a lathe. When you're stuck you do what you have to do without wasting time. You migh get funny looks but if you're making efficient progress without displacing other work the management will note your aggression and inventiveness.

A.K. Boomer
03-19-2009, 10:48 AM
If it works it works, I wouldnt want to try and go production with it but the bottom line for the HSM'er is the measurement and finish of the part thats left in your hand at the end of the procedure's, how you ended up getting it there is entirely up to you.

Bolster
11-04-2010, 09:51 PM
GREAT THREAD! I've been looking everywhere for this information.

What is the opinion on setting up a RoTab on the Mill table so its axis is horizontal, chuck the work supported with tailstock, and then bringing the side of an end mill into the work? A spinning lathe bit as it were? Meanwhile rotating the RoTab and X axis by hand, to move the bit in a spiral pattern across the round work? Is it possible to dimension round stock that way? At least "round enough" to be able to cut threads on it with a die?

Sort of like Evan's setup, except the headstock is just a RoTab, and the mill's bit does the cutting?

As others have stated, adding a lathe isn't always an option. I'm out of money and space, but occasionally do need to lathe a little something, and the project just stops until I can beg someone with a lathe to do the lathing for me. I would LOVE to have even limited lathing capacity on my mill and will try some of these recommendations.

gwilson
11-04-2010, 10:45 PM
Actually,Bridgeport made an attachment to turn their mill into a lathe. You had to swivel the headstock sideways,and get it parallel to the X axis of the table. Quite a bit of trouble,IMO. Then,they had a simple tailstock you had to line up with the headstock.. There was a chuck with an R8 shank to fit into the spindle. The carriage was just a simple bolt on slide such as used on an old fashioned instrument lathe. No threading,no power feeds.

It didn't seem very practical to me,but might have been for use on a ship or where space was very limited. Never saw the attachment in person,but saw catalog pictures.

beanbag
11-04-2010, 11:31 PM
One advantage of using a mill to do lathe work (if the stock is small round diameter) is that the mill spindle is a lot faster than the lathe. Let's you cut down to .125 in a hurry :p

gwilson
11-05-2010, 12:05 AM
The mill's speed vs. lathe speed depends upon the mill and the lathe in question. My HLVH goes faster than my mill.

whitis
11-05-2010, 03:48 AM
Here is a decades old NEMA23 stepper motor mount that we turned on a friend's Enco round column mill out of some scrap cast iron back before either of us had a lathe:
http://i369.photobucket.com/albums/oo135/mwhitis/HSM/IMG_1108.jpg
http://i369.photobucket.com/albums/oo135/mwhitis/HSM/IMG_1109.jpg
The cast iron block is about 2.5inches square and was machined out of a single piece (that protrusion is not inserted) and has examples of boring, facing, and turning. We also turned a brass coupling at the same time:
http://i369.photobucket.com/albums/oo135/mwhitis/coupling.jpg

IIRC, these were the first parts I ever turned on a mill. Only problems we had were voids in the material and surface rust which ate an end mill when squaring off the block. No problems as a result of using a mill for a lathe. Surface finish on the turned portions is better than it looks in the pics and better than the milled sides; it has since been retired (new stronger steppers are weaker with respect to thrust load) and has some rust on it again (this part is about 25 years old), dirt, and dried oil. There is a nice smooth shoulder turned around the 5/8" protrusion that doesn't show up well in the second pic due to light angles and some dried grease and dirt on the part and almost looks like a weld.

This was done with the mill spindle in its normal vertical position and lathe tool bits clamped in the miling vise (in its normal position). Y axis was used to center the tool and X used as cross slide. This setup is good for pieces less than your Z travel and less than half your maximum spindle to table distance. You are also limited by the distance from top of vice to table (though you can angle the tool some), unless you use an elevated tool holder. Been a long time, but I think the block was mounted on a mandrell/arbor for turning the first side, then flipped over and clamped in a collet to bore and face the other side.

Note that the cast iron part could have been made using a boring head with a left handed boring bar mounted backwards to cut the OD or using a rotary table or with CNC but turning gave good concentricity and a consistent finish.

A 4 jaw or even 3 jaw chuck is worth having; use an arbor to mount it if you are stuck with a spindle that wasn't designed to mount a chuck. Like this 4" 3-jaw chuck with R8 adapter (http://www.shars.com/products/view/949/4quot_Three_Jaw_Precision_Chuck_amp_R8_Adaptor)
Tapers: tilt the head
Threading: CNC (or electronic gearbox) with spindle encoder. You can also use taps and dies in some cases.
Ball turning: use boring head and inclined rotary table, or CNC.

If you have CNC, turning on a mill lends itself to gang tooling (http://www.cnccookbook.com/MTCNCDictGangtoKnee.htm), eliminating manual tool changes.

Evan
11-05-2010, 07:46 AM
Here is a video of my mill operating as both a mill and a lathe on the same part without changing the setup.

http://www.youtube.com/v/vblWvnH997g?fs=1&hl=en_US

Weston Bye
11-05-2010, 09:47 AM
The Summer 2010 issue of Digital Machinist ran a story about using a CNC mill for turning work. You can see a picture of the tooling on the cover of the magazine here:

http://www.digitalmachinist.net/comingsoon/contents/view/dm/20100706

The operations included turning, boring and broaching a hex socket.

note: check out the authors.

JoeLee
11-05-2010, 09:50 AM
Most of us are bound by the same problem with this set up........ max. dia. of stock able to fit in the collet is 1" and the length about 3" the tooling setup looks to be a bit of a time consumer.

JL...............

Weston Bye
11-05-2010, 11:05 AM
.... the tooling setup looks to be a bit of a time consumer.

JL...............

I should have mentioned that the CNC setup was for a production job.

Bolster
11-05-2010, 02:48 PM
Here is a decades old NEMA23 stepper motor mount that we turned on a friend's Enco round column mill ...

Color me impressed! That's pretty amazing work to do on a Mill. Evan! Very cool video!

Still curious about the likely outcome of trying to lathe, using an end mill in the mill's head (say in the 3 o'clock position as crudely drawn below), and rotating the work in the rotab while moving the table back and forth in the X axis? Could this be used to roughly dimension round stock, say, when you plan to use a die to thread the turned-down portion? I'd expect a less-than-lathe-smooth finish for the part, but in a pinch for rough dimensioning?

http://www.cmp-usa.com/interest/RoTab%20Bit%20Placement.jpg

Evan
11-05-2010, 03:44 PM
Side milling the part in that setup won't work unless you have the most rigid setup imaginable. End milling the part will work but the results are not as good as you might expect. The chip load has to be very light to avoid displacing the part. The problem is that a milling cutter is, by it's nature, always making an interrupted cut.

beanbag
11-05-2010, 05:39 PM
A 4 jaw or even 3 jaw chuck is worth having; use an arbor to mount it if you are stuck with a spindle that wasn't designed to mount a chuck. Like this 4" 3-jaw chuck with R8 adapter (http://www.shars.com/products/view/949/4quot_Three_Jaw_Precision_Chuck_amp_R8_Adaptor)


Nice find. But I wonder about the rigidity...
Is there such a thing that clamps on the non-spinning nose of the spindle and acts like a tailstock to support the end of the work piece?

Bolster
11-06-2010, 12:49 PM
http://www.leevalley.com/us/wood/page.aspx?c=&p=20202&cat=1,42500

Here's a low profile live center designed for a table...

jugs
11-06-2010, 03:17 PM
That question comes up often and I always cringe. If you can afford to buy a mill and are now needing a lathe just buy a lathe. To do lathe work on a mill is rediculous to me.

First it is not designed to do that and second it is not rigid enough to do it.

You will spend more time, effort and money to make the mill do something it can't really do than it is worth.

Carld,
You give us a silly set of statements there.

1- If you can afford to buy a mill and are now needing a lathe just buy a lathe.
just because someone can afford a mill does not automatically mean they can afford / want / have space for a lathe.

2- To do lathe work on a mill is ridiculous to me.
Shows a lack of experience on your part

3- First it is not designed to do that and second it is not rigid enough to do it.
Not true, I have turned some 36"dia x 3" flywheels on an Adcock & Shiply 2e mill because they wouldn't fit in my Chipmaster (10"x20") or my Cardiff (15"x30") or my Willson (24"x30"), should I have gone out & got a bigger lathe for a one off job

4- You will spend more time, effort and money to make the mill do something it can't really do than it is worth.
Not so, see 3 above.

The op may have no cash but loads of time, so being efficient may not be the high priority


john
:)

jugs
11-06-2010, 03:32 PM
Mill/turn ballet
http://www.youtube.com/watch?v=AV6m5_DZ-tk&feature=related

http://www.youtube.com/watch?v=qrfB_d_wMdM&feature=related

enjoy

john
:)

whitis
11-06-2010, 07:46 PM
http://www.leevalley.com/us/wood/page.aspx?c=&p=20202&cat=1,42500

Here's a low profile live center designed for a table...

Not suited for turning, though, as you lose the Z travel.

clutch
11-06-2010, 07:53 PM
When I was trying to use my lathe to fix my lathe for the first time, I needed a plug to lock the feed dial so....

http://wess.freeshell.org/making_brass_plug.jpg

Clutch

whitis
11-06-2010, 10:14 PM
Nice find. But I wonder about the rigidity...


Rigidity will probably be ok for most purposes, particularly for the size parts which are generally practical to machine on a mill.



Is there such a thing that clamps on the non-spinning nose of the spindle and acts like a tailstock to support the end of the work piece?
There is if you make one :-). But it might not be that much improvement. It would be nice if more vertical mill spindles had a mount for an overarm, like used on horizontal mills. Mounting a tailstock this way would be a step up in rigidity (though a little trickier to align) but you are still limited by the rigidity of the pivot on the mill head plus the combined flexing of the various axes.

For short parts, turning on the spindle should be within the mills rigidity limits. It takes about the same amount of force to make a given size chip whether you are turning or milling. But the mill generally isn't designed to handle the cutting forces being on the end of a, for example, 18" moment arm so for long stock you are better off using a rotab and/or spindle and tailstock mounted on the table and a lathe cutter mounted in, on, or in place of the headstock.

If you are using a slow rotary table as your turning axis, you can rough out the part with an end mill then switch to lathe tools for finishing.