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View Full Version : how much smoke should there be when machining?



andy_b
03-01-2008, 11:02 PM
no, i don't mean should the electronics and motor be smoking. :)
i mean how much smoke should be coming off the piece you are machining?

i was making up a pulley for a project i'm working on (hooking a motor up to an old Singer 153W102 sewing machine), and i had the chips smoking pretty good a few times. i mean almost at the billows of smoke stage. i was just using WD40 and 10W30 as cutting oil. i just started with some 3 1/4" diameter steel the local fab shop had laying around.

http://home.ptd.net/~hamrdog/images/153W_pulley.jpg

i was also playing around with cutting RPMs, feed speeds, and depth of cut. i never realized that a lot of cutting problems can be fixed with a faster, deeper cut. i have an old SouthBend 11", and i thought i was going to stall it/slip the belt a few times, but she kept on chugging.

i did learn that if the cutting tool starts SPARKING, that you have just killed the cutting edge and need to resharpen it. i learned that one twice. :)

andy b.

A.K. Boomer
03-01-2008, 11:12 PM
I wonder if you lost your bit unit pressure doing that pulley and thats why it heated things up some? try to only use a certain percentage of the tip, hard to do when wedging into a pulley sometimes...

Carld
03-01-2008, 11:28 PM
WD40 or engine oil will always make lots of smoke. WD40 is not a good lube for cutting anything but aluminum. Engine oil is not a cutting oil.

When machining do it dry. Using a real cutting oil such as a sulfur based oil will still produce smoke. If you feel the need to use a cooling agent use flood water based coolant.

There are few times you will need a coolant or oil when machining.

Drilling, reaming, taping, therading and honing need a lube or coolant.

Manual lathes seldom need a coolant and then only to keep the work cool to avoid dimention changes.

Don't use engine oil for a cutting oil.

If you were plunge cutting that was chancey and takes a lot of force and makes a lot of heat. A pulley groove is best cut one side at a time. Your finish on the big groove looks very rough and if to size then the pulley is defective. It will wear a belt out. The small V groove looks pretty good.

andy_b
03-01-2008, 11:54 PM
interesting, it did seem to cut okay with no oil/coolant/whatever. i just thought you were always supposed to use some type of liquid when cutting. i'll give it a shot running dry tomorrow. i will also empty the 10W30 engine oil out of the container and get some proper cutting fluid.


Your finish on the big groove looks very rough and if to size then the pulley is defective. It will wear a belt out. The small V groove looks pretty good.

yeah, i have to clean the big side up a little more. a 3/8" round leather belt runs in it, and the speed is maybe 1000RPM max. although i'll be running it MUCH slower, my fingers don't move as fast as sewing machines going 1000RPM. :)

andy b.

Carld
03-02-2008, 12:16 AM
You may be able to clean it up and still not have to wide a groove if your careful.

Fasttrack
03-02-2008, 12:19 AM
Yep! Exactly what Carld said ... water-based works great foor coolant and lubrication. On most operations, keeping your bit cool is more important than the lubricating bit.

Engine oil is dangerous to your health! The smoke can cause lung cancer and other disorders!

Oldbrock
03-02-2008, 02:28 AM
I've been at this game for a while and when cutting with hss I most always use soluble oil and water in about a 50 to 1 ratio. If you want a good finish use coolant. Drilling, always, reaming, of course. Screwcutting, always. I mix up a gallon at a time and use plastic hair colour bottles. I don't use coolant on brass, bronze or when I'm using carbide tools. I use A9 on aluminium (spell check doesn't like that), its English, American printers made a spelling error with the first million brochures they printed and it stuck:D I do use rapid tap for tapping steel, saves a lot of taps I can return to my toolbox. Those are the only cutting fluids I use. Grinding your own special tools from hss is an art form you never quit learning. general cutting speeds for hss are- mild steel - 80 feet per minute. cast iron -70, alloy steel - 50 brass and ally 200. your rpm is the cutting speed X 4, divided by the cutting dia. If you follow these simple rules you should never burn a cutting tip. You can double or triple these speeds for carbide. Hope this helps at least one of you, Peter;)

Forrest Addy
03-02-2008, 04:33 AM
I've smoked my shop up so bad running over oil stripes from steady rest journals, hot chips falling in oil puddles in the chip pan, etc that I couldn't see to the opposite wall of my 30 ft long shop. It can get smokey at times but if you manage your work a little and keep hot chips away from oil you won't get much smoke.

Some operations like parting using oil can get a little smokey but if you're bothered by it you can hook up an extractor from stove pipe and a mobile home sized furnace blower. Blow it outside for the neighbors to enjoy.

John Stevenson
03-02-2008, 06:54 AM
As other have said motor oil isn't a cutting fluid and to be honest it's not much use at all.

The smoke is caused by the cutting oil [ whatever it is ] getting hot That's obvious so lets examine what we can do about it, industry has had this problem for years and they cope.

Neat cutting oil as opposed to soluble oil which is often white and called suds is better for the job and machine. In some resects it's a lubricant as well and finds it's way into the slides and protects as well and leaving a film over everything to prevent rust.
That's the pro's.

The cons are it's more expensive and smokes under heavy cuts.

Soluble oil or suds is usually mixed with water in a concentration of from 15:1 to 40:1 depending on use, materials and brand.
It cools better then neat oil due to the fact it's water based and it's cheap, that's the pro's

The cons are it gets into slides and can stain or cause rust.

According to the books the water can evaporate and you add more water to bring it back as a coolant.
Well very sorry but I have never found this.
What I have found is the water evaporates but the heavier oil sticks to chips etc and gets throw out leaving crap in the tank and you have to start again with adding a fresh solution.
Most of the people I take to find this as well so adding water is advertising crap put out by the makers to make you think you can save money.

Sorry you can't , it's a consumable like tips drills etc.

So neat cutting oil looks to be the best bet IF we can stop the smoke?

Well that's dead easy, you put a full enclosure round the machine, sliding doors and use at least two 1" pipes and nozles to bring enough oil to the tool that it doesn't get hot.

You can't do that ? well sorry it's now time to make a compromise.

Neat oil and put up with the smoke on heavy jobs or coolant and put up with the mess and cleaning it causes.

I have a 12" x 24 centre lathe that's on neat oil and it work OK except for heavy drilling like 3/4" upwards and then it smokes.

I daren't put the next size lathe a 14" x 40" on oil as it does far heavier work and it would cause problems.

That's where I draw the line but these are on normal pumped systems, if you are relying on brushes or drip feeds than the smoke will get worse on neat oil.

.

Your Old Dog
03-02-2008, 07:07 AM
Clumsy bastard that I am I cut dry for the most part except when parting off :D

Sparky_NY
03-02-2008, 07:28 AM
The subject of cutting oil has been covered well enough, nothing to add there BUT one thing I did not see mentioned was the metal you are using. I see it was a piece of unknown metal (most of us do the same). Some metals just love to work harden in the lathe, especially with light cuts. When it work hardens the cutting pressure required produces chips that are much much hotter than normal, sometimes close to glowing red, blue being common. The work piece also gets extremely hot.

I was just thinking that any cutting oil will smoke if the surface its hitting is hot enough. A sharp bit helps here also.

loose nut
03-02-2008, 11:31 AM
Are we talking cigarettes or stogies,

but seriously, take my lathe, Please. It's a Hendly Yuongman.

If you don't want to get into the full blowen coolant supply system, tanks pumps etc. then just get an old mag. indicator base, lose the round bit sticking out the top. glue on a needle valve or other fine control valve with some flex hose and tip on it so you can position the oil flow were you want it to go and connect a hose back to a bottle you can hang upside down and you have a gravity fed coolant system. Just stick it to the cross slide when you need it and remove it when it's in the way. These work great, limited amount of coolant though so use it judiciously, don't flood everthing.

Carld
03-02-2008, 12:02 PM
I machine dry and when I have to cool a hot part to check true size or to finish to size I have used a trick that works well for me.

I have some pint sized squeeze bottles that you can get from wal mart. I fill them with water and with bottle in one hand and air nozzle in the other I aim the nozzle at the top of the work spinning at about 100 rpm and invert the water bottle and carefully squeeze some water out in the air stream. If carefully done it turns into a heavy water mist that quickly cools the work. The water for the most part is blown to the back of the lathe and what falls on the ways is easely wiped off and the ways reoiled.

It's cheap, fast and I have never had a lathe rust if done right. It's kind of like a SUPER MISTER on the cheap.

Another trick is a pan of water between the ways and the work and a rag to squeeze water over the part without the work turning. You can lay a rag on the work and use a can to pour water over the rag also. You have to rotate the work by hand as you cool it. Don't just cool one side or it may warp.

I don't like water based flood coolant on a lathe because it gets into the chuck and causes all kinds of problems. I am with John in that oil flood is better if your dead set on flood coolant.

andy_b
03-02-2008, 12:03 PM
thanks again for the tips! i went out this morning, sharpened up a bit to the proper profile, and had at it with no cutting oil or fluid or coolant of any type. i was surprised at how nice it cut! it is just a piece of generic hot rolled steel. i don't know the specific variety. i edited the original photo to show the piece last night, and the results after this morning's experimentation. as i said, i just did the cut dry. i am very happy with the results. and both belts still fit. :)

thanks guys!!!

andy b.

Carld
03-02-2008, 12:08 PM
The thing with the round belt is the pinch factor that a V belt has won't happen with a round belt. With that in mind you could machine it to run in the bottom of the groove.

Your Old Dog
03-02-2008, 12:43 PM
I beg to differ with the original question. The better question is, how much fire? As an example, and for illustrative purposes only and not to hock my wares I offer this picture. This had plenty of smoke and flame.

http://raymondswan.com/dp/weldingbook.jpg

John Stevenson
03-02-2008, 01:01 PM
Clumsy bastard..............


.

Scishopguy
03-02-2008, 01:38 PM
Looks like someone forgot to keep his thumb on the dead center. As I have found (from personal experience), they will get hot and make a mess the instant your mind wanders.

quadrod
03-02-2008, 02:37 PM
i am a pure hobbyist, and have seen the misters in use on a mill before, can a mister be set up on a lathe? also is there a light oil for the mister or only the water soluble lubes. when i am cutting i have always used cutting oil and apply it with a flux brush ( lots of smoke ), i thought using cutting oil was the rule unless using carbide.

Thomas Staubo
03-02-2008, 05:24 PM
Can anyone explain what neat cutting oil is?

One of the definitions of 'neat' in my dictionary is:
"Not diluted or mixed with other substances"

Is that what it means?

Is neat sulfur based oil synonymous with neat cutting oil?


.

Doozer
03-02-2008, 05:33 PM
I'd like a whiskey, neat.

--Doozer

Your Old Dog
03-02-2008, 07:00 PM
Looks like someone forgot to keep his thumb on the dead center. As I have found (from personal experience), they will get hot and make a mess the instant your mind wanders.

Actually, if you're referring to my pic, I forgot to take into account temperature coefficient of expansion!!

Because of that incident, I recently bored a 2" inch hole in 6061 to fit a shaft and because of the heat I let it cool down before taking the finishing passes. It fit perfect! I try to learn from my mistakes. I make a mistake 15 or 20 times and I catch on right away.

Thomas Staubo, I rooting for you to get an answer as I'd like to know too.

jimmstruk
03-02-2008, 08:24 PM
Yes, I want to know whats neat oil ,but I wont show my ignorance by asking!! JIM

Doozer
03-02-2008, 08:50 PM
Straight cutting oil, like MobilMet Omega.
Didn't you ever order a neat whiskey?

http://www.mobil.com/USA-English/Lubes/PDS/GLXXENINDMOMobilmet_Alpha_Sigma_Gamma_Omega.asp

--Doozer

tattoomike68
03-02-2008, 08:57 PM
http://raymondswan.com/dp/weldingbook.jpg

Thats why a dead center is almost worthless, use it on a headstock with a dog but not in a tailstock. I have a dead center and it has never been used one time. I though about cutting on it and making something useful out of it. hell I might weld a boring head on it, that would be better than what it is now.

J Tiers
03-02-2008, 09:29 PM
Can anyone explain what neat cutting oil is?

One of the definitions of 'neat' in my dictionary is:
"Not diluted or mixed with other substances"

Is that what it means?

Is neat sulfur based oil synonymous with neat cutting oil?


.

yes, undiluted...... I'd call the term "neat", used that way, more a British usage. It exists in US usage, but "neat" in the US tends to mean "interesting", "good", "way cool", etc. isn't language wonderful?

Cutting oils are formulated differently from lubricating oils, and some lube oils have sulphur, such as older 90 weight gear oils used in automotive differentials etc. So while many cutting oils have sulphur, not all sulphur-containing oils are cutting oils.

After all, the best lube oil might reduce cutting action........ you want it to allow cutting, but reduce re-welding of the cut material to the tool or the work.

Just don't confuse "neat oil" with "Neat's foot oil". That goes on leather..........

tattoomike68
03-02-2008, 10:11 PM
one time there was a screw machine making a part and the HI-SPEED/LOW-SPEED clutch got stuck in HI SPEED and it went from a 10 second parts to 2 second parts and smoke was blasting from all the tools. All tool feeds were rapid traverse.

We cought it before it smoked and thrashed the tooling but it did make good parts super fast. It was funny as hell..

quadrod
03-02-2008, 10:45 PM
so, how about a mister on a lathe, practical or not?

tattoomike68
03-02-2008, 10:47 PM
so, how about a mister on a lathe, practical or not?

Works fine for turning or boring but you might want more for drilling.

andy_b
03-03-2008, 12:44 PM
I'd like a whiskey, neat.

--Doozer

i like my women neat. (and the cuffs to match the collars).

andy b.

Scishopguy
03-03-2008, 05:38 PM
[QUOTE=Your Old Dog]Actually, if you're referring to my pic, I forgot to take into account temperature coefficient of expansion!!

Because of that incident, I recently bored a 2" inch hole in 6061 to fit a shaft and because of the heat I let it cool down before taking the finishing passes. It fit perfect! I try to learn from my mistakes. I make a mistake 15 or 20 times and I catch on right away.

YOD...don't feel too bad as things can go from just fine to a dissaster in just a few seconds. My old boss, the navy guy, told me that when he was a kid in Atlanta, working for GE in an electric motor plant, he was learning how to turn commutator bars on big old 30 HP motors. He was hapily watching the lathe on a long cut and decided he could run over to the water cooler for a drink and get back before the cut finished. He forgot to check the center and put some more white lead on the point before leaving. About the time he was heading back there was a giant "Whump" and that armature jumped out of his lathe onto the floor. He said that after that, he was told to always keep your thumb on the dead center and watch for temperature rise as the shaft puts more pressure on the point.

Thomas Staubo
03-03-2008, 05:42 PM
yes, undiluted...... I'd call the term "neat", used that way, more a British usage. It exists in US usage, but "neat" in the US tends to mean "interesting", "good", "way cool", etc. isn't language wonderful?

Cutting oils are formulated differently from lubricating oils, and some lube oils have sulphur, such as older 90 weight gear oils used in automotive differentials etc. So while many cutting oils have sulphur, not all sulphur-containing oils are cutting oils.

After all, the best lube oil might reduce cutting action........ you want it to allow cutting, but reduce re-welding of the cut material to the tool or the work.

Just don't confuse "neat oil" with "Neat's foot oil". That goes on leather..........

Thanks for the explanation!

The little I have turned so far has mostly been without any lube.
But I found out that just some small drops of CRC 5-56 (same as WD40) on the workpiece makes a pretty big improvement in finish when taking light finish passes on steel.
But it does smoke a bit, even if not working to high temperatures.


.

Thomas Staubo
03-04-2008, 11:40 AM
so, how about a mister on a lathe, practical or not?

More practical with a mister on a lathe, than a missis.

If you're not thinking of a lathe bed (doesn't sound very comfortable though).





Sorry girls, couldn't resist! :D

.

madman
08-19-2009, 11:36 AM
My shop gets so smoky when i cant see too good anymore I head outside for a smoke break so to speak. Lucky I havent a very good sense of smell or it might bother me.