Fixnair
Well-known member
Where can I get a taper attachment to fit the headstock of my south bend 13" lathe? I would like to start tuning things on centers instead of chucking everything up.
Lathe center
- Thread starter Fixnair
- Start date
rsanter
Well-known member
Try ENCO....or chuck a piece of steel up and turn to a point. You now are ready to turn on centers
Bob
Bob
toms73novass
Well-known member
I have always been happy with the stuff I have gotten here. Tools4cheap
http://www.tools4cheap.net/proddetail.php?prod=closeout5cadaptersb1
http://www.tools4cheap.net/proddetail.php?prod=closeout5cadaptersb1
Kevin54
MEMBER EMERITUS
I personally don't like doing it, but a lot of people will chuck up a center in a 3 jaw or 4 jaw chuck, then drive the dog off of one of the jaws.
Just out of curiosity, why would you rather turn off of centers vs. turning a part in a chuck? I understand if you're making something like a small crank or cam.
Just out of curiosity, why would you rather turn off of centers vs. turning a part in a chuck? I understand if you're making something like a small crank or cam.
spongerich
Well-known member
IIRC, some of the 13" South Bend lathes used proprietary taper in the spindles and others use a standard 4MT. If you measure the bore at the end of the spindle, and also 3-4" inside, you should be able to figure out which one... I don't have the specs on a 4MT handy, but I could look them up if you have no luck with the Google.
Steevo
Well-known member
WhoWhatNow
Well-known member
Kevin54
MEMBER EMERITUS
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It's not always more accurate. That comes from how you put your centers in to begin with. If you chuck up a 15" piece as an example, then flip it around and put a center in the other end, if your tailstock is not exactly dead center in line with the headstock, then you will have a taper. Depending on the lathe, some tailstocks have and adjustment screw where you can kick them off center to cut a taper.
I've been a toolmaker for 30+ years, and only on a few occasions have I had to turn a part running on centers. Running off of a chuck and a center can be just as accurate or more accurate in some incidences.
If your chuck on the headstock is in good shape, then it's way easier to run parts from a chuck. Don't take it the wrong way. I'm not trying to dissuade you from running a part off centers, and it is a great learning experience, but I'm just pointing out to you or others that are interested in knowing, why it's not always the most accurate. One thing everyone should do if they own a lathe, is to check your chuck and tailstock for accuracy. If you chuck up a part in a three jaw and turn it until it is round, only taking a few though at a time....without moving your compound, back your saddle out to the right, turn your piece around, and using the same setting, cut the part with the same setting. If the chuck is right, you should have almost to nothing where the two turned portions meet.
I keep a 1" hardened drill blank in my box for indicating certain parts, and a lathe chuck is one of them. Chuck up the drill blank and with the lathe in neutral and using a 1/10 indicator, check the chuck to see if everything is running concentric. Chucks can be adjusted. I also had a 1" bar made a few years back that I can chuck up in the headstock, put a center in the tailstock, then use an indicator back and forth to see if the shaft is running at "zero" between the headstock and the tailstock.
kevin47
Well-known member
Your right, last and only times I used centers was to make "mandrels" years ago...
rsanter
Well-known member
I turn things on center that already have centers in them like axles and cranks and such. I just chuck a piece of steel in the chuck and turn it to a point to use as the dead center. Don't have to remove the chuck and I know it's true to center
Bob
Bob
I see. So I can adjust the center on my three jaw. Hadn't thought of that. What started all of this was I wanted to run my tail stock up to a tapered headstock piece and center my tail stock. Then using a piece of say 2" stock that has been center drilled, mount it between centers to test the ways for level and wear. Am I going about this properly?
I determined today that I have a #4 morse taper inside my headstock spindle
I determined today that I have a #4 morse taper inside my headstock spindle
Steinmetz
Well-known member
Using lathe dogs and a center always frightened me a bit. I never wanted to be anywhere close to it. I would always avoid it if I could. That's just me.
kevin47
Well-known member
I still can't think of any real use for it besides making mandrels...Maybe old age is catching up w/me...!
Kevin54
MEMBER EMERITUS
If you are wanting to check the bed for wear, use an indicator holder and an indicator. Take your tailstock off of the lathe. Run your saddle all the way to the r.h. side of the lathe where the tailstock normally sets. Now take the indicator and holder and maneuver it around so it is just in front of the saddle and zero it in. Run the saddle towards the headstock and make note of any indicator readings. Take the saddle back all the way to the right and set the indicator on the other lathe wat and run it towards your headstock again.
Now the bad thing is.......if the bed is worn, you are pretty much screwed because you can't grind it back in spec's.
Running anything off of centers other than a precision ground bar, will not do anything for you as far as checking for accuracy. When cutting a piece of barstock over any distance at all, will give you a false reading. All for the fact that you now are involving four different factors into the equation. If you try to indicate a piece of barstock in, you don't know whether the headstock is out, whether the tailstock is out, whether the bed is worn, or how close the centers are on the barstock.
Chances are the lathe, if it has any age at all on it, could very well be worn in the main saddle operation area. On most lathes, that is usually a foot or a tad more from the headstock. If your tailstock is adjustable, you could adjust some out of it, but now you would be cutting straight at the far right hand side, but when getting close to the headstock, then it will start cutting the other way.
If you are planning on making real close precision parts on an old lathe, forget it. If you are looking at making really close precision parts on a new lathe, forget it. When you get down to wanting close tolerance parts, you want a surface grinder.
One thing you can do to eliminate a lot of error when making parts is to make as much as you can without ever taking the part out of the chuck. Look at a part and see how you can best utilize all of your cuts. All facing, turning, boring, plunging and so on, you basically want a finished part as close as can be without unchucking the part. And never run a part to size if you are not using a cold waterbased coolant. If you are making parts with oil or no lube at all, and that part is hot to the touch, go have a beer break until it cools down completely. If you have a part that you are boring out and it has a thin wall on it and it gets hot and you finish the part to size, by the time it cools, it will be undersize on both the inside and outside due to the thermal expansion.
I've always told anyone I ever trained to be a machinist or a toolmaker...."become one with the material / become one with the machine"
By that I mean to learn what different materials do. See it in your head. See the material expanding with heat, see the toolbit cutting the material. You don't have to physically watch it, but mentally you need to see everything going on. All material will cut different. Stainless will cut different than tool steel. Cold rolled steel will cut different than aluminum. Aluminum will cut different than other aluminum. Some aluminum is so damn soft it does nothing but gum up a cutter. Other aluminum may put off a real nice curl 15' long. Another piece of aluminum using the same exact setting, will do nothing but put off chips.
So if you want to make parts that are within .0001 on the lathe, forget it unless you get lucky. Any cutter you use will flex material, whether it be a high speed cutter, ceramic, or carbide. A cutter will push material away. Also if the machine is wore just a little, the material can push your tool away.
My Mentor taught me when I first started in the trade, that a good machine does not make a person a toolmaker, but a good toolmaker can make the machine do what he wants. All you have to do is learn everything about the machine.
Anyways, sorry for rattling on. Either pick up a drill blank and indicate in your chuck, or turn a piece down round, cut it off, then put the absolutely round piece back in the chuck and indicate it. If it is running out, then your chuck is running off center. If you want to absolutely want too check a bar from one end to the other, see if there is a machine shop around that does centerless, or center grinding and get a 1 1/2" ground bar made up. It would cost a few bucks, but you would have something that you could check between centers from one end to the other
Now the bad thing is.......if the bed is worn, you are pretty much screwed because you can't grind it back in spec's.
Running anything off of centers other than a precision ground bar, will not do anything for you as far as checking for accuracy. When cutting a piece of barstock over any distance at all, will give you a false reading. All for the fact that you now are involving four different factors into the equation. If you try to indicate a piece of barstock in, you don't know whether the headstock is out, whether the tailstock is out, whether the bed is worn, or how close the centers are on the barstock.
Chances are the lathe, if it has any age at all on it, could very well be worn in the main saddle operation area. On most lathes, that is usually a foot or a tad more from the headstock. If your tailstock is adjustable, you could adjust some out of it, but now you would be cutting straight at the far right hand side, but when getting close to the headstock, then it will start cutting the other way.
If you are planning on making real close precision parts on an old lathe, forget it. If you are looking at making really close precision parts on a new lathe, forget it. When you get down to wanting close tolerance parts, you want a surface grinder.
One thing you can do to eliminate a lot of error when making parts is to make as much as you can without ever taking the part out of the chuck. Look at a part and see how you can best utilize all of your cuts. All facing, turning, boring, plunging and so on, you basically want a finished part as close as can be without unchucking the part. And never run a part to size if you are not using a cold waterbased coolant. If you are making parts with oil or no lube at all, and that part is hot to the touch, go have a beer break until it cools down completely. If you have a part that you are boring out and it has a thin wall on it and it gets hot and you finish the part to size, by the time it cools, it will be undersize on both the inside and outside due to the thermal expansion.
I've always told anyone I ever trained to be a machinist or a toolmaker...."become one with the material / become one with the machine"
By that I mean to learn what different materials do. See it in your head. See the material expanding with heat, see the toolbit cutting the material. You don't have to physically watch it, but mentally you need to see everything going on. All material will cut different. Stainless will cut different than tool steel. Cold rolled steel will cut different than aluminum. Aluminum will cut different than other aluminum. Some aluminum is so damn soft it does nothing but gum up a cutter. Other aluminum may put off a real nice curl 15' long. Another piece of aluminum using the same exact setting, will do nothing but put off chips.
So if you want to make parts that are within .0001 on the lathe, forget it unless you get lucky. Any cutter you use will flex material, whether it be a high speed cutter, ceramic, or carbide. A cutter will push material away. Also if the machine is wore just a little, the material can push your tool away.
My Mentor taught me when I first started in the trade, that a good machine does not make a person a toolmaker, but a good toolmaker can make the machine do what he wants. All you have to do is learn everything about the machine.
Anyways, sorry for rattling on. Either pick up a drill blank and indicate in your chuck, or turn a piece down round, cut it off, then put the absolutely round piece back in the chuck and indicate it. If it is running out, then your chuck is running off center. If you want to absolutely want too check a bar from one end to the other, see if there is a machine shop around that does centerless, or center grinding and get a 1 1/2" ground bar made up. It would cost a few bucks, but you would have something that you could check between centers from one end to the other
HoosierBuddy
Well-known member
+1 Perfectly acceptable quality on everything I've bought there plus good customer service. And...IT IS CHEAP!
If you need "commercial quality" I'd go elsewhere, but for homeshop use...it's plenty good enough.
Phil
HoosierBuddy
Well-known member
Kevin54...
Great stuff, man!
Phil
Great stuff, man!
Phil
rlitman
Well-known member
It is probably out of the league of most, but beds sure can be re-scraped. It does require a precision straightedge and a huge amount of time involved.
The down side is that based on the time involved, the effort is not generally worthwhile on most lathes.
Kevin54
MEMBER EMERITUS
You are correct that they can be rescraped. But you line up 100 people that worked in a machine shop, I think you'd be lucky if you could find one that could do it.
We had a crew come in from Gossinger to rebuild a lot of our machines. We had a small Hardinge Toolroom Lathe that was getting worn pretty bad. To the point that if you took too large of a cut, the compound would jump. A Hardinge Toolroom Lathe is a sweet little lathe. This was the one without power feed. But the compounds are a *************. No way to really lube them, and if they get used in the certain few inches over a few years, any grit or anything that gets in them will wear them. The guy from Gossinger was going to scrape it in. He worked on it for a week. We got it back and you couldn't hardly turn the knob. I readjusted the gib somewhat and loosened the nut for the thread which act as a jam nut, and it was not better than it was to begin with.
And just to give a little piece of advice, if you ever run across a Hardinge Toolroom Lathe, or it may be called a Speed Lathe you had better know how to check out the compound. I've had to send our out twice. Both times it was over $5000 to rebuild them and $10,000 for a new one. Don't get me wrong, they are a great little maintenance free lathe other than the compounds. This is the type of lathe I'm speaking of that has the manual compound and not power feed.
