Speed/Feed ???

Jackie
I went back and reread what you posted above, and it finally sank in...my mistake.
Please keep post anything that might help.

Jerry
What is K-land ??

I can't thank everyone enough for the helpful information you so freely provide.
Sure save me a lot of trial and error, and money!!! .

Thanks again
Hal
 
Hal said:
WSnider.
What shape are the WPEX and the DCGT inerts?
Click to expand...

WPEX trigon. Only potential downside to these is they are directional Right or Left so if you want both directions you will need two different inserts for different directions. I use only Right at this time for cutting tenons. These are the inserts Speedy G used to recommend except he used an IC20 grade which is no longer available in this insert. Useful tool holders for this insert are SWAPR & SWBPR

DPGT and DCGT 55° Diamond

The WPEX is more useful than the DCGT and if I had to I could get by without the DCGT.

For counterbores I use Circle Machine TPCH CG5 & TDAB CG5 in Circle machine carbide bars. They used to have promotions on these bars. You got free bars for the price of the inserts.

I have some ISCAR VCMT IC 908 w/SM chipformer and they do not work as well on barrel steel as the above mentioned inserts. I mention this because you can waste money on inserts you think will work but sometimes don't. I have found if someone has something that works well get exactly (brand, style, chipformer, grade, etc...) what they are using if you can and better yet see it in use in person to see if the results suit you. Inserts can get expensive and more so if they sit unused in a drawer because of poor performance for your application.
 
Hal said:
Jerry
What is K-land ??

I
Thanks again
Hal
Click to expand...

"Carbide" inserts are made from metallic powders. According to the insert grade there will be a mixture of Tungsten Carbide, Talladium Carbide, and a few other metallic carbide powders. This powder is then pressed into the desired shape in machines called pill mold presses. These presses were originally designed to male pills like aspirins and such. These very fragile pressings are then cooked at very high temperatures in ovens called sintering ovens.

Since this product has no crystalline structure it is still somewhat fragile even though it is nearly as hard as diamond. To keep the square edges from chipping there is usually a small radius polished on the edges. This radius is sometimes included in the insert description. If the insert edges are not radiused, and are used for machining stock like burned out stainless steel, the insert maker will actually grind a small flat across that sharp edge. That flat, usually only about 0.002"-0.006" across is called a K-land.

Long story, short subject. Fancy name for a beveled cutting edge.

A triangular insert could be a TPG-432T for example.

http://shopswarf.orconhosting.net.nz/ansiinsert.html
 
Rigid Cutting Oil

jackie schmidt said:
We have switched over to the high sulphurized Ridgid Black Cutting Oil. We buy it in 55 gallon drums. It is as good as any I have used in the way of heavy sulphurized cutting oils.

jackie
Click to expand...


Jackie,
Are you talking about the Rigid cutting oil that is used for pipe threading machines?

Lou Baccino
 
Crowning tool

Hey Jackie could you post a pic of the crowning tool that you have talked about before. I have tried a couple different profiles on HSS but they don't seem to cut a perfect edge. And I agree that the right insert sure makes a huge difference in the cut quality. Still lots to learn from you guys.

Joe Hynes
 
Lou

That's the Stuff. They make several grades, the one with the highest sulphur content is what we use.

Texaco used to make a fantastic high sulphur heavy black cutting oil, Sultex -D they quite about 3 years ago. The stuff they blend now simply is not as good for our applications.

The very best cutting oil we ever had was back in the old days. It was a old black stuff that actually had lard in it. You could pour that stuff on steel and shavings would fly off........jackie
 
Thanks for the pointers

Mr. Shmidt and the others that answer lathe questions, let me add in my thanks also. I have been reading the last several months when i see your post.

I just fired up my China 12"x37" (all i could afford) last week and have a lot of questions. Most of the time i can find the answers right here on BC.

One day i'm gonna thread and chamber a rimfire bbl, that's where i'm headed. I never cut threads before but i'm learning on some alum round stock. (got some steel stock coming for practice also) Probably could have bought a bbl already threaded a little cheaper but i'm in for the adventure also!

I'm lost on proper threading tools. I don't know what the proper shape to grind either. If anyone could point me to the correct tool i need for threading a bbl i would purchase it today.

i don't want to hijack anyone's thread but i did want to say i'm out here lurkin and to say thanks: joe
 
Lil Joe, the secret to a perfect crown is to tap a bullet in the muzzle, face off from inside out!!!!! Depending on if you use HSS or carbide you'll find out what is the best speed once you've done it a few times. If you have any questions email me. jaberegg@charter.net

Jeff
 
jGEE said:
Mr. Shmidt and the others that answer lathe questions, let me add in my thanks also. I have been reading the last several months when i see your post.


i don't want to hijack anyone's thread but i did want to say i'm out here lurkin and to say thanks: joe
Click to expand...

jG, in threading a barrel, (or any single point threading-that's what threading on a lathe is called) you must determine the thread profile AND thread pitch.

Thread profile is the shape of a cross-section of the removed metal. Thread pitch is how many threads per unit of measure, (TPI=threads per inch, example, a Remington 700 has 16 threads per inch-- metric threads are a measure of how far it is from one thread to another measured in millimeters).

http://www.finelinehair.com/home/Threads.pdf

I'm sorry you bought a ChiCom lathe but do the next best thing, go to ebay and order a "How to Run a Lathe" book by South Bend Lathe. This old book has more information in fewer pages than anything you can buy.

http://cgi.ebay.com/How-To-Run-A-La...5|66:2|65:12|39:1|240:1318|301:1|293:1|294:50

http://cgi.ebay.com/SOUTHBEND-HOW-T...ptZLH_DefaultDomain_0?_trksid=p3286.m20.l1116
 
Done it, book ordered!!

JerrySharrett said:
jG, in threading a barrel, (or any single point threading-that's what threading on a lathe is called) you must determine the thread profile AND thread pitch.

Thread profile is the shape of a cross-section of the removed metal. Thread pitch is how many threads per unit of measure, (TPI=threads per inch, example, a Remington 700 has 16 threads per inch-- metric threads are a measure of how far it is from one thread to another measured in millimeters).

http://www.finelinehair.com/home/Threads.pdf

I'm sorry you bought a ChiCom lathe but do the next best thing, go to ebay and order a "How to Run a Lathe" book by South Bend Lathe. This old book has more information in fewer pages than anything you can buy.

http://cgi.ebay.com/How-To-Run-A-La...5|66:2|65:12|39:1|240:1318|301:1|293:1|294:50

http://cgi.ebay.com/SOUTHBEND-HOW-T...ptZLH_DefaultDomain_0?_trksid=p3286.m20.l1116
Click to expand...


Mr. Sharrett thank for the info and links. The finelinehair link came up as an ALERT in my browser and i did not log on, said it had been reported the site installs spyware. Probably a false alarm but i didn't visit that site.

Thanks for the link on e-bay, i purchased the book for $18 bucks.

What determines the depth of the thread? is it the angle of the tool? i'm a little lost here. I have been practicing 16tpi threads.

On the China lathe, i know they are "hated" here but.....
I have a 1942 9" southbend. Got it 10 years ago or so and it was wore out then. I had to epoxie the ways, they were grooved so bad. I had to shim the tailstock with a hacksaw blade on one side to get close to center. i replaced the crossfeed screw and nut a couple weeks back, it was wore so bad, had about 1/2 slack, lol. It had a bucket of change gears and i didn't have a clue what to do with them.

Anyway i have made a lot of small widgets, bushings and such when i had my old car automotive shop. I always wanted something i could thread with and something that would turn a piece square, without running in or out .010 or so ever 6 inches.

I know china stuff ain't that great but it will hold a gun bbl betweeen centers and go thru the head stock. the 9" has a 3/4 spindle bore, china has 1 1/2". China has a 2hp where my SB was lucky if it had 1/2hp. The China came with a 3 and 4 jaw, don't have a clue how to use the 4 jaw for now and a few other sundreys.

I read a thread here at RC and 1 member made a post that helped me a lot. He said the mistake a lot of people make is they never make up their mind on what to buy and never get a lathe, that was me. He said one day just buy something or you will miss a good experience. that has stuck with me for several months.

I finally scraped up some money and China was $2106 with stand delivered to my door. The only thing i can say about it for now it's a lot better than a poor old wore out 9" South Bend. But i have had to oil and make some adjustments. I didn't like the way the gears meshed going down to the threading and travel gear changes. I had the gears off China and need to shim the gear out .050 to fully enguage the teeth. Well a short story long i fired up my trusty South Bend and made the shim i needed for my new China, lol..... I still like my South Bend even wore out as it is- it's still in the corner on stand by!!

Sorry for the windy post but i appreciate all the help you "lathe salts" can offer!! thanks, joe
 
jGEE said:
Well a short story long i fired up my trusty South Bend and made the shim i needed for my new China, lol..... I still like my South Bend even wore out as it is- it's still in the corner on stand by!!

Sorry for the windy post but i appreciate all the help you "lathe salts" can offer!! thanks, joe
Click to expand...

This link is pretty good explanation on threading.

http://www.metalartspress.com/PDFs/60_degree_threads.pdf

As to ChiCom lathes, they are pretty good for the price. Buying a multi-function lathe for the price of a riding lawnmower ain't bad. I, myself, just hate to send money to the Communist Chinese to advance their ability to build machine tools that will build armament that will be used to kill us one day.
 
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