Lathe tooling and other questions.

[Sapper]

I am slowing getting used to the lathe at work and I am find the complete lack of bits annoying. I can't find a local supplier for bits so I started searching Ebay. I found some that look kinda like the ones at work but I am not sure what I should be looking for. What do people reccomend for cutting and facing bits.

I kinda broke a couple of the parting bits and now need to replace them with new ones. Again I am not really sure what happened other than I was taking a bit too much off in one pass I think and it bound up VERY QUICK and the bit and my work piece was destroyed.

I am also curious what kind of bits are needed to turn down something like a 203 shaft. I seem to have a few laying around and none of the bits I currently have collected seem to even make a dent on the 203 shaft. Just a lot of noise with slight polishing of the area but not even a groove in the 203 shaft. I am thinking that if I get bits that will cut this then I will be able to cut anything and begin making my driveshafts as well as pinion conversions.


Sorry these are what I found on ebay.....

http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=250036215045&ssPageName=MERC_VIC_RSCC_Pr4_PcY_BIN_Stores_IT&refitem=250034295111&itemcount=4&refwidgetloc=closed_view_item&usedrule1=StoreCatToStoreCat&refwidgettype=cross_promot_widget


Also the same lathe as in this thread...
http://www.offroadfabnet.com/forums/showthread.php?t=730&highlight=lathe

[bigrippen]

do you know how to make your own tools? you should be able to sharpen the tools that you broke. for somebody that doesnt know how, i would recomend carbide inserts.like these
http://cgi.ebay.ca/Kennametal-KTFR-10A-Carbide-Insert-Lathe-Tool-Holder_W0QQitemZ200034133116QQihZ010QQcategoryZ104 241QQssPageNameZWDVWQQrdZ1QQcmdZViewItem.
it uses these
http://cgi.ebay.ca/100-TPG-321-C5-TIN-COATED-CARBIDE-INSERTS-NEW_W0QQitemZ280033477220QQihZ018QQcategoryZ633QQr dZ1QQcmdZViewItem
i bit more expensive but easier to use which makes better parts.
as for feeds and speeds, the only book you need, the machinery handbook. consider it the bible of machining.

[bigrippen]

machinery handbook http://www.amazon.com/Machinerys-Handbook-27th/dp/0831127007/sr=1-1/qid=1160113421/ref=pd_bbs_1/102-0728709-3800968?ie=UTF8&s=books

[Azzy2000]

Im thinking youll need a carbide bit to get through the hardened 203 shaft.. the bits you have are probably for HSS and other easily machined materials.

Im pretty new to this also .. i just picked up an old south bend 13x60.. glad you brought this thread up.

[Azzy2000]

There are also some good books on ebay and other places to show you how to run the lathe through all its operations and explain the proper way to use it.

Heres a link to one of many..

http://cgi.ebay.com/HOW-TO-RUN-A-LATHE-South-Bend-Screw-Cutting-1966-Manual_W0QQitemZ110039413229QQihZ001QQcategoryZ252 81QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[Sapper]

I think it was the sharpening them on the grinder that killed them. I admit I need to do my reading as this is not one of those things I am just figuring out how to do. I can definately respect those that use these everyday even more than I did before.

What is the advantage of those tools that you posted above? Are the for parting? Facing? Will they work on a pinion or output shaft? I am using these as a reference as I believe them to be the hardest material I will be working with. Also I can read the chart on the side of the machine for cutting threads but what type of bits are needed to do it?


I have been practicing on aluminum just to get used to everything and maintaining my required measurements.

[bigrippen]

the tools that i linked to will work for facing and general turning. carbide is a harder material than hss but more brittle. there are different styles of carbide holders as well as inserts. some for parting, some for threading, etc.
to cut threads. threading insert w/holder
http://cgi.ebay.ca/CARBIDE-TOOL-HOLDER-W-16-NEW-THREADING-INSERTS_W0QQitemZ330034419853QQihZ014QQcategoryZ25 258QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
carbide parting tool
http://cgi.ebay.ca/NEW-ISCAR-Parting-Tool-10pc-ISCAR-Carbide-Inserts_W0QQitemZ220034231805QQihZ012QQcategoryZ58 204QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
you should look into local community colleges that have a machinery program.

[PTSchram]

First off, learning to grind your own bits is the first thing one should learn befor emaking chips.

Enco is your friend.

PT

[D60]

Parting tools require a little extra care, but you may have broke yours because you were pushing it too hard, your speed was wrong, or your tool height was wrong. Tool height is critical. We'll assume you had the correct rotational direction ("up" vs "down").

Carbide inserts are prolly the way to go if you'll be doing this a lot. You can also buy a lot of bonded carbide from Enco for about $45, Enco finally got off their ass and sent me a sale catalog, try part #FT383-4500

Finally, if you're just working w HR or CR steel, use something like a threading tool to put a nice big notch in your part and then finish it off w a hacksaw w the lathe spinning at a relatively high speed. Then face to length. Kinda a PITA but way cheaper than parting tools. Altho I'd guess a hacksaw wouldn't touch heat treated shafts.

If your shop doesn't have a diamond wheel grinder just get the carbide inserts. The Baldor grinder is around $850 and I don't think that includes the wheels, knock-offs are $250 to $400. You'll need to periodically sharpen the Enco units I mentioned. The ebay link you provided is 3/8", I'd prolly lean toward 1/2". Do stay w grade C5/6 for what you're doing. If you get the inserts you might consider even larger, like 5/8" or 3/4". It wouldn't hurt to take a quick glance and see what your tool post can handle.

[PTSchram]

I buy a package of carbid ebits every time they go on sale at Enco. For what they cost, I throw them away and go on!

[Billetburb]

Sapper,
If the lathe you have is the same one in the picture, then you have a good rigid machine. One thing you will learn in machining is rigidity is every thing. The tool post will accept larger tooling (probably) Get the largest tool holder that will fit. And get one like I have linked here. The replacement inserts are always on sale somewhere. That way the geometry of the tool is always right.


http://www.jlindustrial.com/Indexable/Turning_Tools/CHT-72634K/SEARCH:CATEGORY/Y/product.html


As far as what you are doing wrong..everything:flipoff2: that's what is called the learning curve...and a scrap barrel..you will need one of those also..
Gary:D

[Sapper]

I am going to try and grab some pictures of the tool post and fixtures that I currently have. I am seriously considering buying a new tool post similar to this.

http://www.littlemachineshop.com/products/images/1785.jpg

I have some carbide bits on the way and I am going to give them a try and then decide if it is worth it to purchase the tool post. Currently there is no boring bar and I would really like to be able to use this ability for somethings. Also my parting bits look just like this and the the chatter I am getting is poor to say the least even with a VERY VERY Slow and light feed rate.

http://www.thetoolgarage.com/images/aw2k/LotImg29.jpg

Which is another reason I would like to get an different tool post.

[Billetburb]

Sapper,
Good choice, a quick change tool post will make you money from the day you buy it. Try to get a set that will take 3/4 square tooling. Those tools are the most common in the HD world. They come up on ebay every day:)
Gary

[ZAG]

just get good holders and quality inserts http://www.coromant.sandvik.com/

[jnutter]

I am also curious what kind of bits are needed to turn down something like a 203 shaft. I seem to have a few laying around and none of the bits I currently have collected seem to even make a dent on the 203 shaft. Just a lot of noise with slight polishing of the area but not even a groove in the 203 shaft. I am thinking that if I get bits that will cut this then I will be able to cut anything and begin making my driveshafts as well as pinion conversions.



I asked the same question when I started to shorten and re-spline axle shafts. A guy on the HSM board had done several and he suggested an MCLN tool holder. This uses CNMG 432 carbide inserts. I experiemented with different grades of carbide and found that C6 gave me chatter, but C2 cut nice - so that is what i use. C6 is what a carbide manufacturer would reccomend, but you have to go with what works.

Your lathe looks good and solid, so I think the MCLN tool holder should work for you too.

For cut off I use a carbide cut off tool to cut through the case and then band saw through the core with a cheap HF 4x6