Parting Tool Sharpening

[Sprue]

I've been doing some research on tool sharpening but I cannot locate anything about the proper way to sharpen this Parting Tool.

I know that there are much better tools out there but this is what I have, in fact its a loaner cause I'm new/novice to lathes and turning plus, my tooling is next to nothing at this point.

Any tips are welcomed as to how to get this thing to cut decently. And please, its rather easy to get over my head on this lathing business.

And yes, what you see is work in progress on a Lube Sizer die for my ole .351 WSL (I hope anyway LOL).

Its getting close to Parting off.......



http://i258.photobucket.com/albums/hh266/spilihp_2007/PartingTool.jpg


Thanks

[Red River Rick]

Sprue:

Where's the cutting oil?

RRR

[dragonrider]

That tool you have is the worst, but it can be sharpened, the top surface must be flat, if it isn't make it so. then grind the front until you have sharp corners at the cutting edge. Be sure it is set up on center when cutting and use some kind of oil, wd-40 will work in a pinch.

[Red River Rick]

........ and use some kind of oil, wd-40 will work in a pinch.

Use a cutting oil..............not some oil. Rapid Tap will work wonders for parting as well.

RRR

[Bret4207]

Any of the older lathe instruction books have plenty on that style parting tool. Never had any luck with mine.

[Marvin S]

These will work fine when used right. Dont grind the top just the front, set it just a hair above center and dont extend any further than needed . You can grind it with the leading edge a little long on the right or left side depending on which piece you want to have a burr free face on. Good oil will help, go to the hardware store and look for some dark thread cutting oil.

[Jon K]

Get some oil, move the tool closer to the head for rigidity, and go slow.

Jon

[leftiye]

Like john said, shorten the tool protrusion from the holder to the shortest it can be and still part off the piece. Do the same to the holder in the toolpost for as much rigidity as is possible. After you grind the cutting tool, finish sharpening with a diamond hone or a good sharpening stone. Sharp really makes a difference. Set your lathe on its slowest speed, and finest feed, and flood it with oil. Continually. I use a cutoff tool with a bac rake (5*) on top, every little bit helps. Cutoff is the operation where the most things go wrong. So don't be too upset if you break something. When you get a good setup, and a process and tooling that works it isn't too bad though.

[TCLouis]

Dang glad me and my lathe didn't read this in the past.

All those chips would have never been made.

[Sprue]

Gotter done..... without any kerchunks, bangs, thuds and still have all digits. Its easy with a Team like you guys.

I tried all sorts of ways, heres what worked. I put a relief in the center of the Parting tool. Along with that, slowing the machine down and keeping it wet with oil ........ and wallah.

Now, all I have to do is to bore some lube holes and turn down the center pin.

Thanks for all that great tips/help !

Listen..... I can hear the ole .351 Winny starting to kick like a mule in barn. Bette go and oil him down.


http://i258.photobucket.com/albums/hh266/spilihp_2007/DSCF1182.jpg

http://i258.photobucket.com/albums/hh266/spilihp_2007/DSCF1184.jpg

[deltaenterprizes]

Parting tools with carbide inserts are made like that, it makes the chip narrower than the groove and stops the chips from binding in the groove.Nice work!

[Cap'n Morgan]

Good thinking with the notch in the parting tool!

Sharpening a HSS parting tool is fast becoming a lost lore. The common error is grinding too large a cutting angle on the front, as the tool will pull itself into the part - especially if you use a large rake angle on top of the tool as well. With the correct cutting angle the tool "rests" against the part during the cut.

If anything else fails the hacksaw is your friend :-D

[Char-Gar]

I couldn't get the parting tool to cut until I ground a relief behind the top edge. This worked OK, but it work better when I ground the relief to a straight upward angle and polished all the tool marks off. Now it cuts just fine, providing I keep brushing on the oil and removing the chips at the same time. I run the lathe at the slowest speed without using the back gears. Bigest problem is to get it set so as not to leave a little teat of metal.

Oh yes.. life is easier if you keep the tailstock center in while parting. Things can get cramped, but it can be done.

[Dutchman]

Though some have already mentioned a couple things I'll repeat for my own sake..

Your work is extended too far from the chuck. The rule of thumb is 2 1/2 times the diameter.

Being inexperienced you should be parting using back gears. Parting can be a very dramatic event when something goes wrong... which is how most of us learned. You haven't lived until you've had a dramatic parting event.

Oil, yep.

The front rake on your tool is too much. Think 5 degrees front rake. The angle you have will produce chatter/vibration.

The tool holder you have.. isn't the best. The absolute best, IMO, is the gooseneck made by Armstrong and Williams. It has a vertical relief cut in the gooseneck which produces a spring action which effectively dampens vibration and eliminates chatter. I looked for a picture but couldn't find one fast so I'll try and take a photo of the one I bought not long ago to adapt to my QC tool post. Its a large gooseneck type.

I wouldn't make a grooved tool like you did for one reason. The edges will dull fast and cause tearing. HSS in thin cross sections isn't strong nor does it retain it's high red-hardness. And since you're not using back gears to part this will become apparent the more you use that particular grind. IMO.

Dutch

[theperfessor]

I hope you meant that you keep the tailstock center in the tailstock and not in the piece. Cutting off a piece between centers is a sure way to have a "parting incident".

[Red River Rick]

Cutting off a piece between centers is a sure way to have a "parting incident".

Yes, but who ever tries that.....................will only do it once!

RRR

[briang]

Here's a little trick to set the tool so you don't leave a nub. Lightly pinch a 6 inch rule between the tool and the stock, if the top of the rule leans away form you the tool is to high and if it leans back it's to low. Do this with the lathe off obviously.

[Buckshot]

http://www.fototime.com/BE4B06482FE9A4A/standard.jpg

..........I use 2 parting tools. A carbide insert type on the left and a HSS blade on the right.

http://www.fototime.com/12375D46A9E5AEF/standard.jpghttp://www.fototime.com/9B0D0524E52D685/standard.jpg

Left photo: The carbide insert has built in relief to cause the chip to form a "V" as it peels off. Parting off a pump handle attaching screw for M1902 Rem 22 pump. Right Photo: Parting of a chain link pin. My cousin's husband does field repair work on construction equipment. The regular 'Real' machine shop he normally uses was busy making door latch parts for Aluet (French helicopter company) so he asked me to make them. Using sulpher based cutting oil and parting off hard and fast.

http://www.fototime.com/2024DF1D694C1DC/standard.jpghttp://www.fototime.com/D03172DC0FF3AFC/standard.jpg

Left Photo: I grind in top relief and good clearance (HSS bit). Right photo: It cuts a real clean chip that comes off light tan and hits the chip tray almost blue. This old camera photo is kind of washed out. The danger with this (top relief) is play in the crossfeed screw, as the work could suck the bit in, then 'Bang! Broken bit. I'd installed a new 5/8" screw a couple years ago (replacing the 7/16" one) but I still snug the gib screws down.

If you get chatter try increasing your feed some, or grind a bit of relief on top of the blade. I always use cutting oil when parting off, and have use a 4 oz plastic bottle with a metal needle applicator. You don't need a flood of it as it doesn't cool well, and just a little cutting oil makes a big difference in finish of the part, and life of the cutting edge of the blade.

...............Buckshot

[lathesmith]

I have read stories around the web that back in the old days there were quite a few one-eyed lathe operators due to parting-off "explosions". Definitely a tricky skill to master, but there are several good ways to the the same successful end.
lathesmith