Parting off tool from Grizzly?

[oscer]

Has anyone tried the carbide insert T10012 parting tool from Grizzly? If so what do you think of it?

[BIGGUNDOCTOR]

Unless you are parting off at high speed,doing production, or cutting hardened materials, you probably don't need the carbide insert style of parting tool. Most of the parting I do at work is done with the HSS blade type of parting tool. I have some thin brazed carbides that I use for some instances.

You chunk a HSS blade, and all you do is resharpen it. You chunk an insert,and you toss it in the carbide scrap can. Most of the ones I have seen broken cannot be flipped around, as there is nothing left to hold onto. I have HSS blade parting tools that I have had for over 20 years, and they still have a lot more life left in them.

[arftist]

BGD nailed it. Carbide insert tooling is very expensive if used when not required.

As an aside, I would hesitate to buy any machinists tools or equipment from Grizzly, but that is just me.

[oscer]

BGD nailed it. Carbide insert tooling is very expensive if used when not required.

As an aside, I would hesitate to buy any machinists tools or equipment from Grizzly, but that is just me.

I've heard similar reports over on PM. about Grizzly. I have very little experience with their metal working tools but am pleased with recent wood working tools although the early stuff leaves a lot to be desired.
As far as hss parting tools go I must either be doing something wrong or have the wrong holder or ... cause it's not working for me.
I'm clamping a hss blade in the holder that came with the phase II quick change tool post. It looks like a poor clamping set up to me because there is no support at the back of the blade. The blade pulls down (I think)and digs into the work, usually slips the belt and then everything is in a bind.

[arftist]

I've heard similar reports over on PM. about Grizzly. I have very little experience with their metal working tools but am pleased with recent wood working tools although the early stuff leaves a lot to be desired.
As far as hss parting tools go I must either be doing something wrong or have the wrong holder or ... cause it's not working for me.
I'm clamping a hss blade in the holder that came with the phase II quick change tool post. It looks like a poor clamping set up to me because there is no support at the back of the blade. The blade pulls down (I think)and digs into the work, usually slips the belt and then everything is in a bind.

Are you setting the edge of the tool to the exact center? Is the blade square to the work? Are your feed and speed correct? How much of the blade is overhanging the holder? Are you locking the carriage when parting? Do you have a proper clearence angle? What material are you cutting?

[bigfootnampa]

A parting tool can be pretty dodgy to use. As usually applied they tend to be very unstable and even dangerous. I have had great success by using the diamond type parting tool and sharpening it with a slight hollow grind on one face which I then turn a burr on as you would a card scraper I use it with a more downward angle then so that it cuts with very little chance of any sort of grab. The tool cuts slightly slower that way but more gently and with great reliability. As with a card scraper you can renew the burr a time or two before you have to regrind. This technique has really helped me and I use a similar strategy on face scrapers too. You do have to pay attention so that you present the tool with the hook or burr up and this also makes the tool a one sided cutter instead of being reversible. You can try it on a diamond parting tool without the hollow grind on the top of the face as that works reasonably well too... but it works even better when you are brave enough to commit and do the hollow grind.

[oscer]

Are you setting the edge of the tool to the exact center? Is the blade square to the work? Are your feed and speed correct? How much of the blade is overhanging the holder? Are you locking the carriage when parting? Do you have a proper clearence angle? What material are you cutting?

Yes to center and square as for speeds and feeds I played with it some. I used to part off with a verticle boring mill at about the same speed as I turned at although with less feed rate. Tool overhang is min. required.Locking carriage. Cutting both mild steel and 4140. with similar results.

[BIGGUNDOCTOR]

Having a rigid setup is paramount. You want the bit pretty much on center. Some books say .015" above, so that the torgue draws it down to center, but I usually just center it. To get center you can use the tailstock center as a guide. Make sure the blade is perpendicular with the part, if not it will drag on a side, and possibly grab. Another thing is a lathe that is tight. Too much play in a compound, or cross slide can allow the bit to grab also.

I usually throw a small radius on the top edge to help curl the chip, say .1875-.250 back starting at the tip, and maybe a .1875 radius. I just use the edge of the bench grinder to do this.

If you are doing a really deep cut, run the tool back so only 1" sticks out. When you bottom out extend it another 1", etc. This will help to cut down vibration, and help the rigidity.

With HSS your chips need to stay original color, not getting any colors from heat. Also keep the cut well lubed with oil, or coolant as you make the cut. I was doing some parting at work Friday. Speed was around 400 on a 1" steel bar, continuous oil flow, and a steady feed rate. The chips should curl up into little rolls. As you feed it into the part it should be cutting smoothly. If it is ringing, either slow the speed down, or increase your feed rate to load the tool. I have parted some parts as slow as 80 rpm, so you just need to play with the speeds, and feeds to find what is optimum for your setup.

[oscer]

Having a rigid setup is paramount. You want the bit pretty much on center. Some books say .015" above, so that the torgue draws it down to center, but I usually just center it. To get center you can use the tailstock center as a guide. Make sure the blade is perpendicular with the part, if not it will drag on a side, and possibly grab. Another thing is a lathe that is tight. Too much play in a compound, or cross slide can allow the bit to grab also.

I usually throw a small radius on the top edge to help curl the chip, say .1875-.250 back starting at the tip, and maybe a .1875 radius. I just use the edge of the bench grinder to do this.

If you are doing a really deep cut, run the tool back so only 1" sticks out. When you bottom out extend it another 1", etc. This will help to cut down vibration, and help the rigidity.

With HSS your chips need to stay original color, not getting any colors from heat. Also keep the cut well lubed with oil, or coolant as you make the cut. I was doing some parting at work Friday. Speed was around 400 on a 1" steel bar, continuous oil flow, and a steady feed rate. The chips should curl up into little rolls. As you feed it into the part it should be cutting smoothly. If it is ringing, either slow the speed down, or increase your feed rate to load the tool. I have parted some parts as slow as 80 rpm, so you just need to play with the speeds, and feeds to find what is optimum for your setup.

Thanks I'll try the 3/16' radius on top that sounds like it should help Are you using the tool holder,that I described, with good results? it came with the phase II tool post.
I'm using a SB 10L there is about .025" of backlash in the compound this could be causing the binding problem. I noticed there are 2, 1/4" 20 threaded holes in the side of the compound are these for set screws to lock it? they are empty and they would line up to the top corner of the dovetail. I've been meaning to get some brass tipped set screws to lock it for certain apps. but haven't been able to find any locally.

[BIGGUNDOCTOR]

pics would help.

The screws may be holding the gib. The locks that I have seen are singular in nature.

[oscer]

pics would help.

The screws may be holding the gib. The locks that I have seen are singular in nature.

They aren't the gib screws' they're on the opposite side of the compound. I could keep the compound from moving while parting though by tightening the gibs. It would be a little easier to just back out these set screws when finished than to readjust the gibs. Any way I'm not sure this backlash is even part of the problem.

[oscer]

I'm bumpin this thread because I found the problem and I believe it is fixed. It had nothing to do with tooling or set up but was caused by too much play in the South Bend spindle bearings. This is easy to fix on the older lathes with cast iron bearings,you just put a test indicator on the end of the spindle, put a rod thru the spindle and lift with a force of 75 ft lbs. measuring the deflection. I used one of those hanging scales to be sure I was lifting hard enough.I think I learned this on Steve Swells site. The spindle should deflect between .0008 and .0013 check both ends of the shaft and remove shims that are between the headstock and the bearing caps. Mine was out of speck by about .0005 at both ends and after adjusting this bearing clearance the chatter is gone. If there is a boss on top of your bearing caps with adjusting screws in it you have a newer lathe than mine and you don't want to remove the caps,there is a different procedure wich I can't remember the particulars of. you can find it on sswells or over on PM I thought this might help some owners of the very old SB lathes
oscer