I think I have a parting problem........

Good thing the blade didn't park itself in your hide Glenn! You dodged a blade-bullet :D
Mark S.
ps I hate parting off
 
not sure where I saw this but I have made several parting tools from a carbide tipped table saw blade - yup that's right. you can get a bunch of them from one 10" C-T'd blade. Just go easy on the feed and use a diamond wheel to reshape the cutting 'point' to suit your fancy.
 
Guys, parting is a royal pain and we all agree on that. But I have a different question: Where do I get a stubby (Short) Morse-3 dead center to insert into my headstock, attach a lathe dog, when it's "leg" can actually reach a hole in a faceplate? My standard length MT3 dead center is too long for that.
 
markso125 said:
Woah you should never power feed on the x axis when parting on a manual lathe. The reason for this you ask, the surface speed decreases on the tool the smaller the diameter gets, that is a quick way to kill a tool.

But in all honesty I usually don't recommend to any of my students on using the power feed on the x axis at all on a manual lathe for that same reason. A lot of the time you will set your feeds and speeds to the outer diameter and the outer 1/4 of the part has a great finish but as you get closer to the center you end up with galling on the face of the part, and just a crappy finish overall. That is because of the different surface speed with the center running slower then the larger OD. If you have ever watched NC machines run you would be able to see they make up for this by speeding up the spindle the closer you get to the center of the part, this creates a constant surface finish on the part. I have found I can get a smoother surface finish about everything I run on a lathe by feeding the x axis in by hand and I can usually do it a lot quicker then messing around with the feed levers.
Click to expand...
Why I love variable speed, change on the fly, only thing better would be constant surface speed like on some of the Harrisons and a few others.
 
NortonDommi said:
Why I love variable speed, change on the fly, only thing better would be constant surface speed like on some of the Harrisons and a few others.
Click to expand...

If running from a VFD, install a slide potentiometer to carriage and cross-slide, its slider goes to the VFD speed input as normal, its ends go to the wipers of a pair of rotary pots each across the VFD 10v analogue supply - hey Presto, (nearly) constant surface speed with max/min settings :)

Dave H. (the other one)
 
Hmmmm, it seems that Parting is causing a lot of people "separation anxiety"...

... Sorry, sorry, sorry... I had to get that out of my system.

Ray

PS: Rigid setup, proper feed/speed, blade alignment, positioning, practice and luck is all it takes. Other than that, it's really easy :black eye:
 
I posted a thread about this a few days ago, but if you have one of the little 9x20 lathes with the two-bolt compound base, do yourself a HUGE favor and make a four-bolt base. It really makes a difference when you are parting. You also get over-all better performance turning and facing.
 
On My SB 10L I set a thin blade on center and straight with the chuck hand feed with cutting oil , haven’t had a problem Don’t know what I’m doing rite.
 
buster said:
not sure where I saw this but I have made several parting tools from a carbide tipped table saw blade - yup that's right. you can get a bunch of them from one 10" C-T'd blade. Just go easy on the feed and use a diamond wheel to reshape the cutting 'point' to suit your fancy.
Click to expand...

I tried something like this. It worked just great on my Craftsman AA 109 lathe, as well as the Jet 1440 at the now defunct Techshop. It did not work on my South Bend 9. I am not sure why, but I suspect backlash in the cross slide. The parting blades are free, but they require a lot of labor to cut out. After I break 2 in a row (bang problem again), I start to compute effective hourly wages, which is what I usually do when I am not having fun. Eventually, I am afraid that I'll break something on that lathe if I don't figure out how to get it right.
 
I'm running an Atlas/Clausing 618 or MK2 lathe.
I replaced the plastic gibs on the cross slide and compound with steel gibs. Actually I've replaced the compound with a new non-adjustable tool block. Anyway, for parting, I put a little pressure on the gib (which is on the wrong side of the cross slide to have the right effect). I recently needed 6 pieces of 6160, 1 3/8 diameter by .500 long. I chucked up a piece in the lathe, put a center in the end, and cut all but .400 off all at one time, then cut them off with the manual hack saw. Not a problem at all. I kept the tool wet with A-9.
 
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