Lathe rear parting tool

[SLK001]

I'd really like you to repost your content too.
And also, I part from either side of the spindle centerline.
Why? Cause the rear mount post has a little parting blade that won't do more than an inch. The front mount is an old workhorse that changed my world when I first got it... and it'll do an inch and a half I think.

Nice cross-slide. Is it original to the lathe, or something that you made?

 

[Pescadora]

State of mind is anything but intimidated.

Sarcasm is how I respond to arrogance, but in truth, I should not post opinion in a space where I am not qualified.

 

[Manual Mac]

Go a ahead and post.
Fresh ideas are always welcome.
I’ve been working as a machinist most of my life, and there’s lots on this site I’m not qualified to comment on.
but I still do.
and I like new ideas

 

[jwmelvin]

in truth, I should not post opinion in a space where I am not qualified.

You are qualified. This forum, like many, is based on individual experience. You sharing your experience, regardless of the original motivation or justification for the action, helps us.

 

[Navy Chief]

State of mind is anything but intimidated.

Sarcasm is how I respond to arrogance, but in truth, I should not post opinion in a space where I am not qualified.

What makes your experience any less valid than anybody else's experience?

Sent from my Pixel 5 using Tapatalk

 

[SLK001]

State of mind is anything but intimidated.

Sarcasm is how I respond to arrogance, but in truth, I should not post opinion in a space where I am not qualified.

As a hobbiest, you're always qualified to post an opinion.

 

[jwmay]

Nice cross-slide. Is it original to the lathe, or something that you made?

Its a casting sold by http://www.mlatoolbox.com/S-4382.html

 

[WobblyHand]

State of mind is anything but intimidated.

Sarcasm is how I respond to arrogance, but in truth, I should not post opinion in a space where I am not qualified.

I read and saw your original posts. Thought you did a great job making a tool that works for you. Please update your posts with your original content. We are a great big family at HM, and sometimes have dustups, but we all support each other in our endeavors. Everyone, from professional machinists, to those who have never used machine tools before and anyone in between, are welcome here. We all learn from each other, including good techniques, and lets just say, things we did, that we never should have done. We even have a blunder thread. Generally, this is a good place to hang out. Please don't have the comments of one person drive your behavior towards the whole group. Remember, if someone really, really gets out of line, report them. HM very much wants this place to be welcoming. They do enforce their rules.

Everyone is entitled to their opinion, period. You did make something and it did work. Therefore you are allowed and encouraged to speak. You are more than qualified to discuss your project! You are more qualified than me, who is a mere hack and beginner. Come on back.

Been wanting to make one of these back mounted parting tools for both my mini-lathe and my G0752. Neither of my lathes have tee-slots, so creating a firm cross-slide mount is slightly more complicated, but should be doable. Would be nice if the drawings were re-posted. Thanks.

 

[mikey]

The rear slot is not needed and it actually increases the risk of cracking, since it reduces the amount of metal in the post. That said, it probably won't fail in any one's lifetime, since the flexure is small and infrequent.

Hmm, my first prototype did not include the rear expansion slot. After a few months some stress cracks began to show on the top shelf just where the front slot ended. This told me that I needed some flexure to reduce stress so I incorporated the rear expansion slot. Since then, no more stress cracks and there seemed to be better clamping force applied to the blade. It has now been over 25 years and not a single stress line has shown up so I think the rear slot is important.

 

[Pescadora]

Appreciate the support. I am usually a closed-mouth guy. Opinions are like you-know-what, and typically I like to keep mine covered. A while ago, I asked a question about parting. One of the nice fellows here answered me privately with some drawings and suggestions. Those are posted now in the first post. Took some measurements on my machine, which is a 1030PM, and then adapted the concept.
Parting on the 1030 was always an iffy affair, with the tool holder tip held to a different height with every in or out adjustment, making height and squareness difficult to achieve, with the quick change post on top of the compound and that on top of the cross-slide. With chips piling up in the slot and the invariable dig-in and stall of the spindle. Every time. Took to dismounting the work and using a bandsaw. And then mounting in the mill's radius jaws and squaring off the end.

After a few weeks of spare time in development, had it done. Gave it a try on a chunk of 1.5 1018 round bar (hot roll). Blade tip was dull. Forgot to add lubricant at first. Did it matter? No. I sent my mentor thanks and a couple of photos. He suggested I post on here. Did that, but offered some unwarranted opinions also. Sorry for that. Sorry also for the comment about arrogance. Came back on to delete that, but it's quoted already.

Can't recover the text in that post as it is gone. Here are the photos.