Parting on the Lathe

[TomG]

(12-08-2013, 06:16 PM)Micktoon Wrote: Hi Tom , thanks for another great video , like Shawn says you and others who take the time to make this type of video are really helping the homeshop type guy that is starting out in his own shop trying to make things
So once again
I also thought Shawn's idea of an ask Tom type section is good and glad to see you thought it was good idea too.
keep up the good work

Cheers Mick.

Thanks Mick, I'm glad you liked the video.

I've already installed a Q&A plugin for the website, now I just need to learn how to use it. This website design stuff is way outside of my comfort zone.

Tom

[Hawkeye]

I was just doing some parting on my 'new' lathe. It was going well under power feed when the spindle stopped. The belt was slipping. The tool wouldn't back out until I loosened the chuck.

After watching your video, I think it was either insufficient oil or alignment. I ran the cutter up against the chuck, but I think there may have been some swarf in the holder. The tapered blade may have been out a bit at the bottom.

Another excellent video. Thanks.

[TomG]

Thanks Mike.

It sounds like the tool wasn't going in straight and bound up in the groove. Proper alignment is key to successful parting.

Tom

[awemawson]

Nice video Tom,

You were grinding your tool to have a neutral cutting action. Do you not ever grind the tool to have a slight angle on the cutting edge, either left or right, to determine if the pip is left on the part or the stock?

I confess these days I tend to use insert indexable parting tools, and these come in either left, neutral, or right cutting varieties. My rear tool post however has an HSS parting tool that I custom grind to the job in hand depending which piece needs to be the finished part.

Andrew

[Micktoon]

Good point ther Andrew, I have also done that rather than having an annoying little pip left on the part you want. I was going to get another holder and have one of each.

Cheers Mick.

[TomG]

(12-08-2013, 10:08 AM)EdK Wrote: Tom,

What brand is that cutting oil you used? It's getting hard to find sulfur based cutting oil.

Ed

Ed,

Dark sulphonated cutting oil is available at Home Depot.

Tom

[TomG]

(12-09-2013, 04:13 AM)awemawson Wrote: Nice video Tom,

You were grinding your tool to have a neutral cutting action. Do you not ever grind the tool to have a slight angle on the cutting edge, either left or right, to determine if the pip is left on the part or the stock?

I confess these days I tend to use insert indexable parting tools, and these come in either left, neutral, or right cutting varieties. My rear tool post however has an HSS parting tool that I custom grind to the job in hand depending which piece needs to be the finished part.

Andrew

Andrew,

That works on small parts, but on larger parts with more tool extension, it can cause the tool to creep sideways and bind up.

Tom

[awemawson]

For larger diameter stock you really need a wider parting tool so that it is sufficiently rigid to avoid that effect. If the tool is sharp and wide enough it shouldn't be an issue. Flood coolant also helps not only to keep the job and tool cool, but lubricate the chips and wash them out of the progressively deeper groove.

Andrew

[TomG]

I get that Andrew, but we need to keep in mind that hobbyists don't always have that option. My AXA post takes a 3/32" parting tool and a thicker blade is not available without going to a larger post (also not an option ;) ). I do grind the end of the tool at an angle on occasion, but only for small parts because it doesn't take much to make that thin blade start snaking around.

Tom

[awemawson]

My 'preferred' width is 2 mm using a Sandvik 151.2-21-20 parting insert holder, and I must confess to pushing too far sometimes on larger diameter stock as I'm too mean to lose more off the stock with a wider blade

https://www.google.co.uk/search?newwindo...B140%3B138