Paid for Groovin!

jwmelvin said:
Soluble oil doesn’t have the smoke/smell problem of cutting oil. While misters seem best, if you don’t have air supply then a little squeeze bottle with a needle tip could be good for parting.
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Do you have any recommendations for a particular none stinky/smokey soluble oil?
 
Will bacon fat work? the smell is nice.
 
brino said:
Wait, what?
Parting with tail-stock support?!?!
Isn't that the recipe for danger?

Ahhhhh, It must have been a plug that fills the ID from end-to-end and then the parted off rings would simply collect on the plug?

I had a picture in my mind of the "push plate" that @extropic suggested pinching the tool and then throwing everything around.......

-brino
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Wait... are you not supposed to part with TS support? That is the only way I ever do it.

Snug up lightly and lock. Once the nub breaks loose the part sort of floats until I move the TS.

Never had an issue and the rigidity boost is very welcome.
 
Doug Gray said:
I'm continuing to gnaw. I ringed up a plywood dampener with an aluminum centre drilled plate on the back side. This seemed to help the ringing some. It is a good safety feature in any case. There is not tons of surface on the back end of the jaws. If this were to let go it would not be pretty.
Still searching for that elusive feed and speed to avoid chatter. These inserts part well in small diameters but this six inch is tough. Normal y in small diameters, slightly aggressive, consistent feed works well. Anyway I got 4 knocked off tonight. I'm hoping the 4 inch are like a holiday after these. Thanks for looking and for the suggestions.
View attachment 365992

View attachment 365993
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A six jaw chuck would definitely be your friend if you continue to do tube work. More points of support with help with chatter. Also smaller width inserts to reduce cutting pressure.
 
In my shop - for the same reason as you - I use synthetic water soluble coolant in a squeeze bottle. The same stuff they run in CNC machines as flood coolant. If properly concentrated, it will not rust your machines and typically does not have a noticeable odor. Don't make a 5 gallon bucket though because it can go rancid in large quantities when mixed with oil.

I filled 2 vending machine coke bottles with the concentrate at an internship and it has lasted me probably 8 years. A gallon - the way I use it - would last a lifetime.
 
macardoso said:
Wait... are you not supposed to part with TS support? That is the only way I ever do it.

Snug up lightly and lock. Once the nub breaks loose the part sort of floats until I move the TS.

Never had an issue and the rigidity boost is very welcome.
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Interesting!
My only lathe training was in high school metal shop....and I do NOT remember it as a hard rule from there.
It is something I learned not to do many years later on my own metal lathe.
I believe I also saw it posted on this site as a general rule.

Now I will part "almost thru" with the tailstock support, but I either:
i) back it away for the final plunge, or better
ii) take the work to the bandsaw for final cut thru and come back to the lathe for facing.

With tailstock support the parted-off piece cannot just fall safely out of the way.
The parting tool can get pinched in the slot and either or both the tools gets broken or the cut-off get fired out.....
I liken the problem to kick-back on the table saw.

I would love to hear from trained machinists on this one!

-brino
 
brino said:
Interesting!
My only lathe training was in high school metal shop....and I do NOT remember it as a hard rule from there.
It is something I learned not to do many years later on my own metal lathe.
I believe I also saw it posted on this site as a general rule.

Now I will part "almost thru" with the tailstock support, but I either:
i) back it away for the final plunge, or better
ii) take the work to the bandsaw for final cut thru and come back to the lathe for facing.

With tailstock support the parted-off piece cannot just fall safely out of the way.
The parting tool can get pinched in the slot and either or both the tools gets broken or the cut-off get fired out.....
I liken the problem to kick-back on the table saw.

I would love to hear from trained machinists on this one!

-brino
Click to expand...
Huh, I see the potential issue, but personally I've had good luck with it. Definitely does not mean I am right.

I've found that once the part breaks loose, without any torque to drive it, it just sits there. I just shut the spindle off, and back the tailstock out and bam a clean part.

I too would love to hear more opinions.
 
I don't think I would part completely off while using a center or pusher in the tailstock.
I'd part "almost through" and finish by hand. YMMV

In this case, the OP is only grooving, not parting.
 
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