Newbie help hole boring

[dfox1787]

Hi guys

I have a hobby mat mini lathe im pretty new to using it.

Im trying to bore a nice smooth hole which is fairly deep but i cannot get a smooth finish.

The outside finish is really nice. if i reduce the length of the boring bar i.e bringing it closer to the tool post the finish improves. Ill upload some images later you can see what i mean.

My question is really if i am using the correct type of boring bar or if there is a way easier way of getting the nice smooth interior finish.

[mekanik]

What material are you trying to cut, if it's aluminum you might be best with a HSS tool as opposed to the tipped tools.
Regards
Mike

[dfox1787]

What material are you trying to cut, if it's aluminum you might be best with a HSS tool as opposed to the tipped tools.
Regards
Mike

its steel bud. Im making a mould injection machine so i need it to be a smooth as posisble. I just did have a thought. I havent check the height of my cutting tool to make sure its set on center. Im wondering if that is causing an issue.

[mekanik]

Yes tool needs to be @ centre height,would still use HSS tool.I tend to run a fairly slow speed to prevent vibration in the boring bar,when you get to the bottom of your bore reverse the feed and you will find it will probably take a fine cut on it's way out. some sort of cutting oil will help.

[dfox1787]

Yes tool needs to be @ centre height,would still use HSS tool.I tend to run a fairly slow speed to prevent vibration in the boring bar,when you get to the bottom of your bore reverse the feed and you will find it will probably take a fine cut on it's way out. some sort of cutting oil will help.

Thank you ill give that a go later. I am running my lathe @ 2000 rpm. I have either 250, 500, 1000, or 2000 rpm options.

[mekanik]

Try 250 see how it goes, it's a bit of trial and error depending on material/machine stiffness ect. just have a play