Printable View
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.
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.Quote:
Originally Posted by 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.
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.Quote:
Originally Posted by 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
By the sounds of it, you want a less springy boring bar.
Use as large a boring bar as possible, and if you really do have to use a relatively long overhang from the tool post, a carbide bar will help as it's not as springy.
As mekanik says, HSS should help, as it's a sharper edge, and not relying on a blunt edge with brute force to cut the metal. Although one thing you could try if you have an insert bar, is use an aluminium insert, as they typically have sharper edges than inserts for steel. You won't be able to take as big a cut, and the insert won't be as durable, but should produce a smoother finish.
And a key thing with inserts, is keep them cutting. Don't let them rub.
thank you for responding.
Still struggling with it not sure if i reach the limitation of my lathe if its my tools. Ill see if i can find some more time to have another go.
Attachment 24211
Attachment 24212
Attachment 24213
Have you got a fixed steady to support the end of the tube ?
i havent no. i could look at making one if that is what i needQuote:
Originally Posted by cropwell