# New Forum Member Intro to Lathes



## jlsmithseven (Jan 16, 2017)

Hi
Just joined the forum today! Looks like a great place to find and give information regarding CNC and manual lathes and mills.
I'm in my 2nd semester at a Technical School right now. We learned the basics of each machine. Our first project this semester is a thread bar made on the manual lathe.

Can I start with that? I've been having  a slight issue lately. I've noticed I am using a #4 center drill to drill holes for my dead and live centers. Before  I think I was using a #2 or #3. I have to go all the way up on my #4 just to make sure there's clearance at the back of the center drill for my dead center. Is there any sort of way to measure this so I don't have to make my center drill hole so large, yet still not touch the back of the inside? Thank you!
Justin


----------



## jpfabricator (Jan 16, 2017)

Welcome aboard!

Sent from my SM-S320VL using Tapatalk


----------



## Ed ke6bnl (Jan 16, 2017)

jpfabricator said:


> Welcome aboard!
> 
> Sent from my SM-S320VL using Tapatalk


Does this help
http://www.carbidedepot.com/formulas-centerdrills.htm

Sent from my SM-T377V using Tapatalk


----------



## jlsmithseven (Jan 16, 2017)

Thank you. Does anyone know any good beginner videos on YouTube that I can subscribe to? Someone who describes the processes of external threading, etc.


----------



## jlsmithseven (Jan 16, 2017)

Ed ke6bnl said:


> Does this help
> http://www.carbidedepot.com/formulas-centerdrills.htm
> 
> Sent from my SM-T377V using Tapatalk



It certainly doesn't hurt. That's a cool chart. Now that I have that information, how can I measure my dead center point to make sure it doesn't hit inside my center drilled hole? Obviously it's a 60 degree angle of course. This seems simple but I don't know how!! Thanks for the help!


----------



## T Bredehoft (Jan 16, 2017)

Standard center drills are manufactured so that the center of a live or dead center will not encounter the end of the drilled hole.


----------



## Joncooey (Jan 16, 2017)

Hi Justin.  Watch anything by Tubal Cain.


----------



## jlsmithseven (Jan 16, 2017)

Joncooey said:


> Hi Justin.  Watch anything by Tubal Cain.



Thanks I have been watching Tubal Cain's videos. They've helped a lot. Just wanted to see what else was out there. I realize that standard center drills are made this way. Most people tell me to take 2/3 of the way up the cutting edge on the center drill, is this correct or should I go all the way to the end of the grooves.


----------



## British Steel (Jan 16, 2017)

Not to the end of the tapered section, or the centre will ride on the end of the centre drilling instead of the 60* taper - approach full depth of the 60*, a deeper centre will take greater loads so if you're going to be making heavy cuts use a larger centre drill where possible. Lots of lubrication, too, unless you're using a revolving (ball-bearing) centre!

And welcome!

Dave H. (the other one)


----------



## jlsmithseven (Jan 17, 2017)

Just to show you the project I'm working on. It's ready to start threads. Will be my first time. I'm using a practice piece first, not this one.

View media item 95700View media item 95701


----------

