Which way to turn?

[11echo]

When your cutting threads on a lathe sometimes it's easier to do the cutting away from the headstock! ...To do this you have to be able to turn CCW. So esentually your threading upside down. ...It works I'm here to tell you!!!

[trying-it]

Most manually operated lathes are ran CCW so that if a chuck wrench is accidentally left in the lathe chuck, and machine is started, the chuck wrench is instantly thrown at the operator. School of Hard Knocks: Crash Course, Pass/Fail grade options

A few posts back it was mentioned that drills are used with the machine operated in CCW. I wonder if those posting individuals have ever seen a left hand twist drill? They then require that the lathe be ran in a CW direction for proper cutting action. Any ideas why I may want to use a LH drill vs a RH drill for some applications?

[OlCatBob]

Stan, there are a couple reasons off the top of my head for left-handed bits. Most used are smaller ones for drilling out broken off bolts. As the drill works, it heats up the bolt, and as the bit drills through the bottom, it will actually back the broken piece out. The other use is for gang drills, as every other quill turns backward to the next; ie, cw-ccw-cw-ccw as the gears mesh.
Bob

[hdwarner]

left hand drills , ahhhhhhh
i used to run screw machines and the high range was ccw and when you went to tap
you shifted to low range and the machine would run cw and reversing the tap went into high range

[hdwarner]

left hand drills , ahhhhhhh
i used to run screw machines and the high range was ccw with left hand drills to drill the hole and when you went to tap threads , right hand threads that is
you shifted to low range and the machine would run cw and reversing the tap went into high range

[trying-it]

Yes when using a LH twisted drill rotating in a CCW direction many RH threaded broken bolts and studs can be removed almost as fast as the bolt or stud broke. If the item is not removed with this method you now have a hole drilled for an Easy-Out.

BTW: If you are getting paid to remove the bolt or stud for a customer, tell them the price of the machining charges up front. Also might be a good idea to have them step out of the shop for a cup of complimentary coffee or something. My minimum charge for this type of work was $20. I was usually finished in 5-minutes or less total time!

[drone]

Lathes turn counterclock wise for most applications. The only reason I can think for a lathe to need to be turned in the opposite direction is to make left handed screw threads.

[JosephPrivott]

My small Sherline is CCW. The reason is because we live in a right-handed world. All of the controls are meant to be adjusted with the right hand, meaning the headstock is on the left, supporting Dodge's claim.

[orgtwister]

theres one thing that i havn't seen metioned now i'm not a machinest but i do have 3 lathes and i have ran them cw when needed but when running them cw if you were able to jam the cutting bit theres is the possablity of unscrewing the chuck off the head stock i did hear of some one doing it with one of those china 7x12 lathes the had got it at a tool sale and i guess the chuck wasn't tight and they turned it on in cw and it flew off and hit him not shore of how or why i just got the info from my buddy who is tsr for the company that sold it