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Gallery, Projects and General => The Design Shop => Topic started by: Kinkajou on June 28, 2017, 12:15:22 PM

Title: Need help with cutting a thread in a lathe...
Post by: Kinkajou on June 28, 2017, 12:15:22 PM
Good morning.
I have been using a very simple Grizzly 3 in one machine, you know, a small footprint equipment that has Mill/Drill and lathe. When I got it I did not know of all the limitations, I consider myself a self taught noob and try my best with what I have.

So I need need advise. I have read books and watched you tube instructional videos which have been great. But almost everyone has the same procedure regarding thread cutting on a manual lathe. They start by the tool which has to have specific angles and they use the compound on the lathe.
Problem is that I do not have a compound on the lathe that has a dial, so I can not move the tool in a diagonal fashion.

How can I solve this? Should I only use the X and Y feed on the lathe?
I can not make a nice part so far, but I do not want to do it with a  Tap an Die because it always end eccentric.

Thanks in advance for the patience and advice.

Title: Re: Need help with cutting a thread in a lathe...
Post by: wheeltapper on June 28, 2017, 12:52:34 PM
It's quite possible to cut a thread without using the compound / topslide.
it only comes in handy when cutting a deep thread as by turning the topslide to the thread angle the tool only cuts on one side.

for smaller threads plunging straight in works.
in fact I removed the topslide from my import lathe because it suffers from weeble wobble itis. i only fit it to turn a taper ( and it's not much good at that either.

you do however have to have the correct angle on the tool which also has to be square to the work.

Roy.




Title: Re: Need help with cutting a thread in a lathe...
Post by: John Stevenson on June 28, 2017, 01:52:36 PM
A very good reply. I always do it that way
Title: Re: Need help with cutting a thread in a lathe...
Post by: Kinkajou on June 29, 2017, 12:33:40 AM
Thanks Roy, the same applies to internal threads? I will try it tomorrow.
Title: Re: Need help with cutting a thread in a lathe...
Post by: 69CamaroZNut on October 04, 2017, 07:16:52 PM
I have a Harbor Freight 3-in-1 machine.  If your machine is 8" to 9" to center of the chuck you can purchase any of the HF or Grizzly 3-in-1 compound rests/slides with the calibrated feed screw in Inches or MM dial for your lathe.

John