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jfsmith
05-01-2003, 06:12 PM
Well, I got my dies and handles in to cut this thread. I have nothing that will hold the arbor without rotating. Should I give up in this method and cut the threads with my lathe?

Jerry

Al Messer
05-01-2003, 07:19 PM
Partially cut them with the lathe and use the die just to put the finishing touches on the threads.

SGW
05-01-2003, 08:15 PM
Yeah -- I think the best approach for "big" threads is to help things along by screwcutting in the lathe first, then finish to final form with a die if you have one. (Or tap, if an internal thread.) I've done 1 1/2 - 8 threads for a chuck backplate that way. I don't have a clue how I'd ever turn a 1 1/2 - 8 tap otherwise. Cutting to within about 5 thou in the lathe, then running the tap in, makes it easy.

Aside from reducing the force required by about a gazilliion percent, it also gives much greater assurance that the resulting thread will be square to the work.

G.A. Ewen
05-01-2003, 09:03 PM
Of all the turning operations that can be done on a lathe, thread cutting is my favorite. http://bbs.homeshopmachinist.net//wink.gif
As far as I know it's the only way to cut a perfect thread. A skill worth learning. Practice, Practice, Practice.

Oso
05-01-2003, 11:59 PM
I have forgotten what you wanted to thread. If it is an Atlas backplate, I would not have bothered with the tap.

Cast iron is nice cutting, and if you have a problem, you can always turn the thing by hand the last turn or so to avoid running into an invisible internal shoulder etc (or just mark the boring bar!!!)

Since you have the tap, might as well use it, but I think that thread cutting on the lathe is way over-rated as to difficulty of learning. In reality it is easy to grasp and not hard to do.

Carl
05-02-2003, 12:20 AM
<font face="Verdana, Arial" size="2">Originally posted by G.A. Ewen:
Of all the turning operations that can be done on a lathe, thread cutting is my favorite. http://bbs.homeshopmachinist.net//wink.gif
As far as I know it's the only way to cut a perfect thread. A skill worth learning. Practice, Practice, Practice.</font>

I agree, threading on a lathe is my favorite operation too. I think that threading is probably the most important function of an engine lathe. Remember, a lathe will cut a thread of any pitch on any diameter within the capability of the specific machine. The threads cut on the lathe are concentric and square to the axis of the work piece, and are created in easy progressive steps. Try tapping a large hole in a small work piece, while trying to hold the piece against rotation, apply enough torque to the tap, and try and get the thread started straight all at the same time. You soon realize the value of the screwcutting lathe!

lynnl
05-02-2003, 07:00 AM
Agree with all above. Lathe Threading is:
1) Important to learn.
2) Lotsa fun.
3) Not at all hard to learn or do.
4) Good for your ego and self-esteem
5) Makes you appear sexy to opposite gender
6) Other benefits too numerous to mention

Ragarsed Raglan
05-02-2003, 08:49 AM
lynnl,

Regarding point 5) above ~ please elaborate further. Do I have to be proficient in left hand as well as right hand threads??

RR

Thrud
05-02-2003, 09:47 PM
RR

Dang! Beat me to it... http://bbs.homeshopmachinist.net//tongue.gif http://bbs.homeshopmachinist.net//biggrin.gif

KitCat
05-03-2003, 07:50 PM
A man that knows how to thread proficiently, be it right hand or left, is always sexy. http://bbs.homeshopmachinist.net//wink.gif

ibewgypsie
05-03-2003, 08:08 PM
HUH? I am so confused.

John Stevenson
05-03-2003, 08:13 PM
<font face="Verdana, Arial" size="2">Originally posted by Ragarsed Raglan:
lynnl,

Regarding point 5) above ~ please elaborate further. Do I have to be proficient in left hand as well as right hand threads??

RR</font>


Not unles you are a pig http://bbs.homeshopmachinist.net//biggrin.gif

John S.

Alistair Hosie
05-04-2003, 12:43 PM
I am also lost is this some kind of sexual innuendo http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gif Alistair ps and on a Sunday too

lynnl
05-05-2003, 10:45 AM
RR - I think it kinda depends on which gender one wishes to appeal to. I guess a multi-talented person's appeal would be universal. http://bbs.homeshopmachinist.net//biggrin.gif

...or maybe Kitcat has it nailed down! (BTW, I'd think the same would hold true for a women. http://bbs.homeshopmachinist.net//wink.gif )

KitCat
05-06-2003, 08:28 AM
Thanks lynnl, for your last sentence. Didn't mean to cause confusion, just putting in my opinion. http://bbs.homeshopmachinist.net//smile.gif