12-06-2016, 06:30 AM
Hi Sean,
The pitch of your leadscrew doesn't matter when you are threading or feeding, as the gearbox has been set up with these parameters already. All you need to know is what pitch thread you wish to cut, or the feed rate that you wish to use. I'm actually going to dumb it down a little and define both of these. I apologise if you already know this.
Threading is the process of cutting a thread into the work (either external or internal) using (most commonly) a single point tool. The tool is ground to give the thread type (60° US or Metric, 55° Whitworth, 29° ACME etc). Threading is done using the leadscrew, which is the long ACME threaded bar that runs from the gearbox to the end of the lathe bed. You engage the half nuts to move the tool at the right speed to cut the selected thread.
Feed is when you use the gearbox to move the tool across the work when turning, boring, facing or parting. The saves you from having to manually wind the handles and gives a much better finish. You lathe may use the leadscrew to do this (in which case there will be a slot running the length of the leadscrew) or it may have a separate shaft. I'm guessing your lathe uses the leadscrew. You will have a different lever or knob on the apron to set the feed and another to set whether the feed is longitudinal (z axis) or transverse (x axis).
There are lots of videos on YouTube that will show this in action and I recommend Tom's Techniques (even though he does talk funny
).
I've taken the liberty of taking your original picture and showing the settings to thread 10tip and 32tpi threads, as well as to set a .005" longitudinal feed rate. Some of us are visual learners and can read a book until we are blue in the face whilst seeing it once makes absolute sense, so I hope this is helpful.
Setting for 10tpi
Setting for 32tpi
Setting for .005" feed
Don't - we all had to start somewhere and it is best to ask than jump in and do some damage!
The pitch of your leadscrew doesn't matter when you are threading or feeding, as the gearbox has been set up with these parameters already. All you need to know is what pitch thread you wish to cut, or the feed rate that you wish to use. I'm actually going to dumb it down a little and define both of these. I apologise if you already know this.
Threading is the process of cutting a thread into the work (either external or internal) using (most commonly) a single point tool. The tool is ground to give the thread type (60° US or Metric, 55° Whitworth, 29° ACME etc). Threading is done using the leadscrew, which is the long ACME threaded bar that runs from the gearbox to the end of the lathe bed. You engage the half nuts to move the tool at the right speed to cut the selected thread.
Feed is when you use the gearbox to move the tool across the work when turning, boring, facing or parting. The saves you from having to manually wind the handles and gives a much better finish. You lathe may use the leadscrew to do this (in which case there will be a slot running the length of the leadscrew) or it may have a separate shaft. I'm guessing your lathe uses the leadscrew. You will have a different lever or knob on the apron to set the feed and another to set whether the feed is longitudinal (z axis) or transverse (x axis).
There are lots of videos on YouTube that will show this in action and I recommend Tom's Techniques (even though he does talk funny
).I've taken the liberty of taking your original picture and showing the settings to thread 10tip and 32tpi threads, as well as to set a .005" longitudinal feed rate. Some of us are visual learners and can read a book until we are blue in the face whilst seeing it once makes absolute sense, so I hope this is helpful.
Setting for 10tpi
Setting for 32tpi
Setting for .005" feed
(12-05-2016, 01:22 PM)Seanlogie Wrote: ...now i feel like a dork...
Don't - we all had to start somewhere and it is best to ask than jump in and do some damage!
Hunting American dentists since 2015.