WM210V how to cut perfect threads

[weston1968]

The machine as shipped is not well set up for cutting threads. I think it can be made to do both metric and Imperial well. If you use a threading dial and mount an end stop on the bed to the right of the carriage you should be able to cut threads. The end stop allows you to accurately place the carriage at the same spot after every pass. The threading dial allows you to cut from the same spot on the lead screw every time.

The correct way to cut the threads is advancing the carriage at a 29 degree angle so as to only cut one edge at a time.

The problem is that although a threading dial is available for sale you have to modify the machine. No end stop exists.

I have ordered a threading dial which has a gear that sits on the feed screw and is connected to an indicating dial. I will print a plastic adapter that does not require modifying the lathe, I will also print out an end stop. After verifying that this does what I think it will do I will order parts from a machine shop.

If you use an end stop to position the carriage at exactly the same place on return after each pass, then wait for the threading dial to come to 0 and then engage you should be starting your thread at the same position on the feed screw regardless of the thread.

My dial is divided into 16. I will have to put a 16 tooth gear to follow the lead screw. Every mark on the dial will have the lead screw in the same position. One turn of the lead screw moves the dial to the next tick.

I was not clear and have edited this post

If there is any interest I will order parts for sale.

 

[RJSakowski]

Unless you are referring to something different., thread chasers are not intended for cutting new threads. They are used to restore damagerd threads. Also, just setting a stop on the lathe won't ensure that you will start at the same place on the thread as this also depends on the spindle angle. This is why lathes have thread dials, to make sure that you maintain the relationship between spindle and the lead screw and the lead screw and the carriage.

 

[WobblyHand]

Unless you are referring to something different., thread chasers are not intended for cutting new threads. They are used to restore damagerd threads. Also, just setting a stop on the lathe won't ensure that you will start at the same place on the thread as this also depends on the spindle angle. This is why lathes have thread dials, to make sure that you maintain the relationship between spindle and the lead screw and the lead screw and the carriage.

I found a reference to what is called a thread chasing dial, which is what you and I know as a threading dial.

To cut threads with a metric lead screw one can use a specialized thread dial that has different gears, for different thread pitches. This is unlike using an imperial lead screw with a thread dial. The imperial lead screw thread dial combination allows practically any TPI thread to be synchronized, so we can engage and disengage the half nuts. On an metric lead screw, there is no one dial or single worm gear that will allow all combinations. If one changes gears on the thread dial assembly, then some small subset of pitches can be used with engaging and disengaging the half nuts. All other pitches can only be done, if one has the right gear, or one leaves the half nuts engaged the entire time while threading. As far as I know, if one has a metric lead and wants to cut an imperial thread, then the half nuts have to be engaged all the time.

 

[RJSakowski]

I believe that thread chasing is an archaic term for thread cutting but what is sold as thread chasers nowadays are retreading taps or dies.

 

[WobblyHand]

I believe that thread chasing is an archaic term for thread cutting but what is sold as thread chasers nowadays are retreading taps or dies.

It was the first that I heard of it, and had to look it up. Thread chasers nowadays, at least in the US, are as you say.

I searched on "thread chasing dial on lathe machine" and was able to glean that it was a thread dial.

Also searched on "can one use a thread dial for metric threading" to learn that it is possible to have a thread dial work on metric lead screws cutting metric pitches. All that said, it seems like it is not that easy to do, since one needs to swap gears on your thread dial to do some pitches.

Personally, faced with that situation, it would motivate me to look into an ELS.

 

[weston1968]

Unless you are referring to something different., thread chasers are not intended for cutting new threads. They are used to restore damagerd threads. Also, just setting a stop on the lathe won't ensure that you will start at the same place on the thread as this also depends on the spindle angle. This is why lathes have thread dials, to make sure that you maintain the relationship between spindle and the lead screw and the lead screw and the carriage.

I am probably using the wrong term. It is a dial connected to a gear that rides on feed screw. When it rotates to the top and the carriage is at an end stop it will always cut the same

 

[weston1968]

I found a reference to what is called a thread chasing dial, which is what you and I know as a threading dial.

To cut threads with a metric lead screw one can use a specialized thread dial that has different gears, for different thread pitches. This is unlike using an imperial lead screw with a thread dial. The imperial lead screw thread dial combination allows practically any TPI thread to be synchronized, so we can engage and disengage the half nuts. On an metric lead screw, there is no one dial or single worm gear that will allow all combinations. If one changes gears on the thread dial assembly, then some small subset of pitches can be used with engaging and disengaging the half nuts. All other pitches can only be done, if one has the right gear, or one leaves the half nuts engaged the entire time while threading. As far as I know, if one has a metric lead and wants to cut an imperial thread, then the half nuts have to be engaged all the time.

If you use an end stop to position the carriage at exactly the same place on return after cut, then wait for the threading dial to come to 0 you should be starting your thread at the same position regardless of the thread.

 

[weston1968]

It was the first that I heard of it, and had to look it up. Thread chasers nowadays, at least in the US, are as you say.

I searched on "thread chasing dial on lathe machine" and was able to glean that it was a thread dial.

Also searched on "can one use a thread dial for metric threading" to learn that it is possible to have a thread dial work on metric lead screws cutting metric pitches. All that said, it seems like it is not that easy to do, since one needs to swap gears on your thread dial to do some pitches.

Personally, faced with that situation, it would motivate me to look into an ELS.

If you use an end stop to position the carriage at exactly the same place on return after cut, then wait for the threading dial to come to 0 you should be starting your thread at the same position regardless of the thread.

 

[MrWhoopee]

An end stop (carriage stop) is not necessary for threading. As long as the threading dial is in the correct position when the half-nut is engaged, the position of the carriage is irrelevant, the cutting tool will be in sync. This applies to cutting inch/imperial threads on a lathe with an inch/imperial lead-screw. It does not apply to cutting metric threads on an inch/imperial lathe. I can't speak to metric threads on metric lathes. Suggest you watch more you-tube videos on single-point threading.

 

[benmychree]

Mr Whoopee said it all, a stop is completely un necessary for threading with an inch lead screw, only the thread dial is needed. For metric threading on an lathe with an inch lead screw, the half nuts cannot be disengaged, the lathe must be reversed and the tool backed up to the starting point.