Chasing perfect threads in the home workshop

[@allengentz7572]

Thank you so much for your information well described that an old head could absorb, Please continue to help out those of us who are making a late start into this great Hobby .

[@Lukers_tinkering]

Will do, thanks for the positive comment!

[@michaeleykelhof3377]

Thanks Luke I'll try your chasing method for internal threads as i always tend to struggle with it

[@Lukers_tinkering]

Make sure the height is correct, that's the only tricky part... Let me know how it goes!

[@aceroadholder2185]

Good stuff. Your handbook will give you the correct size for the thread major diameter for the thread being cut. If you are doing work for someone else, always check to see that the thread pitch diameter is correct with the three-wire method or a go/no-go gage (if you are lucky enough to have one for the thread being cut). The nut you got at the hardware store doesn't guarantee that what you made will fit what they have. When setting up the lathe to cut threads there is one change in the order of operations I would make vs. what was shown in the video. Bring the cutting tool up close to the work and stop when the cross-feed handle is at about the 10:30 position and set the cross feed dial to zero. Then bring the compound slide up to the work and set it to zero. Doing this allows you to snap the thread cutting tool out of the work and you can easily cut threads at a higher rpm (e.g. 200rpm). I usually don't bother cutting any thread relief and just pull the tool out of the work on each pass. Do it a few times and you will see that it is pretty easy to do. The higher rpm actually makes this easier to do. If you are cutting fractional inch threads (e.g. 11 1/2 tpi) or metric threads where you can't disengage the half-nut on an imperial lathe with a thread dial there is a trick you can use. When threading to a shoulder the trick is to snap the tool out of the work, open the half-nut, and cut the power and let the lathe coast to a stop. Notice that your mark on the thread dial hasn't moved much past the set mark. Reverse the lathe and when the mark comes back to the correct spot, re-engage the half nut and back the carriage up to the start position for the next cut. Cheers from NC/USA

[@madmodder123]

You should make a video about clocking threaded parts to certain positions by calculating how much to sand off one end or shim with a precision washer

[@Lukers_tinkering]

Ok, need a little more info on this method, can you elaborate?

[@madmodder123]

@@Lukers_tinkering Here's my notes on it, let me know if you need some more info :) Imperial Threads: 32 TPI (Threads Per Inch) Example: 1 inch divided by 32 = 0.03125" per revolution Or .03125" for every 360 degrees ( 1 revolution ) .03125" divided by 360 (degrees) = .0000868" For every .0000868" you remove from one of the mating faces, you will get a +1 degree rotational change If you need to clock forward +45° it would be 45 x .0000868 = 0.003906" (or -45° if adding a washer of that thickness) Metric Threads: It's easier in metric as the pitch is expressed in terms of travel on the thread. If you need to clock a thread back 45 degrees you need a washer with a thickness of (45/360) × pitch. Or to clock it forwards you can trim off part of one of the mating faces. M5x0.8 Example: Angle Needed (45) divided by 360 = 0.125 0.125 multiplied by pitch (0.8) = 0.1mm washer (for - rotation) or 0.1 trim (for + rotation)

[@madmodder123]

@@Lukers_tinkering Here's some notes, let me know if it helps Imperial Threads: 32 TPI (Threads Per Inch) Example: 1 inch divided by 32 = 0.03125 per revolution Or .03125 for every 360 degrees ( 1 revolution ) .03125 divided by 360 (degrees) = .0000868 For every .0000868 you remove from one of the mating faces, you will get a +1 degree rotational change If you need to clock forward +45° it would be 45 x .0000868 = 0.003906" (or -45° if adding a washer of that thickness) Metric Threads: It's easier in metric as the pitch is expressed in terms of travel on the thread. If you need to clock a thread back 45 degrees you need a washer with a thickness of (45/360) × pitch. Or to clock it forwards you can trim off part of one of the mating faces. 0.8mm Pitch Example Angle Needed (45) divided by 360 = 0.125 0.125 multiplied by pitch (0.8) = 0.1mm washer (for - rotation) or 0.1 trim (for + rotation)

[@madmodder123]

@@Lukers_tinkering YT keeps deleting my comment :(

[@madmodder123]

Imperial Threads: 32 TPI (Threads Per Inch) Example: 1 inch divided by 32 = 0.03125 per revolution Or .03125 for every 360 degrees ( 1 revolution ) .03125 divided by 360 (degrees) = .0000868 For every .0000868 you remove from one of the mating faces, you will get a +1 degree rotational change If you need to clock forward +45° it would be 45 x .0000868 = 0.003906" (or -45° if adding a washer of that thickness) Metric Threads: It's easier in metric as the pitch is expressed in terms of travel on the thread. If you need to clock a thread back 45 degrees you need a washer with a thickness of (45/360) × pitch. Or to clock it forwards you can trim off part of one of the mating faces. 0.8mm Pitch Example Angle Needed (45) divided by 360 = 0.125 0.125 multiplied by pitch (0.8) = 0.1mm washer (for - rotation) or 0.1 trim (for + rotation)

[@gertjevanpoppel7270]

Also a myth is that when single point threading on a lathe that the compound must be at a angle ( 29,5 degrees for example). This is not necessary and I found that it depends on how you learned it. I learned cutting thread by using the parallel method. Most people who learned threading by setting the compound on a angle are convinced that using the parallel method will ruin the thread or it is less accurate. They don't know that when cutting thread in the parallel method that by every infeed off the compound we also move the compound a little bit perpendicular to the workpiece. And there are charts for this that will show you for every infeed how much you move the cutter perpendicular. Using these 2 steps your cutter ends up at the same point as when you move the cutter with the compound on 29,5 degrees.😀 Imagine a triangle with a angle of 29,5 degrees , there are also 2 sides on the triangle that are at a 90 degree angle. These 2 represents the movement of the cutter when using the parallel method 👍😀.

[@Lukers_tinkering]

The parallel method also works but keeping track of feeding on dials becomes cumbersome. The angled taper slide method is easier to follow because you feeding only one dial and only in advance, everything else goes back to zero. The parallel method also becomes difficult if you cut as many different thread types as I do. If you only cut metric then its a little easier. I also don't understand the 29,5Deg story, for one, the increments on the taper slide aren't that accurate, and setting to the correct angle gives perfect results as shown in the video, with two different methods on a very fine thread cut? Thanks for the comment!

[@troutfitter547]

Thank you, I really enjoyed the video!