Metric Threading with an Inch Lead Screw

welcome back doc stools on so um tonight we got kind of an interesting experiment that we're going to do the other day when I started working on this x-ray transformer plug which was a 18 millimeter by one thread pitch that we're going to single point in the lathe I made the comment during the video that when you're cutting metric threads with a lathes with an inch lead screw you need to keep the half nuts engaged during the whole threading process well technically this is true um there is a practical way actually to disengage the half nut and I'll allow you to run up to a shoulder and disengage a half note so it's actually a practical solution to the problem this was a pointed out to me by a viewer and I'll post the link to the the article at the end of the video here so you guys can read the article that he he put a link up to um in in this case I do have to run up to a shoulder so it's a bit of a problem to stop the machine and pull out of the thread all at the same time well this is actually a very practical solution to the problem so what I want to do is I want to demonstrate that I tried it already and it works wonderfully seems to work wonderfully so I'm going to we'll go over to the lathe we're going to cut the past thread and I'll show you a couple different shots of the the half nuts and the practical application of this this technique and I have to say this is just what I love about this this whole process is that I've been doing this stuff for years and I still learn stuff all the time so this is a great little a great little trick and it never even crossed my mind try this you know usually you want to get in there just get the job done you know when you're you're you're getting paid to do the work you just get it done the way you know how the quickest way so you don't always have the opportunity explore different ideas well here in my play shop I get to try that kind of stuff and it's great so let's pop over to the lathe and we'll get the blank set up and we'll go through that process and I'll demonstrate this metric threading with an inch lead screw okay so here's our victim here it's just a piece of bronze rod and so I'm going to prepare the blank kind of like I did for this one so this is the little sample piece that I tried and I disengaged the half nut with this technique multiple times and the thread came out nearly perfect so and I wasn't trying very hard I just wanted to make sure that I got the moves down so let's let's prep this blank here I'm going to cut a thread relief in this particular one here let's uh let's go to there you you in this case we don't really care about the diameter we just want to try this just reading techniques I just want to turn it nice and round that leave we will back champ for this you up in this is reading too long all right so let me I'm going to change the the settings here let's see what I want here let's do 200 rpm something like that see that looks like alright verify my gearbox settings eh okay so that should be one millimeter pitch there okay so um let's see how should I show this here I think what I'll do is I'll come down to the I'm going to come down to the chasing dial here and show you the chasing dial on the first engage and then we'll come back to this okay okay so here we're looking at the the thread chasing dial and then this is the half net lever here so what we're going to do is we're going to start on just because it's easy to remember here we're going to start on line one and I want to mark it it's easy enough to see it okay so I'm going to start the lay then I'm going to engage the half knot when the one line comes up to the pointer here okay and that'll be my first pass my first pass it'll be a scratch pass here I'm just going to go in a couple of thousands and it'll be my scratch pass to confirm my my gearbox settings okay but we're going to use the same technique when we come out and you'll see that in just a sec okay so here we go and you'll watch okay so we're coming around to one and then when one comes up I'm going to engage the okay so now we're getting ready we're threading here we go there it goes and when I come up to my relief I'm going to pull out and I just very calmly stop the machine so I release the lever okay I came up to my thread relief okay and they just very calmly release the lever and you can see that I've overshot here now here's the trick part is I backed out now I'm going to put it in reverse okay putting into reverse and you see it's coming up the one again well I'm going to re-engage and come out now so technically I'm in the same groove okay all right so now what we're going to do we're going to do that again just so you guys can see it so now well okay mr. wizard check the thread pitch okay that looks good all right so we're going to come in and we're going to do another let's go into ten thousandths okay all right we're going to so now I'm engaged again I'm engaged in line one right so here we go our second pass there's the cut is tracking disengage stop the machine and I backed out okay I'm clear now I'm going to come back reverse re-engage and I'm coming back out okay so what's going on here is I'm still in groove one okay even though I've been engaging and disengaging the half nut the trick is that we're not moving the carriage in between okay and we're using this to track where we were okay so now let's maybe come up on top let me I'm going to do that one more time okay and then I'm going to come up on top and you can actually see the cut let's go back in let's go to 15 okay all right and here we go cutting and it's tracking beautifully disengage pull out stop the machine you know technically that there's no reason to stop the machine in a hurry as long as I don't do multiple revolutions right okay so I'm clear make sure reverse re-engage and come out and I can just let it coast to a stop and when I come back out because there's nothing in the way okay so let me change the camera around we'll come back up on top and you guys can see it from the top side okay so here we go I'm going to come in let's see my last cut was at 15 I'm gonna go to 20 okay alright my half nuts engaged and so we're just going to go ahead and as soon as I fire up its going to start it's going to start tracking okay there it goes and you can see I went right back in the groove so I'm going to come out i disengaged my half nut and I want to make sure I back up so that I'm clear and now I'm going to reverse and drop back in with the half nut okay and there are tracks on the way out okay like the 20 let's go 25 okay skip hold up lubrication there okay so I'm clear all right I'm going to go in Reverse greengage back back out okay and one more time remember where I was let's go to 30 just because they don't even have there's no rush okay there's nothing exciting you just got to get the sequence down okay and and not get confused greengage in my line I'm back out and all is good okay okay so let's show it from a little farther away this time so my last pass of the 30 I'm going to go to 40 okay half that's engaged we're on line one and clear the part okay and UCI coasted a little bit past and I'm disengaged now okay reverse reengage and we're 40 before let's do 45 okay one let's take 50 okay let's we'll come back up here for one more view up here as the threads pretty much the depth now pretty close anyway and we'll get a look at it and I think that's it yeah clear out of there okay so there's our kick it in the neutral there there's our thread and have a rag handy anyway yeah you can see that obviously it tracked well and it came out real nice so the technique works it's just the sequence so try it out so now you can you can thread with an inch lead screw laid up to a shoulder without danger of crashing into the shoulder or doing anything bad that way you just got to remember yes you still have to stay on the same line but you can temporarily disengage it so that's the key here okay so that concludes this uh this little demonstration of this new thing that I learned anyway I'll post a link like I said the the article where you guys can can read the whole article for yourself anyway like I said this is what I love about this kind of stuff is people post things and from other sources and and old dogs can learn new tricks and anyway thank you guys very much for posting the posting the link now I have a new tool in my toolbox and you know how much I love tools so thanks for watching you

Channel: oxtoolco

Views: 147,815

Keywords: Metric Threading, Lathe change gears, Half Nut, Inch to metric thread, Metal Lathe, Inch lead screw, How to thread on the lathe, Tom Lipton, Oxtool, Nothing too strong ever broke, Screw Thread, Leadscrew

Id: HXt4TWa382Q

Length: 16min 6sec (966 seconds)

Published: Fri Apr 25 2014