Looking for tips on three wire thread measuring

I use electrical tape to hold the wires because it is much more flexible than other types of tape. I lay all three wires on one end of the tape, side by side, then remove the middle wire and set it on the other end of the tape. Fold it to hold the wires, and then you can hold them with one finger while they drape over the threads. Digging around in the chip bed looking for a piece of .040 wire is a bad way to spend an afternoon.
 
Hello,
After forty-five years, in large and small shops, I, have found the old three wire method, to have the most flexibility, and best value. Thread mics, do have limitations, as far as pitch range, and dia. You can measure threads from #4-48, to whatever you have the mics. to measure. Using a stub, barrel shank, as a gage, will work when the thread is to the proper pitch dia., but does not tell you when to start taking smaller cuts.
The easiest, and only way that I, was taught to use wires, was to loop a rubber band aroung each end(double if needed)
Then place 1 wire between the left thumb, and index finger, the other 2 wires, go between the right thumb, and index finger. Place the single wire, on the top, and the 2 wires, below the shank. These will for a triangle, when properly placed.
After some practice, you will feel the anvil seating on the bottom wires, as the spindle is tightened slowly. A combination,
of lateral movement, and rocking over the crest, will get the job done.
Regards,
Bob
 
Cut-and-Try fit to specific action

I was under the impression that a lot of smiths thread the tenon to achieve their custom or desired fit to the action, rather than have the goal of cutting a thread that would conform to Machinery's Handbook, for the sake of having a standard thread------basically use the action as a try-nut.

I've watched a pretty good machinist use the 3-wire measurements to warn him that he was getting close----and then finish with repeated cut-and-try cycles with the action until he got the fit he wanted.

I understand the value of a thread that conforms to standards but also like the idea of a custom fit to a specific action.

A. Weldy
 
Lucky,
What you describe, is quite probably the best way, to a happy ending. IF, you know the pitch diameter, of the internal thread, you can be quite safe, in working to finish, without the receiver, in hand.
In most cases, you are told 1.062"x 16tpi. In that case, you grab the pack of thread wires from your box, and refer to the chart, which tells you which size wires to use, along with an add factor, which is the dimension, that is added to the basic major dia. of the thread. to determine the target dimension, with the wires in the thread grooves. If the threads, are chased, then there is no guarantee, of the internal major dia.,pitch dia, or fit, without getting close, and then creeping up, as you described.
Where the Machinery's Handbook, really shines, is in working with a special thread, having an odd major dia. and/or pitch,
multiple lead combination. It will help you establish the pitch dia., best wire size, and reading over the wires. If you, do not have the best size wire, you can work to a solution, with the closest wires, in your box, and other formulas available.
Regards,
Bob
 
Cut a piece of 1/4" thick rubber or neoprene 1" square.Then drill 3 holes the same size as your wire approxamately the same center distance as the desired pitch diameter and thread pitch.Push the thread wires into the rubber about 3/8' deep. It's an easy,cheap and quick way to hold the wires.
 
Each time I see this thread I want to laugh, why would anyone want to mess around with thread wires when mics are available? For those who are not trusting in mics, may I ask what won-hung-lo brand you have? Why not just buy the mics, buy a set of standards, and measure the threads? I don't get it.

There's all this conversation above going as far as one person saying mics are a pos. I wonder how many of these guys are saying this while measuring the wire dimensions with a pair of calipers. It would really make me laugh if someone was doing so with digital calipers! Now there's a pos for ya. Ya know, the junk that needs re-zero'ed every time you pick em up? Yea, those.

Next, we have a myriad of advices above, yet nobody has mentioned how the slop in the threading drive on the lathe in question affects the pitch. Hmmm... You might say that's unimportant, but several above seem to think wires >= mics. So, lets remember mics already factor that error, and the helix angle error into the final number.

Lastly, there's the ones above who say measure with wires to get close, then measure with the stub and the receiver. Well, if you're ultimately gonna measure with the receiver, wth do I need the wires for? A blind man can eyeball that.

PS. Machineries handbook also mentions the advantage to measuring over balls vs wires... Just before the part about measuring thread angle error with wires. They also have an entire section on understanding the errors involved with the 3 wire method. Alright, so if you're gonna now say we don't need to bother with the involute helicoid formula, then wth is wrong with using mics? Doesn't seem to matter what angle I look from, about the only thing I can see wires being good for is saving someone money on buying thread mics >2"
 
Yes, it is a money thing. If I were equipping a commercial shop, that would be one thing. I am not. What I would like to be able to do is measure, record and communicate the dimensions that relate to barreling in a manner that is reliably reproducible. I have the mic., and some wires. The reason for the thread is that it did not take me long to recognize that I could really benefit from some insights into technique, which posters have so kindly provided. Thank you all, and anyone else who adds to the collection.

The next goal is to come up with a depth mic. and a tube that has a little longer than the distance from the back of a go gauge to the face of a barrel shoulder, and which has an ID that is a little larger than the largest 1.0625 tenon that I will encounter, with ends that are square to the ID.
 
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Guys, I can take a small set of outside spring calipers, (yes, spring calipers), match the pitch diameter of a tenon thread to one just like it to within .001.

Of course, I have idea what "size" it is, but the object is to match it to an existing tenon.

Of course, if I am required to produce a thread off of a print to an exacting tolerance and class of fit,, I will use thread wires.

Ever measured a 12 inch diameter 2 tpi with wires. Grease will not hold them in place.:D
 
Boyd Allen said:
Yes, it is a money thing. If I were equipping a commercial shop, that would be one thing. I am not. What I would like to be able to do is measure, record and communicate the dimensions that relate to barreling in a manner that is reliably reproducible. I have the mic., and some wires. The reason for the thread is that it did not take me long to recognize that I could really benefit from some insights into technique, which posters have so kindly provided. Thank you all, and anyone else who adds to the collection.
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Boyd, I'll accept the cost as a determining factor if someone isn't going to measure many threads. Or, as I said earlier, if you're talking about a particular range of threads you won't do often, such as 2" or greater. Most of us don't do many of them, and even if we do, they are not done to a tolerance that justifies going overboard with the tools. Jackie mentions the 2tpi thread, but, that 2tpi thread has a LOT of tolerance on the PDs, vs 1-1/16 x 18. If someone wants to use them that's fine by me. I just don't want to sit and hear how they're "better" (cause they ain't).

The next goal is to come up with a depth mic. and a tube that has a little longer than the distance from the back of a go gauge to the face of a barrel shoulder, and which has an ID that is a little larger than the largest 1.0625 tenon that I will encounter, with ends that are square to the ID.
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Bore a hunk of alum, face it nice, and do a cutoff with a tool ground to be sharp pointed on the right side of the tool. Do that all in one operation, chamfer both ID's so it doesn't sit on your tool radius, and so there is no burr on the cutoff side, and you're done.
 
4mesh,
Normally, I, would ignore the noise that you make, but today I, will make an exception. If you live in a small world, where the only thing that you thread are barrel shanks, with 16tpi, and you are too clumsy to use a set of thread wires, thread mics, will do the job. As to your remark about using digital calipers to measure larger dia. threads, if that was aimed at me,
I, have a set of Starrett#226, & #436 mics w/ carbide faces. Both are 0-6". I, also have a set of Starrett #445 depth mics
5" base 0-15", with a set of Starrett half base depth mics 0-6", that are surface ground to match the 5" set. The 0-6" rods
are ground to a conical end. I, also have Starrett 2.5"-12", and 4"-40" inside mics, and Starrett 0-24" vernier calipers, for the really large threads. Let's go to indicators: 2-Interapid .0005", agd#2 dial indicators 0-.5", in .001", .0005", .0001", and a 0-.5"x.0001" reverse acting indicator, for testing the reverse face of a mold part with a tolerence of +.0005"/-0.0000".
I, have made a lot of thread blocks, which mold the neck details, on plastic bottles. Those threads are milled into the cavity, using a form ground carbide cutter, which must be tilted to match the helix angle of the thread.
I,was helping a local gunsmith, when I, was seventeen, by threading 10"-15" sections, of rifle barrels, to fit H&R 922 revolvers, and adding Williams sights, for the local coon hunters.
Do you have any more funny remarks to make?
Regards,
Bob
 
Bob,
Looks like your tools are about the same as mine. I also have 2 surface plates and Etalon mics to 10", but mine is just a hobby shop.
Butch
 
Chip Soles said:
4mesh,
Normally, I, would ignore the noise that you make, but today I, will make an exception. If you live in a small world, where the only thing that you thread are barrel shanks, with 16tpi, and you are too clumsy to use a set of thread wires, thread mics, will do the job. As to your remark about using digital calipers to measure larger dia. threads, if that was aimed at me,
I, have a set of Starrett#226, & #436 mics w/ carbide faces. Both are 0-6". I, also have a set of Starrett #445 depth mics
5" base 0-15", with a set of Starrett half base depth mics 0-6", that are surface ground to match the 5" set. The 0-6" rods
are ground to a conical end. I, also have Starrett 2.5"-12", and 4"-40" inside mics, and Starrett 0-24" vernier calipers, for the really large threads. Let's go to indicators: 2-Interapid .0005", agd#2 dial indicators 0-.5", in .001", .0005", .0001", and a 0-.5"x.0001" reverse acting indicator, for testing the reverse face of a mold part with a tolerence of +.0005"/-0.0000".
I, have made a lot of thread blocks, which mold the neck details, on plastic bottles. Those threads are milled into the cavity, using a form ground carbide cutter, which must be tilted to match the helix angle of the thread.
I,was helping a local gunsmith, when I, was seventeen, by threading 10"-15" sections, of rifle barrels, to fit H&R 922 revolvers, and adding Williams sights, for the local coon hunters.
Do you have any more funny remarks to make?
Regards,
Bob
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Yea Bob, plenty. Should we all inventory our toolboxes now? Ewww... No doubt, I have a lot more than many, and less than others. Pretty much like anyone. Maybe we should all tell what difficult threading jobs we've done? Hmm?
As to your remark about using digital calipers to measure larger dia. threads, if that was aimed at me,
Click to expand...
Yer really sharp there Bob. :rolleyes: Are you the one who said thread mics are a pos?

Unless you work in an industry where you do really large parts, threads of greater than 2" imo, then I say, wires are a pain in the ass. Waste of time. For big stuff, they make sense. But barrel work doesn't fall into what I call big. The only other way I'd use them is if I rarely threaded a part, and that ain't the case for me. And see, I had to spell that out for ya cause you couldn't catch it the first x times I said it.
 
4Mech: Are you one that holds tolerance to the magic zero when setting up a barrel? Hold's a tolerance of .0001 at the kitchen table when turning neck's? Over-haul's, and accurize's powder scales? Now your threading barrel's by feel. When you have a thread that won't screw together; Is it the barrel shank, or internal thread that is to tight? Is the thread botteming in out at the root? Are the thread's truly 60 degree's included angle? Are the tread's 90 degree's to the tool? Do you set up the threading tool using that funny looking little fish shaped scale?
 
4mesh,
The originator, of this thread, asked for pointers, on the best way to use thread wires. At no time did he ask for your ultimate opinion, about the proper tool for the job. I, did attempt to answer his question, and bring out some of the limitations of thread mics. If you think that I, called your choice of tools, as you say a POS, then your skin is too thin to work around people. When you get on your stage to talk about laughing at other peoples methods, when you are
totally ignorant about what they know, or want to accomplish, you sir, are over the line of decency. If you prefer to use
thread mics, and your work load, justifies the extra expense, by all means do continue to march down your path. Do not expect all the world to follow you. As has been said many times;"Opinions are like A__ holes, everyone has one, and a lot of them stink."
Regards,
Bob
 
Boyd: I am not even sure what that scale is called, so I looked it up. It is called a 60 degree center guage. It is a very cheap guage to set up the tool angle at 60 degree's encluded angle, and set the work in the lathe at 90 degree's to the tool. 4Mesh would want this tool to set a handle on a outhouse door.
 
Boyd Allen said:
Getting back to simple questions (from a simple guy) "funny looking fish shaped scale" ????Please explain.
Boyd
Click to expand...
I believe he's referring to a profile gauge that you use to set the proper angle on the tool, and in some cases might use it as a guide for grinding as well. Ya hold it up to the light with the tool in it and you can see what direction you still need to go to get the tool angle proper. However, it's hard to tell what he's referring to.

For both of you, who have now repeatedly read something I didn't write, you should really go read the thread if you want to dispute parts of it. Yes Bob, I fully understand you attempted to help. If you care to read back, you will notice that you are the one who addressed me when I never referred to anything you wrote. Other than if you cared to group yourself with the people who are fitting by feel. And while I have no problem with someone doing that, I don't then understand the reasoning for measuring with wires, mics, or anything else, if they're not going to use the measurement anyway. This is my point. Well, one of them.

Above, it is Mr Johnson who said....
B.Johnson said:
A thread mike is a piece of ___ compared to wire's. You really need to go back to manual training 101.
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Post #17. Now, the word that was removed by the forum software is pretty easy to guess. There's not a lot of options. So, then after reading that, I am confused as to what a pair of thread mics might have as a fault to make them a POS vs wires?

The trouble with people responding to a thread they didn't read is becoming obvious. And, it's difficult for me to convey what I say, without retyping the whole damn thing for you guys who somehow read whatever it is you wanted to.

In any case, yes Bob, the world is sorta following. Consider that most people who do any amount of threading will go purchase the tools to do it most easily. Clearly, you have purchased a tool or two, so it seems that eventually when a need arose, you got the tools you needed to do particular jobs. I bet you don't use your set of mics from 4-12 near as much as the ones that are smaller. I certainly don't. (Yes, I have em up to 12" too, with standards!). A set of thread mics costs about as much as a trip to a shooting match. I don't think it's unreasonable to think that a person who buys a lathe, wouldn't want a set. Seem reasonable? Especially if you consider that most of these lathes the guys here are talking about are not ever going to work on huge parts. 0-2 should cover about every threading job they'll ever touch. And 2 sets of anvils would be sufficient as well.

Yea, wires are all fun to play with at first, and they're a necessary evil sometimes. But, consider this. For all the threads here on BRC about thread wires, take note there's no corresponding thread for how to use a set of thread mics.
 
Thread mike's: I'll bet they read on the pitch line. If the lathe is set properly to allow such a thing.
 
4mesh and chipsoles, I believe if you both visited face to face you would find a common ground. You both have made a chip or 2. I have thread mics to 2" and a set of wires. As I stated before I use action inserts as my go gauge. I do not want a sloppy thread, but certainly not a tight one. I want the barrel to fit and tighten square to the receiver. I don't want a too tight thread keeping that from happening.
This thread to me is like trying to straighten a crooked bore with a setup. It don't happen. You do the best that you are capable and then you will be much better off at the range practicing.
Butch
 
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