aligning a welded-on nut with existing threads?

I'm making up a weldment in which the design calls for a continuous 2" of internal threading. About 3/4" of it will be a threaded hole, and the rest will be part of a rod coupler nut. I don't want the threads to bind. What I'm thinking is to drill the 3/4" deep hole as though I were going to tap it, then make up a scrap screw with the end 3/4" turned down to be a slip fit into the tap hole, then use the scrap screw as an alignment tool to hold the coupler nut centrally, clamp it tightly, weld it up, then remove the part to the hand tapper and chase the threads in the coupler nut and use those to guide the tap to cut the threads below.

I would just drill and tap the 3/4" hole and run my scrap screw in and screw on the coupler nut, clamp it and weld it, but I've seen enough pieces move "just a little" when welding to be leery. I don't want these threads to bind.

The threads are 5/8-11 so if they do bind, it could be really difficult to fix.

Ideas?

GWE

Reply to
Grant Erwin
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Can't offer any better suggestion than what you have already come up with, Grant. Sounds like a good plan for a good result. Good luck - let us know how it worked. Ken.

Reply to
Ken Sterling

Turn the hex off of the coupling nut for 3/4" , bore the hole in the plate to a good fit on the nut, insert the nut and weld? Do you need the full 2" of thread? can you just clearance the plate and use the threads in the nut? Your idea sounds workable but I think that I'd turn off just a bit more than the 3/4" needed to align. Turn up high enough so that the weld distortion doesn't bind up the threads on the alignment screw. Make sure that you have room to get a tool on the alignment screw so that if it does bind you can get it out . Might even consider threading the small end of the alignment pin so that you can put a nut on it to pull the coupling nut up tight to the plate. lg no neat sig line

Reply to
larry g

How about welding the coupler nut in place first and then drill the pilot hole in the 3/4" stock using the coupler nut as a guide and then finally run the tap through the coupler nut and through the 3/4" piece? Might need a tap extension, but doing it in that order should insure everything is in alignment.

Pete C.

Reply to
Pete C.

Why not use a coupler nut two inches long and weld it into a hole in the plate? The weld will shrink the thread at one end of the nut but that can be chased out with a tap. I am guessing at something like a one inch hole diameter? Randy

I would just drill and tap the 3/4" hole and run my scrap screw in and screw on the coupler nut, clamp it and weld it, but I've seen enough pieces move "just a little" when welding to be leery. I don't want these threads to bind.

The threads are 5/8-11 so if they do bind, it could be really difficult to fix.

Ideas?

GWE

Reply to
R. Zimmerman

Have a design review with the requestor.

3/4" of thread will contribute about zilch to the strength beyond the 1.25" thread length of the coupler nut with 11 pitch thread.

Make a clearance hole in the 3/4" material, let the ample thread of the rod coupler nut bear the load, no worry about aligning threads.

Reply to
Don Foreman

Don that makes too much sense.

Some folks just *have* to make prints with one inch diameter holes in 3/4 inch stock. They cannot be dissuaded ever.

Best thing to do is hand them a handfull of chips, say "here's your job." And no, I'm not giving the money back.

Jim

Reply to
jim rozen

Um, the threaded piece that goes through this hole is only 1" long.

GWE

Reply to
Grant Erwin

Unless it's being used as an adjustment point, in which case, it's not only doing something useful, it may be crucial to the proper functioning of the final product (of which we know nothing other than the fact that Grant is trying to build it) just by virtue of existing.

I still think the best bet on this little project is to get a suitable length and size of all-thread, drill/tap the hole, thread the nut onto the allthread, then the all-thread into the hole, run the nut down the all-thread to butt up against the hole like you would a jam-nut, but not "jam" tight - Just run it down until you've got contact with the base plate the hole is in, then adjust until the all-thread turns easily and start welding it down. Once finished, unscrew the all-thread from both pieces, and I would expect that things will be golden.

Reply to
Don Bruder

I agree with Don... then, if there's any binding at all, chase it with a tap and clear out the material that's causing the binding. Boy, that sure is a lot of thread, but what the hell...

Reply to
Adam

Here's the deal. Weld metal shrinks, so where things get welded, pull. I figure if I run thread through the coupler nut and into a threaded hole, then just weld up the nut, that the nut will be pulled a few thousandths closer because the weld will pull it closer and the metal on the end of the coupler will compress a little.

I noticed a 17/32" drill will just fit through the coupler nut. 17/32" is .531

-- well, I drilled 3/8" then 17/32", and the hole came out .538" not .531" - I'll have to resharpen that drill bit, but when I turned down a scrap bolt to .537" for a slip fit it no longer would pass through the coupler nut. So it would go in the hole in the part, thread on the coupler nut, weld on the coupler nut, then I'd have neatly plugged my hole. Oops. So I just went ahead and threaded the hole in the 3/4" part. Now I'm going to put in a piece of allthread, put on the coupler nut, run it down to where it's just starting to jam the allthread, and then cobble up a beefy little clamp to pull the coupler hard against the 3/4" part. This will emulate the pull of the weld metal. If the allthread moves smoothly without binding at that point, I will weld it up. If not, I can readjust things until it moves smoothly without binding while clamped very tightly.

I don't want to have to chase 2" of 5/8-11 thread. Don't think a standard tap will do the job, and I sure don't want to buy one.

Will weld it up real soon, and post what happened.

Grant

Reply to
Grant Erwin

How about using a piece of internally threaded tubing the entire required length, then sink a hole into the material large enough to accept the tube and 3/4" deep, and weld the tube in place? Might be easier to make and guarANTEES GOOD THREADS. SORRY, I HIT MY CAPS LOCK KEY AND THE FRIGGIN' THING IS STUCK NOW. DAMNIT!

Reply to
B.B.

Reply to
carl mciver

If this is a critical part of your device I would do a test on a scrap of the same plate to see if it binds.

Reply to
daniel peterman

Hey Carl,

I'm a terribly sloppy slouchy typer (notice I don't suggest typist - a skill I don't possess), and have always had trouble with in-advertent key-strikes. Now in the old days, you just went back and corrected. But with the advent of these "smart" keyboards, if you hit one of those keys in the bottom row inadvertently and keep typing because you're watching the key-board instead of the product, you can do lots of nasty things, some bordering on disastrous. So I just "pop" them off any new keyboard I get.

And to the "stuck key" poster, you can pick up whole computers for 5 bucks at garage sales around here, or 2 dollars for just a key-board. New ones start at $15.

Take care.

Brian Lawson, Bothwell, Ontario.

Reply to
Brian Lawson

Hey, I do that all of the time too, but I have no ER doctor to blame. jk

Reply to
jk

| | >> My left pinky finger is crooked from a stupid ER doctor who never | >>learned about tying fingers together to get them to heal straight, so I'm | >>hitting the caps lock all the time either in place of or at the same time I | >>type the nearest letter. That damn "a" does it every time, and it would | >>really suck if the key was a sticky one! | >

| >

| >Hey Carl, | | Hey, I do that all of the time too, but I have no ER doctor to blame. | jk

Grin! For some reason, despite the occasional caps locking incidents, I am learning to type faster and faster, all with bad form, of course. For those of you who know what a manual typewriter looked like, we had to be able to do 20 WPM before we could move up to an electric. It was a classic typing course. Do kids even have typing class in schools nowadays? My kids have gone up to 8 grade and none have used one, although they don't type too well either. At work, the company expects people to be more and more computer savvy, but has yet to offer a typing course. That chaffs my hide, because some of these folks are barely legible. Of course it shows they went to public school where writing skills wasn't as important a class as condom application.

Reply to
carl mciver

Reply to
Grant Erwin

I too am not a great typist. I spent years and never got to be a touch typist. Finally changed the keyboard layout to the Dvorak layout and struggled for about a month. But now can touch type.

I have had people tell me that the speed improvement of a Dvorak keyboard is not very great, and I suspect it is true for those that have good finger dexterity. But for me it made a lot of difference. Now if I was only a good speller......

Dan

carl mciver wrote:

Reply to
dcaster

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