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1/2-10 5 Start Lead Screw Tap

JayAndrew

Plastic
Joined
Oct 5, 2019
Does such a tap exist? I would like to make my own lead screw nuts, but am not overly confident in my ability to cut an internal diameter 5 start thread.

Alternatively would you go about making a 1/2-10 5 Start tap the same way you would approach making a 1/2-10 single start lead score tap?




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The Ballistic Assistant
 
My brother gets access to his university machine shop and has lots of fancier tools then I do. I floated the idea of him making a tap, or just have him make the nuts on the CNC lathe.

I suspect that is probably the solution. Being the “Do it yourself” curmudgeon that am, I wanted to explore that option first.

Since I am not able to find a tap, I figured it was either such a rare thread that a tap is a custom job, or there was a practical reason such as high cutting forces that makes using a conventional tap impractical. I just wasn’t finding a good reason “Why not” online.










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The Ballistic Assistant
 
"Why not" is you are likely to ruin four before you get ONE "good one".

And all you will have learnt is that no one else NEEDS the same oddball in a several year period as should last you the rest of a natural life. Even if you are still young.

Stuff like that, as with headlamps or tires for a motorcar, you "just buy".

If/as/when not "stock" then made by some other Pilgrim who does these things for his own "Day job" and can get it right, first go, ''coz for HIM it is just one more in a long line of similar goods he's already tooled-up for and experienced at doing.
 
I get that, a lot of what I do, I know I’m not going to get it right the first time around. I figure it’s an opportunity to learn something a little knew. I’m used to building a jig or two for a one off job that I could pay someone to do, or purchase the part myself. It’s about the experience and learning for me.

Thanks for the input guys


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The Ballistic Assistant
 
I think your choices are to single point it, or my preference if loading allows, cast one from Moglice.

Ive made 3/8 acme lead screw nuts from Delrin by using a ball end mill to make 3 grooves slightly off center such that the cutting face was slightly hooked and then cut a taper on the od. I didn’t back relieve it. Worked fine at a 1.5/1 L/D.
 
I get that, a lot of what I do, I know I’m not going to get it right the first time around. I figure it’s an opportunity to learn something a little knew. I’m used to building a jig or two for a one off job that I could pay someone to do, or purchase the part myself. It’s about the experience and learning for me.

Well - it isn't IMPOSSIBLE.. it just takes good general skills and a measure of dedication.

Member TRBoatworks is a consumate CRAFTSMAN, new only to metalworking lathes. Already HAS a fine hand and eye, great problem-solving skills.

He made a nut - two-start, IIRC, on his lathe, FOR his lathe, and did it rather well, first go, and from a cold start.

OTOH, his lathe is a Hendey Tool & Gage. One of the simplest systems ever built to do good threads with minimal effort or risk of screwups.

I own an even better one. The inherently inch/metric Cazeneuve HBX series with the "special apron" "B suffix.

Awesome manual threading repertoire.

OTOH, "simple" comes only after standing a dual major in shop practices and advanced mathematics, so to speak. It does not start out "intuitive" at all. One has to learn its curious ways. Only THEN does it come good.

Or so I f****g HOPE it does!

This.. is how yah know you are gittin' old.

Go take a short break for an ignorant s**t, yah have to be re-trained on return...

:(
 
The project is for a 3D printer, in total I need four nuts. I have four lead screws driving two axis’s. Loading isn’t going to be high. I’m using the high lead screws to get the speed up.

I’ve done some single point threading on the lathe, an I am by no means an expert. The more I do reading on threading for lead screwed with multiple starts, the more I suspect that I will not have the gearing on the lathe to turn it myself. I’m working on an old engine lathe.

It may be something I see what my brother can do and see if he is able to make them and possibly abandon the idea of a tap. I will be a good project for him, he’s going to school for this type of stuff and he enjoys odd ball projects on the CNC lathe.


Check out my website!
The Ballistic Assistant
 
The project is for a 3D printer, in total I need four nuts. I have four lead screws driving two axis’s. Loading isn’t going to be high. I’m using the high lead screws to get the speed up.

I’ve done some single point threading on the lathe, an I am by no means an expert. The more I do reading on threading for lead screwed with multiple starts, the more I suspect that I will not have the gearing on the lathe to turn it myself. I’m working on an old engine lathe.

It may be something I see what my brother can do and see if he is able to make them and possibly abandon the idea of a tap. I will be a good project for him, he’s going to school for this type of stuff and he enjoys odd ball projects on the CNC lathe.


Check out my website!
The Ballistic Assistant

You will get the power requirement loading up a lot sooner than the speed!

Having had hands-on in modifying 8-inch floppy drives and the odd pen-plotter or paper-positioner / document feeder about two hundred technology years ago? Some of that on seriously "deep pockets" cold-war Government scanner contracts?

You really, really, SHOULD be using recirculating ball screws and "stock parts" ELSE anchored synchronous (toothed) belts, metal bands, taut stranded cable, even linear servo motors or "voice coil" positioning for that application, AND NOT higher-friction, higher WEAR sliding action screws and nuts in chronic need of adjustment to try to hold accuracy over time where there is a LOT of movement, even in a SHORT time.

This is not new ground by easily fifty years, already - disk drives and printers, 3-D or otherwise. CNC critters to office automation, all types, dot matrix Okidata 82 A (toothed belt) to CNC machine-tools the size of a house.

Ballscrews or toothed belts are not a luxury for durable, low cost, low maintenance 'puterized positioning, least of all when it gets as fast and furious and unpredictable as anything "rasterized" will need to be even if it is given a few thousands of years head-start on 3-D printing of 'bergs for the next ice-age.

They are a necessity, present economics.

"Futures" OTOH?

Already "out there'.

Must have been 1969 or 1970, IEEE "Eascon" show, Sheraton, DC.

IBM had a quad booth right next to my firm's double booth. THEY had an 80,000 line per minute printer on display. Awesome critter raster-printed 2D characters so fast, all one saw was a tall stack of "superfold" paper vanish from the input stack and show up on the output stack.

"Printer" didn't MOVE the head.

AIMED a jet-stream of sticky carbon particles at that dead-tree paper if it were an open air CRT tube lighting-up phosphors, other end of a glass CRT tube with a beam of electrons.

But it was boring.

Our little nuthin'-much firm had borrowed-back a project we had done for NASA, Greenbelt's OSO G orbital solar observatory satellite. UV spectrophotometer monitored sunspot activity.

The "world's first" computerized colour digital display. On a Ball Brothers Research Vacuum-tube lab-grade industrial CRT display and heavily modified, even so.

All of 64 pixels by 64 pixels, and "bleeding edge" for its day, if you can relate THAT to what we take for granted NOW?

:)

And yet? It was INTERESTING to watch where the "world's fastest printer" was BORING.

So we clocked more visitors than IBM... even though our piddly little annual turnover would not have bought their well-paid staff's LUNCH for even a single day.

Look at the colour digital display on even a cheap handheld.

Keep on innovating.

There's always hope....

:)
 
The project is for a 3D printer, in total I need four nuts. I have four lead screws driving two axis’s. Loading isn’t going to be high. I’m using the high lead screws to get the speed up.

I’ve done some single point threading on the lathe, an I am by no means an expert. The more I do reading on threading for lead screwed with multiple starts, the more I suspect that I will not have the gearing on the lathe to turn it myself. I’m working on an old engine lathe.

It may be something I see what my brother can do and see if he is able to make them and possibly abandon the idea of a tap. I will be a good project for him, he’s going to school for this type of stuff and he enjoys odd ball projects on the CNC lathe.


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TheHarryHomeshopidiot

Again..."Buy them"..
And NO I don't want to visit your website, please stop posting that at the end of every post.
 
Those that have a website can put it in their profile NOT IN A POST.
An exception might be if what's in your website is relevant to the thread.


It is part of my signature line. It’s not something I am typing in every time. I am still learning to use the tapatalk app, and I didn’t realize that It could turn that off on a reply, or that unlike the on the computer it would should up as part of the post rather down below the signature line.

I think that I have fixed that here. Sorry, still learning.

Anyway...


Posts saying “Go buy the part” aren’t helpful. Yes McMaster sells them for $65 a piece, and i can buy them. I bought the lead screw stock from McMaster. Having more time then money, and having a desire to learn, I want to try and figure out a solution, as if I couldn’t just go buy the part.

If it’s something that is best done on a CNC lathe, which I am thinking it is, I have a brother who would love to tackle something like this. So it helps him try something new and learn.

The reason I am going with lead screws instead of a belt drive is that the printer has a heavier print head then most and I would like to swap out the print head for a engraver. Based on what I have seen in the market the lead screws were a better option then cogged belts.

Ball screws are an option but for me it came down to the budget.

Movement speed for the X and Y axis are 50mm/s which is fast, to me, but is on the slow end for printer. The 1/2-10 5 Start is .500 per revolution, which gives me (in theory) a resolution of .0025 per degree. Which is far better then the resolution that we can expect from extruding out plastics. It is a good balance between speed and precision based on the stepper motors I am using.


Definitely not trying to reinvent the wheel here. 3D printer are built on decades old tech with some modern computing thrown in. A lot of the component selection and the design is based on a lot of seeing what has been done with other builds.
 
Does such a tap exist? I would like to make my own lead screw nuts, but am not overly confident in my ability to cut an internal diameter 5 start thread.

Alternatively would you go about making a 1/2-10 5 Start tap the same way you would approach making a 1/2-10 single start lead score tap?




Check out my website!
The Ballistic Assistant
Make a tap, it's pretty easy. Last one I made was for a delrin nut to I used some stressproof. Was it perfect? No, the geometry left some to be desired but it cut a nice enough thread to achieve my goals.

Sent from my SM-G973U using Tapatalk
 
Make a tap, it's pretty easy. Last one I made was for a delrin nut to I used some stressproof. Was it perfect? No, the geometry left some to be desired but it cut a nice enough thread to achieve my goals.

Sent from my SM-G973U using Tapatalk

Does the number of starts or high lead angle complicate cutting the thread with a tap? I’E are the cutting forces so high with a tap that you’re more likely to break the tap then to cut?

I think that’s what some others were eluding to here.
 
Does the number of starts or high lead angle complicate cutting the thread with a tap? I’E are the cutting forces so high with a tap that you’re more likely to break the tap then to cut?

I think that’s what some others were eluding to here.
Maybe. Lotta variables, but the biggest one is- what's your nut material? Maybe I missed it. Next Q- will your lathe cut 2 tpi?

Cool thing about making your own tap is that it can have a really long taper to ease those forces. As for 5 starts, most lathes won't accommodate that without some help, the thread dial isn't divisible by 5. Swing the compound's travel axis parallel to the spindle axis and that's how you work your starts.

Sent from my SM-G973U using Tapatalk
 
I’ll have to take a look. I am long ways off from work for the holidays.

The nut material will either be a leader free machining brass, or a bearing bronze. I know those are two different materials but haven’t decided which I want to go with.
 
Posts saying “Go buy the part” aren’t helpful. Yes McMaster sells them for $65 a piece, and i can buy them. I bought the lead screw stock from McMaster. Having more time then money, and having a desire to learn, I want to try and figure out a solution, as if I couldn’t just go buy the part.

If it’s something that is best done on a CNC lathe, which I am thinking it is, I have a brother who would love to tackle something like this. So it helps him try something new and learn.

The reason I am going with lead screws instead of a belt drive is that the printer has a heavier print head then most and I would like to swap out the print head for a engraver. Based on what I have seen in the market the lead screws were a better option then cogged belts.

Ball screws are an option but for me it came down to the budget.

Movement speed for the X and Y axis are 50mm/s which is fast, to me, but is on the slow end for printer. The 1/2-10 5 Start is .500 per revolution, which gives me (in theory) a resolution of .0025 per degree. Which is far better then the resolution that we can expect from extruding out plastics. It is a good balance between speed and precision based on the stepper motors I am using.


Definitely not trying to reinvent the wheel here. 3D printer are built on decades old tech with some modern computing thrown in. A lot of the component selection and the design is based on a lot of seeing what has been done with other builds.

You are kidding yerself on the "budget" to think you know something that MMC and suppliers do NOT know as to the manufacture of the goods and their real-world costs.

Multi-start leadscrews - or for that matter "helical CAMS" can assuredly deal with rapid movement.

Think rifled firearms - clear up to 16"-50 Mark 7 and its "super heavy" projectiles - proven AFTER the war to blow right though IJN's heaviest Yamato class turret-face armour samples and keep on truckin'.

But you no gots the option of using explosives for power, nor having one of the major components designed to be used exactly ONCE!

:)

Back in the world you DO have ..the wear-rate and the forces go way up compared to a low-friction ballscrew simply rotated at a higher RPM.

That ain't theory.

Lotta grey-hairs here have had to deal with repair to similar goods, have SEEN them plumb wore-out. Why d'you think they are such "minority use" goods to begin with?

Don't try to solve one problem by designing-in a worse problem, yet.
 








 
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