I have a friend who is a blacksmith. He recently bought an old fly press and it is missing the top collar. It is a 2.25"-10 nut, and he can only find 2.25"-8 and 2.25"-12. Does anyone have any ideas?
You can make such a nut on a lathe with some effort. It could potentially also be cast, but that would be trickier.
7 Likes
+1 for making it on a lathe. You’d just need to find a shop or team that can do it. Maybe see if there’s a local highschool that could have a student whip one up (not sure how developed the manufacturing/trade education is in your area)? This would have been a great project for one of our grade 11 or 12 students to practice turning internal threads at my school.
You will need some accurate measurements to do it. Bringing the threaded part to the machine makes it easier!!!
1 Like
Absolutely.
This is one of those seemingly simple things that can have a lot going on.
You start with accurate measurements, then you make sure you know how your machine works, then, depending on the part and it works with existing parts, you learn to “tune” things to fit the way you want.
Having access to the part it will fit on is a big deal but also working out how to do a test fit in a way that you can continue your “tuning” is big deal. It’s one thing to make a nut for a bolt that you can test fit right on the lathe and make an adjustment but what if you need to remove the nut to do a test fit on your machine. Now things just got more challenging - how do you get things back into the lathe the same way so you can pickup that thread and open it up just a little bit because it’s too tight?
All this stuff is doable and it brings a lot of interesting things right to the forefront that can help demonstrate a lot of cool and valuable principles.
When I first got my machines, a buddy and I coined a term - we called it “machining on purpose”. Say you’re making a spacer for something; it’s not critical but can be anything from .850 to 1.100" thick.
You could just whack at something and be able to almost eyeball something to that range with a carpenters tape measure or you can decide that you are actually going to have a plan, a sketch or something, and actually make it to that. You might say, “I want it to be 1.000” thick" and try for that. Now you’ve got a goal, and with a goal, you can see how well you hit it. Is it the planned thickness? Is it parallel? Are the sides perpendicular? How well did I do? What could I do to make this better or easier now that I’ve done it all the way through?
Whatever the target, you’ve got a way to see how it ended up, how it measured up. You do that a few times, and you find yourself getting better, becoming more of a craftsman, able to actually make the things you envision to closer and closer tolerances. I put a lot of effort and pride into simple things like spacers or brackets - I want to show I care and I love to install that sense of pride and accomplishment among the team members.
This might seem like just making a nut - and it is - but it’s a something you’re making on purpose, to a plan, and that’s always been where I learned the most.
And yeah, a lathe is the way to go.
This could be a fun project with a lot of takeaways in terms of building skills and knowledge.
4 Likes
Before you do anything on the lathe, 3D print what you want. If you get the thread count or the diameter or something wrong, you’ll know it. Then, after you get it right, have it milled up.
No guarantee that you won’t make multiple trips to the lathe, but it should help.
9 Likes
That’s a great suggestion that I hadn’t considered! That thread is coarse enough that you could hope to get a decent functional one printed.
I’d also plan to check that the thread angle, actual precise pitch, and whether its acme or V-thread…
Just for all of us machine nerds, any chance of a few photos?
The next question is would a 3d printed nut be good enough. Do you really need a metal one? Or, considering the hourly labor rate, would getting a metal 3d printed one from online be easier?
You might want to take a look at Thread-drawing modules for OpenSCAD.
Ask at a local community college. One of my sons was in a “Manufacturing Engineering” program and had courses on how to operate mills, lathes etc.
I wouldn’t expect a 3D printed metal one to work at all… tolerances won’t play well.
The 3dp nut is fine for fitup and to see if you got the pitch right.
3 Likes
Nah, SLS metal prints should be more that enough for 10 TPI; I have some 8-32 stuff floating around, didn’t even need to be chased with a tap. The real issue there is that it’ll cost more than just, like, making an actual metal nut on a lathe.
3 Likes
Because I’m a software guy and ML is needed for everything, I asked Dall-E for a photo of a squirrel with a highly customized large nut:
I assume this counts as machining.
13 Likes
As a Machinist, it absolutely does.
3 Likes
I had not thought of 3D printing something as a test for fit. My team has a lathe. The issue is my friend is west of Cleveland and we are in Columbus, so the going back and forth to try to tweak it makes a difficult task even more difficult. But potentially 3D printing one out of plastic and checking that one could work. I am going to explore that idea. 3D printing it from metal is probably possible, but might be more than he can spend right now.
You could machine it on a cnc mill or rigid enough router and thread-mill the thread. An expensive option would be to hand tap the thread. Fractional Thread Tap 2-1/4-10 - HD Chasen Co
That is a nasty large thread to hand tap, bright side it looks like a jam, so there may be a softer metal for something like this that would work.
Also looks like a fair few extra operations can be avoided, a piece of steel tube, bored, threaded, chamfered/parted and two flats milled. Doesn’t seem too bad, but I have never done something so large, so there may be some nuance I don’t know about.
As it’s just a jam nut you could replicate it… make a tubular form with a bottom shelf and a hole for the screw. Put a couple of coats of wax on the screw. Stick the form around the screw and seal the bottom with modeling clay or hot glue. Pour in JB weld and let it set. Wrench it off, clean,band your done!
You could also heat from polyethylene into the threads.
It looks removable; that makes taking it to the lathe much easier!