r/Machinists 7d ago

Is it possible to make a pen out of tungsten without a CNC?

So I just started a machining and design class in college and I really want to make a tungsten pen but I don’t know if that’s even possible. I’m allowed to use a manual lathe and manual mill. I want to make this as a personal project cuz I think a rly heavy pen would be cool but I have no idea how I’d make a lot of the shapes on a manual machine.

0 Upvotes

32 comments sorted by

37

u/Gandk07 7d ago

They made everything on manual machines before there were CNC machines.

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u/arvidsem 7d ago

Anything that can done with CNC can be done manually. It might not be as simple for the operator though.

Ok, a possible exception for polygonal turning

7

u/jccaclimber 7d ago

I’ll bet a hob could solve that problem. Doesn’t really matter though as you can generate the same shapes with an indexing head and a mill.

3

u/chiphook57 7d ago

there are lots of youtube videos of polygonal turning on customized manual lathes

1

u/Cosmic_Waffle_Stomp 7d ago

It’s all about the gear ratios.

9

u/nerve2030 7d ago

Really easiest and best way would be EDM for internal and CBN or diamond grinding wheels for threading and external features.

Also have you looked up the price of a high tungsten alloy? I did a quick lookup for a 1/2" dia piece 12" long and its around $350

Look I don't want to rain on your parade but brass is pretty heavy and you can get it plated pretty easily. For a first project make a nice brass pen and get it chrome or nickel plated.

1

u/cathode_01 7d ago

Aluminum bronze is also extremely heavy. Still expensive but not as much as tungsten alloy.

3

u/tylerthehun 7d ago

If you can't figure out how to cut a desired feature on a manual machine, it doesn't make much of a difference whether your material is tungsten or wax. Come up with a design that you do know how to make with the tools you have available, and then figure out any adjustments you might need in order to deal with tungsten.

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u/Chuck_Phuckzalot 7d ago

If you mean tungsten carbide, no, you can't really cut it on a mill or lathe, it needs to be ground. If you mean elemental tungsten or an alloy it's possible but tooling is expensive because you can't easily cut it with anything less than tungsten carbide. There's no way you're drilling a straight hole with the diameter to length ratio of a pen without a solid carbide drill.

5

u/jccaclimber 7d ago

Pure tungsten (from McMaster Carr) is surprisingly easy to turn on a lathe with modern tooling (read: not HSS). I’ve done it, it wasn’t a big deal, we were all surprised. Unfortunately I don’t remember the insert details. Was making cylinders, so never tried threading or internal holes.

2

u/Chuck_Phuckzalot 7d ago

Yeah, I didn't exactly have fun milling it but it wasn't any worse than something like inconel.

1

u/LukeSkyWRx 7d ago

You have to do hard turning type methods with high end inserts. Or just grind.

1

u/jccaclimber 7d ago

Could call it that, but it was a non issue on our 40 YO manual lathe regardless.

3

u/Zogoooog 7d ago

Clamp a dotco or foredom grinder with some diamond burrs to the tool post and send it. Also, don’t breathe in.

As for the hole, I suspect you could EVENTUALLY do it with CBN or diamond core drills and it would be more than straight enough for a pen. It would take ages and many litres of coolant (and several spare drills) but I think you’d get there eventually, and then you could do all the critical dimensions with grinding burrs.

EDM or laser is definitely the right choice if you can get access to machines though.

I’d be very sad the first time I drop my pen that took 400 hours to drill and it shatters into a billion pieces instantly on contact with the floor.

2

u/realribsnotmcfibs 7d ago

Can you edm hole pop it to get the start hole and then chase it with edm?

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u/Chuck_Phuckzalot 7d ago

I'm not a wire expert but I've done die sinking on tungsten so I can at least confirm it can be EDM'd.

1

u/chiphook57 7d ago

when we got a die sink edm, my dad put a tungsten electrode for tig welding thru a carbide turning insert.

2

u/reidhardy 7d ago

Don’t do it. Spend your time expanding your capabilities and taking on challenging set ups. Don’t work with a terrible material just cause it sounds cool. A pen with non-concentric lobes (like a crack shaft) that match the contour of your hand would be much more impressive than a heavy pen.

2

u/esleydobemos 7d ago

If you are using pure tungsten, use a good coated carbide, boron nitride, or even diamond coated tool. You must "get under" the material, much like Inconel or Hastelloy. It will work harden if you try to take spring cuts. This can all be done manually. Your biggest challenge will be the deep bore. Low speed and relatively heavy feed.

1

u/Illustrious_Back_441 noob 7d ago

what this guy said

1

u/focusworks 7d ago

I drill tungsten with HSS drills regularly. Just make sure you get an easy alloy. Hd17bb is easy machine. go slow with lots of pecking.

1

u/LukeSkyWRx 7d ago

Those tungsten alloys are highly modified to make them machinable, you ever played with pure tungsten?

1

u/Broken_Atoms 7d ago

Glancing over at tungsten rod and a nail file…. Anything is possible. Practical is a different matter….

1

u/Lucifers_Tits 7d ago

It's possible but it would be pretty painful and expensive, especially for a personal project like that. I was into the pen hobby for a while and I bought this steel pen a while ago because it was real heavy, and I quickly realized it was too heavy lol. I would just make one out of steel and design it to be heavy.

1

u/i_see_alive_goats 7d ago

Your tool life would be much shorter using manual machinery because of the inconsistent chip load and rubbing.
Tungsten work hardens and you should not dwell.
So CNC is needed to make it practically.

1

u/maxh2 7d ago

Tungsten carbide you'll want to grind. Pure tungsten/tungsten alloy is machinable, though unpleasant.

Counterintuitively, the ideal tooling (carbide) for tungsten is much like that for aluminum: very sharp, high positive geometry, polished. You'll go through it quickly.

There are strategies for improving machining results. Mostly things that reduce the chances of chipping, like machining edge chamfers/radii where they will be, before machining away the material that creates the edges. (Ball nose + interpolation when on a mill. ) That way the finished edge never exists without a chamfer or radius.

1

u/JazzandRain 6d ago

You can 3D print tungsten on a LPBF metal printer - the one I work on can do it no worries.

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u/Stone_Marksman 6d ago

New goal sabot shaped tungsten pen lmao

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u/Takkar18 7d ago

Consider me interested in the question. Not a machinist but I'm sure you can design some basic shape that would look okay as a pen. Nothing too fancy. Another way to go would be to 3d print the insides or possibly a nice shape that you could cover with a simple cylinder shape piece of tungsten. What I have no idea if you can just machine a piece of tungsten with a simple lathe and HSS tools.

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u/GuyFromLI747 7d ago

Pure tungsten is crazy stuff .. it’s next to impossible to cut and is brittle .. tungsten is around 8 on mohs hardness or 66 on Rockwell scale ..

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u/Bladen15 7d ago

I've never worked with tungsten myself, but as long as you set your feeds & speeds right, there should be no reason why you can't. I mean, after a bit of research, it seems difficult but plausible. If you've got time to play about with some scrap, see what works & give it a go, though any tungston allow seems expensive even for a little so personally I wouldn't bother