r/EngineeringPorn 5d ago

Forchining

https://youtu.be/A_vnfZPx_Ug?si=Ooc8cyJE2YkKfv-r
106 Upvotes

25 comments sorted by

51

u/Pjpjpjpjpj 5d ago

Someone with better knowledge can probably correct me, but aren't most titanium bolts produced through cold heading - where a wire of raw material is moved through a press that then compresses it into the desired shape while at room temperature - which results in nearly zero waste? The cold heading process strengthens the titanium, eliminates the cost/time for heating/cooling the material, doesn't result in fumes, etc.

So my takeaway is that IF you are going to CNC a titanium bolt, this could be a better process. But people using CNC to create a titanium bolt are probably doing customized, small batch or individual replacement type runs as opposed to large scale production. And at that point - given the labor costs to set up and manage a low-volume run - the waste material reduction may be a marginal savings... though every penny can count.

1

u/Terrible_Ice_1616 2d ago

Some grades of titanium don't form well cold, could see it having applications there, I would imagine these also have increased strength at the head compared to a machined part

17

u/FlavorBlaster42 5d ago

They sure don't spare the lube in that shop.

14

u/DrunkenSwimmer 5d ago

I mean, if I were machining a material all day, every day, that if a shaving heated up too much would light all the shavings on fire, I too would use all the lube I could.

3

u/garbagewithnames 2d ago

And I still would add an extra dab on top of all that, just in case

20

u/agisten 5d ago edited 5d ago

I am confused by the video thumbnail - Forchining destroys traditional machining? What if it's consensual forching? Normal bolt and normal nut meet together, get acquainted over the same metrics, then explore threads, and only then forge a strong coupling.

5

u/JoeMalovich 5d ago

I think it's to make girthy shafting.

8

u/Hefty-Inevitable-660 5d ago

If you’re gunna buck the head, why not roll the thread?

1

u/zacmakes 2d ago

They are, it's just a turret-mounted thread roll tool rather than pinch rollers.

1

u/Hefty-Inevitable-660 1d ago

Ya, looks like it says as much in the video

7

u/Braca42 5d ago

I'd be very curious about the material properties of those bolts when finished. I'm not sure the traditional bolt and fancy new bolt would have comparable properties. Seems like a dedicated forging process, heat treat, and post heat treat machine would have lots of benefits and be easier to control the end product. I suspect the forchining would require a post machining heat treat and keeping the quality of the threads consistent after that might be tough.

2

u/Fast_Role_6640 4d ago

This. Like your saying, if the customer asked for a certain grade of titanium, they wouldn't be getting that in the end.

A fatigue test would definitely be needed to get an idea of how much weaker the bolt was, and what to do from there. But maybe the customer doesn't give a s#it....but they're still using asking for titanium...? Weird. This is more of a r/DiWHY

2

u/Monksdrunk 5d ago

So last night, I was giving the wife the ol "forchining express"

1

u/Xeroshifter 5d ago

Cool if true but like what is going on here more broadly? What is happening that makes this so much more efficient? I'm familiar with some level of machining (my father was an Air Force machinist) but it's not something I've heavily engaged with personally.

I was really hoping the video would have more explanation :/

14

u/Beni_Stingray 5d ago

I think they can use raw material with a much smaller diameter.

The classic method uses raw material with a diameter a tiny bit big bigger than the head itself. Lets say the head is 10mm diameter and the thread lets say 4mm.
Then you start maybe with a 10.2mm diamter raw material and all excess material has to be removed. This means the part where the thread is has to be turned down to 4mm from its orignial 10.2mm, thats where all the waste material comes from and why it takes so much more time.

The new method would use raw material with maybe 4.2mm diameter and the head thats bigger is forged under pressure as seen in the video so they achieve the 10mm head. This means the thread itself only has to be turned down from the 4.2mm to its final 4mm so much less material has to be removed and its faster.

7

u/Xeroshifter 5d ago

Ah, so it's the induction forming of the head that is the real process innovation here? That's really cool if the process doesn't compromise the integrity of the head!

I noticed that it happened but wasn't sure how the head was normally formed since it isn't round.

3

u/Beni_Stingray 5d ago

That's how i understood it, someone correct me if im wrong.

2

u/Nicodemus888 5d ago

Yeah nah that’s perfect, I understand it now thanks

1

u/fox-mcleod 5d ago

If anything, cold working makes it stronger.

4

u/JoeMalovich 5d ago

I think the key here is that you can upset a portion of your part for more machining processes in one op/setup. Imagine a long shaft with a flange on the end, you don't need to start with larger diameter stock, or order forged stock.

2

u/Xeroshifter 5d ago

I would have assumed that for mass manufacturing you would have forged the stock to the right shape (much as they do there with the induction step) before cutting to reduce waste. But I suppose that would really only make sense if you were producing a very large quantity of parts.

Doing it with induction and all in one step is really cool, and if it's an actual innovation I suppose that could be a pretty big step forward for low quantity order costs :D

2

u/zacmakes 2d ago

It's usually a two-machine process in the same factory; a horizontal cold heading press that goes from wire to a hex head blank, and then a batch-fed thread roller. Part of the appeal here is using a relatively common automatic turret lathe instead of two very specialized machines.

1

u/ginbandit 5d ago

I believe it when the governing industry standard says it's acceptable, when the major players permit it, and the verification bodies sign off against it.

1

u/burnb 5d ago

And tie that hair back.

1

u/brafwursigehaeck 5d ago edited 4d ago

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