KS-17 energy/gas key - triangular/triangular - emergency 3D printing

p.kaczmarek2 11 May 2023 08:21 33 3252 Cool? (+8)

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Hello.
Today I'm going to show a short, emergency 3D print that might come in handy for someone - a "triangle" key for KS-17 security padlocks fitted to electrical boxes, for example. The key itself is readily available for a few zlotys, but what can you do when it's Sunday, the shops are far away and you need to open a box in an emergency? That's what you can do - you can use a 3D printer.

The situation was such that one of the padlocks wouldn't open with 'guerrilla' methods, and the other wasn't locked anyway, so I had a disassembled padlock as a model:

In Blender, I started with the shape of the triangle and its dimensions:

I then used it to cut a hole in the circle, boolean subtract:

At this stage I have made a few prints for the fitting, as a trial:

Successful fitting:

The next step was to give the project real depth:

I helped myself with the mirror tool. The triangle shape is cut out, so there are no problems with the supports and it saves a bit of material:

Finished print:

Fitment:

Weight and printing time with Cura:

Two grams and 20 minutes! That's very little indeed.
Still to be seen - identical keys on a Polish auction site:

So buying this key would cost me about £6, plus shipping costs (of £9?), and let's not forget the waiting time.

Summary
I would rather not normally print this, but an emergency situation forced me to do so and fortunately it went off without a hitch. Was it worth it? For the sake of time, yes; but even so, you have to admit that such a key itself is quite cheap, although the lack of a good stationary shop nearby also complicates things a bit, because then you have to add shipping as well. My printed key costs only as much as some two grams of filament , that is, with the price of 50 PLN per kilogram it is pennies, even if you add the electricity/maintenance of the printer, it still remains pennies.... I'm not counting design time (playtime) here.
Maybe this will be useful to someone - I've put the downloads below.
Do you have any other similar print ideas or experiences where the printer saved the situation and allowed to produce a sufficiently durable equivalent of some popular tool?

Attachments:

elekey4_KS-17.zip Download (87.45 KB)

About Author

p.kaczmarek2 wrote 13929 posts with rating 11733 , helped 630 times. Been with us since 2014 year.

Comments

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bsw 11 May 2023 10:24

Emergency situation... And how long did it take to design + final print? [Read more]

p.kaczmarek2 11 May 2023 11:06

Hmm you have the printing information in the topic, such a gadget prints 20 minutes. The design itself is a dozen minutes, it's just a few basic shapes, with me doing three test prints (this increased... [Read more]

miszcz310 11 May 2023 11:09

Looking at the size of the part and complexity it's probably 15-20 min to design and probably 10-15 min to print. Especially as this is supposed to be usable and not pretty (read can be sped up considerably).... [Read more]

p.kaczmarek2 11 May 2023 11:16

I didn't optimise the printing time, everything went on the default settings, probably if the speed was set higher, it would also be shortened a few times. All in all, as I was printing bulk containers... [Read more]

miszcz310 11 May 2023 11:33

Super fab! Did you design it yourself or was it downloaded from somewhere? [Read more]

p.kaczmarek2 11 May 2023 11:59

This is a project from the web, quite popular, it was described here: https://www.elektroda.pl/rtvforum/topic3719527.html [Read more]

metalMANiu 11 May 2023 12:27

Even if you bought a ready-made key, there is no guarantee that you would have chosen the right size, a triangle being unequal to a triangle. You could also get a size too big by mistake from the seller.... [Read more]

Anonymous 11 May 2023 12:40

Given the final cost of this gadget, I use what I call a flat pincher in emergency situations. It has worked well on many occasions. Of course, it is good to have such a key, but it is not a reason to... [Read more]

metalMANiu 11 May 2023 13:06

[Read more]

miszcz310 11 May 2023 14:15

It seems to me that this article is not about convincing you to buy a printer, rather what you can do with it once you have it. [Read more]

ArturAVS 11 May 2023 16:15

I made one for myself from thick-walled copper tubing shaped by heat. :D [Read more]

trojan 12 11 May 2023 16:27

Just what is there to work so hard for? Old triangular file, grind the edges and hammer into the steel tube. Measure - if the screw head doesn't go in, hammer in some more. Quick and cheap. I didn't write... [Read more]

miroskop 11 May 2023 18:11

I would not, however, give the hole through, but to the required depth. This will always strengthen the structure and, in the position in which you are printing this key, no slides are needed. [Read more]

teskot 11 May 2023 19:51

Leaving aside the design and the printing (full credit where it's due - I'd sooner make such a key out of a piece of anything using kitchen tools), the first thing that popped into my head was: If there... [Read more]

Jacek Rutkowski 11 May 2023 23:14

The tube shape is the strongest for torsion :) There is no need to fill the centre ... [Read more]

kotbury 12 May 2023 08:26

Strongest for torsion yes, but made from the same amount of material - a tube made from 1 kg of steel will yes be stronger than a bar made from the SAME AMOUNT of material, i.e. a kilogram (which will... [Read more]

szeryf3 12 May 2023 09:05

Nice project. @pkaczmarek2 tell me what is the durability of such a key compared to the one from a well-known auction site? [Read more]

miszcz310 12 May 2023 16:11

And rightly so, but this is improving year on year. There are also different strategies for mechanically reinforcing the prints and you can get comparable strengths. [Read more]

miroskop 13 May 2023 12:32

For the same outside diameters, a solid bar is stronger than a tube, this follows from the torsional strength formulae. After all, a rod is also a tube with a wall thickness equal to the radius, so it... [Read more]

FAQ

TL;DR: Need a KS‑17 triangular utility key fast? A printable version weighs 2 g and takes ~20 minutes; “Two grams and 20 minutes!” solves Sunday emergencies. [Elektroda, p.kaczmarek2, post #20575557]

Why it matters: Field techs and makers can open authorized electrical enclosures without waiting for shipping or stores.

Quick Facts

- Print time: Approx. 20 minutes on default Cura settings. [Elektroda, p.kaczmarek2, post #20575557]
- Filament use: ~2 g; cost is pennies at 50 PLN/kg. [Elektroda, p.kaczmarek2, post #20575557]
- Typical design effort: “a dozen minutes,” plus a few test fits. [Elektroda, p.kaczmarek2, post #20575740]
- Speed-ups: Increase “Print Speed” and use on-printer speed scaling (e.g., Ender 3 Pro). [Elektroda, p.kaczmarek2, post #20575752]
- Buying instead: ~£6 plus ~£9 shipping; wait time applies. [Elektroda, p.kaczmarek2, post #20575557]

What is a KS‑17 triangular key used for?

A KS‑17 triangular key is a simple drive tool for utility padlocks and cabinet latches on electrical boxes. It mates with a triangular recess and lets authorized users open or secure enclosures. The forum project replicates this geometry for emergency 3D printing when a store-bought key is unavailable. [Elektroda, p.kaczmarek2, post #20575557]

How long does it take to design and print the emergency key?

Design takes about a dozen minutes using basic shapes. The author also showed a similar shape modeled in roughly two minutes for demo. Printing the working key on default settings took about 20 minutes. Total turnaround, including a few test fits, stayed short enough for same‑day use. [Elektroda, p.kaczmarek2, post #20575740]

What’s the total time if I rush it end‑to‑end?

Community guidance: design in 15–20 minutes and print in 10–15 minutes. Faster printers, like a tuned Voron, can push a usable print below five minutes. “Including even test prints you can have such an item under an hour.” [Elektroda, miszcz310, post #20575743]

Which software and workflow were used to model the key?

Blender was used: create a triangular prism to match the lock, subtract it (boolean) from a cylinder, mirror for symmetry, then add depth. The cut‑through triangle simplifies printing without supports and saves material. STL was sliced in Cura with defaults. [Elektroda, p.kaczmarek2, post #20575557]

How do I print it? (3‑step How‑To)

Model the triangle and boolean‑cut it from a round body; add depth and mirror for symmetry.
Slice in Cura at default settings; estimate ~20 minutes and ~2 g.
Print, test fit, and reprint if needed; tweak “Print Speed” if time‑critical. [Elektroda, p.kaczmarek2, post #20575557]

Can I speed up the print safely on common printers?

Yes. For simple shapes, increase the slicer’s “Print Speed.” On an Ender 3 Pro, use the front‑panel speed scale during printing to shorten time with minimal visible quality loss. Always verify fit before applying high torque. [Elektroda, p.kaczmarek2, post #20575752]

How durable is a printed key versus a metal one?

It won’t match metal, but good design and print strategy can reach usable strength for light utility torque. Experienced users report mechanical reinforcement options and improving results year over year. Favor dense walls, adequate layer height, and stronger filaments when possible. [Elektroda, miszcz310, post #20577479]

Should the triangular hole go through, or stop at depth for strength?

One contributor recommends a blind (not through) triangular recess to increase structural strength and resist deformation or tearing. Since the key prints in a stable orientation, supports are unnecessary with this approach. [Elektroda, miroskop, post #20576283]

What if pliers or improvised methods fail?

The author noted one padlock would not open using “guerrilla” methods, which prompted printing the key. This edge case shows why a well‑fitting driver profile can succeed where pliers slip or deform. [Elektroda, p.kaczmarek2, post #20575557]

Is there a quick non‑printing alternative that fits the triangular recess?

Yes. An 11 mm hex socket reportedly worked on a reluctant lock. Check that the socket fits the padlock opening and engages fully before turning, or you risk rounding. [Elektroda, mars1, post #20642280]

What does the filament actually cost for one key?

The job used about 2 g of filament. At 50 PLN per kilogram, material cost is only a few grosz (pennies), even before considering electricity and wear. That’s far below buying and shipping a metal key. [Elektroda, p.kaczmarek2, post #20575557]

Why not just buy the key instead of printing?

A ready‑made key costs around £6 plus about £9 shipping, and you must wait for delivery. Printing solves urgent access needs, especially when the nearest store is far or closed. [Elektroda, p.kaczmarek2, post #20575557]

Will printing help during a power outage emergency?

A commenter highlighted the paradox: if power is out, the printer cannot run. Plan for a UPS or use mechanical alternatives when electricity is unavailable. “What, the printer worked by sheer force of will?” [Elektroda, teskot, post #20576425]

Do triangular keys come in different sizes?

Yes. Not all triangular drives match. Buying the wrong size wastes time, and sellers can ship mismatches. Printing to fit the actual lock profile reduces that risk and avoids re‑shipping delays. [Elektroda, metalMANiu, post #20575850]