I 3d-printed a key. When I put it in the lock the pins move but, when I go to turn it the key rips and the lock doesn't turn. I compared it to the real key and it's identical. Is there something I can do to make it work and not rip? Is there some filament that I can print it out of? I used ABS.
I must admit, I've never printed a key...but I think I can help anyway:
Print method: Consider printing on side, solid concentric infill. Or, if you can't manipulate your infill pattern, just increase the perimeter so you get the same effect, several continuous perimeter layers around the outline of the key.
- Elongation before break is important here in addition to tensile strength...you need it to be stiff enough, but not brittle.
- ABS, PLA, or HIPS: Not likely to be successful...but maybe.
- PETG and PETG based filaments like T-Glase, N-Vent, nGen, INOVA-1800: A little better, but still likely to deform and/or break.
- Polycarbonate: Great for this, but is a fairly advanced material which tends to require pre-drying, enclosures, and PVA for hold down as well as a hot end that can handle at least 290C.
- Nylons: Good, but most Nylons may be more "bendy" than you want for this.
- Taulman's Alloy 910: Bingo. This should work nicely if you'd rather not struggle with printing polycarbonate. Alloy 910 prints near ABS settings, sticks well on a PVA-treated heated bed. (I use 85C for bed)
- I would not suggest a CF filled filament for this because they tend to be brittle. Matter Hacker's NylonX with CF is a possible exception since it's nylon based, but I haven't tested it...yet.
That is correct! Take your raw ABS plastic and try to bend and break it. Do it again with a few lengths. Pretty easy to break it right?
You issue is the material is not up to par with your goal. Your heavy duty lock takes too much force to turn.
Your solutions are to
Find a stronger material. These are considered stronger than PLA / ABS
- PETT (SHATTERS!)
- POM, Acetal
Use the PLA to make a lossless cast of the key and use metal
Find a easier lock and or invest in oil for the lock.
"You're going to need a bigger boat^H^H^H^H filament" . Perhaps one of the carbon-fiber-loaded filaments will hold up, or perhaps a bunch of silicone spray dumped into the lock cylinder is needed.
If you want to get really fancy, start with a thin metal key blank and deposit the filament around that. This might give you enough structural strength. I don't know exactly how you'd print on three sides, as typical RepRaps and their ilk aren't set up to work around an object. Possibly printing with the key vertical and zero infil would allow you to insert a metal stiffener after printing.
First step is to optimize the print, layers, shells and infill. While ABS should hold up, if optimized, for at least one use. It may not be the best filament. PLA actually tests higher PLA vs ABS.
As I had posted in a comment, finishing ABS adds strength to the filament bundle. An acetone dip, vapor or hand wash of the part helps bond the outside edges. Parts that I make out of ABS for use on my car and motorcycle I vapor finish then polish with a soaked rag for a much more durable part.
Comparison tests of filaments are out there for the searching SUCH AS THIS ONE which compares strength of common filaments in use as a caribiner. But finding one that does a true comparison like the ABS vs PLA that I linked I have not seen.
If you do look at other filaments I would avoid ones like iron, stainless, brass, carbon fiber, etc. as these actually are shown to be reduced in strength as the particles suspended lower the filament bonding.