A cautionary tale

[teetee]

I recently got into 3D printing and I printed a key for my 2015 Mazda 5 Sport.

The door worked with the printed key so I proceeded to test the key on the ignition lock.

The key worked to turn to the starter position which was a good sign.

When I tried to pull the key out of the ignition, the key only moved halfway before it got stuck. I tried to pull it with an grippy applier and it eventually broke in half. I was holding half of the blade while the other half stayed inside the lock cylinder.

Now that the cylinder stops working and all the online resources on DIY cylinder removal require the cylinder to be turned to the ACC. position to expose the release pin on the side.

My 20/20 hindsight is if I were to do it all over again, I would remove the cylinder and do a bench key test rather than having it tested in the car. That way at least I can rebuild the cylinder myself. But now anything I think of will involve in destroying the housing just to get the cylinder out. Not sure if I should go to the auto shop or the locksmith for them to take out and rebuild the lock cylinder.

If there is a way to bypass the cylinder lock but still give the functionality of all the key positions, I would try it.

 

[ERD50]

I'd try a locksmith.

But I'm not sure what made you think a 3D printed key would be strong enough for a lock anyhow? Those are pretty weak plastic, with lots of weak points in the layers.

-ERD50

 

[old medic]

I'd try a locksmith.
-ERD50

X 2

 

[Surewhitey]

Similar to your story was my ignition on a 2002 Toyota Avalon "broke connection" internally. There is a small cast pc that sends a signal from the key fob to the switch (anti-theft feature). We were living in Mexico when it happened and it was a recall item come to find out.

Well, Avalon is not sold in Mexico and they would not do the repair & could not even get the part. I removed the key portion to bypass this. The only problem is that the steering locks in place (more "security feature")...

Some how it ended this feature and I drove it back to the states hoping it would not lock the steering again & using a screw driver to start it. I felt so gangster for a few days... They fixed it overnight and we sold it a couple of years later.

 

[captain3d]

Heat it up to the melting point of your printer plastic

 

[Sunset]

OP - using a plastic key seems like a bad idea. Next time get a metal key and just file it to the correct shape copying the original key, or get a real copy made.

Don't know your car, but in general:

I'd suggest removing the housing, or loosening it enough to get to the pin, or even calculating where the pin is located and drill a 1/2 hole or 1 inch hole to get to it.
Later you can plug the hole with a rubber grommet.

Our Camry got fussy when turning the key, so I finally took out the lock. Learned I could start the car without the key assembly in there (seemed like lousy security). I took out all the pins to the key except for 1 and that "fixed" our key issue nicely.

 

[teetee]

OP - using a plastic key seems like a bad idea. Next time get a metal key and just file it to the correct shape copying the original key, or get a real copy made.

Don't know your car, but in general:

I'd suggest removing the housing, or loosening it enough to get to the pin, or even calculating where the pin is located and drill a 1/2 hole or 1 inch hole to get to it.
Later you can plug the hole with a rubber grommet.

Our Camry got fussy when turning the key, so I finally took out the lock. Learned I could start the car without the key assembly in there (seemed like lousy security). I took out all the pins to the key except for 1 and that "fixed" our key issue nicely.

With the immobilizer chip being used in my car I think it's secure enough to only have 1 tumbler key in the key cylinder (instead of 8 that requires exact match of the key blade to turn it). Taking out the lock cylinder is my current major block though.

I will try to get the cylinder out by some of the online suggestions this weekend and if it still doesn't work, then I will call the locksmith.

Thanks for all the comments. Definitely learned a hard lesson here. Once I have the issue resolved, I will try it out with the ABS printed key instead.

 

[HarveyS]

Definitely learned a hard lesson here. Once I have the issue resolved, I will try it out with the ABS printed key instead.

Uh, what was the lesson learned if you plan to "try it out with the ABS printed key"??

 

[misanman]

Buy a lock pick set (available online). I was able to use one to remove a key that was broken off inside a lock. Although it was a metal key and that might make a difference. (The lock froze up and grandson was so determined to open it that he broke the key off).

 

[latexman]

Me thinks OP is saying to himself, " What Was I Thinkin' ".

 

[38Chevy454]

I have an idea to get your lock cylinder out. You have the broken off end end of the key stuck partially out in the wrong location for the lock pins - but you also have the rest of the key that came out with the broken end mating half. Use that end as a pattern to cut a *metal* key off the same as the broken mating half. Now install that into the cylinder, which will push the broken off end back into the cylinder to the correct location. This should allow to turn the *metal* key to allow it to get to the accessory position so you can access the pin to remove the cylinder.

Then get a new cylinder with new metal keys. Don't use plastic keys.

 

[OldShooter]

... Once I have the issue resolved, I will try it out with the ABS printed key instead.

Well, at least it will be easier for you when you have to deal with that key broken off in the cylinder.

 

[Sunset]

.....
I will try to get the cylinder out by some of the online suggestions this weekend and if it still doesn't work, then I will call the locksmith.

....

Be cautious with your choice of locksmith. This is a type of service that has many scammers in it.
They advertise, but all the calls go to same call center, then someone does show up, fusses for a few minutes, and announces they have to drill the lock.

The charge is $250 for drilling, plus you now need a new lock now, and maybe someone to install it

 

[Texas Proud]

Why use a plastic key when a metal one can be bought for a few bucks...


Now, if you have a key with some chip in it then it will cost a lot more than that but a plastic one would not work then...

 

[teetee]

For all have suggested metal keys. Thanks.

Unfortunately I do not have any locksmiths in my local area that are cmpetent enough to make a copy of my car keys. I have tried multiple locksmiths and the 3d printed key made was the only one actually worked.

Or I can drive long distance to big cities and try my luck with the locksmiths there. The plastic key does work without much difficulty (or any key really) if the cut is precise for the tumblers in the cylinder.

The plastic fragment in the cylinder is stretched and so J don't have much hope that will still work. As matter of fact when I tested original car key earlier today, I could no longer feel it half way. But it still doesn't allow me to turn the key.

For those think ABS is the same as PLA, They are a lot tougher and more heat resistant which is more similar to the metal key and more suitable than PLA.

But really getting the cylinder out of the car before doing the test on it is the lesson I learned.

 

[teetee]

I was able to use the hammer method (suggested in a youtube video below):

to get the cylinder to turn and exposed the release pin. After the cylinder was pulled out, everything went smoothly from there. The plastic fragment was removed and I even managed not to lose any tumblers or springs when I took the cylinder apart trying to learn how it works. The stock key worked seamlessly after the cylinder was cleaned and regreased and put back into the car.

I am now considering buying a lock cylinder of the same model and some tumblers to re-code it so my stock key will work on it. Then I will have all the time I need to perfect my 3D model modifications and test it on the bench without having to put my mobility at risk.

All the shops shown in google search result asked for at least $200 (some $500+) for this specific lock cylinder alone. I definitely dodged the bullet this time. The fragment was removed from the other end of the cylinder by the same pliers that broke it in the first place: