wizdumb

Thanks for sharing! Maybe I'm missing it, but I don't see the Security Director role listed on the careers page? I do see an Eng Director role listed under the R&D: Security section, however. Uncertain which is which. Thanks again!

Hey everyone!

I wrote an in-depth article about a project I've been working on -- the Open Trickler! In this article, I describe how I built it, how it works, and how you can build your own for under $60! The project is open-sourced and it uses off-the-shelf components. The controller was written with NodeJS and the mobile app with Flutter.

I hope that this content is high quality enough to justify the time you spend reading it, and how much time it took me to create it!

I’d love to hear your feedback and answer any questions!

Author here, thanks for sharing! Happy to answer any questions!

Hey folks,

This is an article I've been meaning to write for years. I finally found the time to do it and am happy with how it turned out. Enjoy!

Hey everyone!

I wrote a quick article to give an update on the incredible progress that's been made to the DIY accelerometer project I shared before[1]. Most notably, it's nearly six times faster!

This project is fully open-source[2] and I have no plans to sell it complete or even as a kit. Keeping it open allows contributors from all different backgrounds, which led to the improvements I describe here.

I'd love to hear your feedback and answer any questions!

1. https://news.ycombinator.com/item?id=18888405

2. https://github.com/ammolytics/projects

Hey, thanks for looking!

Fair enough! I don't have the budget for a machine pistol, but maybe someone who does can try that idea out.

Hi! I see a lot of "you could" in your reply, but I'd like to point out that I released this as an open-source DIY project so that anyone could do whatever tests they wanted. I encourage you to build your own -- I'd love to see what you can make and learn with it!

Nice! I have that board as well, but only played with it briefly. Do you have any data from your use of it on the pistol that you'd like to share? I've love to see how it turned out.

Thanks for the feedback! The Feather board I'm using actually has Bluetooth, but I have not explored using it yet. If it's faster to send data over BLE to an app, then that would make this project even more affordable and smaller because the SD card and RTC are no longer required.

I believe the Feather M0 board I'm using is also capable of running CircuitPython (fork of MicroPython). For this project, I wanted to keep it simple, so I opted for Arduino, though I am more familiar with Python.

If you have any specific advice or improvements you'd like to suggest, I'd love to get them in either PRs or Issues for the project over on GitHub! https://github.com/ammolytics/projects/tree/master/accelerom...

You definitely could! I chose not to simply because I wanted to make it smaller. The Feather boards are a bit smaller than the Pi Zero.

Based on the feedback from my previous experiment[1], I wrote an in-depth article about the accelerometer unit I built. In this article, I describe how I built it, how it works, and how you can build your own for under $50! The project is open-sourced and it uses off-the-shelf components. Data analysis was done using Python, Pandas, and Plotly.

I hope that this content is high quality enough to justify the time you spend reading it, and how much time it took me to create it!

I’d love to hear your feedback and answer any questions!

[1] https://news.ycombinator.com/item?id=18731322

I believe I provided both imperial and metric units for every equation. Maybe I missed one? I'd be happy to correct it if you can point me to the specific instance!

Thank you for taking the time to read it!

Thank you! Yes, as merlincorey correctly mentioned, they're called "violin plots".

[shameless plug] I hope I can convince you to subscribe for when I tackle this topic in a future article! ;)

Thanks for the question! Keep in mind that a huge explosion (with 40,000 PSI) is happening inside the chamber of the gun. Some of that energy pushes the bullet forward and the rest pushes the gun backward. You're right though, the gases escaping the barrel also contribute to this, similar to a rocket engine!

Thanks for the feedback! I've heard this suggestion a few times, and it is an interesting thought. I believe that the calculations I did which show that the bullet has left long before the rifle moves under recoil contradicts this.

That said, I'm more interested in the truth than who is right or wrong. I've open sourced all of my data and want others to try this experiment for themselves and share their results rather than rely on me as a source-of-truth!

Thank you! As I mentioned in the Next Steps section of the article, measuring the effects of bullet sorting by weight & length is definitely a topic for a future article.

There are several physics equations (some I linked to in the article) which discuss this topic. One of the main takeaways I learned from running this experiment and doing some of the math was that my rifle is 900x heavier than the bullet, which is why it is able to accelerate so much faster and leave before the rifle/barrel move at all.

It does bring up a good point though, which I'll cover in the article where I deep-dive into the physics: Knowing the acceleration of the rifle, I should be able to calculate how far it has moved in the same amount of time it took for the bullet to leave.

Thanks for taking the time to read it, and for your feedback!

I shoot with it all the time and haven't noticed any variation because of it (though I admit I have not tested this directly). FWIW, I was able to earn my F-Class Mid-Range High Master classification while using it.

Great feedback! It's definitely true that I need to do some more research on this particular aspect. My trigger is set to 1 pound before it breaks (some folks set theirs to 2 oz!) Pulling it gently, like you're supposed to, shouldnt generate the same acceleration as if you were to "slap" it (which is a bad practice for accuracy and precision).

It may require faster data acquisition, so I hope that folks will contribute to the accelerometer project that I open-sourced to make that possible! https://github.com/ammolytics/experiments/tree/master/recoil...

Thanks again!

Thank you so much, this really means a lot to me!

Thank you for reading it and sharing your thoughts!

I'm just here to learn and share. Hopefully this will help towards breaking down some negative stereotypes about a fun an interesting hobby!

Thanks, I'm glad you found it helpful!

Thank you! Funny story: I built the accelerometer with the original intent to see if I could correlate "bad" shots during 600 yard matches to flinching. That's still a work in progress, but because I had it working I was able to use it for this experiment as well!

I live in Oregon and am fortunate enough to be within 40 miles of an amazing club where I can shoot out to 600 yards every week with an awesome group of people! For what it's worth, you can (and should) drive out to Ohio for the National Matches at Camp Perry in the summer. It's on your way to Cedar Point ;)

Thanks! It's my first time sharing on HN and I'm thankful that it has been well-received.

Thank you for taking the time to read it, and for the positive feedback!

Thank you! As I mentioned, I hope to tackle the physics portion of this topic in another article. I had originally included it when drafting, but it got way too long and off-topic.

That said, you're spot on with your equations, though there are a few others I'll cover as well!

I wrote a long-form article about an experiment that I conducted this summer to explore the question of whether or not recoil-management techniques have an effect on muzzle velocity. It involved a bit of data science (Python, pandas, plotly), some hardware (arduino, 3d printing), and math (LaTeX). I hope that this content is high quality enough to justify the time you spend reading it, and how much time it took me to create it!

I’d love to hear your feedback and answer any questions!