nik12795

I’m a massive Star Wars fan and wanted to be able to use the force. There’s one scene in Star Wars where Obi-Wan Kenobi waves his hand and closes a door. It’s so simple and that’s what I think most people would use the force for, simple tasks.

The video explains a lot but here are some highlights:

- A camera + raspberry pi are used for the gesture recognition so it can recognize my hand movements.

- To open the door, I used some metal wire, a pulley, and a motor. There’s a thousand ways to open a door, but how would you have done it? I also considered a linear actuator.

- I had trouble increasing the speed of the motor to open the door so instead, I made the total length of the metal wire shorter. Assuming the wind up speed of the motor is constant, reducing the length of the wire by 80% should make it 5x faster.

Any questions? Let me know.

Love those ideas! It is voice controlled but the grenade launcher is 100% necessary

It won't let me edit it so an admin would have to. Sorry about that!

Basically +- 4 yards if it's SLIGHTLY uphill/downhill or SOME wind in either direction. If you were STEEPLY uphill/downhill or there was STRONG wind, +- 12 yards. This was just trial and error on the golf course honing it in. Would be cool to have some sensors to make that even more specific.

There were 2 tubes for the ball, so they would need to be reloaded. But my friend Jason did have a design for how I could have 12-15 balls that would automatically feed in. Just didn't have time to implement it :(

Lol love those!!

Thanks so much :) Really glad you liked it. I love making these videos. They just take so long to make. I love these final "showcase" type videos that are really cleanly edited but I'm also considering mixing in "here's how it's going right now" and releasing those videos more frequently to show that process before I release the final video (that is edited like this one).

Any thoughts about that?!

No :( we think it was just swinging it super hard for a while but pretty unclear unfortunately.

Both very informative. Thanks!!

Thank you!!

Confession: I’ve never seen Caddyshack. But after everyone telling me about my bags reference to the movie, I watched the clip where the golf bag shoots out the club haha and I can see the crazy coincidence

Wow that’s a fantastic idea

Oh there are some bloopers..

Thanks! I do that by design so I’m glad you enjoy it

The internet loves stupid crazy things haha

Thanks :)

Haha I knew someone would comment on that. I tend to hit the ball pretty far but definitely not as straight as I’d like

Thanks so much! Haha I would LOVE motorized wheels. That would be a great V2

I grew up golfing and I love to make things, so I thought it’d be pretty funny and ridiculous if I made a voice activated golf bag that shoots out your clubs. Like a robotic caddy of sorts.

The video explains some parts of how I built it and shows it off more (I even got to bring it to England to show Rick Shiels, a popular golf YouTuber), but I’ll highlight a few other key points.

- Getting this thing to rotate and finding the right motor took me a lot of time. A bunch of stepper motors I tried initially were too weak and would “skip”. I did some MOI calculations and talked with some engineers (this math was new to me) and I eventually found a motor that was just barely strong enough. I threw a 10:1 gearbox on it to solidify the torque requirements and called it a day.

- The motor didn’t rotate very accurately in terms of degrees. So trying to rotate 30 degrees would actually rotate 30 degrees +- 4 degrees. Over time, there was a lot of drift and rotating a certain number of degrees became completely inaccurate. I came up with a solution where a microswitch was clicked every time a club went by. That way, the motor rotated until a certain number of clicks happened instead of X number of degrees. The video breaks this solution down more.

- The voice assistant software is Rhasspy, an open source offline voice assistant. It had to be offline since I wouldn’t have internet connection on the course. That runs on a raspberry pi and also has the microphone and speaker hooked up to it.

- Originally I was going to use a fancy microphone that has lights and that took up all the pins on the pi, so I planned to use I2C to send commands to an Arduino to control the motor (and solenoid valves which controlled the airflow to the air cylinders that actually shot out the club). I set all that up then changed the microphone at the last minute. If I had more time, I would have removed I2C and just used the Pi. Since I didn’t have time, the current implementation is a Pi and Arduino talking over I2C.

- The video shows how I 3D printed some parts to make the clubs stay aligned in one direction so they don’t smash into each other when they eject from the bag. Just wanted to call out I’m really proud of this solution :)

About a month ago, I found a toy cap gun at my parents house. Remembering how fun they were, I decided to make the World’s Largest Cap Gun. The video shows how I built it and showing it off to David Dobrik and his friends (it almost didn’t work; the video covers that too), but I wanted to highlight a few other interesting things.

- I didn’t know David Dobrik before this video and was thinking about how to contact him. I decided to make a TikTok explaining that I was building this ridiculous thing and thought he’d enjoy playing with it. It got over 4 million views and he commented on it and DMd me to figure out the details. You can view that TikTok here: https://www.tiktok.com/@nick_ohara/video/6985282649858329861

- The biggest problem I had was trying to create the explosives. I use Armstrong’s Mixture which is a combination of potassium chlorate (found in matches) and red phosphorus (found in the striker on match boxes; my research showed you need to scrape it off). It’s pretty difficult to get raw red phosphorus, so I tried another oxidizer, sulfur. It didn’t work and I didn’t have time to scrape a bunch of match boxes. After my TikTok went viral, I only had 1 week to finish the build and ship it to him, so I was super stressed. What ended up working best was crushing up match heads then CUTTING off the striker, taping them together, and smashing it with a hammer. Realizing I could cut the striker off instead of scraping it absolutely saved me.

- I originally used springs to power the hammer to cock it back but found they weren’t reliable enough. The springs would stretch too far and would get to a point where they wouldn’t spring back. So I used latex tubing which was much more dependable.

- Shipping this beast was super expensive. I had a custom crate built by some friends who made it for free. Two day shipping was $9,000 and 5 day shipping was $1,500. I obviously opted for the 5 day shipping.

- Once we arrived in LA on Sunday night, we tested some of the explosives with a hammer. The gun was shipped to David’s house directly, so we didn’t have the luxury of testing the whole gun beforehand. I ALWAYS wear safety glasses but forgot this one time. And this one time, the explosion had some shrapnel and it got into my eye. I went to the eye doctor immediately and they cleaned it out. I was very lucky it wasn’t anything major and also that we were filming on Tuesday, so I had a day to recover.

- I highlight a lot of things that went wrong at David’s in the video. But even with all those things going poorly, David was super accommodating, understanding, and patient with us despite being stressed with other bits he was recording and editing.

- Lastly, this project was super expensive. Somewhere around $8-9k. The actual cap gun was around $2,500 (parts, tools, paint, etc), shipping was $1,500, traveling was $3,500 (Airbnb, flights for me and my two friends who filmed, rental car), and then other expenses for filming gear, food, etc.

Well I think you're making an assumption that the consumer would be educated and motivated enough to buy this product and then be willing to stick a camera in their car and keep it plugged in all the time for little short term value to the user.

Plus, with something like this, there is a difference between the end user and the person purchasing the product. The purchaser might be a parent for their child but the end user is the child. I think there's a small percentage of end users who would actually use the product their loved one bought them.

So I guess overall it feels like it would be tough to gain traction and find product market fit.

I can see how that would be an attractive acquisition! Although having a camera installed to watch the driver might be a bit of a pain.

Yeah that's a good point. I also mentioned having a social shaming method where, every time you text and drive, it automatically posts "I'm currently texting and driving" on social media.

For those commenting that this is more dangerous than just texting and driving, I think you're missing the point of this fun and entertaining experiment. I urge you to watch the video since I point out that it's not safer than texting and driving.

I also point out that there are other ways to incentivize the driver to not text and drive, like having the driver pay a fee when they text and drive.

I appreciate the discussion but a lot of these comments are bringing up points that are clearly addressed in the video. Please don't just read the headline and comment; watch the video and then lets all have an informed discussion :)

If you watch the video, you'll know that donating money was another option I considered!

Thank you!!

We answer that in the video! You should check it out :)

That's a good point. And I do agree with you that, although it may be safer with less distractions, the average consumer would not be willing to give up those comforts. How do you feel about self driving cars?

Yes, I'm familiar with Pavlok. I remember watching that episode on Shark Tank a few years ago.

I come to the same "less safe and problematic" conclusion at the end of the video (which was no surprise). It's a real problem and something worth thinking about, at least until self driving cars take over.

Did you watch the video and did you get the sense that this was actually something I thought should be brought to market? It was a fun experiment :)

I totally agree it is not the right approach and, if you watch the end of the video, I say "Is this the texting and driving solution that humanity needs? No, of course not. It makes texting and driving way more distracting and dangerous."

25% of car accidents in the US are caused by texting and driving. Although I think the “real solution” is self driving cars or some other great technology, I wanted to run an experiment where, every time you look down to text and drive, you get shocked.

The video explains some of the technical details and you get to see the hilarious experiment I ran but I'll highlight a few other key points.

- I thought a lot about different ways to detect when I look down. Originally this was just a solution for pausing the TV when I look down to eat so I don’t miss my show (lol), so I thought about using a camera to track my eyes. I started to go down this path but quickly aborted to avoid high costs and an over engineered solution.

- I eventually used the MetaMotionC sensor from Mbientlab which has an accelerator and gyroscope, among other things (more info here: https://mbientlab.com/store/metamotionc/). Their documentation wasn’t great so it took some time to get the sensor working with the Raspberry Pi. The sensor clips onto my glasses, so it was pretty simple to tweak the sensitivity settings and change it from detecting when you eat food to when you look down to text.

- Out of curiosity, does anyone have other use cases for what this glasses sensor could be useful for?

- I thought about using the Pi to send a signal to the collar to trigger the shock. This seemed pretty daunting to reverse engineer. I know I’d need some sort of transmitter to send the signal, but how else might I go about reverse engineering it to send the correct signal to the collar? Any tools, tutorials, etc that people recommend I look into? Might be useful for a future project but for this one, I used a solenoid to press the button on the remote.

- Using a solenoid to press the TV remote/shock collar remote buttons was trivial for me since I recently built a robot that plays Guitar Hero (powered by solenoids). I had struggled and learned a lot in that project so there weren't any surprises this time around.

- The actual texting and driving experiment only took about 30 minutes to run. But making the device, setting up the driving course, filming, editing, etc, made this all take about 6-7 weeks. Similar to my Guitar Hero robot which was on here a while ago (https://news.ycombinator.com/item?id=26843838), it probably cost around $1,000 for everything (traffic cones are super expensive plus smaller costs like Raspberry Pi, shock collar, and misc tech parts).

25% of car accidents in the US are caused by texting and driving. Although I think the “real solution” is self driving cars or some other great technology, I wanted to run an experiment where, every time you look down to text and drive, you get shocked.

The video explains some of the technical details and you get to see the hilarious experiment I ran but I'll highlight a few other key points.

- I thought a lot about different ways to detect when I look down. Originally this was just a solution for pausing the TV when I look down to eat so I don’t miss my show (lol), so I thought about using a camera to track my eyes. I started to go down this path but quickly aborted to avoid high costs and an over engineered solution.

- I eventually used the MetaMotionC sensor from Mbientlab which has an accelerator and gyroscope, among other things (more info here: https://mbientlab.com/store/metamotionc/). Their documentation wasn’t great so it took some time to get the sensor working with the Raspberry Pi. The sensor clips onto my glasses, so it was pretty simple to tweak the sensitivity settings and change it from detecting when you eat food to when you look down to text.

- Out of curiosity, does anyone have other use cases for what this glasses sensor could be useful for?

- I thought about using the Pi to send a signal to the collar to trigger the shock. This seemed pretty daunting to reverse engineer. I know I’d need some sort of transmitter to send the signal, but how else might I go about reverse engineering it to send the correct signal to the collar? Any tools, tutorials, etc that people recommend I look into? Might be useful for a future project but for this one, I used a solenoid to press the button on the remote.

- Using a solenoid to press the TV remote/shock collar remote buttons was trivial for me since I recently built a robot that plays Guitar Hero (powered by solenoids). I had struggled and learned a lot in that project so there weren't any surprises this time around.

- The actual texting and driving experiment only took about 30 minutes to run. But making the device, setting up the driving course, filming, editing, etc, made this all take about 6-7 weeks. Similar to my Guitar Hero robot, it probably cost around $1,000 for everything (traffic cones are super expensive plus smaller costs like Raspberry Pi, shock collar, and misc tech parts).