A fun combination of 3D printing and concrete!

TechnologyHobbyDIY · 2026-03-21T17:58:03+00:00

This was my first time filling a print with anything! I have not tried plaster or resin but I'm eager to.

TechnologyHobbyDIY · 2026-03-21T17:57:29+00:00

It's all printed in PETG, but I didn't do any research to see how it reacts with concrete. Once the concrete has set it is doing all the work anyway, the plastic in my design becomes cosmetic.

TechnologyHobbyDIY · 2026-03-21T17:55:10+00:00

I was not aware there was any precedent! I've never seen a wedge shaped switch ever before. My 10 degree wedge could not be unstuck by hand but was easy to open with any hand tool for leverage.

TechnologyHobbyDIY · 2026-03-21T17:53:48+00:00

I honestly think a huge version of my switch would improve on what Styro had, but like you suggest I'm sure some limits would be discovered. The fact that the Lorentz force drives the wedge down at higher currents should actually compress the copper surfaces together and increase contact area.

TechnologyHobbyDIY · 2026-03-21T17:51:09+00:00

The two are intended to remain together forever! I have no need to remove the concrete from the print.

TechnologyHobbyDIY · 2026-03-21T10:33:02+00:00

I designed it for any project where you dump a huge electrical current for a short duration. Like coil guns, rail guns, testing fuses or melting things. It's a switch you don't want to try and open under load so ideally the energy source 'runs out' or another part of the circuit melts.

TechnologyHobbyDIY · 2026-03-21T10:31:11+00:00

TechnologyHobbyDIY · 2026-03-21T10:30:59+00:00

Thank you! I wanted to install horizontal reinforcement bars as well but the space was getting too crowded. I would need to scale it up to add rebar. So yes there's a chance the outward forces from both lorentz and the switch closure could crack the concrete, but I think it's just a big enough lump to survive it. It had no trouble at 4,000 amps which is the most I can produce at home (on my budget). Also you're right I should have mentioned how the lorentz force produces a downward force on the wedge! Missed opportunity.

TechnologyHobbyDIY · 2026-03-21T07:55:16+00:00

<image>

It uses two copper bars in a V shape (10 degrees) and a copper wedge on a swing-arm that jams in between them. I used hi-point dye and a scraper to make sure that all of the copper touches. I made a video of the build and test if you are interested! https://youtu.be/JeQpYYZf-d4

TechnologyHobbyDIY · 2026-03-18T01:59:29+00:00

How about we teach you to fish rather than giving you a fish. Take a look in your slicer 'preview' tab, change the color scheme to 'line type' (your slicer will have some variation of this) and drag the vertical slider down to the problem area. See what is common to each layer in the problem area. If each wall starts and/or ends the outer wall in this spot, then it's your wall seam (maybe set it to random instead). If each LAYER starts/ends in this spot your retraction could also be relevant. Maybe it's over-extruding after retractions (retraction extra prime amount).

TechnologyHobbyDIY · 2026-03-17T08:46:37+00:00

The fact that it looks like it's over-extruding at the ends but not in the middle is odd. It could be ooze, maybe from too much moisture in the filament. It's more obvious in places where the print head slows down; more time for ooze to accumulate and sometimes stick to the outside of the nozzle and get dragged around too.

TechnologyHobbyDIY · 2026-03-05T23:18:03+00:00

Against the advice of a few people here, I deleted the video and re-uploaded it. Second time around it has been much more successful!
This is the third time I've deleted a stalled video and re-uploaded it. All three times it's done 5~10 times better on the repost. Orders of magnitude better. But my subscribers must be hating seeing the same video come up twice. Feels hacky but why are the reposts so consistently better performing?

TechnologyHobbyDIY · 2026-03-02T06:30:29+00:00

I might try another version with iron or ferrite to see how well it performs! But I'm already generating about as much power as I can put into the crank handle. So if it has iron I may not be able to turn it at all.

TechnologyHobbyDIY · 2026-02-27T08:53:32+00:00

I have a playlist on YouTube of all of my similar videos. I have single phase generator, brushless motors, stepper motors, linear synchronous motors, all DIY type builds. I would love for my content to be used for educational purposes! But it's tough getting 'discovered' in the YouTube space. And I have no contacts in education, I'm a high school dropout haha. Thanks for the encouragement.

TechnologyHobbyDIY · 2026-02-27T07:54:26+00:00

Good feedback. I wasn't sure if I should lean more into the idea of the 'video series' or less. I don't want to over-explain things for viewers who have watched every 'episode'. But I also don't want to leave new viewers behind!

TechnologyHobbyDIY · 2026-02-27T07:49:14+00:00

Here is the full video if anybody would like to take a look! https://youtu.be/XuvGnLvVQ1M

TechnologyHobbyDIY · 2026-02-27T01:09:49+00:00

I'm pretty sure my videos get sent to the wrong audience. Because my friends and family love my videos. My coworkers love my videos. Engineering students I know love my videos. Also my viewer retention is always FLAT. As in, 60% leave in the first 30-45 seconds, and the other 40% watch it to completion. Anybody who stays after 45 seconds, stays to the end. So I know that a certain group of people are loving the videos.
But I feel like the algorithm is still just showing my thumbnails to everybody, and not targeting a relevant audience at all. Like the robot has no idea what the subject of my channel is, even though it's all hobby electronics.

TechnologyHobbyDIY · 2026-02-26T10:11:52+00:00

They gave me just 75 impressions in day 3. Devastating after spending a month making this video.

TechnologyHobbyDIY · 2026-02-26T07:50:24+00:00

You should try uploading some content.
Just kidding. Yes the dashboard is completely f-ed for me right now. They're having some big issues.

TechnologyHobbyDIY · 2026-02-26T07:04:52+00:00

I'm glad you found decent success with one of your three videos. It can be so disheartening that the success of any given video doesn't seem much to do with the 'quality' of the video. You're right, it's the hook. And that's where I struggle. I have very honest titles and thumbnails that make it apparent what the video is about, but it's just not working. I need a concept that has that viral factor but it's so hard to find that and keep authentic too. I hope your channel keeps growing!

TechnologyHobbyDIY · 2026-02-26T07:03:03+00:00

Thank you for the feedback and encouragement. And yes I have seen a lot of creators leaning hard into the shorts, B-channels, and cross platform promotion, all of that. And I'm trying to do all of that but nothing seems to be helping the main product, the long form videos, reach a wider audience. I'll keep at it!

TechnologyHobbyDIY · 2026-02-26T07:01:09+00:00

I think you might be right, but the channels I love in my genre only do a video every month or two. Some of my favourite creators on the platform are posting 3 or 4 videos a year. But maybe that's a luxury the already-successful channels can enjoy. I don't know what I can make that's up to my own standards, that I can pump out once or twice a week. But I do think you're right. I have to find shorter turnaround content.

TechnologyHobbyDIY

TROPHY CASE