Introduction: 3D Printed Radio That Works!! Easy to Make

I'm thrilled to unveil my new 3D printed AM radio! I was inspired by the diy crystal and foxhole radios of the early 1900's, but I created my own design to be as simple as possible.

I put a lot of work into the video. It should explain everything so check it out and thanks for watching!

Step 1: Materials

Picture of Materials

Download link for 3D model:

1 Piezo Earphone

1 Coil of 24 AWG Magnet Wire (aka Enamel Wire)

1 1N34A germanium diode

1 small piece of aluminum foil

1 paper clip

1 package of Hildie & Jo 45 Cord Ends (5x10mm Springs)

These should be easy to find online. The springs I got are sold at Joann Fabrics. Search Silver Cord End Springs but any similar 5mm diameter springs should work.

Step 2: Overview

Picture of Overview

I think it is important to show you an overview of the circuit and how everything will hook together before we get started.

Step 3: The Coil

Picture of The Coil

This is a very important part. Wind the wire tightly around the 3d printed coil holder and make sure there is no overlapping and that each layer is tightly pressed together. Take this part slowly and use tape to hold the ends and tape it if you need a break. See the video for reference.

Then we need some of the metal revealed on the front so use some sandpaper to gently remove some of the enamel. Too much sanding may cause the metal to short out. Wipe away any sandings when done.

Step 4: Assemble 3D Print

Picture of Assemble 3D Print

The coil holder will slide securely into the printed base. Feed the left side wire thought the small hole on the base and clip to the side. The right side will go into the right side spring but sand off the enamel first so it makes contact.

Step 5: Paperclip, Diode, and Earphone

Picture of Paperclip, Diode, and Earphone

Open the paperclip and flatten it. This will fit into the two sides of the base. It should be close to the coil without touching it. Cut and sand off the ends of a small piece of wire to connect the paperclip to the left side spring.

Attach the diode in between the left and center springs. Either direction will work.

Attach the piezo earphone to the center and right springs.

Step 6: Tuner

Picture of Tuner

Cut and fold a small piece of foil and loop it through the paperclip and wire coil. It should touch both the paperclip and coil of wire. Fold it through the printed tuner.

Step 7: Setup

Picture of Setup

The antenna wire should be layed out flat about 15 to 20 feet or more and go into the left spring. The longer the better. Sand a few inches off the end of the ground wire and wrap it securely around the metal sink faucet. Connect the other end of the ground wire to the right side spring. Sand the enamel off this end too.

Step 8: How to Use

Picture of How to Use

Slowly slide the tuner back and forth and you should hear faint static sound and eventually you will find a radio station!


Connect to an amplifier if the volume is too low.

Make sure everything is connected correctly, reference the video.

Metal objects and also your body can affect the radio so occasionally step back.

Make sure all connecting wires are sanded to expose the copper for best connections.

Play with the antenna. Try to tape it up higher, change the direction, or make it longer.

I hope you enjoyed this! Thank you and see you next time. :)

Step 9: Alternative

Picture of Alternative

This is just an option. The diode can be replaced with a safety pin pressed into the lead of a pencil tip that makes a point contact on a razor blade that has been heated until it turns blue. This will allow current to only flow in one direction just like the diode. This is much harder to get working but it is possible.

I like to make 3D animations, 3D programming, and 3D printing on my channel so subscribe to see more!


BobR151 (author)2018-01-16

Can a speaker be substituted for the ear piece so a group of people can hear it working, say a class?

3DSage (author)BobR1512018-01-16

This would be a great class project. If one person wants to hear this, then the piezo earpiece is the only thing that would work. Now if you use an amplification device, then any speaker would work. I used my guitar amp in the video and that would be enough for a classroom to hear.

BobR151 (author)3DSage2018-01-16

Thank you for the response. Guess I should have waited till I got home from work and watched the video though.

Have a STEM career day coming up, and this may be the kind of project that can capture imaginations. Thank you for sharing it.

trike road poet (author)2018-01-11


I made so many crystal radios as a kid my mother was sure I'd never get out of the house. DXing (Late night station hunting on am) was my first real hobby. This makes a lot of old memories come to mind, and now I have to see if I can still make a radio. Want a real challenge, try making a crystal radio as small as possible that still pulls in stations from a hundred miles out at night. Thanks for posting such a creative idea.

3DSage (author)trike road poet2018-01-16

I'm glad to hear this brought back those great childhood memories! I would like to make a really small version and 3D printing would make that possible. Thank you for the nice comment.

LOL and miles of wire stretched across the bedroom - mum would go nuts!

GrantLevy (author)2018-01-12

One thing to keep in mind is to be sure that your home has copper or iron pipes through out. Some modern homes use PEX tubing instead of copper plumbing. Since PEX is plastic, it won't work for grounding the radio (or going to earth). If you home has PEX tubing you could try wrapping the ground wire around the pipe where the water comesinto your home, that should be metal. The alternative is to buy a grounding rod and pound that into the ground. Then, attach your ground wire to it.

3DSage (author)GrantLevy2018-01-12

Good to keep in mind but I looked at my sink and I have plastic pipes but it still works. So I was trying to make sense of that. Maybe there is enough metal in the whole sink for the current to flow to. Or maybe the current can flow from the pressured water in the pipe down until it eventually reaches metal or the actual ground. Not sure but I think mine worked ok. An actual metal rod stuck in the ground might be an alternative for troubleshooting.

AlphaOmega1 (author)3DSage2018-01-15

It's not the metal, it's the connection to earth, either through the water or via electrical earth bonding of the metal sink.

Yes a rod in the ground will work. needs to bee deep and into wet soil

AlphaOmega1 (author)2018-01-15

Looks cool. We used to make these as kids, when the 3D printer wasn't even a gleam in a sci-fi writer's eye!

Most important thing is a long aerial and a good earth. Any germanium diode should work. The original "cat's Whisker" used a Galena crystal although a peice of coke was said to work

wongwaiyin.wong (author)2018-01-13

1N60 can work?

3DSage (author)wongwaiyin.wong2018-01-15

It might work but I hear most people recommend the 1N34A germanium diode for best results. If you try it and it does work, let us know. Thank you.

laith mohamed (author)2018-01-13

That is likely AM radiio

3DSage (author)laith mohamed2018-01-15

Yes this will only recieve AM stations.

LeftPawn (author)2018-01-12

Remember making something like this with my dad - but used a block of wood, scrap aluminum rod and a germanium crystal (1950's equivalent of 3D printing!). Great update!

Thanks for returning me to the past!

3DSage (author)LeftPawn2018-01-12

Wow that sounds like a fun father and son project! Yes I hope I revitalized peoples interests in this great educational and entertaining project.

abbasporyazdanpanah (author)2018-01-11

That is good idea

Thank you for saying that!

ede53 (author)2018-01-12

Great....Thanks for sharing...

zaphodd42 (author)2018-01-11

A foxhole radio was my first electronics project 15 years ago. I love the journey of discovery and making that it started me on!! I hope this one does the same for someone else!! Great 'ibble!!!! Thank you for posting.

3DSage (author)zaphodd422018-01-11

I couldn't agree more! I understand this, I designed it, and still when I use it I find it mesmerizing. I hope this gets people excited to create and have fun.

procter (author)2018-01-11

That is a superb presentation of what should be a compulsory science project. Lots of learning moments, clearly laid out and comprehensive.

My view: (a) the video was well worth the effort (absolutely complete and very interesting); (b) we all did chrystal sets but this is a fresh, stimulating re-introduction, I'm glad you did it; (c) throw in more humour (I love it!).

As for reasons to use 3D printing... because you can - that's good enough for me (I don't have a 3D printer but I'm smart enough to know I'd use it a lot).

Don't leave town!


3DSage (author)procter2018-01-11

I love what you wrote! Thank you for taking the time to leave this comment. It makes my day to know all the late nights and designing frustrations paid off! I have many more fun projects in mind so I'll be around. :)

heuretic (author)2018-01-11

Ahh! A 5th grade class project. Boys and girls each made their own sets. 3/4" pine base board, 1" wood dowel for the coil. Sheet metal strips for the wiper and connectors cut with tin snips from a coffee can. 10-32 screws and wing nuts. 1N34 diode in a tiny glass globe. A Philmore headphone set. The 50K watt A.M. radio station 10 miles away would blow the diode if the antenna wire was too long

3DSage (author)heuretic2018-01-11

Yes! A very fun project. I could see a teacher 3D printing several of these sets for a classroom and the students could keep the radios. That would really be a memorable class project.

Build_it_Bob (author)2018-01-11

Very nice work. My Dad and I made several radios years back. I like the 3D printed frame.


3DSage (author)Build_it_Bob2018-01-11

This would be a great father and son bonding project. And thank you I am happy with how the 3D printed frame turned out.

BruceF11 (author)2018-01-11

I can't figure out why I'd 3D print this instead of using an old board and wood screws... like I did when I was 9.

CharlesD82 (author)BruceF112018-01-11

Funny! My brothers and I used oatmeal and salt containers.

RickeyH1 (author)CharlesD822018-01-11

I used the same making these in Cub Scouts back in the 1960's.

jbmullis (author)RickeyH12018-01-11

Uh-huh, same here except the 1950s. We used a pine board, cardboard toilet paper roll, and some wood screws. Didn't look pretty but worked just fine.

3DSage (author)CharlesD822018-01-11

Haha yeah I guess you can really use any non conductive items. Makes you feel like a real life Macgyver.

3DSage (author)BruceF112018-01-11

You can, I just wanted to design my own. I like seeing what creative things people find to make their crystal radios.

geoclay (author)BruceF112018-01-11

because 3D printer are awesome LOL

3DSage (author)geoclay2018-01-11

Hell yeah they are! I'm with you on that. :)

misterxp (author)2018-01-11

Wonderful! Thanks for sharing we used to make these at school too ! I had forgotten all about it unfortunately. Now you reminded me I will have to make one with my son!

WarenGonzaga (author)2018-01-11

Awesome project!

3DSage (author)WarenGonzaga2018-01-11

Thank you! I'm glad you liked it.

robbo42 (author)2018-01-11

Like a lot of others who commented, this took me back and left me with a big smile on my face as I recalled making crystal sets. You did a great job with the video production and illustrating the nature of AM radio transmission.

3DSage (author)robbo422018-01-11

And hearing that puts a smile on my face. :) I'm glad to hear that and thank you I am trying my best to improve my videos.

HowardS31 (author)2018-01-11

I made a bunch of crystal sets when I was a kid (loooooong time ago), first with cat's whisker on galena crystal, later with germanium diodes (e.g. 1N34). Most were with magnet wire coiled around cardboard toilet-paper tubes, then varnished. Some with a slider, some without. This might work better with a small capacitor (.01uF ceramic) across the earpiece.

Incidentally this childhood hobby led to a very successful career as an electronics engineer, now retired. Thanks for the memory.

3DSage (author)HowardS312018-01-11

Yes I heard about the capacitor trick but I was happy with how clear mine sounded but I guess it kind of depends on how close you are to the radio tower. I'm glad to hear this brought back good memories! It's interesting that the technologies of today, 3D printers, can be used to make technologies of the past, crystal radios.

RamachandranP (author)2018-01-11

This was my first electronic project in the year 1976. This was called crystal radio, though a semiconductor diode was used. My first version was similar to this one, then I used a variable capacitor for tuning. Why is this called a "3D printed Radio" ?

3DSage (author)RamachandranP2018-01-11

Yes I think this project is a great first project into electronics. And I was thinking of making a variable capacitor but my final design seemed easier to make for beginners.

DanF43 (author)RamachandranP2018-01-11

I guess it sounds more "high-tech" than plain "crystal radio".

deluges (author)2018-01-11

Nice project.

I find your alternative diode very puzzling - what is happening here? How does heating the blade affect its electronic properties?

3DSage (author)deluges2018-01-11

I'm adding a layer of oxide to the steel. This method is called a fox-hole radio and there are some great explanaitions on how they work online.

deluges (author)deluges2018-01-11

Oh it's making a semiconductor. Duh

TexBoyd (author)deluges2018-01-11

This was called a fox-hole radio in WWII where you used a razor blade and pencil for the diode. In my childhood (born in 41) we used a cat whisker and lead+sulfur home-made crystal: <>. My uncle made a mold out of clay; melted a bit of lead; put a small pea-size piece of sulfur in the mold; poured the melted lead over it; and behold a useable crystal to use with the cat-whisker which he already had. And that was the beginning of me becoming eventually a college professor of physics! The rest of the radio was basically the same as in this project.

3DSage (author)TexBoyd2018-01-11

Yes I wanted to do my research and to be accurate and I found fox-hole radios so fascinating and creative. That's so interesting how you made yours. Maybe this project will light a spark into the professors of the future generations. Thank you for sharing that!

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