3D Printing - A New Hope

[McGee2021]

Many of us have heard of 3d printing, and i certainly have, since i have just purchased a 3d printer with a considerably large print area. 3D printing has been used for quite some time now, but until recently, was not available to the average consumer willing to purchase one. Here, in the NBTVA, you might have seen the 3d printed 52 mm hub for connecting nipkow disc to motor shafts in club sales, or the 3d printed mirror drum project in the news letter, which i have been taking part in, printing around the figure of 4 mirror drums, all of them slightly different. In-fact, what prompted me to write this post was the completion of a new mirror drum a few minutes ago! But, in my mind, the most important part of 3d printing for the club, would be reproduction of replacement parts for building models of radio chassis, chassis for televisions of any era, or even complete radios themselves, which i have been trying to do, building a scale cabinet for a Baird radio receiver, and printing it with wood infused filament, and printing a circuit board, now possible with the event of electrically conductive plastic filament. I have even printed microphone cases, modeled to resemble the microphones used by the BBC in the late 1920's to the mid 1930's, and have put a little hole in them to insert an ordinary carbon button microphone out of a telephone handset. End of rant.


Also, i will be posting a few .STL files for models that i have produced myself, such as the BBC microphone, later in this topic.

[gary]

Many of us have heard of 3d printing, and i certainly have, since i have just purchased a 3d printer with a considerably large print area. 3D printing has been used for quite some time now, but until recently, was not available to the average consumer willing to purchase one. Here, in the NBTVA, you might have seen the 3d printed 52 mm hub for connecting nipkow disc to motor shafts in club sales, or the 3d printed mirror drum project in the news letter, which i have been taking part in, printing around the figure of 4 mirror drums, all of them slightly different. In-fact, what prompted me to write this post was the completion of a new mirror drum a few minutes ago! But, in my mind, the most important part of 3d printing for the club, would be reproduction of replacement parts for building models of radio chassis, chassis for televisions of any era, or even complete radios themselves, which i have been trying to do, building a scale cabinet for a Baird radio receiver, and printing it with wood infused filament, and printing a circuit board, now possible with the event of electrically conductive plastic filament. I have even printed microphone cases, modeled to resemble the microphones used by the BBC in the late 1920's to the mid 1930's, and have put a little hole in them to insert an ordinary carbon button microphone out of a telephone handset. End of rant.


Also, i will be posting a few .STL files for models that i have produced myself, such as the BBC microphone, later in this topic.

Alas, they are still very expensive, at least in my part of the world, but it's interesting to see they can be put to good use at least!

[Steve Anderson]

...and printing a circuit board, now possible with the event of electrically conductive plastic filament.

I wonder how conductive the electrically conductive plastic filament really is? I'd be surprised if it were anywhere near as good as copper, but I guess it would improve over time. My concern would be power rails, ground planes and earth traces. Decoupling/bypassing might be required for every device instead of using one cap per 4-5 chips. For some signal lines the resistance coupled with inherent device capacitance might slow logic edges down or restrict bandwidth in analogue circuits.

Also, can you solder to it? After all you do need a reliable contact with device pins/leads. Or is there some other method?

But it's an interesting development which I'll certainly keep an eye on!

Steve A.

[McGee2021]

...and printing a circuit board, now possible with the event of electrically conductive plastic filament.

Also, can you solder to it? After all you do need a reliable contact with device pins/leads. Or is there some other method?

But it's an interesting development which I'll certainly keep an eye on!

Steve A.

Soldering, all you have to do to solder is put a soldering gun to it for a short time, on low heat, and fuse the plastic around the metal. No solder required! (Perhaps its called plasticing...)

[McGee2021]

I have just started to print a 3d scanner, a device that you put objects onto a platform and it makes a CAD model of the object, and hope to bring it to the Early Television Convention in Hilliard, Ohio in May, and hopefully i can convince Steve to let me scan a few of his precious mirror drums and mirror screws! Perhaps even his Televisor, and its parts, without disassembling it.

3D scanner:

http://www.thingiverse.com/thing:1762299/#remixes

[Steve Anderson]

Following up on the conductive filament:-

We measured the conductivity using a fixture we machined that clamps a sample between 2 sheet conductors and 1cm cubes printed on a Printrbot Simple Metal and machined from solid resin. Here are the results:

Volume resistivity of molded resin (not 3D Printed): 15 ohm-cm
Volume resistivity of 3D printed parts perpendicular to layers: 30 ohm-cm
Volume resistivity of 3D printed parts through layers (along Z axis): 115 ohm-cm
Resistance of a 10cm length of 1.75mm filament: 1.8Kohm
Resistance of a 10cm length of 2.85mm filament: 600ohm
Link to original kickstarter for more information:

http://www.kickstarter.com/projects/137 ... r-filament

The site that came from was:-

https://www.proto-pasta.com/pages/conductive-pla

Steve A.