Hack Chat Transcript, Part 1

A event log for Back to Basics Hack Chat

Keep it simple, Simplifier

Dan MaloneyDan Maloney 07/15/2020 at 20:210 Comments

OK everyone, thanks for coming, let's get started. I'm Dan, I'll be your moderator today, and I want to welcome Simplifier to the Hack Chat. You've probably seen a few of his projects that we've covered over the years, including DIY vacuum tubes and solar cells.

Welcom, Simplifier! Can you tell us a little about how you got interested in getting back to technology's roots?

sfrias112:01 PM
MSX-BASIC, Z80-BASIC, poke/peek haha

Simplifier12:02 PM
Sure! I started off being interested in programming, but eventually got tired of the fact that my programs always had to run in someone else's playground (hardware manufacturers, VMs, etc.), so I started getting interested in hardware. From there it was a slippery slope, and I found I was only truly satisfied when I was able to make technology from natural materials.

Simplifier12:02 PM
Turns out that's a lot of fun, actually, so I started documenting it.

For reference:

Hackaday Dan Maloney

Home Brew Vacuum Tubes Are Easier Than You Think

It all began with a cheap Chinese rotary vane vacuum pump and a desire to learn the witchcraft of DIY vacuum tubes. It ended with a string of successes - a working vacuum chamber, light bulbs, glow tubes, diodes, and eventually this homebrew power triode and the audio amplifier built around it.

Read this on Hackaday

Dag Spicer12:04 PM
How did you learn the techniques involved in making your own vacuum tubes? Is special equipment required?

Dag Spicer12:04 PM
Ah! OK thanks!

Hi Dag!

Simplifier12:05 PM
I mostly just figured it out as I went along. My vacuum tube projects probably had the highest ratio of experimentation to research out of anything I've done. I think the only thing I looked up was which metals seal to which types of glass, and did the rest by trial and error.

Simplifier12:05 PM
As far as equipment, I just used a rotary vane pump intended for servicing AC units, a little oven I built myself, and a chinese induction heater module for firing the getters

Simplifier12:06 PM
Oh and a bunch of pipe fittings

Ethan Waldo12:06 PM
Have you delved in to optics and making lenses? That's a tough nut to crack for the uninitiated.

Dag Spicer12:06 PM
Were any dangerous materials used? Mass produced vts often had thoriated filaments and electrodes I believe.

Dag Spicer12:07 PM
The audio amp is GENIUS!

Simplifier12:07 PM
@Ethan Waldo I've thought about it occasionally in the past, and I may do so if I need a lens I can't buy off ebay, but honestly lenses are so simple it would have to be a matter of practicality; I can't really justify writing an article on it at the moment

Simplifier12:07 PM
simple technologically, I know they're hard to make properly

Simplifier12:08 PM
@Dag Spicer For the tubes, not at all. I just used plain tungsten; thoriated filaments don't like a poor vacuum

Ethan Waldo12:08 PM
My understanding is mirrors are simpler to make than lenses

Andy Pugh12:08 PM
A friend of mine (now dead, he was much older) tried to make vacuum tubes out of baked-bean tins and jam jars. I believe it was going quite well, though the vacuum looked like a tough nut to crack. But then some real valves turned up in the hut one night. Possibly from one of the guards... He was a guest of Stalugluft III at the time ( )

Andy Pugh12:10 PM
I guess that valves looked a bit less mysterious back when they were more everyday items.

Simplifier12:10 PM
@Ethan Waldo That makes sense, a mirror only has one critical surface

Andy Pugh12:11 PM
I tried maching a lens once. Finding a starting material with a low-enough turbidity is difficult.

Nicolas Tremblay12:11 PM
On what project are you working on right now?

Simplifier12:11 PM
@Andy Pugh That was really one of the biggest discoveries for me, was how mundane they are. They're just a hot wire in an empty bottle, really.

Simplifier12:11 PM
@Nicolas Tremblay I'm working on an electrochromic printer, using some of the same chemistry as for my cyanotypes

Simplifier12:12 PM
Well, I *will be* working on it. For now I'm having fun making prints.

Dag Spicer12:13 PM

19-rsn-00712:14 PM
Hello people, so what are you guys talking about?

So how ill it be electrochromic? Can you get the color change with electricity as well as with light?

@19-rsn-007 :


Back to Basics Hack Chat

Keep it simple, Simplifier Wednesday, July 15, 2020 12:00 pm PDT Local time zone: Hack Chat This event was created on 06/19/2020 and last updated 9 days ago. Join this event's team Simplifier will host the Hack Chat on Wednesday, July 15, 2020 at noon Pacific Time. Time zones got you down?

Read this on Hackaday

Simplifier12:15 PM
@Dan Maloney Yep, that's it exactly. I made some sensitized paper once and probed it with a battery while it was wet, and it changed color just as it does with light. I'll be experimenting with keeping it damp (using glycerine, maybe?) and keeping it stable in storage so it doesn't auto-develop.

Simplifier12:16 PM
From there I'll probably make some sort of drum and stylus mechanism to print lines of data

Nicolas Tremblay12:16 PM
You could seal it in plastic?

19-rsn-00712:16 PM
Yeah I saw this, that's why I joined. but I saw you guys ware talking so I thought I'd have a heads up about the current discussion instead of just breaking into an ongoing conversation

19-rsn-00712:17 PM
the thing that got me triggered to join was "“Have I built anything permanent?” Chances are good that most of us will have to answer in the negative"

19-rsn-00712:17 PM
about 99% of my projects never leave the proto stage :P

OK, gotcha - right now, it's electrochromicity of cyanotype solutions to make a printer. Which is pretty cool.

19-rsn-00712:18 PM
been prototyping today at work also. I needed a quick and dirty max232 circuit for debugging a controller card at work today

19-rsn-00712:18 PM
it looks like shit, but hey it works and it was build in like 5 minutes

Simplifier12:18 PM
@Dan Maloney Yep! It's nothing new, the earliest fax machines used the same mechanism. I just want to play with it and see if I can get clean results.

19-rsn-00712:19 PM
it got me to debug to thing and get it working again.

19-rsn-00712:19 PM
gonna build a nicer version soon

Simplifier12:20 PM
I'm also planning to play around with prussian blue films on conductive glass; I read a paper awhile ago that mentioned you could toggle the color, so I'm curious to see if I can get something like e-paper out of it.

Nicolas Tremblay12:21 PM
With the circuit painted on the glass?

Dr. Cockroach12:22 PM
That would be great to look into.

Simplifier12:22 PM
Right, you'd have your segments/pixels etched into the conductive layer and plated with the pigment, then have some sort of electrolyte sandwich structure to enable toggling

Simplifier12:23 PM
I've seen demos of it, but I'm curious as to the cycle life and the persistence of the toggled color

19-rsn-00712:23 PM
heheh reminds me, I have an unused bottle of conductive paint

19-rsn-00712:24 PM
really have to try it some day

That's interesting - what two colors does it toggle between? Blue and nothing, or different shades of blue?

Simplifier12:26 PM
Blue and transparent, IIRC, but different shades of blue might be possible with partial toggling. Basically Prussian blue can be reduced to prussian white (which is colorless/transparent), and prussian white can be oxidized to prussian blue. You see the latter happen if you overexpose a cyanotype; you get solarization in the dark areas, but within a day it turns blue again from the oxygen in the air.

Simplifier12:27 PM
Well, if you overexpose a normal cyanotype. My version doesn't do that.

Is that because of the extra steps you take with oxalic acid and tannic acid?

Simplifier12:28 PM
It's mostly due to the pigment former and the sensitizer being in equal molar concentration. The usual recipe has excess sensitizer, which is a reducing agent.

Andy Pugh12:31 PM
Apparently prussian blue has applications as an oral medication for heavy metal poisoning. (and that isn't a joke about Deep Purple)

Simplifier12:33 PM
It's true! The pigment molecule is shaped like a box, and metal ions can get stuck in the middle of it. You can use this to change the color of cyanotypes; if you soak a print in lead acetate for example, it turns purple.

Simplifier12:33 PM
Kind of a nasty way to get purple, though.

Which project do you think took you down the deepest rabbit hole?

Simplifier12:38 PM
Either solar cells or boiled linseed oil. Solar cells just because of how long it took (I expected a month, it took a year), but boiled linseed oil because it led to all of my other coatings projects.

Simplifier12:39 PM
Coatings were definitely more fun; solar cell research is absolutely exhausting.

Love the smell of linseed oil...

Simplifier12:40 PM
Not to say I won't come back to it, however; an efficient homemade solar cell is the holy grail, after all.

Simplifier12:40 PM
Haha same here; I've learned to judge its stage of dryness by smell.

Ethan Waldo12:40 PM
Will you continue with solar cell stuff? Very interesting IMHO.

True. Have you looked at perovskites at all?

Nicolas Tremblay12:40 PM
How efficient did your solar cells got to?

Simplifier12:41 PM
@Dan Maloney I was typing the word "perovskite" as you posted that, haha. Yes, I'll definitely get back into them later, I just have a bunch of other projects in line first.

Simplifier12:42 PM
@Nicolas Tremblay IIRC about 0.3%. Pretty low, but I haven't seen any homemade cells do better than that.

Hello guys anyone working in Lora space here? I want to know the actual range of RA-02 Som

Simplifier12:42 PM
@Nicolas Tremblay For reference, about 10% is useful, and modern silicon is around 20-25>#/span###

Simplifier12:44 PM
I've also considered revisiting selenium-based cells; my primary issue with them was adhesion to the glass (selenium is sulfur-like and has weird surface characteristics), but I never actually tried selenium on zinc oxide.

Simplifier12:44 PM
They'd be a lot simpler than perovskites, but the efficiency limit is low (5-10%)

Andy Pugh12:45 PM
Interesting experiments on that YouTube about whether boiled linseed oil rags really will catch fire. (not for him, but close enough to believe that they could)

Simplifier12:45 PM
Oh yeah they certainly can. Commercial boiled linseed oil is ridiculously fast-drying (a bad thing IMO) so thermal runaway is a real possibility. I designed mine to avoid this.

Hi @KITARP, we're doing the "Back to Basics Hack Chat" now with @Simplifier:


Back to Basics Hack Chat

Keep it simple, Simplifier Wednesday, July 15, 2020 12:00 pm PDT Local time zone: Hack Chat This event was created on 06/19/2020 and last updated 9 days ago. Join this event's team Simplifier will host the Hack Chat on Wednesday, July 15, 2020 at noon Pacific Time. Time zones got you down?

Read this on Hackaday

Andy Pugh12:46 PM
@Simplifier Selenium diodes smell famously bad when they fail. So that might be a smelly experiment.

Simplifier12:47 PM
@Andy Pugh Oh believe me, I know the smell. I tried making the oldest style of selenium cell, where you literally paint it on while hot. Not a smell I'm likely to forget.

@Dan Maloney sorry for interruption

@KITARP, no worries, join in the fun! We'll wrap up in about 10 minutes or so

Ethan Waldo12:49 PM
Which is the highest efficiency solar cell tech do you think is doable homebrewed?

Nicolas Tremblay12:49 PM
@Simplifier What reading material would you recommend?

Simplifier12:50 PM
@Ethan Waldo Perovskites are easily simple enough to be DIYed right now, and they can hit low-20s%. Their problem is moisture sensitivity, but I've seen a few papers recently about working around that.

Ethan Waldo12:50 PM
Not bad, thanks!

The exciting thing about perovskites is that they're at 20% eff already, whereas it took six decades for silicon PVs to go from 6% to the current 27-ish>#/span###

Simplifier12:52 PM
@Nicolas Tremblay I don't really read books, I generally just absorb bits of data from wherever I can. Books tend to have low information density (older books are better about this, though).

Simplifier12:52 PM
Right, and 20% is huge for how simple it is to fabricate them.

Nicolas Tremblay12:53 PM
@Simplifier Ok, any website then?

Simplifier12:55 PM
@Nicolas Tremblay Sure, here are a few of my inspirations:

Ethan Waldo12:55 PM
Unfortunately low voltage limits before breakdown limits optimizing cells by improving collector focus

Simplifier12:56 PM
Collector focus, as in using a lens? That always seemed like cheating to me.

Ethan Waldo12:58 PM
Hah, whatever it takes :) that's how the big boys do it. It can actually be lethal to be near a large solar array that uses mirrors to better focus the incoming light for higher energy gain.

Simplifier12:59 PM
I've just always preferred the simplicity of a stationary panel. Lenses and tracking take away from the elegance IMO

Simplifier1:00 PM
A lot of what I do is based on recognizing that simplicity in exchange for an efficiency loss is an acceptable tradeoff

Oh, wow, I didn't notice we went a little overtime. This is the point where we usually call it a day so the host can get back to business. But as always, whoever wants to stay on and continue the chat is more than welcome. I just want to say a big thanks to Simplifier for his time today, and that I learned a lot.

Ethan Waldo1:01 PM
Sure, and they're not always mutually exclusive to each other

Simplifier1:01 PM
@Dan Maloney Thanks for having me, it was fun.

Ethan Waldo1:02 PM
Thanks, will have to dig more in to your work.

Nicolas Tremblay1:02 PM
@Simplifier Thank you for taking the time for this chat. It was very interesting.

Simplifier1:02 PM
I'll probably stay and talk for awhile if you guys still have questions; I'm in-between projects now, so I'm not in a big hurry to get anything done today.

Absolutely, I agree. I guess what I learned most was how much chemistry is really the root of all technology

I'll wait a little bit to pull the transcript, then, to capture everything. Thanks all, and don't forget next week's Chat:


Ubuntu Update Hack Chat

Rhys Davies and Alan Pope from Canonical will host the Hack Chat on Wednesday, July 22, 2020 at noon Pacific Time. Time zones got you down? Here's a handy time converter! Everyone has their favorite brands, covering everything from the clothes they wear to the cars they drive.

Read this on Hackaday

Simplifier1:03 PM
@Dan Maloney Definitely. Chemistry is basically what magic would be if it actually made sense. It's super useful; it's a shame that it's usually taught in such a boring way.

Boian Mitov1:04 PM
Thank you @Simplifier and @Dan Maloney :-)

Nicolas Tremblay left the room.1:04 PM

Simplifier1:09 PM
Alright, well it looks like everyone is heading out, so I will too. It's been fun, thanks for all the questions and be sure to check out my website if you haven't already:


Dag Spicer1:16 PM
Thank you Simplifier and Dan!!!