Spring break week! Old electronic equipment salvaging.

Midterms are (semi) over! Springbreak is here! What best way to start spring break than by doing some electronics salvaging!

Cleaning up the basement, I realized I had an old all-in-one printer, and an old scanner, taking wayyyyy too much space. Instead of just throwing them out, or giving them away, I decided to salvage them for parts. I knew I would end up with a few DC motors (enough to make a battle robot maybe?) and a few precision-ground shafts.

This is going to be a looooong, image heavy post of me disassembling both.

Printer

Starting with the printer. It's an HP Photosmart C-3180 all in one printer.

Each sides have 2 screws, and are easily removable. No clips! What kind of madness is this? I was expecting clips everywhere! From this side I already see one of the shafts.

And gears!

Two screws on the case-side of the cover holds the whole top. This time there are tabs on the front, but just gently sliding the cover up and forward makes it pop off.

Under it, we find the top control panel, and the clear glass. The glass is held by 2 tabs on the right corners, and 1 piece of plastic screwed in the top, holding the left side.

Here's a better view of the piece of plastic holding the glass, along with the LCD and control panel on the left.

With the top gone, we now have the digitizing head exposed. Humm, why is the ribbon going to the motor so big? what is going on?

Wait...is that...yes! that motor has relative-position feedback!...or maybe speed? In any case, i'm pretty sure both can be done with this encoding wheel.

Going deeper, removing those two screws let you remove the whole top where the scanner thing would slide on.

And we're in like Flynn! From here we can see the cartridges, along with their controller.

This thing is what controls the jet of ink. It also has positional feedback thanks to a ruler with very fine lines printed on it. A photodiode shines light through that ruler, and a photo receptor then send a signal every time a black bar flies by. And I do mean FLY by. The lines are barely visible to the naked eye, and the print head is moving awfully fast! If you want to know more, go here.

The power button! So cute! And a ferrite bead just for it? wow.

Here you can see one of the 3 precision-ground rod used in the printer. This is the one the printhead slide on! It's held in place on both side with a circlip, and on this side, it's also attached to a spring. Is it for positional accuracy (so that the rod would always come back toward the back side) even though the sheet metal work can't be too accurate, or is it a structural vibration thing? no way to say easilly...and i'm too lazy to actually put everything back together test it with the spring on, remove everything, remove the spring, and try to see if there's a difference to the print quality (or vibration, but I don't really have the tools to test for that)

Once the circlip is removed, the rod slides out easilly.

A few pictures of the printhead. I couldn't find a way to remove the pcb from the plastic casing...so all in the trash it goes!

Some more sheet metal removed. We see 2 more rods, and 2 motors! Nice!

I must admit, the way this rod attached to the sheet metal was...weird. I broke the plastic to remove it, but it sure felt there was a correct way to remove it...

Part of the gear train that is used to take pages from the tray, and push them around in the printer.

Most of those gears are press-fit. What really surprised me was that the rods have small gear-like tooth cut into them. Apparently, the plastic gear is molded with the hole being a bit undersized for those tooth, and the press fit operation actually force them in the plastic, forcing them to be solidly attached in rotation.

From this point on, I don't really know what I was doing. I was simply trying to get to that last rod.

Final loot. Many push-buttons, 3 DC brushed motors, 4 precision-ground rods, 4 springs, a few gears I probably won't use, and 1 pane of glass.

All in all, that was quite fun to disassemble. It's always interesting to see just how much engineering goes into even a cheap printer. All the molding, the sheet-metal work, and the easy of assembly (or disassembly). Now, hopefully one of those motors have the same specs as one of my other ones so I can build something with two wheels...

Scanner

Humm, the top fell off...

Removed the 4 screws. The doesn't want to pop-off...humm...oh noes

Clips, clips ALL around the border. This isn't gonna be easy. humm, why is it only that black border that came off? why is everything still in one piece?

MOAR clips! Sorry for the blurry picture. The top was ALSO held with clips. Pretty much everything is held with clips.

The glass pane is actually double-sided-taped on

The electronic board for whoever's interested in those kind of things. I'm not qualified to say anything about it.

Well, that SURE looks like a 3d-printer drive...

No circlip here. The injection-molded shell has a clip for the shaft.

Looong shaft.

The belt is tensionned used a spring. Quite ingenious. i'm surprised I haven't seen that in any belt-driven 3d printers...but then I haven't seen that many of those either so meh.

I guess that's the CCD control board...

It says caution everywhere...halogen lights drivers?

The lens.

Yep, it was the CCD control board. The money shot! That's my first time seeing a "naked" CCD.

Allright, enough electronics, people will wonder why i'm in mechanical engineering again...let's look at the motor. Wait, does it has 4 wires going to it?

Yes, yes it does...humm, that....that is not a DC motor. Can't find a Datasheet, but according to alibaba, that's a 2 phase stepper motor. I have no idea what it's resolution is, but i'll be testing it later. Using this, they didn't need to use a linear encoder like the printer did.

Loot from the scanner. I'm keeping the CCD because...well, i'm sure i'm not the only one who's never seen one. The motor and the shaft will be useful, the rest i'm keeping mostly as curiosities.

Update on my Goals for this year:

I've been bad. With midterms coming, I focused on that, and set the goals aside. Had I tried a bit harder, I could've fit everything in. 

I was starting to hit a wall with the guitar, where I could play each song up to a certain level...but then any harder and everything comes crashing down. I think I need to review that a bit, maybe start trying to learn specific songs using tabs, instead of rocksmith, and play them in slow motion, and then faster and faster.

As for the Ocarina...well, everyone around me apparently hates the sound of it. So I stopped doing that too, as I was getting yelled at. I'll start again when I can play outside I guess...which means not right now, because I don't enjoy frostbites.

As for math, until my midterms, I've had problem finding exercise sets.

During spring break I got a sudden windfall of money, in the form of the vive being WAY too expensive for me with the current Canadian dollar. As such, I ordered some silicone and urethane resin to finally finish Dark Repulsor. This should be coming in the next week.

Finally, I read a book! One that wasn't related to engineering! It had been such a long time, I had kind of forgot what it even felt like, how you could get sucked into it. The book I read was "An Astronaut's Guide To Life On Earth" by Chris Hadfield. Now, i'm tremendously bad with names, I can barely remember the name of some people I interact with every week! Mr. Hadfield is one of the people, along with Adam Savage, Phil Plait, Elon Musk, Carl Sagan, Neil de Grasse Tyson, Bill Doran, Gabe Newell, Bill Nye, Charles Guan, and Stephen Colbert, whose names I remember easily, because I look up to them. So, it was that much easier for me to read the book.

What I took from the book was this: Humility is one of the most important thing. Be a knowledge sponge. Aim to be a zero, that is, to not be seen as a drag ( a minus one) nor as a know it all, above everyone.

Those, without ever having being said that way, have always been my goal as a human in engineering. Coming from a family with many technicians, all I ever heard about engineers was "Stupid engineer did X again, we told him it was a dumb idea" "We all know, they never listen to us technicians" "Stupid engineer, always so full of themselves, always making themselves to be more important, to appear more intelligent, more X than us". I don't think that is healthy, in any organization.

That is it for this post. Spring break is coming to an end (notice how I said it just started in the first paragraph...). This is probably going to be my worst post ever, as I just want to get it through the door...in a timely manner, and not in June. Next up! Rocket Building (maybe), French robot battle rules posting! Working on my first mold! And other unforeseen stuff.

Robot fighting document translation

One of the things that annoyed me when I was working as a FIRST team manager was how, whenever I mentionned robots and competition together, people would always, ALWAYS, say "Oh, you mean robot fighting, like Robot Wars?" (Except they're saying it in french). Now, unlike the USA, and Saskatoon, we don't have fancy pansy robot fighting league, motorama, or Dragon-con.
Even though, if you talk to pretty much anyone, they'll remember robot wars, or say how cool robot fighting is...well, everyone except for university deans who say it's too violent and is contrary the school values, when in reality, beside the battles themselves...it's really just like FIRST, with teams helping each others, knowledge sharing, community building, etc. Some actual engineering competition are way more toxic.

I find that really sad, how a sport that EVERYONE think is cool, literally doesn't exist in my province. Now, since everyone seem to like it, maybe all it needs is a little push. In order to give that little push, I reached out to SPARC and asked them if I could translate all their documents in french. You have to remember, many people in this province speak only french, and, while they might be comfortable enough with English to browse Amazon, reading pages and pages of rules, standards, and specification is asking a bit too much.

So, I added a new page, on this blog, in french only, where the french translation of these documents will live. Here's the link, but it should also be in the top-bar. The first one, "Règles des matchs" should be coming by the end of February.

I will do my best to spread those document to makerspaces in the province, and hopefully this seed will sprout into a competition or two. Now, I cannot guarantee I will be able to continue translating these documents as new revisions come out, but I will try. I doubt there will be huge revisions anyway.

Turnigy Receiver Tear-Down:

I've had intermittent failures on my receiver. So I decided to open it to see if the last crash it had broke something internally.

It is quite well made for dissection. There are no clips holding it. It's only 2 screws (nothing hidden!) and 2 tabs on the other side, so it's built a bit like the battery-cover on the back of your calculator!

Gotta admire the simplicity of the thing. what I thought would be right-angled pins, are actually straight pins on an angled PCB. The only thing holding the PCB there is the solder...which is fine, since in that enclosure, the only force the thing will ever see is straight pulling force.

Now, I don't have a microscope...so I can't actually tell you what any of those pieces are. especially not those tiny resistors...or caps?...or whatever is in these...0201...01005? I don't know, at this size, i'd rather replace the whole thing than having to try even PLACE those things.

Anyway, turns out my problem was in mechanical interference. The case doesn't have proper tolerances, so in some places, the connectors push on the case, and then push on every other connectors subsequently placed...so if you remove one later, it also pulls on the second, making for a shoddy connection. I could have found that out without opening it...but then, curiosity got the best of me.

Dark Repulsor

I did the plans for it before, but I need to make this cosmetic piece at some point. One method I wouldn't live without anymore is making the plan for whatever piece i'm making on Inventor, and then sticking it on the stock i'm about to cut. For complex pieces like this, it's WAY faster than taking a pair of calipers and scribing cutting marks, and for simpler pieces, it is often simpler and faster to do it anyway because chances are you've already made a plan anyway...unless you want to just cut a rectangle, then it is simpler to cut to length and not stick

Dremel and Bandsaw time! Which it is ALL the time for prop-makers.

Dremel is love, Dremel is life...And I ended up with something like 6 inches of sawdust on my shirt (exagerating of course) Remember to wear a facemask/respirator when sanding that much off wood.

And how it looks from the same-ish angle as the anime. I still need the work on the handle, and then cast this piece to have an identical copy on each side. Sadly, because I hand sanded my piece, I have some overhangs in some place, so i'll need to use silicone resin, instead of cheaper plaster, to make a mold and cast the piece in urethane. Because

And compared to my source:

The handle is WAY shorter...because it's not a 4-handed sword!

Space Gun:

One of my plans this year was to make a gun prop. Recently, japan outdone themselves (as usual) and released a copy of the Dominator from Psycho Pass. If you haven't seen it, it's worth every second of this video:

AFDWHAFWCDQRWDX WANT! HOW MUCH IS IT? 86 thousand yen? WTF?...welp...

Guess what prop i'm gonna try to make? ;P I don't tink it's going to only take this year to make though, but then, it might end up being a collaboration!

Ocarina:

As some of you may remember, one of my goals this year was practicing Ocarina at every few days, sometimes with sheet music. Well, finding free (because poor student) sheet music for Ocarina is hard! Some websites, like STL Ocarina's forum and Songbird Ocarina have Tabs (fingering charts pretty much) but no sheet music. Even if I wanted to pay for it, the quantity of work made for Ocarina is...lacking.

As such, i'm going to take some of those tabs and translate them to sheet music. I'm going to put some of them (depending on their copyright licences and terms of use) right here.

So far i've been able to play bad apple without mistakes...at the correct speed...with only one or two slowdowns where I keep forgetting how to move my fingers.