Draw me to the moon…

…Led me sweep among the stars

 

So, I have a long therm project that will require a display with some particular needs.

I want it to work with 3V3, retro-looking and curved.

Yup, nothing off the shelf is going to work for me (flexy o-led displays with a big aspect ratio are not going to be a thing in time, and they don’t exactly look the way I want the thing to look anyways.

We could say I want to inspire the display in these:

The gorgeous HDSP-2000’s wich are nigh impossible to obtain nowadays at good pricings (and besides, they are small for my application). But the amber dot matrix look is just too gorgeous to let it pass, so I started drawing my concept:

8×8 groups of leds, using a SN74LVC244 line driver as row selector, and 74HC595’s shift registers to select the columns using a clock signal (and a start pulse). The thing is, when I started this, I was not sure I could program a microcontroller well enough to actually use such a display (for some people it would be awalk in the park, but to me, programming is always a chore I don’t particularly like to do). Of course, since this post doesn’t have a doomed kind of tittle, and I’m actually writing this post, is fairly evident I succeeded.

Oh, sorry, spoiler alert. XD

 

 

Anyways, so I just put myself to Altium the shit out of this thing, one schematic at a time:

Then PCB it:

Damn altium. XD

For a moment, I was also afraid I would have to chase every individual led, however Altium was kind enough to group them in couples of 8 leds:

At first I just put them horizontally, altough I knew I was going to rearrange them to be as compact as possible (1206 led footprint):

90º rotation and compaction afterwards:

The other componentry:

It’s not like it’s a particularly difficult board, but I spent an insane amount of time compacting it for a 2 layer board. (remember, this is a prototype to test my programming skills (and secondarily. that the circuit worked).

8 row input lines, a clock input and traveling pulse input.

And, since I was at it…made it BLACK:

Nope, there was no way of avoiding those three jumpers without heavy board remodelling, and I was tired of it already. Two weeks later:

First, a bit of testing:

Once I was satisfied I assembled the rest, and lo and behold!

Consumption is moderate at 40-ishmA, as per design.

However, not everything was perfect in the land of the led. Previous tests where only lighting one led at a time sequentially, and that is innefficient both because I designed a parallel load, AND because reduced overall light intensity per led. Given that I was already working at very low levels (5/8mA per led) reducing it even more was not going to help with visibility. When I tried to start doing more, this happened:

 

That line was supposed to be one led thick, but somehow, the line was doubling horizontally.
Hummmm…
Quick check with the scope:

LMAOOOOOOOOO, no wonder the leds where doubling, I had made the software in such a way that it put the (blue) led activation, in between column pulses. XDDDD
Some softwareing later:

Nice and cozy!
Beautiful pulse-within-pulse (blue led activation, yellow, column selection).

After some more fiddling with the STM32F103:

BAHAHAHAHAH…Had to be done, sorry-not-sorry. XD

Some more poking:

The software side, in the next post, folks!

See ya!

Tapestuck

Fucking fuck of fucks!

And that can ruin your day pretty quickly, dear lads.

Stimpak, an overkill mechanical paste dispenser.

In the age of internet, some people think it’s weird not looking up if something exists. I myself I’m in the leage of “buy the tools if possible”, because I don’t like spending time creating the tool I need AND then more time to do what I intended to do in the first place.
However, in this case, it didn’t cross my mind that it could be possible that what I needed already existed (not in a egotistical way, I just didn’t thought much about it). Anyways, I wanted a mechanical paste dispenser.

Easy enough, a screw, a syringe, and something in between to hold everything together, right? Well, normal metric screws do not bear well with pressure, they tend to bind, so I figured that, at least as a test, I could go by with a micro fine pitch screw. As I didn’t had such a screw (or tap, for that matter) at hand, I had to make my own:

That’s like half a millimetre or less pitch screw in a 8mm diameter shaft. That would need a keyway guide AND machining the end to accept a standard plunger tip:

Since I had made it at home, I also had to make a tap for the nut/actuator wheel, wich was simply done by putting a cone on a threaded shaft and some relief cuts so a sharp edge with all the threads would engage on the nut material:

The point here, tough, is that the shaft was 8mm, so in order for the tap to work, I had to make an undersize hole, probably in the order of 7.8mm or so in the nut, but I don’t happen to have a drill in such diameters at hand AND they are usually expensive. However, if I freezed a drill bit to -12ºC, I could achieve somewhat the same effect:

Super cold alcohol+water mix to freeze the drill bit.

And there we go!

Shaft threads haven’t been deburred yet on this photo.

So, did it work? Well, more or less it did:

However, the nut bind easily because of the shape of the screw threads AND the friction against the backplate. As expected,  I stripped the nut threads, as acrylic is not the best material to machine high load/friction parts. But the concept was there and somewhat solid, now it needed a real trapezoidal screw, a technic material for the nut and some bearings.

As before, a tap is needed for this screw:

With that I could thread a delrin wheel and machine the leftover screw end to accept the plunger:

Also machined two flats on the screw, as I did not like the keyway idea in the first prototype:

With all that done, a needle bearing (and some acrylic machining I did not photograph) there it was:

The bottom plate captures the syringe in place, and the top bearings both grab and guide the axle so the gear can do it’s job. The needle bearing removes stiction between the top plate and the gear.

It is made to be easily removable/serviceable:

In action:

Note how fast stops the paste extrusion. (nothing exceptional, just that it does XD! )

It will have a ratchett mechanism to actuate the wheel and a small nut on top to make the needle bearing captive, but it sorta works now, wich was the objective.

Primitive-ish Technology.

Apart from being the name of the most awesome chanel in Youtube, this is what can happen if left to my own devices without supervision:

In a post-apocalyptic world, when all knowledge is lost, if I ever arrive to an abandoned SMT lab, I can always make survival tools to puzzle everyone who finds my corpse.
Closeup:

XD

U hungry?

Reel feeders, what the heck do they have inside?

This is just one type in the feeder world. I will photograph the pneumatic ones when we get to use them.

And, what does a feeder do?

Sorry for the background sound, it’s a portable generator we’re using while the electric company decides wether or not to provide power to our machines.

When the feeder nozzle picks a part, it briefly interrupts an opto switch. Once the interrupt is gone, it advances a piece. It doesn’t actually know what the piece spacing is, you have to program it (via button presses) to set both step and fine tuning the center.
Part centering is only critical as small as the part goes, but not for the machine itself to pick it up, you can adjust pickpoint as you please from the GUI, but if you wander too far, the pick won’t trip the optoswitch, and hence, not advance a part, generating an error (vaccum error I think, will check tomorrow)

Barebones

Some time ago, I mentioned some weird led packagings that we would be seeing in the future…

Well, the future is now, more or less:

If you’re not surprised yet, just watch this:

I mean, this is almost the absolute minimum, bar making the ceramic substrate thinner.
In the race for material efficiency, whe’re reaching really absurd heights.

The Machinist, episode 0: Tango for two.

And so, it begins…

Just test fitting one of the two (or three) SMT lines we will have, for the electricians to make the apropriate connections. Won’t be filming that or the enclosure build, because I’ll be busy working, but you’ll have full coverage of the real fitting, starting and everything else of the machines. Enjoy! (XD)

What we’re moving (in order of appearance):

1. Solder paste dispenser.
2. Vacuum cleaner.
3. (set aside) dual stacker for the yAOI* machine.
4. Destacker. Dual operation, from rack or bare board stack.
5. Conveyor, (1m).
6. Pick and place unit. (six nozzles, up to 10.000 components/hour).
7. Conveyor (just 3 frames, 50cm).
8. (set aside) yAOI machine.
9.  Second pick and place unit.
10. (set aside) dessicator chamber for component storage.
11. /TOP SECRET/
12. Oven (5meters)
13. Stacker (board line to rack)
14. yAOI destacker.
15. yAOI machine. Artificial vision board inspection. (it’s AOI, but I have added the “y” for fun, look it up)
16. yAOI stacker, dual rack (good and rejected boards)

After that, we moved one pick and place to check for spacing for a second line, or even a third, that has to be decided.

As you can see, there are no special crews or anything like that to assemble the machines. Just two guys moving the machines they will be operating (that’s my boss, by the way, as you can see, he did as much work as I)

Look for the tag #The-Machinist to see the complete series once it has more than one episode.

SkyFall

This is the end
Hold your breath and count to ten
Feel the earth move and then
Hear my heart burst again

For this is the end
I’ve drowned and dreamt this moment
So overdue I owe them
Swept away, I’m stolen

Let the sky fall
When it crumbles
We will stand tall
Face it all together

Let the sky fall
When it crumbles
We will stand tall
Face it all together
At skyfall
That skyfall

Skyfall is where we start
A thousand miles and poles apart
Where worlds collide and days are dark
You may have my number, you can take my name
But you’ll never have my heart

Let the sky fall (let the sky fall)
When it crumbles (when it crumbles)
We will stand tall (we will stand tall)
Face it all together

Let the sky fall (let the sky fall)
When it crumbles (when it crumbles)
We will stand tall (we will stand tall)
Face it all together
At skyfall
[…]

This is the end…

Or…is it not?

A story ends…a new stage begins…

I will soon be moved off from production to become a SMD machinist. I’ll be heading towards controlling not one but three SMT assembly lines. I have no fear in me from long workdays and odd hours, but I keep wondering what will happen to me. Will anything from the old me remain when the training is over and I’m on my own?

As said, I have no fear, but I do contemplate the fact that I might burn up quickly. I’m not sure my bosses take that into account.

I haven’t chosen the song lightly either. When it says we will “face it all together”, it’s because as long as I’m able, I am going to keep a journal, both in video and text, of what it is to become a machinist, what do you do, what do you learn, and if I burn up, you’ll see my fall.

On the other hand, I wonder if my new boss fully understands what he’s got with me. He hasn’t done any interviews, as I have been just hand picked. He barely knows me, just that I like machines, machining, electronics and stuff…but that I also don’t see my bosses as superiors but as equals.

If I see something wrong, I say so. I will always spoke my mind. I will also work more like a robot than a human (I don’t drink coffee, I don’t smoke, so I don’t loose time in nonsense. I like efficiency above everything else, and I don’t waste my time at work, or if I do it, it is in a fully approved way by the A.S. Enrichment Center).

It is interesting because I am going to apropriately meet him in a road trip across the country to get the machines. I don’t know if sitting in a car for 10 hours with your future boss is the best way of being introduced to someone.

Also, he doesn’t know that this is a reverse job interview. He doesn’t have to like me as a worker, I have to like him as a boss, otherwise I’ll pass the offer along to the next coworker who is adequate for the job. I’m not sure either where this self assurance comes. I know the job must meet some basics like let me play around, document things, carry my bag-o-tools, mount my own boards, use the tools for my personal projects, etc…plus some extras I plan to add to better fit the job timetable to my needs. Basically I don’t especially need more money (altough I could use it for something, sure.) and I don’t need being stressed, yelled, forced to overtime and work outside a normal job envelope. And since I don’t need that, I feel free to say no if all that doesn’t come with a set of bonuses and benefits as big as a mountain, apart from the money, I mean.

Of course there are still posts to be written (and some drafts to be published too) about the laser, the CNC router and if I ever finish the 3D printer, that too.

Because of too much KSP, I just feel like going too fast in a reentry…

Titanic.

Nope Ledonardo, you won’t fit in the footpint:

XD!

Thaumetopoea Pityocampa

Who will get the joke?

For the lazy ones.

Now that you’ve seen it…

HOW, JUST HOW, does this happen? Note that all the diodes are soldered between them too. Mulder, I think this one is for you.