You can’t cheat physics…

…and neither can I.

So, where have I been? Up to no good, apparently.

Up until now, I have skipped altogether the way I was going to pattern the chips. The thing is, you can either have not super expensive paterning tools and expensive resists, or expensive tools and cheap resists.
Obtaining the expensive resists is, well…expensive, plus they are very especialized and sensitive. Also, the optical setup needed is not an easy task either. While looking into it, I found out that acrylic (PMMA) can be used as resist, however, it requires e-beam paterning, wich in turn means you need an electron microscope, wich is not cheap.

Some countries have kind of a market for secondhand electron microscopes, however mine doesn’t. The thing is, if you don’t actually need to scan the thing, but just to shoot electrons at it, could you use any other electron gun?

In theory, you could. It is not a question of voltage (this paper talks about very low voltage PMMA paterning) but to get the assembly to the adequate vacuum conditions. It is not enough to have a good mechanical vacuum pump.

In case you don’t believe me, here’s what a CRT tube does in 40 microns of Argon vacuum:

Here’s the setup:

Having proven that I needed a High vacuum pump, I started working on an oil diffusion pump.

However, the pieces I practiced on where 0,5mm stainless, wich proven trycky, but doable. The final pieces where only 0,25mm thick, wich, unfortunately, altough possible in short runs, it did pierce the sheet on start, wich left the pieces unusable. Shame, they where looking gorgeous:

Now that I had to start again and spend more money on it, a consensus was reached between me and an expert (to be mentioned when, if he, permits it) to try to go for a turbomolecular pump, wich are quicker to reach and stop vacuum, clean in their operation and they look like miniature turbines, wich, to be frank, turns me on. XD

 

This Boring Company II

(GO TO PART I)

Finally got to install the temperature probes. I began by drilling/reaming a vertical hole from the heat face, so even if it was crooked, the start point was correct.

After that, a bigger hole was drilled on the other side to accept a ceramic separator that came with the probe:

To make space for the probe dome and cables, a sharp scrapper was used:

And it looks like this:

The ceramic retainer is attached to the metal plate with screws, with their head on the inside, so they can’t work loose. Also, dual nuts where used:

Now looks like a partial eclipse:

In the meantime, the plasma cutter arrived, and made my life much easier by allowing me to cut simple shapes with zero effort. So, a 3D model of what I wanted was made:

That was transferred to CAD, and then lasercut some MDF stencils to gide the plasma torch:

Other project stencils, but you get the point.

And panels where made.
Plasma cutting by hand (with stencils) is tricky for internal shapes, and thus, all holes had to be tweaked with a file for the modules to fit.

I am slowly getting better at welding (and thick sheet metal helps):

After power sanding:

First test fit alongside the oven:

The control box is upside down. xD

Nuts where welded to hold the cover:

And tabs where added to hold the box away enough from the oven side:

And then the integration began:

Power cabling:

A quick note on fiberglass covered power cable. You MUST crimp the ends before cutting the fiberglass, or it will unravel and create isolation issues. I did mine with some brass tube and parallel pliers:

Since I was not in the mood to make more holes in the box, I opted for the easy cable routing:

And no, the heatsinks can’t get hot enough to damage the fiberglass cable or the silicone cable, altough the second one might get sleeved up to the probes at some point. Let’s say it is workshop friendly as long as there are no kids around. XD

When you want a compact unit, things like this happen:

Testing the power section to ensure everything is ok:

I left it cooling overnight and then installed the timer. It is NOT connected to the power section, it’s just a convenient place to have a programable clock/alarm.

The controller also has a double circuit switch to deactivate the SSR’s, so the oven power is OFF but I can still monitor the temperature.
The oven now just requires some external quartz tube supports, but it can be used as is for now.

See ya!

Saw. (I want to cut a game).

Do you own a cheap metal bandsaw?

Let me guess…You hate to manually adjust the cutting angle in the clamp, right?
Me too. It is a hassle, and unless you spend a considerable amount of time setting up, it won’t be spot on, and sure enough, you will have to switch between angles amidst job, ruining the setup. Also, the clamp will move under pressure no matter how much you tighten it up, making a mess without you knowing.

Here’s what I did:

1.- Spend the necessary amount of time setting up my 90º angle. Tighten like there is no tomorrow.

2.- Drill, and ream to a hardened pin.

3.- Repeat for other angles (22,5º for a compound 45º, and 45º)

4.- Enjoy cutting.

The pin will fall down if left unattended, I have a pastic sleeve on it’s top, to prevent it from falling through.

Be careful where you drill, not all angles will have enough material underneath to support a pin, or they might be too thick. Either way, 90º-45º-22,5º should suffice for most jobs.

See ya!

Charge that bitch up. (practical plasmas under bad vacuum)

So, here are the videos I recorded while experimentint with the refrigeration vacuum pump:

SETUP:

• Voltage: 350/500V
• Current limiter: NO.
• Plates: Aluminium.
• Vacuum: Around 300 microns.
• Plasma trap spacer: 4,5mm.

1.- Just testing the magnetic trap with lower gap. Glowing hot aluminium can be seen at some point.

2.- Wondering what would happen if the magnet was inside the chamber? Magnet is at positive potential, copper foil is isolated.

3.- Same setup, but copper foil at positive potential.

4.- Magnetic effects on the residual plasma bubble

5.- Magnetic effects on the residual plasma bubble, in slow motion.

6.- Trying to start the sputtering plasma without low enough pressure, generating sparks in the ionized gas. Once the vacuum gets further down, the plasma stabilizes.

And that’s all I got with the not-so-good vacuum pump.

See ya!

Emergency blowtorch ignitor

Because I could not find any gas lighter around the house.

No regrets. XD!

DISCLAIMER:

Doing this you will damage the front end of the blowtorch, use it only in an emergency case.

HVAC or not HVAC, valve is the question.

On your baby steps towards medium/high vacuum, you will be tempted to go cheap on some things. Tubes and connectors are fine, there is not much that can go wrong with those, however, there is a point that will bring you failure real soon.

Valves.

You will probably have started with a refrigeration vacuum pump (we all do, don’t be ashamed) and it’s interesting, but headachy 1/4SAE connectors. For those, there are not that much range in valves to choose, and the most common is this one:

For sure there should be high quality ones out there, but if you have the money for those, better skip this step and go with KF flanges and a good pump.

For the ones trapped in the 1/4SAE world, be careful. If you must use one of these valves, they WILL NOT seal the same way from one side than the other.

Here’s a hand drawn schematic of the insides:

As you can see, the only confiable seal is the rightside. the rubber gasket is under pressure from the ball and the body, so, if any of those seals has to be any good, this one will be. The leftside seals are not especially bad, nor extremely good, they will do, up to a point.

However, the ball actuator o-ring, sitting between two metal plates is something to be aware of. Altough the ball axle itself is polished and nice, the o-ring seat in the body will leave much to be desired, thus, making a less than improbable good seal. Should you have your vacuum chamber connected to the left (vacuum pump to the right) of this valve, I assure you it’s vacuum will not last, both open and closed valve.

Having it the other way around will not prevent circuit leaks (keeping you from the ultimate vacuum your cheap pump could attain) but at least with the valve closed, your chamber stands a chance.

See ya!

The Ideas Factory. (Jingle Bell Labs)

So, what have I been up to?
Well, as I mentioned before, I was moving location, and indeed I did. An important part is that It wasn’t me alone, I was a package comprised of a man and a workshop, so here’s the interesting bits:

Just after arriving:

Making bases for the Mill and Lathe. (75kg of cement + 4cm thick foam insulation)

Positioning mill before sliding it into place:

Mill in final position, before tramming vertical column and inserting head:

Lathe, minus carriage and tailstock:

Computer table (also mill head on the bottom right   XD ) :

Adding wheels to the table so I can access the bandsaw:

Assembling the electronics table:

Avengers assembled!

Laser tetris:

Sideview of the laser tetris.

Preparing the air extraction for the laser:

Convoluted air path:

Cleaning the inside of the tubes from unneded joint supports:

Mockup of it’s placement:

Heat formed pvc linkages for the extractor:

Rubberized wood support for the fan, it goes into the window well:

Installed:

Custom tool to dismantle power strips:

Power strip modding to make them wall mounted, for M4 nylon screws:

M4 threading:

Temporary metal screws while waiting for the nylon replacements:

Preparing electrical distribution, 16mm PVC tubing, gray boxes, 2,5mm2 cable:

Power connection on the cheap:

Welding cart:

Welding shelves for the electronics table:

Yeah, that’s space saving, baby!

Lighting, because of productivity reasons:

Materials shelf:

Router water cooling, hidden underneath a corner table:

Humidity protection for the table top:

Router casing and placement:

Noise isolation:

Lighting distribution casing:

Bluetooth relay board:

Power connections inside the box:

Welded and trimmed:

Light control APP testing, custom raped from an open source bluetooth SPP app, using android studio:

Sort of final layout:

And here it is in all it’s splendor:

I’m quite happy with it, altough some more meters would be nice, it’s way better than what I had back in the old home. It allows for so much more and direct applied creativity…you’ll see, soon ^^

Up Next:

What has been sidetracking me:

Weird and wonderfuck

So, we have this vapor phase oven at work, and recently, the vacuum hood began to raise crooked:

Technician came in, said we broke the pistons due to overpressure…

Wait…WHAT?

Yes, you read that right. A 70.000€ industrial machine that supposedly requires an external pressure regulator that the installation technician DID NOT put in.

Because wait…what is THIS for, then?

Apparently, NOT for those pistons, just for the flimsy pneumatic scissor door.

Now, enjoy some damage x-rays:

Adaptron!

Recently I binge bought this lovely miniature ratchet:

It has a certain je ne sais quoi that was irresistible.

Anyways, I also have some sets of 4mm hex bits, wich I would like to use with it, however, I found out that the only company making such an adaptor was Wiha, with this:

Wich doesn’t particularly appeal to me, really. What to do then?

Well, machine the crap out from an extension adapter:

Lathe out the end bit, saving the magnet in the process and there you go.

Nice and compact:

Also added a nylon cap to it’s end to make it easy on the finger when removing the adaptor, and, coincidentally, easing the insertion into the 1/4 socket.

Extremely happy with the result, I must say!

See ya!

Splice

Apart from being an awful 2009 movie, this is what we should do when a component strip is about to end:

Howeverr, in reality we rarely do it,mainly because the machine swallows the strip faster than you can comfortably splice it without risk of dropping the tool/ripping the strip. (Paper strips are tougher, but plastic ones can get damaged easily.

Also, shit sometimes we have to do:

Yeah, that is the same continuous strip… :/