tooling progress (mill)

A great many projects are waiting for the mill to return to service. I have news about that.

The new phase converter arrived a while back. I've had it mostly-wired up for a week. I've been
er, not well, and also busy as f__k, and so I didn't really think my purchases through. So I still
don't have every thing I need to make it all go. I do have all but one thing, however, and it will
arrive tomorrow afternoon. That one thing is a 3-phase, 4-pole twist-lock connector that I
didin't happen to have on hand. Everything else is in place. When it arrives it will be a matter
of 20 minutes to be online.

Herewith an aside on the futility of saving good quality useful parts for a rainy day:
I have a boat-load of twist-lock connectors of all sorts - recessed inlets and panel mount outlets,
cord connectors, conventional outlets, and more, all for various voltages, currents, phases, et-
bloody-ceteras. And every time I have need such a thing in the past ten years, I have gone through
that collection, and literally nine times out of ten (probably more like 99 in a 100) I have come up
empty handed. The percentages do not make the space taken up (not to mention the capital
value) of them just sitting around here. So I am going to sell every twist-lock and similar power
connector I have (which is a lot, I assure you) on eBay and make a whole bunch of money to re-pay
my recently-raped hobby fund a little, even if I blow them out the door at bargain basement prices
as I intend to do.

I also ran out of money, through some serious miscommunication and well, never mind that.
That's being corrected.

So, by the next time I can find or make some free time in between self-schooling and work, I will
be able to make some parts for the Mad Scientists Light Switch, the triggered spark gap switch,
and so forth and so on.

tooling updates, part the second

Ordered: new heat gun. Old heat gun was old, and died. New heat gun is: A) higher quality, B) not suitable for stripping paint, C) lower wattage, D) highly suited for electronics work in tight places.

This will enable progress on one other project, which was waiting for exactly this.

short update on vacuum

I am still chasing leaks, but I have bigger worries which must be addressed first.

1. I need to replace the motor. A 3/4 HP motor rated for fan/blower duty is VERY different from a 3/4 HP motor rated for compressor duty. If I carry on with the motor that's mounted on it now, it'll overheat. I had to set up a fan on the motor to keep it cool. I actually have a compressor duty 3/4 HP motor on hand... that doesn't turn. BUT: I believe I know what's wrong with it and that it's easily fixed. I will be looking into that today.

2. There are several switches and pilot lights -- on both the Veeco system and the outboard vacuum tube Veeco gauge controller -- which need to be replaced. One of them is causing erratic readings on a T/C gauge.

One needs the basics working properly before one can presume to troubleshoot something.

Meanwhile, I also have plenty to do on main components for the MSLS, and hope to work on that as well, unless I get diverted onto the honeydew list...

More as it happens. Stay tuned.

further ado about nothing

Hmph. This evening I reassembled my high vacuum system and not terribly surprisingly, I still have a gross leak... according to the gauges built into the system... the system I bought at an auction for $20... the system which I and a good friend have systematically rebuilt from the ground up... with the exception of the gauge electronics.

Well, I've got the roughing pump running at least. VERY rough. If I could believe the panel gauges (and I cannot) the pressure is bottoming out at just over 100 millibar.

The reason I've revisited the vacuum system so soon is that I have constructed a device (ye gods how I love that phrase) which I wish to encapsulate in epoxy. (it's another special effect for the Mad Science Light Switch)

To do encapsulation properly (ie; without voids) one needs a reasonable vacuum pump. I now have a reasonable vacuum pump again, although I do wish its vacuum were a bit MORE than reasonable. I'll need a few more bits of plumbing to connect the plasma cleaning chamber I'm going to use for this to the vacuum cart, but I ought to be able to get it done during the next week or two.

The hilarious part - to me - is that the electronics in the "trusted" gauge controller are so old, I will have to apply power to them gently -- slowly increasing the voltage from zero, using a variable transformer -- over the period of, say, an hour. This old-timer's trick may preserve the old high voltage filter capacitors inside which need to be "re-formed" after having sat idle for many years. It would be -- unpleasant -- should one of them fail within the chassis. Ick.

I do love old tube equipment though. Using it in the winter saves on heat. And fire bottles have such a cheerful glow.

What? Oh that? That's nothing...

Yep, things are proceeding apace, as this here photo will attest:



More writing when I have more to say. Ain't I a tease?

brief status update

Work continues slowly on the mad scientist light switch. Some of the work is rework to fix mistakes, but I'm still pulling ahead slowly. That remains a priority just so I can get all of the parts off of my bench.

I'm also working simultaneously on the micro-Marx generator. I am rapidly gaining respect for the guys who designed the new breed of fast Marx generators in the 60s, 70s, and 80s, because I now realize that every time you want to change one little thing, EVERYTHING else in the system changes. Like Tesla coils, Marx generators look simple as a schematic on paper, but turn out to be surprisingly complex in actual physical design and the calculations required to determine said physical design. The best performing examples are finely tuned devices. I am aware that I'm probably smarter than the average man on the street - tho I'm no genius - but the guys who do this stuff for a living are considerably smarter than I.

I'm in the process of evaluating two physical layouts for the insert panel which will hold the spark gaps on one side and the caps on the other. The winner will offer the best tradeoff between number of stages which will fit into the available space and self-inductance. I was surprised to notice for the first time a few weeks ago that the design I am working from as a stepping-off point creates a helical current path when the bank erects. I can't help wondering whether that is deliberate or accidental. As near as I can tell, any stray or self inductance in the system is undesirable. Stray capacitance quite the opposite, as it can be used to decrease erection time significantly.

I've also changed the sphere gap size, which required an extensive redesign in SolidWorks and as I still do not have a SolidWorks platform at home I'm limited to working on that task on my lunch hour and after work hours. It's taking a while. Any readers out there feel like donating a semi-modern Windows box for me to use as a CAD (SolidWorks) platform?

I am attempting to learn how to calculate all of the stray inductances and capacitances so as to determine the device's characteristic impedance. I'd like to include such design parameters in my spreadsheet-based "Marx Calculator". Good thing I'm studying calculus this year. At least in theory. Free time seems to be at a minimum lately.

There are some physical machining tasks for the micro-Marx housing and liner which will not change no matter what happens to the innards. I can start on those whenever I have the MSLS done.

So things are happening, they just aren't happening quickly, and I haven't any photogenic progress to show off for the moment. I might be able to post something along those lines near the end of next week. I want to put up some images, notes, and calculations from the micro-marx design I am working on.

The Mad Scientists Light Switch

Good evening Mr. and Mrs. America, and all the ships at sea.

While attempting to clear my workbench in preparation to make a somewhat precise high voltage low current measurement, I realized I had more stuff than real estate. My bench was rapidly becoming eleven pounds of shit in a ten pound bag.

One of the projects that's been occupying space either on said workbench, or on the riser shelf above my workbench, or parts of both at the same time, is: "The Mad Scientist's Light Switch". Kindly imagine while re-reading that phrase that it is being shouted through a large public address system with a fair bit of reverb thrown in for good measure.

I thought for sure I'd written a piece in this very journal about it, but a quick review last night turned up nothing but a short reference to it. Perhaps I was thinking of my partial coverage of it over at my Flickr page.

So anyone reading that one little mention here must have thought I'm a bit 'round the bend. They'd not be far wrong of course, but that's entirely beside the point.

In order for me to make room on my bench, I needed to get this damned project -- I shall call it the MSLS for short -- off my bench. As it happens, the MSLS was designed from the start to mount on the wall. Of course, back at the start, it hadn't been quite so complicated. But I'm getting ahead of myself.

For starters, if I could get this thing set up on the wall temporarily, I'd have lots of bench space. So I decided to push on this a while since making a small amount of progress on it would enable any progress on measuring that damned capacitor.

Not that the capacitor has anything to do with any projects whatsoever - for the moment - but it could, and I'll have more idea of how likely that is... AFTER I AM ABLE TO TAKE THIS DAMNED MEASUREMENT.

*ahem*

So anyway, here's what this MSLS thing is, how it all got started, and er, caught a case of Creeping Featuritis.

A really long time ago (decades), an old U.S. Air Force buddy offered to give me a "great big old fashioned knife switch" - hereinafter referred to as the Giant Ass Knife Switch, or GAKS, which he had found somewhere, probably eBay. After hearing his hyperbole about this thing, I eagerly accepted his offer, although he didn't actually have it with him at the time... *cough*

Some time passed and I asked him about it. He thought about it a while, and eventually realized it was buried in a closet which was blocked with quite literally several tons of amateur SETI ground station receiving equipment in three full-height racks... I just sighed and told him to let me know when (if) he ever saw the inside of that closet again.

Several years passed.

We got together for the first time in several years, and I was shocked to hear that he had decided to dump the entire amateur SETI project, had sold all the racks of equipment, and was in the process of cleaning out the previously-blocked closet. He promised to find that switch and get it to me the next time we got together.

Several more years passed.

Did I mention at the outset that this was going to be a long story? No? Well, it is.

To make a painfully long story slightly less painful but not shorter at all, I got my hands on the thing quite a few years ago, found that it was quite as beautiful and impressive and archaic as promised, and it has been languishing around my workshop ever since, looking for a purpose. It's got three poles, a solid slate base about 5/8" thick, lots of copper and brass, nicely constructed.

It could probably handle several hundred amps closed, but there are limits to how much voltage across its contacts (or current through them) that I'd be willing to use with that switch with my bare hands on it. Now with a bit of rope and an arc flash suit, that would be a different experiment story.

ANYWAY, between the moment I first heard the rumor of this GAKS's existence and the moment I got it in my perspiring hands; I had bought a quite nice, but slightly smaller, Big Ass Knife Switch. We'll call it the BAKS for short.

MSLS, GAKS, BAKS. Got all that? Good.

I had the idea that it would make for a great (tho fantastically dangerous) actual light switch for the lights in my workshop. It's not for nothing that Frankenstein is always shown throwing the big switch that powers up the laboratory AFTER he has located the handle with a lantern, torch, or candle. He's also usually wearing thick rubber gloves up to at least his elbows. I used to have a pair of lineman's gloves like those until I outgrew them. They're not for show, and they're very expensive.

You can do things with GAKS that aren't exactly safe to be close to unless you are wearing good protective gear. And don't forget, a lot of the old special effects for those 1950's mad scientists movies were real working, mad science equipment like Tesla coils and huge jacob's ladders built by Ken Strickfaden. His equipment actually WAS dangerous, there wer no optical effects, the camera recorded what was actually happening on the set. At one point, Boris Karloff refused to go onto a set because he thought Strickfaden's equipment was too dangerous.

But I digress. Sorry, favorite topic.

I am actually fairly safety conscious. I've had a few close calls, and I've listened carefully to every one of them. Usually the communication medium has been pain.

So it occurred to me, I could set up the knife switch with six volts across it, hide a short circuit under one side of it so that it shorts the two poles when it is "closed". Then use the six volts to control a relay capable of operating all of the lights that I intend to put into the re-modeled workshop.

Ah, that'll b about four times as much, and more evenly distributed, than it has now. It will be bright. It needs to be. I've learned this lesson over and over again. I have a twin 40 watt fluorescent fixture under the riser shelf of my workbench. It's priceless.

So anyway, anywhere from 5 to 10 amps of modern, T5-HE daylight and warm mixed lamps with high frequency electronic ballasts (no visible flicker, probably consumer about as much energy as my old starter type fixtures do now). I'll need a good sized relay, but I probably have one lying around, no problem.

Well okay, I gotta come up with a 6 volt power supply. Needs to be well-isolated from the power line - so add an isolation transformer...

Gee, it sure would be cool if that big impressive knife switch could actually DO something, or pretend to, when you threw it.

An old friend from fandom once described to me a device which made some impressive noises when activated, and I think it was related to a light switch. I thought about this for a while.

It occurred to me that a small Jacob's ladder would be a cool addition. But you know, Jacob's ladders are cool and all, but it would get seriously annoying once you were done admiring it. I'd better add a timer relay to turn it off after five seconds or so. Amusing when you turn on the lights, and then you can forget about it.

You can see where this is going.

The design got complicated. From the very beginning, the aesthetic I had in mind was half steam-punk and half atomic era science fiction. Big ribbed insulator bushings! Round dials mounted with brass screws! Baked-on crinkled-enamel cabinetry! Heat sinks! Fins! Cooling louvers! High voltage anti-corona spheres! A hand-crafted jacob's ladder with custom fittings to allow mounting in a big copper pipe elbow, with turned brass electrode holders, brass electrodes, and art deco finned finger guards to keep curious fingers from offing their owners! Uh, an extra neon sign transformer because a single piddling little 5mA NST couldn't generate enough heat in the arc to create the hot air that causes the arc to rise.

And so on and so forth. Plus, the wires all still need to be connected to interesting looking things, so that they appear to actually do something, preferably something arcane and vaguely dangerous looking. I want a physicist specializing in high power electronics to look at this thing and say, "okay, I can see it is beautifully constructed, and probably quite dangerous... but what in the hell does it DO??"

You have the general idea. If you've had the patience to read down this far, you deserve a small reward:



This is the main control box, hereinafter known as The Device. It will contain the neon sign transformers, 6VDC supply, isolation transformer, timing relay, and some associated gewgaws. Eventually, it will also contain a solid state sound record/playback chip, a small Class B amplifier, and a small speaker, so it can make interesting sounds (think Krell Mind Amplifier turning on, or turbines spooling up).

The upper left and upper right quadrants above the meter will contain a pilot lamp and an override switch respectively, in case something goes wonky with the power supply or 6V wiring, I can still turn on the lights in the shop. The finned bits on top will be extended upward a little with some contrasting tubing (they are actually power resistors).

The mini-Jacob's ladder looks like this, so far:


It includes customized copper piping and the obvious elbow. Not yet installed is a finned art deco vent at the top that will allow warm air to escape and keep all but small conductors (held by very stupid people deserving of electrocution) away from the 3,750 VAC (to ground) inside. I've cut the parts, but still have some very careful drilling and gluing to complete that bit.

The Jacob's ladder will mount through a custom brass flange (which I am working on now) to the side of The Device.

Please note the custom fabricated shelf brackets with pulp science fiction inspired "lightening" holes. The wooden shelf itself is not yet complete - it will get some kind of edge treatment - routing at minimum, possibly a metal rail of some sort.

The conical insulators on the front panel will carry a whole 6 volts through some big impressive coiled wires to the BAKS. (The GAKS was too big to fit where I wanted to mount a light switch.) Something like this:



Note that you're looking up from roughly my 5'10" nose -- the top of my workbench and drill press pulley housing are visible at lower right and at the extreme left edge of the image is a pass-through about 7 feet in height.

The lower connections of the BAKS will be wired to yet more impressive but ultimately non-functional greebly bits.

And that's the way it is.