An (Almost) Free Apollo-Era Rocket

According to recent news reports, NASA’s Marshall Space Flight Center in Huntsville Alabama wants to give away a piece of history — an engineering test article of a Saturn I Block I booster. The catch? You’ll need to pay to haul it off, which will cost about $250,000. According to C|Net, the offer appears to be for museums and schools, but it’s likely that price tag would probably scare most private buyers off anyway.

On the other hand, if you are a museum, library, school, or university, you can score cheap or free NASA stuff using their GSAXcess portal. In general, you do have to pay shipping. For example, a flexible thermal blanket from the shuttle costs $37.28. A heat tile runs about $25.

Continue reading “An (Almost) Free Apollo-Era Rocket”

Fail Of The Week: Supercapacitor Spot Welder

[Julian] needed to weld a bit of nickel to some steel and decided to use a spot welding technique. Of course he didn’t have a spot welder sitting around. Since these are fairly simple machines so [Julian] set out to build a spot welder using a charged supercapacitor. The fundamentals all seem to be there — the supercap is a 100 Farad unit and with a charge of 2.6V, that works out to over 300 joules — yet it simply doesn’t work.

The problem is in how the discharge energy is being directed. Just using the capacitor would cause the charge to flow out as a spark when you got near the point to discharge. To combat this, [Julian] put a microswitch between the capacitor and the copper point he expected to use as the welding tip. The microswitch, of course, is probably not the best for carrying a large surge of current, so we suspect that may be part of why he didn’t get great results.

The other thing we noticed is that he used a single point and used the workpiece as a ground return. Most spot welders use two points near each other or on each side of the workpiece. The current from the capacitor is probably just absorbed by the relatively large piece of metal.

The second video below from [American Tech] shows a 500F capacitor doing spot welding with little more than two wires and it seems to work. Hackaday’s own [Sean Boyce] even made one out of some whopping 3000F caps. It did work, although he’s been pursuing improvements.

Continue reading “Fail Of The Week: Supercapacitor Spot Welder”

[Jessica] Is Soft On Robot Grippers

It is an old movie trope: a robot grips something and accidentally crushes it with its super robot strength. A little feedback goes a long way, of course, but futuristic robots may also want to employ soft grippers. [Jessica] shows how to build soft grippers made of several cast fingers. The fingers are cast from Ecoflex 00-50, and use air pressure.

A 3D-printed mold is used to cast the Ecoflex fingers, which are only workable for 18 minutes after mixing, so it’s necessary to work fast and have everything ready before you start.

Continue reading “[Jessica] Is Soft On Robot Grippers”

Print Your Own Heat Shrink Labels For Factory-Chic Wire Naming

Heat shrink tubing is great for insulating wires. Labeling wires in a bundle is always useful, too. [Voltlog] has a cheap Brother label printer and discovered he can buy knock off label cassettes for a lot less from China. However, he also found something else: cassettes with heat shrink tubing in them made for the same kind of printer. Could he use the heat shrink cassettes to make neat wire labels? In his first video the answer was sort of, but not really. However, he later had a breakthrough and made a second video explaining how to do it. You can see both videos, below.

At first, the printer didn’t even want to recognize the cassette. It seems like Brother doesn’t want you using exotic tapes with cheap printers. No worry, this isn’t sophisticated DRM, just a sense hole that you need to cover with tape. This discovery was made using the extremely scientific trick of covering all the holes that were not on a regular cassette.

Continue reading “Print Your Own Heat Shrink Labels For Factory-Chic Wire Naming”

1940s Portable Radio Is A Suitcase

The meaning of the word portable has changed a bit over the years. These days something has to be pretty tiny to be considered truly portable, but in the 1940s, anything with a handle on it that you could lift with one hand might be counted as portable electronics. Zenith made a line of portable radios that were similar to their famous Transoceanic line but smaller, lighter, and only receiving AM to reduce their size and weight compared to their big brothers. If you want to see what passed for portable in those days, have a look at [Jeff Tranter’s] video (below) of a 6G601 — or maybe it is a GG601 as it says on the video page. But we think it is really a 6G601 which is a proper Zenith model number.

According to [Jeff], 225,350 of these radios were made, and you can see that it closes up like a suitcase. The initial 6 in the model number indicates there are 6 tubes and the G tells you that it can run with AC or batteries.

Continue reading “1940s Portable Radio Is A Suitcase”

Retrotechtacular: Predictions That Just Missed It

Few occupations are more fraught with peril than predicting the future. If you are a science fiction author, it might not matter, but if you are trying to design the next game-changing piece of hardware, the stakes are higher.

It seems like, for the most part, even if you manage to get some of the ideas right, the form is often way off. Case in point: telemedicine. Today you can visit a doctor using video conferencing with your phone or a PC for many common maladies. A new idea? Not really. Hugo Gernsback wrote about it in Radio Electronics back in 1955.

Gernsback wrote:

The average medical doctor today is overworked and short-lived. There are never enough doctors anywhere for the world’s constantly multiplying population. Many patients die because the doctor cannot reach them in time, particularly at night and in remote regions.

…[H]e can only see a few [patients] during the day. With increasing traffic congestion, many doctors refuse to make personal calls — execept in emergencies. Even then they arrive often too late. Much of this dilemma will be archaic in the near future, thanks to the Teledoctor.

Gernsback envisioned a doctor using what we now call Waldos similar to what people use to manipulate radioactive material. These super mechanical hands (Gernsback’s words) would allow the doctor to write a prescription, pour liquids, or even diaper a baby thanks to a sense of touch built into them.

Oddly enough, Gernsback’s vision included renting a teledoctor from the drugstore for $3.50 a day. This way, the doctor could call on you and then follow up as well. The drug store would deliver the machine and it would — get this — connect to your phone:

A cord with the a telephone plug attached to the teledoctor instrument is now plugged into a special jack on your telephone. Future telephones will be provided with this facility. The TV signals and telehand electronic signals, etc., will all travel over the closed circuit telephone lines.

In a footnote, Gernsback notes that you can’t send a 525-line TV signal on current phone lines, but a 250-350 line picture was possible and that would be sufficient.

Visionary? In some ways, maybe. The basic idea is coming true today, although it isn’t likely doctors will do surgery or inject you remotely in your home anytime soon. The special telephone plug sort of came true and is already obsolete. The images, by the way, are the ones that accompanied the original article in Radio Electronics.

Continue reading “Retrotechtacular: Predictions That Just Missed It”

NanoVNA Is A $50 Vector Network Analyzer

There was a time when oscilloscopes were big and expensive. Now you can get scopes of various sizes and capabilities on nearly any budget. Vector network analyzers — VNAs — haven’t had quite the same proliferation, but NanoVNA may change that. [IMSAI Guy] bought one for about $50 and made a series of videos about it. Spoiler alert: he likes it. You can see one of the several videos he’s posted, below.

NanoVNA is tiny but sweeps from 50 kHz to 900 MHz and has a touch screen. The device uses a rechargeable battery if you need to haul it up to an antenna tower, for example. Just as a quick test, you can see early in the video the analysis of a rubber duck antenna. The device shows return loss as a plot and you can use a cursor to precisely measure the values. It also shows a Smith chart of the reactance.

Continue reading “NanoVNA Is A $50 Vector Network Analyzer”