I’ve been refraining from asking you where this swap meet is located. Sounds like a lot of fun. Here are some insights into tech scrapping.
I used to collect up a lot of tech trash when I worked at the Hewlett-Packard Labs. I’d literally climb into the dumpsters and strip the expensive parts off all the lab equipment I found in there. I had a few big scares when a giant piece of furniture would shift an nearly crush, lacerate or impale me. Some of the best stuff was way at the bottom of the bin and it was dangerous to go after. I got a lot of parts for CNC and robotics projects. I ended up giving most of it away or selling it off when I left Silicon Valley a few years back.
Security watched me over cctv. They knew me. The deal was Simm’s metal would put a special dumpster out for metal scrap. They either paid us a little to put it there or they hauled for free. Their secret was they would divide off the valuable surplus and auction it to scrap hounds in Silicon Valley. I met some in the PCB (precious metals) recycling biz and learned the game. These guys were a relatively small community of slobs who used social connection, cash and a box truck to collect up old electronics. They’d sort in their backyards in San Jose and create a super fund site next door to you. Then they’d sell the “ore” to a company who refined the metal into an ingot of mixed alloy containing aluminum, copper, gold, silver, tin, platinum, palladium etc.. The actual collectors did no chemistry. One giant place did it. They’d crush the electronics in a cement mixer filled with cannon balls. Then they’d incinerate the dust and collect the molten metal. The metal would be assayed I believe using an XRF machine and then based on the weights and % concentration of metals the scrapper would be paid cash. The ingot would go to a mining operation in Canada where it would be smelted with natural ore.
The valuable components were divided off - switches, valves, motion control, bearings, motors, sensors, microwave components, optics, micrometers, cameras etc. and warehoused by different collectors. It would then be sold off back to hackers or startup founders in kind of an ecosystem of people comfortable with using used and possibly defective tech. The markets ranged from dusty warehouses to eBay. I bought a lot of this stuff when I started a tech biz on a shoestring. It has ups and downs...a lot of stuff is one off so when you need to scale your business you’re SOL because you cannot get anymore. Some is broken or defective. A lot is undocumented. It is good when you can incorporate surplus into a product and make a high profit but it is hell when you find you designed yourself into a corner with one off parts. That when the scrap dogs laugh at you and say “Sclass there’s no more you bought everything!”
When I say these guys were slobs I mean it. Their yards looked like dumps. They wore dirty clothes with fat bulging out for all to see. A kind of misfit. They basically found an easy way to survive off the fat of the land and they fell into this lazy ass life. Collect trash, sort and take to metal recycler. Take money to strip club/drug dealer/fast food joint repeat. It was an alternative life for the lazy yet resourceful techie who didn’t want to be an employee at Hewlett-Packard. I dealt with enough of them over the years buying and selling old equipment to learn the basics of the trade. Beware of the gravy train was my lesson. The job becomes you. In some ways it was an intriguing lifestyle but the characters were not people I’d aspire to become.
Simms metal eventually locked their dumpsters at Hewlett-Packard. I was told by my buddies in facilities that they discovered all the juicy tech hardware in their “scrap” was being disassembled and stolen by a dumpster diver

before they got it. I was very good at taking the most expensive components because I designed the same equipment for HP. But instead of returning the items to inventory I just took them home and listed them on eBay industrial supplies. I got tired of selling this stuff and moved on to better things. I still wonder if I contaminated myself touching all that gear used in advanced materials research. Another danger in this game. Nasty stuff.
As a tech entrepreneur I dealt with a lot of these guys. I was able to start my first business with really small amounts of capital because I bought up all their new old stock to outfit my factory. I also used second hand components in my products. My second startup was venture funded and we basically bought everything new. Our engineers had a religion not to use recycled goods because of the inherent uncertainties baked into unknown ingredients. So there we ended up dumping off our unused inventory to the same people basically for free.
Recently I met a bunch of young guys at a trade show who refurbed CNC equipment. While there is a ton of machines available as surplus the challenge is the non standard controllers. If you play with .nc files you’ll be unpleasantly surprised to find out there are dozens of CAM formats to drive these machines. The code is similar but different enough that a particular brand of machine uses a different “out” file as they’re called. It seems that it is a tradition in the industry to roll your own and the CAD/CAM software accommodates the big players.
So what happens is you get a big pile of servo/steppers, some amplifiers and some digital controllers. The refurb guys scrap the digital controller and add a Linux based system that has some standardization built in. Then you have a working machine. The original systems they source the parts from are dirt cheap at auctions. Like $0.10 on the dollar. They’re everywhere. So what was found in the trash was a system somebody didn’t want to bother with. I built my CNC mill using parts from a gene array tool I found in the trash. It was pre Linux CNC so I hacked together my own interface using something made by some CNC hobbyist guys back in the day who basically were salvaging old robotics to make CNC tools.
Once I built one machine I realized I could use that machine to build more machines along with all the motion control parts I’d found in the trash. But I lost interest and moved on.
So there is real money in refurbishment of these systems. I forgot the name of the business but I recall the guys doing this and reselling Linux retrofitted machines were in San Bernardino. They’re undoubtedly older and more experienced now. They said they usually got a mill for $1000 to $5000 and sold it for $30,000 after retrofitting it with their own encoders and CAM electronics. So my advice is dump the digital controls, keep the motors, mechanicals and amplifiers. Don’t bother with the proprietary controller. That custom interpreter hardware is what makes these expensive machines become trash in the first place.
Love your thread. Makes me want to go treasure hunting at the swap meets. But I now have two homes with garages packed to the ceiling with stuff that needs to be collected, sorted and sold off by swap meet hounds.