obligatory obscure reference

self-deprecating yet still self-promotional witty comment


Lasersaur + accessories for sale UPDATE 18 Mar 2024

Filed under: Lasersaurs and laser cutters — jet @ 18:17

Important update!

I’m tearing it down for parts. Will put the cooler and some of the parts up for sale on eBay this spring.

— cut here —

Selling my lasersaur. Going through a career change and I live 15 minutes from three laser cutters that are well maintained. And maintained by someone not me!

This is located in Pittsburgh, PA. Moving the lasersaur will require four people (one on each corner). The rest of the equipment is on casters, or light enough to pick up and carry.

I’m looking at $6500, non-profits get first shot.

The Lasersaur Manual contains all the details. Mine is based on a 14.03 with the second-to-most-recent controller.

It has a 120W RECI tube but it is DOA, won’t even cut paper. Power supply tests ok so I’m pretty certain it’s the tube.

Here’s all the accessories that come with the lasesaur. There’s also
a flickr album of these.

  • NIB Ruida RDC6445G DSP Controller kit. I was going to upgrade the
    lasersaur board with this controller. This contains the display, the controller, and a bunch of cables. The plan was to use the
    exiting PSU in the lasersaur and drive the steppers with the controller.
  • Custom-built table: 72.5″ long, 48″ deep, 35″ tall. One side has a shelf for storing wood, the other side has an open space for the cooler and ventilation filter. It’s on casters to make it easier to move in a shop after you disconnect the filter and cooler.
  • Charcoal fume ventilator based on this design. It’s really amazing, I’ve used it in the middle of winter and could barely smell any smoke in the air.
  • Ventilator parts including a spare HEPA and more charcoal. When the HEPA clogs it goes from working fine to not working at all within a few minutes. I kept a spare so I could do an emergency fix in the middle of a job.
  • A CW-5200 cooler. This works very well, even in the summer heat. I’ll even toss in the half-bottle of coolant (I use coolant for GTAW welding rigs).
  • Spare PSU that was working as of 25 Aug 2015.
  • Spare PSU that I was told works, but I’ve never used it.
  • If you want it, a gas regulator so you can run nitrogen instead of compressed air.
  • Two spare PC controllers. One has a burned relay and doesn’t transmit 24V power, easy to fix.
  • Spare RECI 120W tube. No idea if it works. It’s a nice decoration if it doesn’t.


COVID-19 vs. my Etsy store vs. My Failing Laser

Filed under: digifab,Lasersaurs and laser cutters — jet @ 17:00

My last cut for Etsy didn’t cut properly.  I got out my laser power meter, locked down the studio, put on my $$$ CO2 safety goggles and did a test.  My 100W laser is now cutting at around 40W.

Well, that’s not good.  I need to sell a lot of product and buy a new laser.  I’ll use the Protohaven laser and oh look, I’m out of Baltic Birch.

A few months ago, maybe March?  April? I called the local plywood company I’ve used for years and placed an order for Baltic Birch.

Well, started to place an order and was informed that there is no Baltic Birch coming in to the US in the know future and everyone is out of inventory.

I called my backup dealer (same quality, longer drive to will-call) and got the same basic story:

  • Containers that used to rent for $4,000 now rent for $20,000.  These are the big semi-shaped boxes you see on all the cargo ships.
  • There are only “a handful” (maybe 5 or 6) companies that make Baltic Birch and they are all in China or Russia
  • None of the companies will even take an order because they have no idea when — or IF — it will ship.

I do have some acrylic I was going to use for a new synthesizer stand and I can cut that with 40W.  Not sure what the profit margin is, but let’s say I do have $3,000 to buy a 200-250W laser.  How long will it take for that laser to get from China to the east coast?

Etsy store is effectively closed until I sort this out.  Not the best news for my fiscal year.


DIY Laser Cutter Fume Extraction – Update

Filed under: Lasersaurs and laser cutters — jet @ 16:13

Between making PPE and cranking up my Etsy sales I’ve learned  few things I’d like to share:

  • Etching rubber stamps will clog your filter.  I knew etching would kick up a lot more dust, I just had no idea how much.  My pre-filter and my HEPA clogged after about 3 hours of etching.
  • You need the HEPA filter.   Mine clogged just as I was finishing a cut, so I pulled it and ran just with the pre-filter and the charcoal.  Smoke came out of ventilator, enough that I needed to ventilate the studio by opening the garage door.  Except it was 20F outside.
  • You either need two HEPA filters or a way to buy a replacement within an hour or two.  All of my clogged HEPA filters went from “pulling smoke just fine” to “completely clogged” in less than hour.  Maybe I could put some sort of wind-speed sensor in the hose but it’s easier  to order two HEPA filters and have a replacement on hand.
  • HEPA quality varies by brand.  I didn’t keep records of cuts between filters, but one filter lasted a few months, another almost a year.  These were knock-off, mail-order brands, for the next filters I’m going to keep some simple notes on how many things I cut.  I already do this to track nitrogen usage and plan on tank replacement.
  • There’s no inventory of HEPA filters that have overnight shipping as an option, at least within my budget.
  • A better pre-filter would help, maybe use the fabric wraps we use on standalone HEPA filters?


APRS using a RPi3 and some old MFJ gear

Filed under: Amateur Radio — jet @ 15:47

(placeholder, will add some detail later)

Set everything up again on an RPi3 and it works just fine.

Used these instructions:  http://xastir.org/index.php/HowTo:Raspbian



Chicken, sausage, and mushroom jambalaya, the harissa version

Filed under: Cooking and Drinking,Food — jet @ 20:09

I’m guessing that every “rice culture” has a version of this dish.  At Mintt they have a great selection of biriyani, the Indian version of this dish.  Jambalaya is similar to Korean bi bim bap but different in how it’s prepared.

So this is a riff on a classic Cajun dish, jambalaya.  It’s tweaked to remove a couple of things I don’t like and I’ve made some other changes based on what I can find at the grocery stores here in Pittsburgh.  I like spicy food (Tabasco is on the table next to salt and pepper), but I’ve never really gotten the level of spice you find in a good biriyani.  Until I discovered harissa and gave it a try.  Wow.

One of the interesting things about jambalaya is that we cook the rice in the pot with the rest of the food.  This moves flavors from ingredients to rice as the water boils in the oven, it’s not like boiling some rice and dumping chili on top.  (What I just did for dinner while I’m writing this…)

To make this you need a cast iron dutch oven.  I have a vintage 10 1/4 quart #8 oven, but you can find plenty of new ones on amazon at decent prices.  The main difference between vintage cast iron and a new one, say, a Lodge, is that the newer one was probably made in a factory and weighs more than the vintage one.   (How to prepare and care for cast iron is going to be a different post that probably pisses off just about everybody.)

This makes about 6-8 servings depending on other things you put on the table.  I eat a serving after I cook it then stick 5 more in the freezer in plastic containers, each one is an easy meal to microwave while I’m working.


  • 1# chicken cut down to bite-sized pieces. I usually use a breast and a thigh.
  • 12 oz of andouille sausage sliced to 1/4″ pieces.  Trader Joe’s sells a good, pre-cooked chicken andouille sausage
  • large white onion chopped down to 10mm pieces
  • 15 cloves garlic, crushed
  • Tabasco
  • 2 cups long grain rice.  I prefer Zatarain’s.  Louisiana long grain isn’t like Indian basmati rice, it’s more fluffy.
  • 4 cups water
  • can of diced tomatoes, I’m good with 12-14 oz
  • 1 bay leaf
  • 10 oz “baby bella” mushrooms, quartered. I like these a lot more than the generic brown, canned mushrooms.
  • 1 teaspoon Harissa, I use the Trader Joe’s brand but there’s always amazon.
  • olive oil or avocado oil


  1. Set the oven to 200C (400F).
  2. In the cast iron pot, brown the chicken with as little oil as possible, then move the chicken to a resting place.  If you are using uncooked sausage, brown it at the same time.  Don’t try to cook the chicken all the way through, just the outer skin.  This is a “dry” dish where the rice soaks up all the water, so you want the chicken to be moist.
  3. In the cast iron pot, saute the onion and garlic on med/low heat.  You don’t want to brown it, just break it down a bit, this takes about 5min on my stove.
  4. Add the bay leaf, tomatoes, and Tobasco.  I use about 10 “dashes” of Tobasco, cook another few minutes, at most 5 or 6 min.
  5. Add the chicken, sausage, rice, and water; crank up the heat, and wait for it to boil.
  6. Kill the heat and stir in the mushrooms and harissa.  (TODO: try adding the harissa in step #4.)
  7. Put on the lid, put it in the oven, let it cook ~45 min.
  8. When removing from the oven BE CAREFUL.  It weighs at least 5 pounds and is hot enough to give you a nasty burn.

Let’s talk about food

Filed under: Cooking and Drinking,Drinks,Food — jet @ 20:04

Inspired by needing to create a thesis for an interaction design class that might be taught remotely this fall and Alton Brown’s “Quarantine Kitchen”, I’ve created new topics on food and drink.  “What do I have and how can I use it?”


GA Tech and UL on consumer FDM printers and fume hazards

Filed under: digifab,E3D Printers — jet @ 10:44

They have a poster and abstract on their site, paper coming soon:

When I got my first 3d printer, a Cupcake, I gave myself nosebleeds by printing in my home office in the winter. “Duh, don’t breath ABS” took about a week to figure out.  I haven’t had problems with Edge fumes printing near an open window; now it’s time to do some 5 hour prints with the window closed. I suspect my mild asthma will be the canary in the coal mine on whether or not it’s time to build a fume extractor.


Spring project: Rescue honey bee swarms around Pittsburgh and Forest Hills

Filed under: Beekeeping — jet @ 23:37

Drue and I are trying a project this Spring to trap honey bee swarms. Bees reproduce by swarming, about half the hive takes off on short notice and goes looking for a new hive. They need to find a new home within a day or so after they swarm, they can’t transport food to survive on while they are swarming from one hive to a new space. The real problem is that on average, only one in six swarms survive in urban environments. If they can’t find a new hive and start foraging for food within 48 hours after they swarm they will probably die of starvation.

Here’s what we want to do — place “swarm traps” at places near the parks and other areas where swarms are likely. A swarm trap is basically a transportable bee hive with desirable (to a bee :-) characteristics of a good home. If we catch a swarm, we wait until it’s dark, plug up the openings on the trap, then bring it home to put in an empty hive or give it to a fellow beekeeper who has an empty hive. The swarm has no food, so they need to go to a hive with food as quickly as possible. We might feed them during the pick up, that’s only possible in the dark.

Swarms are relatively tame. I helped a friend fetch one out of a tree last summer and the bees were really happy after we put them in a hive-like container. We literally scooped them off the branch with our hands and put them in a box, it was kinda like cleaning up Legos. With a trap, they even do the “put them in a box” work for us.

Here’s what we need to manage a swarm trap:

– permission from the land owner to place the trap on a tree about six feet off the ground. We just ratchet-strap it to the side of the tree, it shouldn’t damage the bark.

– a way for someone to check the trap every day during daylight hours for a new swarm. It can be us or someone near the hive who just takes a look once a day.

– access to the trap after dark to retrieve a swarm, preferably in the evening an hour or so after sunset.

Here’s what we *don’t* need:

– a permit from the city. This isn’t a “beehive”, it’s a “trap”, and the land owner won’t be keeping bees.

– help installing the trap or retrieving it if it’s with swarm. Bees are pretty gentle creatures but it took us a few weeks of practice before we were comfortable handling them in a way that doesn’t make them cranky.

If any ya’ll are interested in hosting a swarm trap, let us know, and we can work out the details in person.  Swarm season usually starts in April/May, but last year’s warm winter had it start so early we had a hive swarm the second week of April.



Western PA Beekeeping Meeting

Filed under: Beekeeping — jet @ 16:04

Just home from the Western PA beek meeting and I learned a lot more this year than last.   Some of it good, some of it helpful in retrospect.

Feral Swarms

The best talk was a tutorial on catching feral swarms. I had no idea this was a “thing”, but the guy giving the talk lives in western Ohio and caught 64 swarms in two months. He constantly bought new hives and ended up with three different yards with 15-20 hives in each, all feral swarms. Primary cost: hives and 2700 miles on his truck.

Feral swarms aalso, it turns out, have amazing genetics relative to package bees from the south (duh). One swarm built 17 frames in a double deep in two weeks, he put on two mediums, those were built in two weeks, then by the end of the flow he had 2 mediums and a deep full of capped honey.

One yard of feral swarms produced 550 pounds of honey from eight hives. That’s 70 pounds her hive, I’m happy if I get over 40 from a hive.

So, hey look, we own two acres of wooded land a mile from here, and that land is within a couple miles of forests and wooded parks. I wonder how many traps I can put up, and more importantly, where I’d put all the bees.  I also have friends who live within a mile or two of the two main wooded parks in Pittsburgh (The City of) and will ask them if I can put swarm traps on their property.

Traps are easy to make out of 1/2″ plywood, two sheets and some 1x2s will make 5 swarm traps.  Just make it the size of a deep, removable lid, 1 1/2″ entry hole, and ratchet strap it to a tree as high as possible.

Dying Hives


It hit the upper 40s today so we cleaned out the three hives that deaded out during winter. It will be 70F in Tuesday and we don’t want any bees rotting/decomposing in the hives. (10 years ago we had 2′ of snow on the ground around this time.) We recovered maybe 10 or 15# of honey and fed the surviving hive a pound of protein patty. It’s going to be warm enough for them to do cleansing flights starting tomorrow but there’s no food out in the wild.

One thing I overheard at the meeting was that it was so cold in Ohio that bee clusters couldn’t survive going and fetching honey from other parts of the hive.  The bee cluster generates warmth by the bees dislocating their wings(!) and vibrating their wing muscles.  It should be close to 90F in the top of the hive, so it’s normally safe for bees to leave the cluster for food then return.  It’s possible that it was so cold last month that our hives suffered the same fate — the cluster ran out of fuel and it was too cold to go for more fuel.


Another hive down

Filed under: Beekeeping — jet @ 15:56

Lost another hive, one with plenty of food remaining.  Not sure if it was mites, disease, or just too damn cold for small cluster of bees.

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