obligatory obscure reference

self-deprecating yet still self-promotional witty comment


Lasersaur + accessories for sale UPDATE 27 Jan 2023

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

Important update!

If I don’t get a hard yes offer before mid February I am tearing it down for parts. Some of the parts will go on eBay, other parts will go in to my bin of Misumi stock for future builds of digifab equipment. We really do need this space for our next jobs, mine as a gunsmith, my wife as a maker of glass art.

— 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?


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.


E3D Silicone Socks Change PID Settings

Filed under: E3D Printers — jet @ 21:00

Getting ready to put E3D’s “Silicone Socks” on my E3D-V6 and thought, “hey, my kitchen oven mitts are silicone and I can handle 450F pots out of the oven, I wonder how much insulation the socks provide and does it change the PID?”

Two PID tunes later, one without the sock, one with, both starting from a room temp 22C V6 and using the g-code “M303 E0 S240 C8”

Without sock:
p 26.95 i 2.45 d 74.19

With sock:
p 32.75 i 3.54 d 75.8

Which makes sense — p’s change means there is more error (heat loss is lower than bare metal), i’s change is the accumulation of previous errors.  The derivative, d, stays roughly the same because p and i have similar changes in value.  (I did poorly in calculus and am trying to explain this to people who wasted a semester and failed Calc I trying to understand how derivatives work.)

What this implies is that the V6 extruders will heat more quickly thanks to the insulation and will cool more slowly after a print finishes.  I can’t think of any prints where I changed the temperature of the print head during a print so this should “just work” after I update the PID values in Marlin.


made a thing: rotating “Lazy Susan” tool rack

(Susan wasn’t lazy, she was efficient. There’s a difference.)

After seeing Adam Savage’s take on mobile tool racks I started designing some for my Big Things studio.

Then I realized, no, I need one like ten years ago for my Small Things studio. Cue the cycle of “design, test, improve” and finally I had a version for me. I like it so much I decided to put copies up for sale at Etsy. If you want a custom version for your own special set of You No Touch These Tools we can work something out.

Having a Lasersaur in the Big Things studio is more useful than I expected.

(p.s. Boxing up S/N #1 for Adam tomorrow afternoon.)


DIY Laser Cutter Fume Extraction

Filed under: digifab,Lasersaurs and laser cutters — jet @ 11:36

[Update:  I added a new post about what I’ve learned about HEPA filters.]

After building my second Lasersaur, the current release candidate, I started doing a lot more cutting and realized I needed to find a good fume filter. I started designing my own and while doing research discovered that someone had already solved the problem and distributed plans on Instructables. It’s a self-contained laser cutter fume extractor and it does a great job filtering out smoke and acrylic. I sit next to it while running jobs and I can’t smell even a whiff of smoke.

While crawling around under the work bench routing the exhaust from the Lasersaur to the filter I was reminded that my studio (a converted garage) is pretty damn dusty. I’m making dust covers for my computer and CNC headend and putting filters over the cooling fans, and I started thinking about where my Lasersaur gets fresh air. The exhaust fan pulls ~400 CFM of air through a 6″ exhaust port but there’s no 6″ port for air to come in. A few test cuts later and it was pretty obvious I needed dedicated air input to balance the exhaust.

My fix is pretty simple: put an air filter on the opposite side of the cutting bed. The question is what size filter and where should it be located? I tried a few variations with cardboard mock-ups and it looks like having the filter planar level with the cutting bed was the best plan. The filter is some leftover HVAC stuff from the box store and it probably needs a better mount than leftover duct tape, but for now it works just fine.

There are some photos on flickr and here’s a short video of tests and the final result:


Laser Cutting and Fume Extraction

Filed under: digifab,Lasersaurs and laser cutters — jet @ 12:43


This is not legal advice or opinion on the rules and regulations for installing or using a laser cutter. These are notes on what I’ve learned and a guide for people interested in having a laser cutter.

What’s all this, then?

I’ve been working with, near, or in toxic fumes since I was a teenager. I’ve wrenched, welded, soldered, used metal working machines, worked on motorcycles and cars, and built CNC equipment, including several 3d printers and a couple of Lasersaurs. I’ve taken and taught safety classes and I’ve still made some stupid mistakes.

It’s easy and inexpensive to get home/shop level digifab equipment like laser cutters but not much out there on what it means to own and operate one.

I wrote this short introduction to laser cutters and fume extraction based on what I’ve learned in work spaces and my studio. I hope that sharing what I’ve learned helps other people interested in setting up a laser cutter.

Fume Extraction

Let’s start by defining what “fume extraction” actually is — removing fumes and particles suspended infumes from an area. Many processes we use create annoying, hazardous, or lethal fumes and fume extraction gets them out of the work area.

Some examples of fume extraction:

  • remove lead and solder fumes from the air around a soldering station
  • remove air containing viral contaminants from a safety area where someone is doing medical research
  • filter or remove greasy smoke out of a kitchen in a home or restaurant
  • remove toxic side-products of welding from a welding station in a closed room

For laser cutters, there are two specific reasons to do fume extraction:

  • remove vaporized particles and fumes from a laser cutter work space to protect the people using the laser cutter
  • clear the air inside the laser cutter to prevent fumes from damaging the media or the laser cutter equipment

Who needs fume extraction?

Anyone generating fumes that are bad for people to breathe, harmful to the environment, or that can damage the tools they are using. That’s a sweeping statement, but there’s a wide scale of materials that can be used as media in a laser cutter. On one end are people who have a business making models but of plywood or cardboard and never cut plastic or etch powder coating off of metal. On the other end is a hacker space, college studio, or Techshop where there’s a “DANGER: do not cut” list and temporarily illiterate laser cutter operators.

Fume extraction isn’t fume filtration!

Note that we’re saying “extraction” not “removal” or “filtration”. Fume extraction means moving the fumes from one area (inside a laser cutter) another area (outside the laser cutter). If you’re laser cutting something that generates toxic fumes and you have wonderful extraction, you’re just moving the toxic fumes to another location. Extracted fumes don’t disappear and an important part of fume extraction is deciding what to do with the fumes. (Saturday Night Live’s “Yardapult” is a funny but real example of what some sites consider fume extraction.)

Laser cutter restrictions

Did your laser cutter come with a manual that explains restrictions on what media you can cut and fume ventilation requirements? Start by reading the manuals and FAQs, there might be limitations on what you can cut or etch because of the materials used to build your laser cutter. One example is what your mirrors are made of — are they backed glass or polished metal? Some mirrors need routine cleaning if you’re cutting smoky materials, even if you have the best fume extraction possible.

What can the fumes damage?

Everything, starting with the person using the equipment and nearby people, then to the equipment (see below), or people near where the fumes are sent as exhaust. If you’re only cutting paper and cardboard and sending the exhaust up a legal fireplace chimney, there’s not much more risk from the fumes than having a fire in the fireplace. If you’re cutting and etching acrylic in volume and dumping the unfiltered exhaust out your garage window, don’t be surprised if the neighbors dial 911 to complain about the smell of burning plastic.

You could also be working with something you think is safe but isn’t. I no longer cut hardboard in my Lasersaur because the heat from cutting the wood also does something to the glue and makes the wood sticky. Not sticky in a good, ice cream sort of way, but a sticky burnt glue that sticks to the moving parts and is hard to remove, even with solvent.

Did you read the Material Safety Data Sheet (aka “MSDS”) for the media you’re cutting and does it cover burning the material or fumes? What happens if you laser cut kevlar or styrene? (That’s your cue to go find the MSDS documents for these materials.) Depending on where the laser cutter is installed, there might be requirements from the FDA, EPA, OSHA, local business codes, labor codes, safety codes, etc. (Reminder: I’m in the US and not a lawyer, so I’m mostly going to make vague references to US legal systems and ignore the rest of the world.)

How bad are the fumes, really?

I took apart a laser cutter for parts and took photos of the wear and tear caused by fumes. It was used in a machine shop with good fume extraction and there was still a fair amount of damage to the internal parts. I don’t know what they cut but the amount of rust and corrosion suggests that it was releasing fumes you shouldn’t breathe.

What do you do with these fumes?

So you’re pulling the fumes out of your laser cutter, what do you do with them other than just vent them out a nearby window?

It still depends on the answer to: “What are you cutting?” Did you read the MSDS? Does it even have a MSDS? Note that a MSDS isn’t going to list “cutting by laser” it’s going to use more generic terms like “burning,” “melting,” “smoke,” or “vapors”.

If you’re only cutting something relatively safe, say paper or balsa, you’re creating “wood smoke” which is an easy problem to solve.

Do you know what the media you’re cutting is made of so you can find the MSDS? Before you etch a stack of Moleskin brand sketchbooks, do you know what they’re made of? PVC. Ok, so what happens when you etch and cut PVC? It releases hot chlorine gas that quickly converts to hot hydrochloric acid, and that acid is not good for a laser cutter’s internal parts or the people running the machine.

What if there’s no MSDS? This is where you get to do some science so you can figure out what fumes you’re generating. Cutting thin plywood generates mostly wood smoke, cutting MDF or hardboard means you’re also cutting a lot of glues or maybe paint. If you’re laser etching old paint, is there lead in that paint and the fumes that comes off the etch?

Plan on filtering your fumes

For recreational or hobby use it’s pretty easy to filter fumes and the cost is relatively low to that of a laser cutter. There are a variety of plans online and you can find one that fits your needs I suspect that using a laser cutter a few hours a week generates less air pollution than a gas lawnmower, but neighbors won’t complain about lawn mowers the way they will about the smell of burning plastic.

If you’re working in a manufacturing or art space, filtration could be cheap or free. If there’s already extraction for welding fumes or metalworking machines, you might be
able to use theirs depending on the fumes you generate.

If I were running a professional job shop or a hacker space a commercial filtration system that could handle the nasty fumes from some plastics and resins would be worth the investment. This also goes back to the issue of local regulations, you might have to have some sort of professional certificate or verification that your filtering system works.

Legal restrictions

If you’re renting or don’t legally own and control your space, you’re going to have to go by the owner’s rules. If you’re at a university you’ll probably need to talk to facilities, if you’re in an apartment complex that’s the landlord, or “ask your parents”.

In the US we have federal, state, county, city, local zoning, and various safety restrictions related to wildlife and waste discharge. It could be as simple as “filter your fumes and don’t annoy the neighbors” — I know a few people who have run laser cutters in their garage and never gotten a complaint.

If it’s a hacker space or business getting a laser cutter there are additional regulations to follow. There might be fire code regulations, safety requirements, or additional rules to comply with along with ventilation rules. I’ve seen local regulations where a permit (which costs money) and inspection (more money) are required for an exhaust vent larger than 4 inches in diameter. The regulations can be as simple as “exhaust vent” or as specific as “industrial exhaust vent for fabrication equipment”. When I was looking to rent studio space within Pittsburgh city limits, if I asked about “exhaust ventilation” the landlord just said “no”. No question of what I wanted to vent, they simply didn’t want to deal with exhaust issues.

Question time!

Please leave questions (and answers) in the comments, if there’s enough interest we can turn this in to a FAQ or wiki.


MendelMax Update

Filed under: digifab,Mendel — jet @ 12:07

The build is almost finished, all I need to do is build the extruder and get host software running on my Mac or Wintel box.

Instead of doing the build (like I planned) I’m spending a lot of time sitting after knee surgery. I do a lot of my hacking/tinkering either standing or sitting on the floor, neither of which has been much of an option for the past few weeks. Deep knee bends (aka “catcher bends”) caused my knee to make a bad noise, the doctor agreed it was bad and to stop making that noise until surgery. Surgery probably fixed it, but now I have ~3 weeks of sitting and taking it easy on my knee.

I’m posting photos to flickr as I make progress.


Engineering Lesson 101

Filed under: Arduino,Hacking,MakerBot,Rants — jet @ 09:46

I think it’s been 10, maybe 15 years since I’ve actually worked on open source software as an author. I’ve helped fix bugs in things like Arduino and ReplicatorG, but I haven’t done anything major on my own.

Until Friday, when my frustration with a certain class of software got the perspective and skill of my being a professional engineer. Instead of complaining, instead of getting frustrated with how someone else managers their project, instead of not being able to pull rank and make them do it my way, I can just go write my own and hand it out.

It’s a nice feeling. I don’t think I’d have gotten here without writing it-cannot-fail code for security and privacy projects as a day job. That sort of rigor is like daily exercise for the brain, like daily exercise or workouts only for the brain.

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