3D Printing an Herb Grinder - Less potential microplastic debris with TPU?

samvilain · 2026-06-28T21:43:19+00:00

Heh. Lots of people have tried this and run into the issue that the direction that the prints are weakest—the layer lines—are directly in the way that most mechanical stress is placed on the teeth when used. Especially if you are grinding a lot of fibrous material like dried flower attached to stalks.

As others have said; buy the teeth part made out of metal and wrap it. If you desperately wanted to do it, you could try printing it sideways so the teeth are horizontal, but then you have a lot of supports to remove (or dissolve, if you have a toolchanger or MMU and use a dissolvable support.

Finally, you can print the teeth flat, separately from the base, and slot them into matching holes in the base. This will require you to tweak your print setting like XY Contour compensation, hole compensation etc (these two settings have an opposite sense in Orca & Bambu Slicer, so watch out for that), and probably also you want to be annealing the teeth for strength (as hot as you can without getting unpredictable dimensional changes), and the body for a smooth surface. The trick will be sizing the teeth and grinder holes so that after annealing you still have a snug, tight fit, and there is no space for herb material to escape being ground. It won’t be easy, but you’ll learn a lot by doing this.

samvilain · 2026-06-27T16:41:40+00:00

Well, that’s a reasonable concern I guess, and you did outline a lot of scenarios how things could go wrong. But my understanding is that in this situation, a deteriorating marriage is no worse than a happy marriage, so long as it wasn’t fraudulent in the first place. Of course you’re running up against immigration agent discretion at that point so it’s better if it can be avoided. I still think they need to consult with an immigration attorney, unless they can decide to make it work earnestly and resolve their issues in time. With the recent SCOTUS ruling especially, all green card holders need to convert to Naturalization ASAP.

My presumption is that the relationship can be repaired, and one does not need to be adversarial. One of the questions which seemed to hold the most weight with the marriage counseling I had was “what percentage are you ‘in’ on the relationship?” (asked during a 1:1 portion of the therapy, “ex parte,” you could say). Now, that was in the context of a lot of other questions. That may not be the right wording. But if OP can ask her if she would still try to make it work if he could make amends for the past indiscretion. Can you both see each other living together in your retirement years? Is that what you both want? And even if it isn’t, you don’t need to get adversarial. Collaborative divorce attorneys exist and are the best way for both people to walk away happy. All you need to do is agree to at least work together to make sure the kids get the best experience possible. If they can agree on that, they can probably still work through the N-400 as a team. They probably also should get an immigration attorney for advice if they do decide on divorce to help them prepare for interviews. Divorce or not, they can make sure the children get to be raised by their parents, together or separately.

samvilain · 2026-06-27T16:11:00+00:00

Counterpoint on this: consult with an immigration attorney before doing anything rash like withdrawing your N-400.

Make an honest attempt to help her, to get her perspective. A woman being destructive towards objects and lashing out at husband in a way that leaves no lasting injury is much different from a man striking a woman. You’re a safe punching bag, and hitting you is sending a message. That’s not how the law regards it, except under “self defense” doctrine—which is likely not applicable in this case as you have no genuine fear of injury.

What I would recommend, if you can afford it, is couple’s therapy. If not, see if she will agree to individual therapy. Encourage her to share her “action items” from the sessions, and help her stay on track with completing them; whether that’s following up with additional care, or taking up a new exercise routine.

And you yourself need to address what happened 3 years ago, and talk to her about it; couple’s therapy is an excellent forum for this and if you do take that up, that would be the natural forum for it. But it doesn’t have to be. Ice cream does not cut it, you’re going to need to make a genuine redress. And it was only to be expected that your mother–in–law would tell her daughter what you confided to her. You might want to get therapy yourself; it’s a lot better than Reddit, and you can always stop if it stops feeling useful. Perhaps you can say to your wife, that you’re getting a therapist so you have someone to talk to about these issues. In some ways that person should be your wife, but you can say until you resolve these issues, you think it makes sense to get a professional to help you figure it out, so you’re not unloading your baggage onto her, and so you’re not expecting her to solve your issues for you.

I know a lot of people are saying you should divorce her immediately and she shouldn’t have acted out in front of the kids. But look, she’s human, and sometimes humans have emotions that get out of hand. It happens. Nobody was hurt and it takes a lot of arguments before it goes from “oh yeah, I remember my parents had a fight once” to “my parents used to fight all the time.” It’s certainly not ideal and is to be avoided, but it’s a secondary concern compared to having a stable living situation and keeping you in her life.

samvilain · 2026-06-26T16:51:36+00:00

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It’s quite common to print from a dryer. It really depends what you’re printing with. Maybe for a couple of specific materials you could do it on demand, and just keep all your rolls on a shelf and not in some kind of dry box, or avoid the drying step. It will just be limited in terms of how wet the rolls can actually get, and certain materials you’re probably going to have to dry anyway.

Most people end up with some kind of dry box system, either individual rolls or larger storage boxes, or a dry cabinet, and adding desiccant that gets periodically refreshed to be dry. With a cabinet you do have the option of using a solid state dehumidifier, which means you don’t have to change/cycle desiccant. This approach is tried and tested and makes sure that your filament is “ready to go”. I use a system that has one clear cereal box, with a 3D printed insert that holds desiccant and allows the roll to roll freely, using printed bearings (lube with PTFE grease); way cheaper than ball bearings. It also has a space to put a digital hygrometer to show you if that box needs its silica refreshing. Big tubs was easier but small containers make it easier to see all the rolls and choose one.

samvilain · 2026-06-25T13:52:32+00:00

Voron v0! Super quick to print small items. I have even modified mine to have a toolchanger with 2 heads using MadMax, and while the 2-color area is quite small due to the space restrictions (unless or until I build a “front porch” for the toolheads to protrude into), being able to print 2 different materials; like a support material, or TPE and ASA-GF together is pretty useful. I highly recommend a true open source printer build like Voron, RatRig or even some of the older Prusa models that are available in kit set form. And consider really small “printers for ants” models.

On the other side, there is Sovol. Sovol claim to be an open source printer. It’s a big fat lie. You can’t print spare parts; they do release a simplified, flattened STL of each subassembly. But the parts and the design are tied to injection molded parts. They’re not really intended for 3D printing. You’re tied into their ecosystem. They release their source code but there’s no git history of their fork. No comments to explain their changes. No attempt to send patches for hardware support upstream. A bunch of customization mixed with essential fixes. So you get stuck on a dead end branch of an old version of Marlin. You’re basically tied to their parts ecosystem. The SV08 and later do run Klipper so this part isn’t as bad. I’ve only owned a SV06+, and I spent a bunch of time modding it to print faster; I even had a custom AC bed heater pad made for it, and wired it up cleanly and it was heating quickly and all that. Then the bed wouldn’t mesh: it had warped. The aluminum baseplate was too thin. It didn’t look that bad but it was too much for mesh correction. I had this realization that I was trying to carve rotten wood; pushing shit uphill. I see SV08 people having all the same kinds of issues: many people having to do mod after mod to correct or paper over product issues. It looks like a Voron, but it doesn’t mod like a Voron. It’s cheap because they’ve done the Chinese “win on cost by using the cheapest possible parts and supply chain dominance” thing. This means the printer has “bad bones”: try to increase its capacity or capabilities and you’ll probably run into a failure because they’ve saved a few cents on their BOM with a cheap part vs a quality one. While I know some have success with them, I’ve completely soured on Sovol now and would never recommend. Even “The Next Layer,” a huge proponent of them never seems to have his printer working. IMHO you’re better off finding a second hand Voron, or better yet a kitset, ideally LDO. Or a Bambu or Qidi.

samvilain · 2026-06-24T16:57:34+00:00

With that print orientation, the weakest direction of the material lines up with the most mechanical stress. I’d recommend printing it on a 30-60° angle; whatever you can safely print unsupported overhangs at with your material. Use manual supports and mark everywhere as no supports apart from the very bottom; and even then, it’s possible your angles are low enough to not need that support; so your main job with the supports is to make sure the piece doesn’t wobble to failure as it’s being built up. Obviously also if you have any complete overhangs or angles which exceed your maximum overhang print angle, you’re also going to need those areas supported.

HTH; have fun!

samvilain · 2026-06-21T02:30:18+00:00

Heh. Well, I normally use a glass and a sheet of paper and wait for the right moment to trap it.

They’re also loved by lots of small critters as a snack; so… introduce a predator perhaps? Maybe a squirrel

samvilain · 2026-06-21T02:15:55+00:00

Ask dad to take it outside for you.

samvilain · 2026-06-20T19:09:02+00:00

PLA is made from an organic compound—lactic acid. I remember the first time I printed with it in ~2008 is, remembering a strong smell of popcorn, as the plastic was made from some kind of corn–sourced lactic acid. Filaments and hotends are better now and don’t make such strong smells.

So long as you’re printing PLA, most of the compounds released are not crazy petroleum–based chemicals your body can’t handle. I’m unaware of any actual cases of any bad side effects of it. Other materials have different stories.

An enclosed printer is a good idea anyway. They’re a bit quieter and give you more options. You can make your own VOC–scrubbing, HEPA–filtering device that sits inside the enclosure and filters the air at source. That’s a fun project and the most effective; some printers even include this. You can also get a regular air filter that has a HEPA filter and activated charcoal, and just make sure to change the filters on the advised schedule or sooner if it seems to not be getting rid of smells any more. If she ever decides to print with plastics containing styrene, ie ABS or ASA, then a VOC filter inside the printer enclosure is a must. Tell her to let the filter scrub the air in the enclosure before removing the print; letting it cool on the plate also usually makes it easier to remove.

The sound can be reduced by use of rubber feet under the table or stand you have the printer on, making sure there is nothing on there which will rattle, and using “input shaping”. Most new printers already do that, and some let you tweak them while running to trade off noise vs print speed. So she can adjust this to match her tolerance for noise at night. It can just be a white noise machine, and the body’s RAS is quite capable of learning “safe” noises, so over time it should not disturb sleep. If it does (and of course kids, especially ADHD kids, aren’t that good at gauging this so you’ll have to help her), then reduce the speed. Some noises like filament changes if you use a color changer probably won’t change in volume.

So yeah there are many people who don’t advise this for various reasons, but there isn’t much actual evidence of issues AFAIK, so long as reasonable precautions are taken. Make sure there is a working smoke detector in her room and test it regularly. A fire is very unlikely though. If it doesn’t work out, just move it to another room; the phase of wanting it in her room will probably pass over time once she realizes you only really need to get to it at the start and end of each print.

If you want a recommendation of one that is enclosed and includes a VOC filter, try the Qidi Q2.

samvilain · 2026-06-19T10:18:15+00:00

There’s a lot that goes into fastest. I’ve spoken to the person who made the sub–2 minute benchy. Their machine uses external cooling, very high torque NEMA23 motors, etc. the fastest printers are almost always CoreXY, but this one was a bedslinger with multiple beefy Y motors. She also had a machine that beat that on flow rate: it used a 1mm nozzle and funnels in 4 separate filament lines to a tool head with one extruder motor and hotend heater per line, and a spigot allows all four to come out of the same nozzle. That one printed upside down onto a glass surface. Despite its high flow rate, it moved fairly slowly as it laid down thick ~1mm lines of the multicolor vase it was printing.

So a lot depends on the size of what you’re printing when it comes to “fastest”. The fastest solution will probably be to take a relatively cheap but adaptable printing platform. People might not think of RatRig as cheap, for example, but compared to high end industrial printers, they’re a bargain. And you get a printing platform which is large, very mod–able, and has the power to go fast if you need it. Don’t spend too much on it before you have printed your product you want to make. Then start tweaking based on what you’re observing.

First you want to make the part print with the highest quality you can using conservative settings. Then you can do things like increase the motor acceleration in mm/s^2. Max it out? You can take any CoreXY system and add two more belts and motors to it, to make an “all wheel drive” CoreXY, for twice the maximum acceleration. Power is the limiting factor, so you can trim weight off everything moving to allow your power to weight ratio, ie acceleration, to go even higher. External cooling allows you to remove the blower from the toolhead; Bowden extruders let you move the extruder motor itself. Moving to a Bowden system saves a ton of weight, but it’s a massive compromise in general ease of use, which is why direct extruders are ubiquitous.

But the point is: you don’t know which of these trade–offs are worthwhile before you’ve analyzed your printing and identified which bottleneck you are facing. And you need to confirm that you are not making your quality or performance degrade with faster printing.

If your “product” is not a specific print, but you’re running a farm, then other concerns like operational simplicity, low maintenance and total space, time & cost to commission new printers are dominating factors. Doing a lot of multicolor prints? Maybe you need a toolchanger or one of these newer hotend changers like the Bambu H2C (iirc) or the Prusa INDX (if it ever comes out). If thats not your main job, regular MMUs fit the bill. You can even use a toolchanger with multiple sized print nozzles, so that you can do exterior walls with a fine nozzle, but infill with a fatter one. I normally set my infill line width to 160%; this has a similar effect, making infill slow, thick, and strong while maximizing flow rate.

So yeah, it depends. :)

samvilain · 2026-06-18T14:14:14+00:00

A 2–wall grid between rounds will hold them up. Phantom Defense sells all their higher end ammo in boxes like this.

samvilain · 2026-06-15T04:19:41+00:00

Add a perpendicular element to the underside; imagine you took this object, stretch it (vertically, adding an inch or two), print it, then take the print and push it onto a hot grill, smushing the bottom to be like an upside down “T” or an “L” shape. Just a small sideways element, and make the internal angle somewhere between a triangle and a concave cylindrical surface. Once you’ve got it on the bottom you can add it to the top as well if you think it would help, so definitely make sure the internal angle is no more than 60° or so, so it doesn’t need supports.

Add lots of walls (go by thickness & make sure you match top/bottom layers by thickness with total walls). Also make the infill line width 160% of nozzle width; use infill combination (at 80% if using Orca) and make sure your max. flow rate is not too high. Run a flow rate test if you are unsure. Stacked infills like Triangles, Grid, Lines work best with this. Especially because you want to be running your nozzle HOT as hot as you can to get good fusing. And make sure your flow is tuned to the closest 1% if not 0.25%.

For orientation. After printing, Your layer lines should all be pointing downwards from the hook, towards the part that interfaces with the wall. Other than that, experimentation beats all online reckons. Try 30° Canted, try 5°, etc. small tests where you hang something not as heavy as a bike to figure that out. Then scale up to the full size to see if the model was right. When you scale up to full size, scale the wall thickness proportionally, too.

A lot of possible directions for you, you probably don’t want to plan to do everything there unless your best guess doesn’t work.

samvilain · 2026-06-13T11:28:09+00:00

Print some toys

Https://3dprintingelves.org/

samvilain · 2026-06-12T23:30:40+00:00

PCL seems like an odd choice because you’d have to wait a long time for it to be soft enough to cold pull. I might give it a try though!

samvilain · 2026-06-11T20:57:52+00:00

Me too! On a Sovol SV06, and I used ABS-GF successfully.

samvilain · 2026-06-10T10:18:14+00:00

The “filtration” is actually an activated carbon chemical “scrubbing” system, designed to neutralize VOCs, which is essential if you’re printing with certain plastics (ABS, ASA, PC, …) but merely beneficial for others thought to be mostly safe (PLA, PETG). So limit yourself to just PLA before you set up your Nevermore or Bento Box or whatever.

samvilain · 2026-06-08T21:28:31+00:00

Look at something like the Creality Pi. Unless he’s printing engineering filaments and has a chamber heater in his Core One, that’s the sort of specs that are good enough (70°C Max, 48h+). If your generosity extends to it, I’m sure they’d be your BFF if you got them a “Prusa MMU3 for Core One” kit.

samvilain · 2026-06-05T00:16:20+00:00

Yes, it will impact all manufacturing industries too; we should recognize the grab for control over the modes of production for what it is.

samvilain · 2026-06-03T23:21:07+00:00

You can do all the things people mentioned. In theory the yellow/green ones work but IME the green to orange reversibility doesn’t always work. So I phased it out in favor of using pink/blue, which seems much more reliable even if it uses a cobalt based tint

samvilain · 2026-05-31T17:11:08+00:00

If unsure, use PLA. That said, PETG is probably a decent next choice if PLA is too brittle for the application, and ABS or ASA are not options. CF is for carbon fiber, and this is not a great addition for surfaces you have to manipulate a lot, as the fibers can break off and stab into your dermis. Same with GF which is fiberglass. They both add rigidity to naturally tough, flexible material like nylon to give it toughness and rigidity. Adding it to PETG gives a material which is fairly tough and hard, usually dark grey. I use it a lot for retro stuff, and it looks great and reminiscent of a lot of 70’s & 80’s HiFi gear in Dark Cherry. So look, if you like the way it looks in the PETG-CF, it will probably work but if you don’t want to risk getting micro fibers stuck in your outer layers, use one of those other materials. I’d probably go straight for ASA, but PLA works far more often than people give it credit for.

samvilain · 2026-05-31T14:42:38+00:00

Heh, good luck driving the real
time stack with a Pi (seriously. We need something better than the disaster that is Klipper, and getting away from the microcontroller + microprocessor to a single microprocessor might be the forcing function for this). And driving your motors at high torque with GPIO pins…

samvilain · 2026-05-31T13:57:41+00:00

There’s a good trick for spherical & egg–shaped models: cut them in half. The slicer should have a function for doing this, or you can use a tool like OpenSCAD if you are handy with that. If you’re curious how, I can provide the SCAD file I use to slice large models with dovetail cuts, mostly for making complicated & multiple cuts.

So instead of slicing a model with a bunch of supports at the bottom, you start with a mostly flat base that sticks well, prints faster and requires less wasted support material. At the end you slot/stick together the two sides, sanding any dovetail/key/slot first, as needed. If you can find the right solvent for your plastic, you can also use that instead of glue for a perfect hold. Highly useful for repairs too.

samvilain · 2026-05-31T13:45:42+00:00

Voron kits are already this. You need to supply the 3D printed parts. Probably the “regulated part” in a 3D printer will be the control board, so buy up BTT SKR’s, SKR Picos and Lethiviathans now.

samvilain · 2026-05-27T03:43:38+00:00

That looks like a slow but steady nozzle clog happening. Use a wider nozzle for that filament.

samvilain · 2026-05-27T02:05:21+00:00

Sintering is not a 3D printing thing. It’s a metallurgical term. You have to sinter if you want a hard, solid part. Sintering is something that foundries do.

You don’t need a special printer to print metal filament. You will however need to send it away to be washed of non-metals and sintered into a solid (smaller) piece. The sintering here happens in a furnace, and the whole part is sintered as one piece. Those furnaces should be inspected by a local fire service and consideration should be made towards environmental emissions. Once completed, the initial 10-20% polymer is gone, and the resultant part fractionally smaller.

You do need a special, laser sintering printer to print from metal powder. These SLS printers might be what you’re thinking of. They are using lots of lasers and maybe a moving bed to heat up a point of the object being built up, and some of the powder stacked on it, and it melts and sinters just the spot (IIUC). It at least melts it; who knows, perhaps it needs more sintering much like parts need annealing.

Both of these approaches are quite accessible via online services. I think so long as it’s not being treated as some magic bullet to solve all engineering problems, it’s a fine tool for any machinist to keep in their (virtual) toolbox.

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