4 ms·

This is a bad idea. 3d printed objects unless filled with food-grade resins are not food safe as they cannot be cleaned (ridges of the layers) and tend to relea

by ta988 5y ago

This is a bad idea. 3d printed objects unless filled with food-grade resins are not food safe as they cannot be cleaned (ridges of the layers) and tend to release a lot of not well characterized compounds.

Youden 5y ago
> This is a bad idea. Why did you have to add this? The rest of your post raises a valid point and then suggests a way to address it. Is one small addressable flaw enough to render the rest of the project "a bad idea"?
- TeMPOraL 5y ago
  I wouldn't call creating a health hazard for your cat a "small" flaw.
  - JoeAltmaier 5y ago
    ...unless you fix it, as described. Then it's not a flaw at all. The rules here say to read each post with the most positive interpretation. Snark is never welcome, and that could have been said differently e.g. "A great idea! Be sure to use food-grade resin!"
    - elif 5y ago
      Please stay on topic you are not a moderator
      - JoeAltmaier 5y ago
        Oh sorry, are you? I did not know.
    - TeMPOraL 5y ago
      Fair enough. Your alternative phrasing sounds much better! Thanks for the reminder. I suppose I'm somewhat desensitized to snark these days; that's not a development I like.
      - JoeAltmaier 5y ago
        Me too! I find myself deleting posts as often as I write them. In that case I go back and read some of what you have written, to remind me how to be calm and considerate.
        TeMPOraL 5y ago
        Me? Calm and considerate? Do you even read my comments?! Seriously though, thanks. While I strive to be what you just said, I also delete roughly half of my comments before even submitting them (and every now and then, few minutes after), and I'm not really happy about the rest. I'm pretty grumpy these days, I'm starting to hate the technology business more with every passing moment. Is this too much HN, or just youthful naivete expiring? (Few years ago I learned that I won the third place in a ranking of HN's top posters of profanities - according to some dataset someone is keeping on Kaggle. This dubious honour made me tone down my language quite a bit.)
        JoeAltmaier 5y ago
        I've never won third place in any contest! Congratulations! I'm impressed.
        TeMPOraL 5y ago
        Why, thank you! In the spirit of keeping the positivity train rolling, you're the third person (after my wife and daughter) to make me smile today, so consider yourself the 3rd place winner of this impromptu contest!
  - spookthesunset 5y ago
    I’m no feline toxicologist but cats only live like 12 years. I don’t think that is long enough for this kind of thing to really have any effect. Plus given it is dry food, I wouldn’t loose too much sleep. I see animal food and water stored in all kinds of dirty, janky contraptions.
    - bradknowles 5y ago
      Dry food is full of oils and other chemicals that can do a real number on porcelain and metal food dishes that are designed to the highest levels of food safety standards, if those bowls aren’t cleaned or changed very frequently. $DEITY only knows what those kinds of chemicals could do to an object that was 3D printed from materials that were not designed to the highest possible levels of food safety standards. $DEITY only knows what kinds of toxic chemicals could be leached from the 3D printed materials, or could be created from the combination of the 3D printed materials and the oils and other chemicals in the dry food. I realize that some people don’t care, and some other people don’t feel like they have a choice. And some people have cats that are finicky eaters and will refuse anything but their favorite dry foods. But you wouldn’t feed your kids a lifetime diet of McDonalds McBurger and McFries with McShakes for every single meal of their life. Why would you do that to your cat(s)? Yes, we feed some high quality dry food. Because our cats insist on a certain amount of that. But we also try to focus the feeding on high quality wet food instead. We are not perfect, but we are actively working on getting better.
    - bradknowles 5y ago
      Oh, and the average lifespan for an indoor/outdoor cat is about seven years. For indoor only cats, this is about fourteen years. But there’s also a long tail to where it is not too unusual to have cats living to twenty years of age, or more. Obviously, there are some regional and breed-related variations to these nationwide averages. And if you live close to a green belt with lots of wild animals like foxes and coyotes, maybe the average lifespan of an indoor/outdoor cat is significantly reduced. YMMV.
inportb 5y ago
For a print this size, I wouldn't use resin. I imagine he used FDM. You might want to consider printing food-related items in PLA. The ridges do present a problem, but could be mitigated by sanding or coating (again, food-grade).
- willis936 5y ago
  PLA isn't considered food grade but a marginally more expensive and difficult to work with, PETG, is food grade.
  - Steltek 5y ago
    I don't think switching to PETG is an automatic win? You still have a rough, porous surface that can trap bacteria. I stay away from food-related prints but I thought the best method was to print in whatever reasonable material you want and then coat it in something food grade, like resin. Then you get the material and print properties of PLA, PETG, whatever but food safe.
    - devmor 5y ago
      Or use the print to make a mold for casting food grade resin.
- GravitasFailure 5y ago
  I believe they were suggesting using a food safe epoxy resin coating, not using a resin printer to make the part. Honestly, since it's dry food the usual food safety risks are fairly limited.
devmor 5y ago
Came here to comment the same thing. Please don't put food on 3D printed surfaces, for humans or animals.
spookthesunset 5y ago
The clear food bin in the video looked like a “normal” bit of plastic—almost like a large licorice container. The only other part that is in long contact with the food is the actual bowl where kitty eats from. Design it so it fits a dishwasher safe bowl of some kind and you are good to go. The “guts” where the food falls through has minimal contact and for a dog or cat I wouldn’t loose too much sleep over. For humans I might do something more… That being said… cleaning the “guts” might be a challenge and I can see it getting kinda skanky over time. Either reprint the parts periodically or find a way to clean them.

by ta988 5y ago

Youden 5y ago

> This is a bad idea. Why did you have to add this? The rest of your post raises a valid point and then suggests a way to address it. Is one small addressable flaw enough to render the rest of the project "a bad idea"?

TeMPOraL 5y ago
I wouldn't call creating a health hazard for your cat a "small" flaw.
- JoeAltmaier 5y ago
  ...unless you fix it, as described. Then it's not a flaw at all. The rules here say to read each post with the most positive interpretation. Snark is never welcome, and that could have been said differently e.g. "A great idea! Be sure to use food-grade resin!"
  - elif 5y ago
    Please stay on topic you are not a moderator
    - JoeAltmaier 5y ago
      Oh sorry, are you? I did not know.
  - TeMPOraL 5y ago
    Fair enough. Your alternative phrasing sounds much better! Thanks for the reminder. I suppose I'm somewhat desensitized to snark these days; that's not a development I like.
    - JoeAltmaier 5y ago
      Me too! I find myself deleting posts as often as I write them. In that case I go back and read some of what you have written, to remind me how to be calm and considerate.
      - TeMPOraL 5y ago
        Me? Calm and considerate? Do you even read my comments?! Seriously though, thanks. While I strive to be what you just said, I also delete roughly half of my comments before even submitting them (and every now and then, few minutes after), and I'm not really happy about the rest. I'm pretty grumpy these days, I'm starting to hate the technology business more with every passing moment. Is this too much HN, or just youthful naivete expiring? (Few years ago I learned that I won the third place in a ranking of HN's top posters of profanities - according to some dataset someone is keeping on Kaggle. This dubious honour made me tone down my language quite a bit.)
        JoeAltmaier 5y ago
        I've never won third place in any contest! Congratulations! I'm impressed.
        TeMPOraL 5y ago
        Why, thank you! In the spirit of keeping the positivity train rolling, you're the third person (after my wife and daughter) to make me smile today, so consider yourself the 3rd place winner of this impromptu contest!
- spookthesunset 5y ago
  I’m no feline toxicologist but cats only live like 12 years. I don’t think that is long enough for this kind of thing to really have any effect. Plus given it is dry food, I wouldn’t loose too much sleep. I see animal food and water stored in all kinds of dirty, janky contraptions.
  - bradknowles 5y ago
    Dry food is full of oils and other chemicals that can do a real number on porcelain and metal food dishes that are designed to the highest levels of food safety standards, if those bowls aren’t cleaned or changed very frequently. $DEITY only knows what those kinds of chemicals could do to an object that was 3D printed from materials that were not designed to the highest possible levels of food safety standards. $DEITY only knows what kinds of toxic chemicals could be leached from the 3D printed materials, or could be created from the combination of the 3D printed materials and the oils and other chemicals in the dry food. I realize that some people don’t care, and some other people don’t feel like they have a choice. And some people have cats that are finicky eaters and will refuse anything but their favorite dry foods. But you wouldn’t feed your kids a lifetime diet of McDonalds McBurger and McFries with McShakes for every single meal of their life. Why would you do that to your cat(s)? Yes, we feed some high quality dry food. Because our cats insist on a certain amount of that. But we also try to focus the feeding on high quality wet food instead. We are not perfect, but we are actively working on getting better.
  - bradknowles 5y ago
    Oh, and the average lifespan for an indoor/outdoor cat is about seven years. For indoor only cats, this is about fourteen years. But there’s also a long tail to where it is not too unusual to have cats living to twenty years of age, or more. Obviously, there are some regional and breed-related variations to these nationwide averages. And if you live close to a green belt with lots of wild animals like foxes and coyotes, maybe the average lifespan of an indoor/outdoor cat is significantly reduced. YMMV.

inportb 5y ago

For a print this size, I wouldn't use resin. I imagine he used FDM. You might want to consider printing food-related items in PLA. The ridges do present a problem, but could be mitigated by sanding or coating (again, food-grade).

willis936 5y ago
PLA isn't considered food grade but a marginally more expensive and difficult to work with, PETG, is food grade.
- Steltek 5y ago
  I don't think switching to PETG is an automatic win? You still have a rough, porous surface that can trap bacteria. I stay away from food-related prints but I thought the best method was to print in whatever reasonable material you want and then coat it in something food grade, like resin. Then you get the material and print properties of PLA, PETG, whatever but food safe.
  - devmor 5y ago
    Or use the print to make a mold for casting food grade resin.
GravitasFailure 5y ago
I believe they were suggesting using a food safe epoxy resin coating, not using a resin printer to make the part. Honestly, since it's dry food the usual food safety risks are fairly limited.

devmor 5y ago

Came here to comment the same thing. Please don't put food on 3D printed surfaces, for humans or animals.

spookthesunset 5y ago

The clear food bin in the video looked like a “normal” bit of plastic—almost like a large licorice container. The only other part that is in long contact with the food is the actual bowl where kitty eats from. Design it so it fits a dishwasher safe bowl of some kind and you are good to go. The “guts” where the food falls through has minimal contact and for a dog or cat I wouldn’t loose too much sleep over. For humans I might do something more… That being said… cleaning the “guts” might be a challenge and I can see it getting kinda skanky over time. Either reprint the parts periodically or find a way to clean them.