8 ms·

How to make (almost) anything (2020)

277 points by akeck 5y ago

chasd00 5y ago
Next weekend can't come soon enough :) I'm in the high power rocketry hobby and got a Prusa i3 mk3 for myself for Christmas. It's pretty amazing to sketch a bit while on conference calls, then after work model my sketch in Fusion360, export the mesh, import to Prusa slicr, export gcode to an sdcard, start the printer and goto bed. Next morning, there's my part waiting for me. Electronics is the next bridge to cross and i really hope this class helps with that. I know a guy in the hobby who went from nothing to selling a custom designed altimeter for rockets on his website in about 6 months which was pretty impressive to me. https://flightsketch.com/store/catalog/flightsketch-mini_1/ https://flightsketch.com/store/catalog/flightsketch-mini_1/
- andi999 5y ago
  What annoyed me was that the slicer does not mantain hole diameters, somehow holes are smaller. In my case I was planning to prototype cnc milled stuff (which is kind of expensive), but this killed to use case.
  - LeifCarrotson 5y ago
    The slicer does maintain hole diameters, but just like CNC milling HDPE, you should expect dimensions to change a little after printing. If you need to have a tight tolerance fit on something, expect to run a drill or chucking reamer through it after printing. If it's really tight tolerances, it's easy enough to melt or press a drill bushing or threaded insert into an oversized hole to get fits tighter than you're likely able to hit with a mill. Your expensive parts likely go through many steps before and after manufacturing already that involve things like fixturing the material in place, rotating it and reacquiring datums, running taps through by hand, deburring sharp edges, etc; you should not expect 3D printing to be as easy as sending the STEP file to the machine and getting a complete part out. Sanding, acetone vapor polish, drilling, reaming, tapping, etc. are normal parts of the manufacturing and prototyping process.
    - andi999 5y ago
      Which slicer do you use? It seems to be a known problem of cura.
      - sokoloff 5y ago
        I use Cura. It’s across FDM printing techniques and is (somewhat) akin to the errors in subtractive manufacturing. Subtractive errors/inaccuracies tend to be of the type that remove too much material. Additive errors/inaccuracies tend to add material. My models for FDM often include a “hole size compensation” user parameter and I tweak it to introduce an offsetting bias in through-holes. (Non through holes tend to get heat-set brass inserts, which are more forgiving of the 0.1mm or less radial errors.)
      - 2muchcoffeeman 5y ago
        You can print a clearance tolerance test to see how accurate your printer is. I use a Prusa mk3s and as accurate as it is, at best my tolerance is 0.1mm. Enough to stop your parts fitting together. I normally build in a 0.2mm tolerance for close fitting parts.
      - _carbyau_ 5y ago
        I have had the issue with both Cura and Simplify3D. For a circular hole, as far as I can tell the slicer commands the hotend path to trace the circle exactly, rather than tracing a slightly bigger circle to account for output thickness. I imagine if you were to use smaller nozzles the issue would be lesser, but not gone.
    - theelous3 5y ago
      Just an fyi drills are not good for tight tolerances. They cut trilobular holes, not circles. Reaming or boring are the route to tight tolerances.
      - elil17 5y ago
        It is much tighter than 3D printing, though - good enough for most cases if you’re using a drill press
  - 0_____0 5y ago
    IIRC there's a param in the slicers I've used that can fine tune hole sizes.
  - chasd00 5y ago
    i've noticed things shrink a bit when the cool off ( at least with PLA ). What i do is print, test fit, adjust dimensions, then print again. It usually only takes one or two iterations to get it just right. I built a deck once, designed it, spec'd out all the materials i would need, optimized for minimal wastage, the whole 9 yards. I learned the hard way that in the real world dimensions are a matter of degree and what's on the label may or may not be what you get (to a ridiculous degree when it comes to lumber). I'm use to software where it either compiles or it doesn't, it either works or it doesn't. In the real world with physical objects it's much more a matter of "is it close enough or not".
    - ada1981 5y ago
      Lumber is regularly sold up to an inch off the label. But that is standard and expected. Meaning people in the trade know how much lumber to buy given the finished dimensions of what they buy. I have no idea why this is standard practice and when building out http://MajikBus.co http://MajikBus.co ran into minor issues.
  - joshvm 5y ago
    This is, I think, partly due to how the slicer routes the filament paths. I've had this problem moving between nozzle diameters and the only reason I could think of was that it wasn't possible for the slicer to maintain both accurate hole diameters and the correct placement of filament relative to previous extrusions. The STL was identical, but the parts printed with a 0.8 mm nozzle were undersized and only the holes. My experience of this was with Cura and an Ultimaker S5. Generally you should always start printing loose holes and tightening them up as you go to see where the limit is. The simplest dimension to control is the perimeter. That can, for most parts, be perfectly accurate because there are no constraints on where the nozzle needs to avoid. However if you print a hole close to the edge of a part then the printer somehow has to lay down both an accurate edge to the hole while maintaining suitable separation from previously printed stuff. Essentially your design is quantised by the nozzle diameter within the perimeter of the part (I may be wrong here, but this seems like a simple explanation). You may have better results if you tune your part to the printer/nozzle you're using so that the slicer doesn't have to worry about leaving/filling gaps that are non-integer multiples of the nozzle size. In theory this shouldn't matter, because the hole perimeter can also be printed first, as it's an "outside" edge, but it doesn't always seem to work that way.
  - dekhn 5y ago
    Holes with interior dimensions close to the width of the nozzle are hard and need to be calibrated if you absolutely need to print them to size. Basically, the plastic is "spreading" a bit wider than the nozzle tip. better solutions, rather than making exactly sized holes, is to increase the number of vertical walls, make the hole size slightly under, and use a precision drill and reamer to get to the target size. Also, make sure you're setting your scaling right (for example, I need to set my object size to be 100.6% of its designed size, because PLA shrinks when it cools).
  - maxioatic 5y ago
    Yeah this is just a thing you have to design around while using FDM printers, as others have mentioned. I really like melting in threaded inserts if you need threads, otherwise use a drill bit or reamer. If you need super tight tolerances (like CNC level tight) then a consumer grade 3D printer likely won't get you there though.
    - 2muchcoffeeman 5y ago
      Prusa uses 3D printed parts and I'm a bit surprised just how good the prints are.
      - maxioatic 5y ago
        I own one and can confirm they are quite nice. Still though, you aren’t getting machining level tolerances (0.001”) on a FDM machine no matter how hard you try.
  - captaindiego 5y ago
    Might be worth checking out heat-set nut inserts: https://www.mcmaster.com/heat-set-inserts/ https://www.mcmaster.com/heat-set-inserts/ I've has good luck pushing these into holes in 3d printed parts with a soldering iron the past.
  - ddingus 5y ago
    Chordial deviations add up on smaller holes. Minimum size line segments and other things come into play on holes less than about 0.2"
- roland35 5y ago
  Next thing you should do is get a raspberry pi with octoprint! Then you can drop the gcode in from your web browser :)
  - NoNotTheDuo 5y ago
    Or even easier, push to octoprint directly from your slicer!
- CobrastanJorji 5y ago
  What kind of parts do you print? I imagine engine parts are right out, and I'm guessing fins might melt as well. Nose cones? Body or internal stuff?
  - Doxin 5y ago
    Not gp, but things you can definitely use 3d prints for related to rocketry: nose cones, fins, motor mounts, electronics mounts, and probably a whole slew of other stuff I'm forgetting at the moment.
  - chasd00 5y ago
    my least favorite part of building a rocket is the motor mount. It requires a handful of parts, a decent epoxy system, and is one of the more expensive parts of the airframe. I've designed a modular mount that i can pull out of one airframe and plug into another. So once the motor mount is done i can use it in all my airframes of the same diameter and motor diameter without any bonding. To cover all my current airframe diameters and motor diameter combinations requires 5 prints and adding a new one is pretty easy. my next thought is modular fin cans. The rule of thumb for trapezoidal fin dimensions are a function of airframe diameter. I would like to be able to make one fin can for each airframe diameter and then re-use those on new airframes. With my current inventory I need 4 fin cans ( 2", 3", 4" and 7.5" diameter airframes )
Metacelsus 5y ago
See also "How to grow (almost) anything": https://fab.cba.mit.edu/classes/S63.21/ https://fab.cba.mit.edu/classes/S63.21/
- forgotmyoldacc 5y ago
  Note that the title is fairly misleading, students don't actually do real practical labs. A random example: https://fab.cba.mit.edu/classes/S63.21/class_site/pages/microbiome/microbiome.html https://fab.cba.mit.edu/classes/S63.21/class_site/pages/micr.... Probably because this class was being held during COVID times. There's no hands on biology work. Homework consists of: - Find a research or journal article - Propose a technology - Propose a methodology etc The 2019 version looks a little better: http://fab.cba.mit.edu/classes/S66.19/S66.19/ http://fab.cba.mit.edu/classes/S66.19/S66.19/
gabrielsroka 5y ago
Here's a complete class listing https://cba.mit.edu/classes https://cba.mit.edu/classes
azinman2 5y ago
I never took this back when I was at the Media Lab and that’s one of my main regrets from that time. This class is very famous, but I’m not sure how useful this is as an online class because as a normal person you won’t have access to the water jet cutters, plastic mould injection machines, etc. Covid aside, hacker spaces were already dying out in SF. I wish there was more push for ordinary people to become makers rather than just consumers.
- chasd00 5y ago
  3dprinters are pretty accessible but you're right about other tools. Also, some of the tools can be pretty dangerous ( looking at you lathes/mills ). IMO one of the greatest things about software development is you can goto walmart and get $500 laptop, sit in a coffee shop, and have access to all the tools needed to build cutting edge high performance software of any type. It's not so easy to do that in meatspace with physical objects.
  - srcreigh 5y ago
    except for video games and deep learning
    - baud147258 5y ago
      depends on the video game. If you target what AAA was doing 5 or 10 years ago in term of graphical quality or even specific style like low polygon, pixel art, 2d art..., you don't really need the cutting edge in terms of graphic cards.
  - adamsmith143 5y ago
    As someone not much into this scene, how useful are 3D Printers actually? I get the sense that they're very useful to hobbyists or for creating prototypes but are the plastics used suitable for production use cases?
    - theelous3 5y ago
DoingIsLearning 5y ago
All the videos linked in the class show me a message "video is not rated", saying I am unable to watch?
- ksdnjweusdnkl21 5y ago
  I wonder how one should host their educational videos to have them be available without ads or other nonsense like this. Any affordable solutions?
  - kragen 5y ago
    PeerTube seems to work okay? More generally internet bandwidth is a lot cheaper now than it was 15 years ago.
  - kleer001 5y ago
    > without ads and > affordable I think lots of smart people with lots of energy have spent lots of time trying to solve this problem with respect to getting customers and keeping them. It's a hard hard problem. Subscription supporting the free-with-ads IMHO seems to be the sweet spot.
- lupire 5y ago
  What do you mean?
  - DoingIsLearning 5y ago
    As in the video is not porn/violence rated and I am too anonymous for Vimeo to know if I am an inocent unsupervised child on the internet.
- jonas_kgomo 5y ago
  you need to login into Vimeo, then you can watch
  - DoingIsLearning 5y ago
nomemory 5y ago
If i am allowed to joke, I was expecting to read an article on Rust.
- bogwog 5y ago
  I think you misread the title as “how to remake (almost) anything”
sanj 5y ago
Gershenfeld helped coordinate a bunch of folks with COVID work too!
pjs_ 5y ago
Someone should add KLayout to this list. Free software for chip design that is absolutely incredible given that it is a free piece of software... https://klayout.de/ https://klayout.de/
- dbcurtis 5y ago
  Where does one go to get a part fabricated, though? It isn't quite as easy as getting a PCB made.
  - kragen 5y ago
    MOSIS, CMP, CMC. Prices start around US$20k in theory but probably more like US$200k in most cases.
HWR_14 5y ago
Thank you for linking to this. There are a couple of topics here that I've tried to find a good source for for all COVID. Mostly I'm excited about the molding/casting. The various channels/sprues are difficult to design, and most sources are too general and unactionable. Yes I know I need them, now how do I compute them! And if anyone has more sources, I'll happily take suggestions.

277 points by akeck 5y ago

Next weekend can't come soon enough :) I'm in the high power rocketry hobby and got a Prusa i3 mk3 for myself for Christmas. It's pretty amazing to sketch a bit while on conference calls, then after work model my sketch in Fusion360, export the mesh, import to Prusa slicr, export gcode to an sdcard, start the printer and goto bed. Next morning, there's my part waiting for me. Electronics is the next bridge to cross and i really hope this class helps with that. I know a guy in the hobby who went from nothing to selling a custom designed altimeter for rockets on his website in about 6 months which was pretty impressive to me. https://flightsketch.com/store/catalog/flightsketch-mini_1/ https://flightsketch.com/store/catalog/flightsketch-mini_1/

andi999 5y ago
What annoyed me was that the slicer does not mantain hole diameters, somehow holes are smaller. In my case I was planning to prototype cnc milled stuff (which is kind of expensive), but this killed to use case.
- LeifCarrotson 5y ago
  The slicer does maintain hole diameters, but just like CNC milling HDPE, you should expect dimensions to change a little after printing. If you need to have a tight tolerance fit on something, expect to run a drill or chucking reamer through it after printing. If it's really tight tolerances, it's easy enough to melt or press a drill bushing or threaded insert into an oversized hole to get fits tighter than you're likely able to hit with a mill. Your expensive parts likely go through many steps before and after manufacturing already that involve things like fixturing the material in place, rotating it and reacquiring datums, running taps through by hand, deburring sharp edges, etc; you should not expect 3D printing to be as easy as sending the STEP file to the machine and getting a complete part out. Sanding, acetone vapor polish, drilling, reaming, tapping, etc. are normal parts of the manufacturing and prototyping process.
  - andi999 5y ago
    Which slicer do you use? It seems to be a known problem of cura.
    - sokoloff 5y ago
      I use Cura. It’s across FDM printing techniques and is (somewhat) akin to the errors in subtractive manufacturing. Subtractive errors/inaccuracies tend to be of the type that remove too much material. Additive errors/inaccuracies tend to add material. My models for FDM often include a “hole size compensation” user parameter and I tweak it to introduce an offsetting bias in through-holes. (Non through holes tend to get heat-set brass inserts, which are more forgiving of the 0.1mm or less radial errors.)
    - 2muchcoffeeman 5y ago
      You can print a clearance tolerance test to see how accurate your printer is. I use a Prusa mk3s and as accurate as it is, at best my tolerance is 0.1mm. Enough to stop your parts fitting together. I normally build in a 0.2mm tolerance for close fitting parts.
    - _carbyau_ 5y ago
      I have had the issue with both Cura and Simplify3D. For a circular hole, as far as I can tell the slicer commands the hotend path to trace the circle exactly, rather than tracing a slightly bigger circle to account for output thickness. I imagine if you were to use smaller nozzles the issue would be lesser, but not gone.
  - theelous3 5y ago
    Just an fyi drills are not good for tight tolerances. They cut trilobular holes, not circles. Reaming or boring are the route to tight tolerances.
    - elil17 5y ago
      It is much tighter than 3D printing, though - good enough for most cases if you’re using a drill press
- 0_____0 5y ago
  IIRC there's a param in the slicers I've used that can fine tune hole sizes.
- chasd00 5y ago
  i've noticed things shrink a bit when the cool off ( at least with PLA ). What i do is print, test fit, adjust dimensions, then print again. It usually only takes one or two iterations to get it just right. I built a deck once, designed it, spec'd out all the materials i would need, optimized for minimal wastage, the whole 9 yards. I learned the hard way that in the real world dimensions are a matter of degree and what's on the label may or may not be what you get (to a ridiculous degree when it comes to lumber). I'm use to software where it either compiles or it doesn't, it either works or it doesn't. In the real world with physical objects it's much more a matter of "is it close enough or not".
  - ada1981 5y ago
    Lumber is regularly sold up to an inch off the label. But that is standard and expected. Meaning people in the trade know how much lumber to buy given the finished dimensions of what they buy. I have no idea why this is standard practice and when building out http://MajikBus.co http://MajikBus.co ran into minor issues.
- joshvm 5y ago
  This is, I think, partly due to how the slicer routes the filament paths. I've had this problem moving between nozzle diameters and the only reason I could think of was that it wasn't possible for the slicer to maintain both accurate hole diameters and the correct placement of filament relative to previous extrusions. The STL was identical, but the parts printed with a 0.8 mm nozzle were undersized and only the holes. My experience of this was with Cura and an Ultimaker S5. Generally you should always start printing loose holes and tightening them up as you go to see where the limit is. The simplest dimension to control is the perimeter. That can, for most parts, be perfectly accurate because there are no constraints on where the nozzle needs to avoid. However if you print a hole close to the edge of a part then the printer somehow has to lay down both an accurate edge to the hole while maintaining suitable separation from previously printed stuff. Essentially your design is quantised by the nozzle diameter within the perimeter of the part (I may be wrong here, but this seems like a simple explanation). You may have better results if you tune your part to the printer/nozzle you're using so that the slicer doesn't have to worry about leaving/filling gaps that are non-integer multiples of the nozzle size. In theory this shouldn't matter, because the hole perimeter can also be printed first, as it's an "outside" edge, but it doesn't always seem to work that way.
- dekhn 5y ago
  Holes with interior dimensions close to the width of the nozzle are hard and need to be calibrated if you absolutely need to print them to size. Basically, the plastic is "spreading" a bit wider than the nozzle tip. better solutions, rather than making exactly sized holes, is to increase the number of vertical walls, make the hole size slightly under, and use a precision drill and reamer to get to the target size. Also, make sure you're setting your scaling right (for example, I need to set my object size to be 100.6% of its designed size, because PLA shrinks when it cools).
- maxioatic 5y ago
  Yeah this is just a thing you have to design around while using FDM printers, as others have mentioned. I really like melting in threaded inserts if you need threads, otherwise use a drill bit or reamer. If you need super tight tolerances (like CNC level tight) then a consumer grade 3D printer likely won't get you there though.
  - 2muchcoffeeman 5y ago
    Prusa uses 3D printed parts and I'm a bit surprised just how good the prints are.
    - maxioatic 5y ago
      I own one and can confirm they are quite nice. Still though, you aren’t getting machining level tolerances (0.001”) on a FDM machine no matter how hard you try.
- captaindiego 5y ago
  Might be worth checking out heat-set nut inserts: https://www.mcmaster.com/heat-set-inserts/ https://www.mcmaster.com/heat-set-inserts/ I've has good luck pushing these into holes in 3d printed parts with a soldering iron the past.
- ddingus 5y ago
  Chordial deviations add up on smaller holes. Minimum size line segments and other things come into play on holes less than about 0.2"
roland35 5y ago
Next thing you should do is get a raspberry pi with octoprint! Then you can drop the gcode in from your web browser :)
- NoNotTheDuo 5y ago
  Or even easier, push to octoprint directly from your slicer!
CobrastanJorji 5y ago
What kind of parts do you print? I imagine engine parts are right out, and I'm guessing fins might melt as well. Nose cones? Body or internal stuff?
- Doxin 5y ago
  Not gp, but things you can definitely use 3d prints for related to rocketry: nose cones, fins, motor mounts, electronics mounts, and probably a whole slew of other stuff I'm forgetting at the moment.
- chasd00 5y ago
  my least favorite part of building a rocket is the motor mount. It requires a handful of parts, a decent epoxy system, and is one of the more expensive parts of the airframe. I've designed a modular mount that i can pull out of one airframe and plug into another. So once the motor mount is done i can use it in all my airframes of the same diameter and motor diameter without any bonding. To cover all my current airframe diameters and motor diameter combinations requires 5 prints and adding a new one is pretty easy. my next thought is modular fin cans. The rule of thumb for trapezoidal fin dimensions are a function of airframe diameter. I would like to be able to make one fin can for each airframe diameter and then re-use those on new airframes. With my current inventory I need 4 fin cans ( 2", 3", 4" and 7.5" diameter airframes )

Metacelsus 5y ago

See also "How to grow (almost) anything": https://fab.cba.mit.edu/classes/S63.21/ https://fab.cba.mit.edu/classes/S63.21/

forgotmyoldacc 5y ago
Note that the title is fairly misleading, students don't actually do real practical labs. A random example: https://fab.cba.mit.edu/classes/S63.21/class_site/pages/microbiome/microbiome.html https://fab.cba.mit.edu/classes/S63.21/class_site/pages/micr.... Probably because this class was being held during COVID times. There's no hands on biology work. Homework consists of: - Find a research or journal article - Propose a technology - Propose a methodology etc The 2019 version looks a little better: http://fab.cba.mit.edu/classes/S66.19/S66.19/ http://fab.cba.mit.edu/classes/S66.19/S66.19/

gabrielsroka 5y ago

Here's a complete class listing https://cba.mit.edu/classes https://cba.mit.edu/classes

azinman2 5y ago

I never took this back when I was at the Media Lab and that’s one of my main regrets from that time. This class is very famous, but I’m not sure how useful this is as an online class because as a normal person you won’t have access to the water jet cutters, plastic mould injection machines, etc. Covid aside, hacker spaces were already dying out in SF. I wish there was more push for ordinary people to become makers rather than just consumers.

chasd00 5y ago
3dprinters are pretty accessible but you're right about other tools. Also, some of the tools can be pretty dangerous ( looking at you lathes/mills ). IMO one of the greatest things about software development is you can goto walmart and get $500 laptop, sit in a coffee shop, and have access to all the tools needed to build cutting edge high performance software of any type. It's not so easy to do that in meatspace with physical objects.
- srcreigh 5y ago
  except for video games and deep learning
  - baud147258 5y ago
    depends on the video game. If you target what AAA was doing 5 or 10 years ago in term of graphical quality or even specific style like low polygon, pixel art, 2d art..., you don't really need the cutting edge in terms of graphic cards.
- adamsmith143 5y ago
  As someone not much into this scene, how useful are 3D Printers actually? I get the sense that they're very useful to hobbyists or for creating prototypes but are the plastics used suitable for production use cases?
  - theelous3 5y ago

DoingIsLearning 5y ago

All the videos linked in the class show me a message "video is not rated", saying I am unable to watch?

ksdnjweusdnkl21 5y ago
I wonder how one should host their educational videos to have them be available without ads or other nonsense like this. Any affordable solutions?
- kragen 5y ago
  PeerTube seems to work okay? More generally internet bandwidth is a lot cheaper now than it was 15 years ago.
- kleer001 5y ago
  > without ads and > affordable I think lots of smart people with lots of energy have spent lots of time trying to solve this problem with respect to getting customers and keeping them. It's a hard hard problem. Subscription supporting the free-with-ads IMHO seems to be the sweet spot.
lupire 5y ago
What do you mean?
- DoingIsLearning 5y ago
  As in the video is not porn/violence rated and I am too anonymous for Vimeo to know if I am an inocent unsupervised child on the internet.
jonas_kgomo 5y ago
you need to login into Vimeo, then you can watch
- DoingIsLearning 5y ago

nomemory 5y ago

If i am allowed to joke, I was expecting to read an article on Rust.

bogwog 5y ago
I think you misread the title as “how to remake (almost) anything”

sanj 5y ago

Gershenfeld helped coordinate a bunch of folks with COVID work too!

pjs_ 5y ago

Someone should add KLayout to this list. Free software for chip design that is absolutely incredible given that it is a free piece of software... https://klayout.de/ https://klayout.de/

dbcurtis 5y ago
Where does one go to get a part fabricated, though? It isn't quite as easy as getting a PCB made.
- kragen 5y ago
  MOSIS, CMP, CMC. Prices start around US$20k in theory but probably more like US$200k in most cases.

HWR_14 5y ago

Thank you for linking to this. There are a couple of topics here that I've tried to find a good source for for all COVID. Mostly I'm excited about the molding/casting. The various channels/sprues are difficult to design, and most sources are too general and unactionable. Yes I know I need them, now how do I compute them! And if anyone has more sources, I'll happily take suggestions.