5 ms·

I've thought about this machine a number of times since the previous post. In that post, there was a movie showing the machine's operation, but it was operating

I've thought about this machine a number of times since the previous post. In that post, there was a movie showing the machine's operation, but it was operating at a slow speed, and he's mentioned multiple times that there's been speed improvements. Does anyone know if there's a realtime movie anywhere?

jacquesm 9y ago
The speed of the machine is mostly a function of the mechanical feed speed of the parts. This is the hopper/belt mechanism and it is by far the slowest part of the machine. Once the parts are on the recognition belt things more very fast, a single part can be scanned and recognized in about 30 milliseconds, so roughly 30 parts / second. Making the machine much faster then means making that feed mechanism faster than it is today (roughly 1 part per second tops) and that's the challenge I'm looking at right now. Ideas more than welcome! Even bad ones, you never know which bad idea with a twist can become a good idea or even a very good idea.
- maxerickson 9y ago
  Perhaps the dumbest idea would be to build a second feeder. Would double the speed and sounds like the rest of it is fast enough that you wouldn't even need to worry about parts falling on top of each other.
  - jacquesm 9y ago
    That's not a dumb idea, however: space is an issue, the rest is fast enough but even so parts do tend to fall in clumps and if two such clumps were to fall at the same time it could lead to a jam which requires manual intervention. Ideally parts would land on the belt in a very regular rhythm, without any kind of irregularity whether the parts are 8 mm round 1x1 plates or 16 long 1x1 bricks. You need about 3 cm of space on either side to make sure the right part gets blown off the belt, that's the most important thing that will eventually limit the speed. Oh, another factor limiting the speed is the maximum acceleration over the stretch towards the camera, otherwise the parts are still moving on the belt when they reach the camera and then you get bad images.
- gboudrias 9y ago
  Not to state the obvious, but if the "hopper" is slow, why not just have multiple of them? Are they expensive? Take up too much space? I assume you've thought of this but I'm still curious. Really cool stuff by the way!
  - jacquesm 9y ago
    Space wise this is hard, also parts tend to fall in clusters so the second belt now has to be much faster than the first one to make sure there is enough separation. I do have a second belt that I have not used yet so if there is no better idea then that is what I'll end up doing.
    - gboudrias 9y ago
      So just to make sure I got this right, you need a way to get a single piece of any size out of a container full of random pieces, and onto the first moving belt, at a rate higher than 1 piece per second? I'm not familiar with the project but this seems like an interesting challenge.
      - jacquesm 9y ago
        Yes, that's roughly the gist of it. This is a hard problem because Lego comes in many shapes and sizes, a pre-sieving step limits the pieces that hit the belt at 42 mm largest cross section. So anything below that (but possibly much longer than that, all the way up to 2x1x16) can be found in the hopper. There are some really good suggestions in this thread, the one that stands out for me most is the brush edged screw feeder, I think that one has most properties just right to work.

jacquesm 9y ago

The speed of the machine is mostly a function of the mechanical feed speed of the parts. This is the hopper/belt mechanism and it is by far the slowest part of the machine. Once the parts are on the recognition belt things more very fast, a single part can be scanned and recognized in about 30 milliseconds, so roughly 30 parts / second. Making the machine much faster then means making that feed mechanism faster than it is today (roughly 1 part per second tops) and that's the challenge I'm looking at right now. Ideas more than welcome! Even bad ones, you never know which bad idea with a twist can become a good idea or even a very good idea.

maxerickson 9y ago
Perhaps the dumbest idea would be to build a second feeder. Would double the speed and sounds like the rest of it is fast enough that you wouldn't even need to worry about parts falling on top of each other.
- jacquesm 9y ago
  That's not a dumb idea, however: space is an issue, the rest is fast enough but even so parts do tend to fall in clumps and if two such clumps were to fall at the same time it could lead to a jam which requires manual intervention. Ideally parts would land on the belt in a very regular rhythm, without any kind of irregularity whether the parts are 8 mm round 1x1 plates or 16 long 1x1 bricks. You need about 3 cm of space on either side to make sure the right part gets blown off the belt, that's the most important thing that will eventually limit the speed. Oh, another factor limiting the speed is the maximum acceleration over the stretch towards the camera, otherwise the parts are still moving on the belt when they reach the camera and then you get bad images.
gboudrias 9y ago
Not to state the obvious, but if the "hopper" is slow, why not just have multiple of them? Are they expensive? Take up too much space? I assume you've thought of this but I'm still curious. Really cool stuff by the way!
- jacquesm 9y ago
  Space wise this is hard, also parts tend to fall in clusters so the second belt now has to be much faster than the first one to make sure there is enough separation. I do have a second belt that I have not used yet so if there is no better idea then that is what I'll end up doing.
  - gboudrias 9y ago
    So just to make sure I got this right, you need a way to get a single piece of any size out of a container full of random pieces, and onto the first moving belt, at a rate higher than 1 piece per second? I'm not familiar with the project but this seems like an interesting challenge.
    - jacquesm 9y ago
      Yes, that's roughly the gist of it. This is a hard problem because Lego comes in many shapes and sizes, a pre-sieving step limits the pieces that hit the belt at 42 mm largest cross section. So anything below that (but possibly much longer than that, all the way up to 2x1x16) can be found in the hopper. There are some really good suggestions in this thread, the one that stands out for me most is the brush edged screw feeder, I think that one has most properties just right to work.