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Davidz90

Eurobricks Knights
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Everything posted by Davidz90

  1. Davidz90
    Sure, but this does not apply here.
  2. Davidz90
    LA has a specified thread pitch and 1 rotation equals to a specific distance. From my measurements, for small LA, 12.5 rotations = 15.8 mm. I used that to build a working micrometer:
  3. Davidz90
    Yes, you are right, this alone is simple to do manually. What is the issue is that the motor is driving the LA with variable speed, given by a pretty complicated formula, and no desynchronization between motor and LA is allowed. A slip at any point in motion would desynchronize the system. I think it is an open question whether using deliberately excessive inputs and allowing for some flex in the system can be done in a way that self-corrects instead of accumulating errors.
  4. Davidz90
    Not a mod, strictly speaking, but I suppose it may be relevant here.
  5. Davidz90
    Finally a contest I'd have a chance of winning
  6. Davidz90
    I think there's no need to be so negative. Number of wheels is indeed a bit arbitrary (and easy to beat with small wheels) but a 78 metre long vehicle is a legit achievement IMO.
  7. Davidz90
    A few more attemts to squeeze a bit more power out of them, mostly failed. I moved to a slightly more complicated design with separate timing mechanism. While it does increase efficiency and RPMs, whole thing is just inherently very inefficient.
  8. Davidz90
    Yes! I'd love to see either more modern, "mundane" cars or some classic, older ones. Like the recent 10321 Corvette but in technic supercar format.
  9. Davidz90
    Here's the math: actuator by David_Z1, on Flickr
  10. Davidz90
    I'd advise against using chatgpt, especially for pretty nonstandard tasks like this. One thing is certain - the linear actuator positions are not a single sin() function unless scotch yoke is used. With standard crankshaft, actuators are moving both vertically and horizontally, and that horizontal motion adds another sin() or cos() factor.
  11. Davidz90
    Oh right. So I think that this kills this idea - no matter how precise the program may be, errors will accumulate anyway... unless one adds slip clutches in actuator inputs? Then, the program can always input, say, 105% of necessary rotation and the actuator will move as far as it can?
  12. Davidz90
    Pretty interesting idea, however impractical it may be. Getting speeds perfect is definitely a huge challenge. Using soft attachment points for actuators (springs, rubber connectors etc.) might allow for some margin of error?
  13. Davidz90
    Amazing!
  14. Davidz90
    Another little update. This one has better timing, but due to the added mass of moving components, overall efficiency is worse.
  15. Davidz90
    yes
  16. Davidz90
    That's genius! Peristaltic pump is surprisingly effective.
  17. Davidz90
    There are many impressive submissions to this contest, but for me this one wins hands down.
  18. Davidz90
    Very unique and impressive! Lego Ideas page has a video.
  19. Davidz90
    Thanks! Yeah, it seems to be only suitable as display model and maybe for vintage aircraft, spinning a propeller. I think I'll try to build a steam locomotive, it can be much smaller than the car while keeping correct proportions to the "cylinders", maybe that will work out.
  20. Davidz90
    One additional, fun thing: how it would sound shifted down by 1 octave and bass boosted
  21. Davidz90
    Here's a full 1920's style chassis. A failure on multiple aspects: engine is woefully underpowered, leaf spring suspension is too soft and I put a steering wheel on one siide despite having a single seat But it does have a working clutch, chain drive to rear axle and engine that is started with a hand crank.
  22. Davidz90
    Exactly. In the crane I built recently, I'm using pretty much the same thing; a stack of mild steel plates in a brick-built basket to hold them. They come from 30 mm x 6 mm x 1000 mm bar (got it for 5$ or so in hardware store) and are cut into 30 mm x 6 mm x 100 mm plates (about 4x13 studs, 2 plates high). Very cheap and cutting is a 5 minute job with angle grinder
  23. Davidz90
    So cute! Amazing job recreating all the functions.
  24. Davidz90
    I finished wiring up the motor. I'm still gonna test the stronger coils when they arrive, but even in the current form the performance is quite satisfactory.
  25. Davidz90
    Thanks! Today I bought a new set of solenoids with 2x longer stroke (1 cm) and more force (0.6 kg). They won't need the long levers and should work fine at a lower voltage, which solves the heating problem. I'll also test if a potentiometer can be used as a throttle.
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