Lego Nerd

Eurobricks Vassals
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  1. Test Poll 2

    Yes. Works for me on Fedora 25 using Firefox.
  2. [MOC] 1977 BMW 320i Group 5

    I'm amazed by how much you can do with bricks! Can you give a picture of the side from ground level? I think that would be a good shot to give. I also really like the amount of detail work that went into the engine and the fuel cell in the rear. I think my favorite shot is of the car with the pieces removed so you can see all the work done underneath.
  3. @Doug72 gave a great answer, but I think there are a couple other possibilities unlocked if you don't connect the two halves of the turntable. Have a look at this page: https://en.wikipedia.org/wiki/Epicyclic_gearing The first picture shows the standard setup. Now imagine the inside of the turntable as the outside (pink) ring. Then place the 8z gears (blue) on a carrier (green). Also, place an 8z gear as the center sun gear. Now if done right, there should be three possibilities of things to hold steady. Doug showed four of the possibilities, but now think of holding the sun gear in place and rotating the carrier. A single rotation of the carrier will spin the ring gear (inside of the turntable) once plus an additional 8 teeth for a total ratio of 1:1.33. When I did this I attached the carrier to one half of the turntable, so I spun that. Of course, it is difficult to hold the sun gear in place while rotating the rest around, but it can be done. Clear as mud?
  4. If you want to increase speed somewhat, hold the innermost gear steady and rotate what holds the middle idler gears. See: http://gears.sariel.pl/ If you look at the picture of the planetary gears that he has, note that keeping the center (red) 16z gear stationary while rotating the 5L beam with the two idler gears on it will cause the yellow outer gear to rotate faster than the 5L beam.
  5. Some vehicles use them in place of a portal axle; the builder uses a turntable and 8z gears inside to reduce the speed of the driven wheel and increase the torque after the driveline. Real vehicles use planetary gear sets quite a bit. For example, most automatic transmissions operate using several planetary gear sets; the various rings can be clamped by the transmission to make the different ratios. In fact, the Ford Model-T used a planetary gearbox operated by pedals. Also, many older cars (e.g. an MGB) had a manual transmission and a planetary overdrive operated by a switch. In that case, it lowered engine rpms -- so added speed. Subtractors also could be said to rely on planetary gearsets, and those are useful for tanks and other things with caterpillar tracks. Those allow tracked vehicles to be controlled using a motor for driving and a motor for steering (see some of Sariel's excellent tanks and this: http://sariel.pl/2009/01/subtractor/). Lastly, if the right part of the planetary gear set is held in place (the center with idler gears), it can be used to rotate two things in opposite directions, as in this set: http://www.bricklink.com/v2/catalog/catalogitem.page?S=8960-1#T=S&O={} The drill has two counter-rotating parts done using a planetary gear set. Does that answer anything?
  6. Impossible LEGO

    Have you tried twisting the 4L rod? Also, sometimes using lots of the half-width 2L beams stacked on the remainder of the 4L as a grip can be enough to overcome the friction, and each individual beam can be removed one by one.
  7. I second this. It's impressive, and has plenty of clever uses of pieces.
  8. [WIP] SUV-SuperCar

    That's kind of an interesting question. According to this article, the castor in the front is to return the wheels back to center. I'm not really sure whether the back axle would need that, because the back axle would ordinarily only steer a few degrees. If it's easier, I would mostly copy the front suspension setup to use at the back. It might help the turning radius if your steering arms were shorter.
  9. Does taking 8448 apart down to the chassis, and building a new body on it count? If so, I've done that far more than I've rebuilt any other set. But it's fun to do because even somebody without much skill can create a fairly good body out of the few panels and lots of flex axles included. The engine can easily be moved to either the front or the back, and the instructions for the functions are all given. And when all that is done, it's fun to play with.
  10. Help understanding tire and wheel sizes

    The total height of the rears should be 30% of 345mm x2 + 20" (Probably what you meant to type). Try using this: https://tiresize.com/calculator/
  11. Glad you like it It would be great if I could build both, but I'd have to somehow collect a lot of expensive/rare red pieces. IMO, it looks better in white than in red, based on picture comparisons, but that's just a personal taste.
  12. General Part Discussion

    I tried the Unimog tires on 8880 wheels, and they do fit together. The wheels are a bit narrower than the ordinary wheels used for the Unimog tires, so the sidewalls are a bit tilted in towards the wheel (about 1.5 mm on each side). The slippage of the tire on the rim isn't any greater than what normal Lego wheels and tires have.
  13. I like how you solved the HOG issue with the roof. Both the convertible and the hardtop have clever placements of the steering knob. Great job!
  14. Technic Photography

    Thanks guys! And Zblj, it would be my pleasure if you borrowed the setup.