cloud

Eurobricks Vassals
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About cloud

  • Birthday 01/01/1976

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  1. cloud

    42083 - Bugatti Chiron

    I've been following this thread for quite some time and haven't had much to add. I'd be lying if I didn't say that I was happy to see one shot of the Chiron to whet my appetite. I'm quite surprised at all the leaks from official sources, but it is understandable in my opinion. Shipping boxes to stores in malls is risky. Especially since most of the stores I've been to around the world(over a dozen now :) have employees building sets for display out in the open. Regardless, I'm most upset about Lepin having an identical box with art and likely the fully produced set ready to go on the same release day. WTF? Who leaked the .ldd file(or equivalent) to them? That person needs to be taken to court, not just fired.
  2. cloud

    42083 - Bugatti Chiron

    As i see it the video hints to an all black Chiron as the rims on the real car in the video match the Lego rims in the teaser photo almost exactly. The real car is all black in the video without even the blue line curving around the door as seen in some paint variants. It could be that Lego chose to display an all black Chiron so as not to give away the real colours. Personally I'm hoping for a light blue on dark blue colour scheme, AWD, and accurate suspension geometry this time. I suppose dark gray on dark blue would be classy too. Why else have an extra 900 pieces vs the Porsche? If it is all extra brick built prettiness on a 2wd chassis I may skip it.
  3. cloud

    [WIP] Volvo EC750E

    I found this page on the importance of axle reinforcement and ways to do it. I'll be trying these options first and see if it helps.
  4. cloud

    [WIP] Volvo EC750E

    Over the weekend I managed to fully build one shoe and solved some wheel placement problems as well as started to add structural support for the x-brace and body. I was able to test the shoe and the performance was mediocre. It has lots of torque and does go up and down in gear ratios as needed. Going up an incline seems fine and it is slow as expected. The problem seems to be that the many dive axles that twist and retain a lot of torsional power like a spring that lets loose once the friction on the drive line is reduced. The end result is a lurching of the shoe on flat ground. This is probably exacerbated by the final output shaft having a 1:1 drive ratio with the drive sprocket. I'm going to try a 1:2 gear ratio at the drive shaft. If that fails I'm thinking I have to redesign the cvt to pass power more directly by gears than by axles. I can't see that being possible, but I haven't tried that yet. Anyone have other ideas as how to lessen the impact of axle twist/spring?
  5. cloud

    [WIP] Volvo EC750E

    After much rework of the same idea, I've got a design that is working. In this image one can see the sprocket solution that I am using at the moment, but it works reasonably well so unless it fails under stress conditions(which is why the sprocket is driven from both sides) it should be fine. A couple more images on the blog including the front side view.
  6. cloud

    Show us your Working Place

    Its nice to see that I'm not the only one working on the floor. My living room is regularly a disaster zone with a 3yr old in the house, The room's explanation is here if anyone would like to read about it.
  7. cloud

    [WIP] Volvo EC750E

    So the latest failure is that I built the cvt in shoe size and only realized after(in my overzealous attempt at ingenuity) that I used the open diffs in a way that does not work, so back to the drawing board on how to fit it all in.
  8. cloud

    [WIP] Volvo EC750E

    Fair enough, but I feel a need to try and I think I have improved on the existing cvt design a little. As for all wheel independent suspension I was thinking of 2L rubber liftarms to provide a dense and short travel for the casters, but more on that later. I have made nothing but failed attempts at all stages, but it all comes with learning about the challenge that I have taken on. So the more mistakes the better as long as I learn something to help me move forward. Off topic: my parents are from the eastern block and they got out in 81. I feel like I know what you are talking about from experience with respect to being stuck in communism.
  9. cloud

    [WIP] Volvo EC750E

    I know all that. Not sure what age you take me to be, but it really makes no difference to the discussion. Lego is highly limited. That is the nature of the system. Thanks for pointing out that liquid doesn't get compressed. I was only pointing out that no hydrolic system exists in Lego, but when one takes the direct energy transfer of liquid in to account a purely mechanical representation is in some ways better than pneumatic. We all accept some lack of realism with Lego. I find it fun to try and make functions that have semblance to the real thing even if it is something as hard to compare as diesel/hydraulic to electric/electro-mechanical.
  10. cloud

    [WIP] Volvo EC750E

    Yes, well I'm not emulating the hydrolics since Lego has no hydraulic system. I'm trying to emulate the functions of the various components at a high level. The real thing has hydrolic everything. I have Lego pneumatic or mechanical to choose from. As I have more mechanical parts than pneumatic I'm sticking to mechanical. Mechanical also arguably takes less space when trying to cram motors and a transmission into a 35x5x10 brick size for each shoe. If Lego had a pneumatic motor that fit, I'd be all over it... now that I said that a steam engine drive comes to mind... hmm mm.Thinking out loud, I wonder if a cvt or pneumatic drive would be smaller. If the only concession is pneumatic instead of hydraulic then the cvt or at least a 2 speed automatic would still be required after the pneumatic drive segment, but it could have some crazy torque. I still think that a purely mechanical cvt is smallest and able to fit in the dimensions required for the model. If I just wanted it to go at various speeds I'd hook up a couple motors to tracks and use a train PF controller. Just to be clear are you pointing out that Lego has no hydraulic system or that the cvt doesn't work with high torque or that the cvt can't possibly replicate a hydrolic drive system accurately?
  11. cloud

    [WIP] Volvo EC750E

    I'm quoting Wikipedia here: A continuously variable transmission (CVT) (also known as a single-speed transmission, stepless transmission, pulley transmission, or, in case of motorcycles, a twist-and-go) is an automatic transmission that can change seamlessly through a continuous range of effective gear ratios. If we look at how various CVT implementations work (Toyota, motorcycles, Honda, industrial tractors) there is such a large difference in internal design that one transmission can not be compared to another except by generic definition of a CVT. I have looked at every Lego CVT that I can find including the un-translated slavic ones. The problems that I found were partially addressed such as in Nico71's use of flywheels. The solution to power loss that I came up with completely solves the problem. The remaining problem of gear range selection depends on the speed and torque of the motors as well as the weight of the vehicle since it is a mechanical speed control. I fully accept the burden of proof on me. I will make a video to show it working. Unfortunately it won't happen soon because I'm gone for most of August and September is always busy with the new school season.
  12. cloud

    [WIP] Volvo EC750E

    The photo of the excavator shoe implementation is coloured the same as the example photo from the blog. I've included an excerpt for explanation. Power from the motor turns the 16 tooth gear that drives the pink differential that drives a grey shaft and a black shaft. The grey shaft drives the yellow gear set for roughly a 1:5 ratio. The black shaft drives the green gear set for a ratio of 1:13. The two gear sets recombine in the purple differential and outputs to the blue 16 tooth gears.The output power equals the motor's output power at all times though the speed varies within the given ratios. In practice the whole system has a problem with using the low gear side even if the motor could drive the high side exclusively because the low side is easier to drive. A simple solution to this is to add a small rotational resistance to the low ratio gearset(green) before it enters the purple differential. The resistance needs to be equal to the gear resistance of running the high side(yellow gears) so that the green side is not used unless it is truly needed because the motor can not drive the high side.
  13. cloud

    [WIP] Volvo EC750E

    I see you have reservations about this working, but could you please explain the problem with my CVT design. In the link I posted to my blog I discuss the problems with the design commonly attributed to nico71 and propose a solution. I have built many of these to test out the idea so I am quite confident that it works. I just haven't built a good structure for it yet so I have no video. I plan on posting one once I have a more complete bottom end for the excavator.
  14. cloud

    [WIP] Volvo EC750E

    Thanks, it is simply an analysis of the problem and it happens that Lego does have a solution. This will be by basis for the shoes. I may still add a friction gear to the low range gear set in case the two L motors don't have enough torque to drive the full weight on flat once it is all together. The friction gear will only bias the gearbox to high gear by default and be overpowered once a real driving friction is encountered.