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Everything posted by 2GodBDGlory

  1. I saw some YouTube video once that suggested opening up the motor and cleaning off the semicircular contacts with a pencil eraser (and then blowing off the eraser dust). I have not tried this personally, but you could give it a shot!
  2. The first suggestion could be worth trying, but I am unsure abho The first suggestion could be worth trying, but as for the second one, I actually started out with that part (albeit with normal tiles on top), but I found the diameter too small to get enough ratio spread, and it seemed less controllable. I am now starting to think about testing this gearbox in a large car model, so any help I can get will be appreciated! I will test with textured bricks soon. My design is a similar one to that bike setup, but mine adds friction to obtain a continuosly variable ratio spread, while the other design appears to have a number of fixed speeds. It is a similar principle though, and one that is interesting to see used practically. Thanks for the feedback! Cool to see the history of that design, as I had no idea it had been used before. I guess no ideas that simple are original these days!
  3. After seeing quite a bit of activity on the CVT front from Sariel lately, I got inspired to try my hand at some designs again. I started trying to make something similar to Sheepo did years ago, but stalled there. In the meantime, I did some research, and saw something that inspired me. It was in the [GBC] Let's build ball mechanical flowmeters post, but the post was very in-depth, and I quickly got lost. Thus, I am unsure what the original use of this mechanism (posted second from the bottom at that thread) was, but it inspired me. After a bit of experimentation, I came up with this design, which has a large spinning dish meshing with a tire. The tire slides along an axle to "mesh" with the dish at various diameters. I did some fine-tuning to get the friction to the right point, and where it is, with drive from an XL motor, there is no slippage in the fast gears, and some slippage in low gears, but only with lots of resistance on the output. This could be avoided by gearing for less torque on the input, but considerable torque is needed to work the transmission (pointing to low efficiency). One of the nice features of the design is that if the wheel is slid far enough to the low side, it will pass over the center of the disc and create a range of reverse gears. It is also important to note that the gearbox cannot be inverted, that is, you cannot put a motor on the output and treat the former input as the output, because the tire will quickly pull itself off of its wheel if this is done. Shifting of the tire can be done in multiple ways, but I used a large linear actuator. An XL one would take up a lot more space, but would allow for some faster reverse gears. It is also recommended to find an older, worn-down wheel, because worn ones will slide along axles readily, while still transmitting drive. P.S. If you are trying to build this design, you should know that I used Technic bricks with the studs facing up to raise the disc slightly, increasing friction. This is sadly not visible in my images.
  4. I agree, the ratio spread over the tire is a bit of a problem, but I could not achieve enough friction with the other tires I tried, and there is at least more surface area with this tire, hence more grip. I suppose its width also contributes to the rubber streaks that showed up on the disc. Another possible explanation for the slippage there is simply that there is more torque available to put towards slipping in that gear.
  5. I would say the 42043 Mercedes-Benz Arocs 3245. It was my first Technic set, and it was great! Great value for the money, and a little of everything. Pneumatics, a linear actuator, transmission driving rings, shocks, turntables, gears, lots of panels, a multi-purpose motor, lots of multi-purpose tires, etc. The main downside is that it is not available new, and has increased in price a little on Bricklink.
  6. Here is a new automatic gearbox design I developed last winter, after I got my first planetary hubs. It is a very unusual gearbox for Technic, without any traditional gears, but offers high strength and efficiency, and can shift for itself. Its operating principle is as follows: The input shaft goes to the input side of the planetary hub, and the output is hooked up to the output of the hub. However, with only this setup, any load will cause the hub assembly itself to turn, rather than the output, so a small tire is added to create friction between the hub body and the input. With this setup, the gearbox will tend to stay at a locked 1:1 ratio, but it is still capable of slipping and sending all its power into rotating the hub body against the friction. To prevent this, a pair of ratchet-type things are added, which only allow the hub body to rotate one direction. Thus, under light load, the gearbox will again spin at 1:1, but at higher loads, the hub body will slip against the rubber in the opposite direction UNTIL it strikes the ratchet. At this point, the body is stopped, so the gearbox works at the standard planetary hub reduction of 1:5.5. The main disadvantages of this gearbox are that it is difficult to adjust the friction, and that it only really works going forwards. If the motors are reversed, it causes the gearbox to automatically shift down into first (good), but it also is able to slip indefinitely, so it is not good for off-roaders that will need to reverse in challenging terrain. Additionally, multiple copies of this gearbox can be attached in series to add more speeds, with one speed being added for each additional assembly. However, this increases in volume rapidly, and the only possible gears are one to powers of five, so 1:1, 1:5.5, 1:30.25, 1:166.375, 1:915.0625, and so on. As you can see, the ratios quickly become far too low for any practical use. I tested this gearbox in my Toyota Land Cruiser 70 model, and it met durability requirements. I used two gearboxes side-by side, essentially doubling the resistance needed for a downshift. Unfortunately, it would very rarely get into the high gear, due to the high weight of the model. Also, the rubber tires I was using got somewhat worn down. I feel that it could be valuable for fast, lightweight off-road buggies that need a little extra torque once in a while to get over obstacles. Let me know what you think!
  7. Yes, I think it does. This could be solved by essentially putting a gear ring around the planetary gearset for the ratchet to mesh with, but I think it would be fairly hard to do in Lego. A large turntable might work, but that would just be... large.
  8. Thanks! That is a good point. It could sometimes be a packaging problem, but it is probably the best way to adjust shift points. Here is V2! It uses the rubber-band ratchet idea, and has an updated friction mechanism using rubber track inserts. It, like the previous design, will wear down the rubber friction elements eventually. https://youtu.be/DY6t_UeW71U
  9. Last night/this morning I took some of these suggestions and built a compact, reversible gearbox, using the rubber band idea. I should get it posted here soon. I am pleased with it!
  10. Good idea. It would be a bit less energy-efficient (always slipping the rubber band), but a whole lot more space-efficient.
  11. I can see that working, perhaps with an auxiliary Servo motor hooked up to the driving channel. It could be hooked up to the ratchet using a rubber axle joiner, allowing it to rotate the ratchet 180 degrees while adding a spring-loaded effect. Maybe when I get some time I can build that...
  12. That sounds like it is probably the best solution for models that require lots of torque in reversing. It is able to reverse on flat ground (with a light enough model), but when the going gets tough, it will give up, so a reverse gear like your suggestion would be good for heavy models or off-roaders.
  13. Yeah, I'm sure that could be done. It would make it larger, less reliable, and less efficient, but it might be worth it.
  14. Fascinating! CVTs are one of the "frontiers" of Technic, I suppose, and that is a very unique solution. I am still waiting for a heavy-duty manually-controlled one, though. Good work!
  15. Sweet! LBG is my go-to-color for almost everything! (Not that it has the best part variety, it is just the only color I have enough of for big cars)
  16. True, but the Control+ system doesn't have an option for a smaller battery like the PF rechargeable or AAA boxes.
  17. I did use a large actuator for steering in an off-road crawler I recently built. It was quite strong, and allowed huge gear reduction, but was very slow. It worked well in a crawler that would sometimes need to lift its weight when steering, but would be a poor choice for something needing responsive steering.
  18. I would go with Power Functions for sure. The Powered Up stuff will likely (eventually) allow for programmability, which is quite nice, but the motors are significantly larger, and there are no switches yet. Additionally, the hub part is quite a bit larger than the PF rechargeable/AAA battery boxes, and has no provision for recharging. There are also limitations in how many motors can be powered off of one hub (I regularly run over ten motors from my PF rechargeable battery, but one would need at least three PU hubs to accomplish that), and there is not currently any way to run multiple motors from one channel. Finally, there is the price. I don't know what prices are like where you are, but a PU hub costs well over twice as much as a PF AA battery and two receivers, and the L and XL motors are 2-3 times the price of their PF equivalents. There are similar trends with the other components. Perhaps the Powered Up system will improve, but currently I think the Power Functions system offers much greater flexibility at a much lower price.
  19. It is too bad that all those great new mechanical parts are only in bright colors. The 20T clutch gear is especially painful, since I have seen official Lego videos (gearbox instructions) that had them in light bluish grey!
  20. That gearbox looks pretty effective. I recall trying to build a similar one, but I kept having the spider gears in the differential skip under torque, and I had a much less sophisticated tensioner. Perhaps adding some kind of auto-clutch like in Sheepo's Land Rover Defender could help smooth out the shifts? I think that I will post my planetary 2-speed auto here soon, while our interest in autos is peaked. Another option would be to add some gearing between the shifter and the rubber-band-beam, to decrease the travel of the rubber band. This would, however, require more powerful (or just more) rubber bands.
  21. Yeah. If I had the money and space to keep all my models built, that would be nice, but I usually can't make much progress on my next model until I get more parts freed up, so I disassemble stuff fast.
  22. This model is the latest of a long series of "Ultimate" supercars of mine, with ever-increasing complexity. This was my first one to go all the way up to 1:7 scale to fit more complexity, and I think I can honestly claim this as the most functionally complex Technic Supercar ever! Of course, this is not the overall best Technic model, most likely, because of concerns about aesthetics and reliability. You should also note that there is no real Bugatti Chiron "Grand Sport 300 Aero," for I decided to build a made-up special edition. The Grand Sport part denotes the fact that this, unlike any factory Chirons, is a convertible, the 300 denotes the fact that this model has the extended rear end and rear aesthetic of the Super Sport 300+ version, and the Aero part denotes the aero flaps I included. So, let's get on to this! Aesthetics: I think the aesthetic can be summed up as complete and detailed, but poorly proportioned. There are no large gaps in the bodywork, and many details are included, but some of the shapes and curves are off, and it is undeniably blocky. There are LED headlights and taillights, and the classic Bugatti two-tone color scheme. Interior: The interior was meant to be very detailed looking, and has many working functions, which will be covered later. One I will cover now is the adjustable steering wheel, which can be tilted and slid forward and backward. Opening Stuff: The hood opens using a large pneumatic cylinder to reveal a smooth storage area. The doors are spring-loaded in their opening and closing, and have spring-loaded latches connected to the handles. Unfortunately, the latches were built to work the way the car was sitting when I built it, so when it was sitting on the ground, they would not latch unless I pushed up on the front end of the car. There is an opening gas cap controlled by a small lever under the steering wheel. I thought this was a fun function, and I got to put some old flex system parts to good use. The glove box opens, and has a simple latch. Finally, there is a simple access panel at the rear for the pneumatic controls, that doesn't correspond to anything on the real car. I know this doesn't really open, but it seems like a good time to mention the switch for the battery, hidden behind the passenger door. Pneumatic Functions: The car has an extensive pneumatic system, with many, many components. An L-motor is hidden under the floor, and runs a single compressor at high speeds. It is controlled by a switch under the floor (I would have put it in a more convenient spot, but I was out of extension wires, and I had no choice really) Additionally, there is a manual pump under the access panel to build pressure more quickly. There is a pneumatic air tank and a manometer. There are six pneumatic switches under the access panel, controlling different functions. Two of them individually control medium size cylinders which slide the seats fore and aft, and two more control small cylinders tucked under the seats to tilt them. A fifth one operates a long, skinny cylinder that controls the rear differential lock, and the final one, as mentioned before, opens the hood with a large cylinder. Another pneumatic function is controlled by a switch in the front of the car, connected to a small axle protruding from the front. When a collision or an impact presses this axle, it opens another valve, dumping the whole air tank into a plastic bag folded into a compartment ahead of the passenger seat, to emulate an airbag deploying. (I didn't think I could fit an airbag into the steering wheel without making it hideous). Suspension: There is four-wheel independent suspension, with two hard shocks per wheel. There is negative camber on all wheels, as well. Unfortunately, the suspension was utterly overwhelmed by the 17.7 pounds of Lego on top of it, so it was perpetually bottomed-out. Park/Reverse/Neutral/Drive Selector: There is a manually controlled drive selector on the central console, which operates a sliding-gear gearbox to choose between park, reverse, neutral, and drive. (Park just locks the drivetrain) Drive: Two XL motors in the rear of the car drive all four wheels through the gearbox (which will be covered more fully later), the drive mode selector, and three differentials. An interesting function is the torque-vectoring on the central differential--essentially, this just gears up the front half-shaft from this differential by a factor of 5/3, which results in more torque going to the rear wheels. There is also a fairly realistic W16 piston engine hooked up to these XL motors. Unlike all other Lego designs I have seen, mine not only had a single crankshaft for all 16 cylinders, but it also managed to use the regular engine block parts! Its main downside is that the shape of the engine looks like a V8 atop an H8, rather than a V8 atop a V8 (Basically, I mean that the bottom eight cylinders are flat, rather than tilted up as they should be). A Servo motor under the floor, attached to the same channel as the drive motors, controlled the gas pedal and the speedometer dial on the dashboard. On the topic of "Drive," I should probably mention that driving is not this car's forte. True, in first gear, I did manage to get the wheels to spin at infinitesimal speeds,, but I am not sure if it even moved, or whether, thanks to the bottomed-out suspension, the wheels were just spinning. Also, the drive from the motors to the gearbox was very poorly designed. I did lots of work making the drivetrain as bulletproof as possible, and then I had to move the XLs from their original position, and made a stupid design choice. I know this model is far too complex to function well, but I decided that I would rather have the challenge of building a super-complex car than the satisfaction of driving a car around. https://bricksafe.com/pages/2GodBDGlory/17-bugatti-chiron-grand-sport-300-aero/17-bugatti-chiron-grand-sport-300-aero-part-2/17-bugatti-chiron-grand-sport-300-aero-part-3 Steering: The steering system may well be the most complicated thing in the entire car other than the gearbox. First of all, it has four-wheel steering, with one servo motor for each axle. Both axles have Ackermann geometry (to an extent), castor, kingpin inclination, and toe-in, and are regular rack-and-pinion setups. The front motor is hooked up to aero flaps in the hood to aerodynamically slow down the inside corner of the car, and the LEDs in the headlights are also attached to the steering motor in order to send their light into the corner rather than straight ahead. The rear axle also has aero flaps, which are built into the rear spoiler. Additionally, the rear servo is controlled through a switch that is attached to the gearbox. This has the effect of causing the car to have regular four-wheel steering in low gears, front-wheel steering in medium gears, and crab steering in high gears. Okay, I will confess. In those last two images, I was actually holding the flaps down with my fingers, since the mechanism was broken at the time. When I got it working later, I don't think it worked quite as well as that. Convertible Roof: An Xl motor is employed in deploying the convertible roof. The mechanism in itself is rather simple, but is very reliable. The motor merely spins some tiny rubber tires (on tiny wheels, of course), which push the system-built roof forward out of its slot, covering the interior. Spoiler: An M-motor in the rear works two large Linear actuators to deploy the spoiler. Brakes: An L-motor under the floor runs two linear actuators through a worm gear drive, which work linkages to deploy the four-wheel disc brakes, but also to work the brake aero flaps (Unfortunately, this has a barely noticable movement). The brake pedal also is depressed by this action. Again, I think I might have had a finger on the corner of the spoiler here, making it look like it worked better than it did. Gearbox: An M-motor in the rear shifts the eight-speed dual clutch sequential gearbox. The gearbox itself is built very strongly and fairly compactly (for a dual-clutch design). I had planned to build a 7+R, but I couldn't get the reverse gear to be strong enough, so I resorted to using an external PRND selector. There was a rear speed indicator, but it ended up rotating at the wrong ratio to work well. Additionally, I had a dashboard-mounted speed indicator, but the diabolical strings of U-joints to get the drive there prevented it from having any accuracy. Suspension Adjustment: There are two more L-motors, one for each axle, that adjust the ride height using two small linear actuators. Unfortunately, this too was overwhelmed by the weight of the car, but still had a minimal effect. Windshield Wipers: The final function is the windshield wipers, controlled by an M-motor through some complicated linkages. It is a rather fun model to include. Other Images: Tractor tires? you may ask To which I would reply, "Why not?" Conclusion: I am very glad to bring this model to a close (And this lengthy post!). It took me over four months to build, which is crazy for me! My previous most complex car took little more than one month! I think the aesthetics were poor, but about all I expected of my mechanically-minded self. The functionality was, naturally, the focus of the car, and I was pleased to stuff so much complexity into a single car. However, not surprisingly, over-complicated mechanicals prevented the car from performing well. Another feature I tried to include was refinement, especially in the interior, and I think I succeeded. I am glad to have built this, but I may not ever try to top it, because I am disinclined to put in that much hard work again!
  23. I currently have three servo motors, plus two that died on me. I think I have 17 motors total, and I think I used 13 or 14 in this model. I thought the airbag was pretty neat too, though it isn't actually original (I came up with the idea myself, and then did a YouTube search, and discovered I had been beaten too it--just not in a complete model). My build process is fairly simple. I don't do any digital planning, and just start with the most complicated mechanisms. In this model, first I built the gearbox, then the axles, then installed the drivetrain, connected the axles, added the rest of the internal functions, built the interior and doors, added the exterior-related functions, and then finished the exterior. Yes, the body shape was definitely limited. For example, the rear end ended up being very squared off because of the position of the IR receivers right in the corner, and I am generally unwilling to buy new parts for each model I make, so I was limited by parts somewhat. Thanks for the tip for photographing; I can try that sometime. I suppose I could try adjusting my photo strategy for my next model. The middle selector does engage with the old catchover switch, but rather than meshing with clutch gears, I used the body of the piece to slide the 20T and 24T gears beside it to mesh with other gears. I find that the new catchover switches are more resistant to skipping than the old ones, and I had used all four of my new-style ones in the two 4-speeds, so rather than put in a relatively light-duty and gear-limited (but smooth-shifting) setup, I opted for a heavy-duty sliding gear setup, and found that that was the most convenient way to control it with the rotary shifters. I understand the reasoning behind making this a more genaric car; in fact, my previous shot at ultimate complexity followed exactly that route (You can see it here). However, I was displeased with its final aesthetic, and I figured that for this model I would try to take advantage of the work of highly-paid automotive designers. Of course, it did mean I had less flexibility, and lost some of the accuracy I wanted. There are pros and cons of both routes. Okay, I can do that next time. This is my first post on EuroBricks, so I guess I am still learning the etiquette here. Well, I have already disassembled this model, so it is too late for any mechanical changes, but I see your point about the list of functions. I will add that soon! Thanks! I appreciate that, and agree with your comments!
  24. Wow! That is fearsomely complicated, and very cool! It seems like there is a lot of math behind it, which is nice. Of course, that would be an awful gearbox to put in a model car, since it is huge and must be very inefficient, but that is not the point at all. Good work!
  25. Thanks! As for the video, I do have one posted on YouTube, and I put the link at the bottom. I would like to embed it, but I am not sure how. My video is pretty low-quality, though, since I would rather build Lego than edit videos...