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Everything posted by Marxpek

  1. I see this is turning into a battery conversation and it already started people making unsafe constructions @sirslayer ... just get a battery holder for 8 aa batteries (or a 10 holder and use rechargeables).. even aa's can start a fire when used badly.. It was not my intention to making this a battery thread, there are plenty of them around. The real buwizz arrived and i have been testing with a car that has a 20:28 (differential) gear reduction using the fast output from a buggy motor, driven by unimog wheels and a servo for steering, a pretty fast and fun setup, that demands a lot of current. My conclusion is that my DIY setup is comparable to the normal setting on the buwizz, not the slow like i initally guessed ( my Lipo always was fresh off the charger giving 8.4v) most likely after a while my DIY solution will run a bit slower due to voltage drop, while the buwizz most likely can regulate this better. Theoretically the buwizz can handle 3 buggy motors but i have not tried that yet, while the sbrick can only just handle 2 from my experience. Buwizz was the winner at first glance and it seems to stay that way for now.
  2. Here is something i created to test if it is worth it for me to buy a buwizz. The s-brick has a brick built case around it, to replicate the Buwizz design. The battery is a 7.4v LiPo ) i had this in the attic from my abandoned rc plane hobby. THIS THING IS DANGEROUS! sorry for the caps but really do not do this unless you are sure what you are doing, shorting or puncturing batteries like these can start a fire instantly, this one can deliver 34 amps, wich is insane (about 10 buggy motors) and never needed in Lego just in rc plane motors. Nothing was modified, not even the battery, the battery wires are just wedged between a regular plate and a 2x8 lead plate, taped to the LiPo. So this basically replicates a buwizz on slow settings, i do not dare to hook up a 11,1v 3 cell LiPo to the sbrick, the sbrick can handle the 11 volts but the LiPo fully charged will deliver something like 12,6v not worth the risk to me. This battery obviously has more amps then what the buwizz battery can deliver but the sbrick here is the weakest link, the buwizz will allow for more amps used and more importantly it will give that beloved 11 volt, which my creation lacks. My conclusion is: i want a buwizz..
  3. The buwizz has great advantages over the rc unit, weight and voltage makes it a clear winner and with the same amount of rc motors and a similar design a buwizz will always win, but making anything out of Lego controllable (and control it) at that speed is an accomplishment and by no means easy.. time for me to get some buwizz... After testing i will adapt the design as always, maybe 4 wheels, but i will not add a extra rc unit for the same amount of motors.. It also is exactly what i suggested as my best option if 3 wheeled skid steering works, using 2 controllers, but not looking forward to work 2 controllers while riding a bike at 35km/h, but.. whatever it takes.. @TechnicSummse since you invested in rc parts now, did you also invest in a gps device? ;D
  4. Once again there is a speed limit to break! This time the aim is 40 km/h and this time i am not alone! After i broke the 35 km/h limit, the record seems in trouble with @TechnicSummse on the horizon! He too is trying to break the 40km/h with Lego and is getting some serious results, until this day i have not broken his (unpublished record) of 38.4km/h, go check out what he does, good fun! I always tried to make my racers look somewhat good, I also tried to build them so they can survive a crash, that's all out of the window now, lightweight, low roll-resistance, all the proven concepts i will have to use here. This is fully untested, except for the steering unit, this has functioned fine on a 30km/h+ testdrive, but on my old setup with the wheel in the back. The steering setup resembles a shopping cart wheel setup, with the pivot point way in front of the wheel so it wants to go straight by itself, but it allows for accurate and low drag corrections. I might try to reduce its weight a bit more. sorry for the weird setting in the pictures, ill make better ones later on when it's final.. Now i am waiting for the right moment to do some test runs, the lack of time and the rain on days when i do have time, can be somewhat frustrating for me since i am eager to test this. I have a good feeling about this, but of course i would be glad to take suggestions and consider them. What are your predictions on it's speed? Place your bet before the test runs! ;D
  5. 4 wheels give more rollresistance and weight more, however with the motorized front it might be different, i'll see into it. The 4 motor finished design rides pretty straight, but it does not like big bumps.. the other is unfinished I think it will be pretty hard to run the motors at 12 volt with a Lego solution.. ive seen a 18v version wich was pretty complex/dangerous but all Lego..
  6. i considered this, to prevent this, or partially even it out, i was planning to crosswire the motors and maybe use a frictionpin version of a limited slip diff between the rear axle, of course this only works with drag steering. not with electrical steering (in wich i have little faith but will most likely try) i have little faith in air rudders, it is just another way of causing drag, and my guess is it would need quitte a big surface and thus be bulky, so no i have not tried it and i doubt i will, i say: convince me! hey perma welcome to EB and the thread, im using rc units here, if you read the thread you can find out more ;)
  7. good to see the competition is still strong aswell! This will be the year 40 will be broken by Lego alone, im sure. (and lets take the buwizz record aswell, that is my new aim at least) these and some spares ;) both will be up and running yes too all, since you managed to use it for that long, it got me convinced, and i can burn through 3 spare units if i have to... did you ever burn one up with 3 motors? i am just hoping the radio interferrence is doable with 3 units, (tests showed significant more random input, but my experience is that the controllers will override it, mostly..) i tried this, the turntables are not ment to be loaded vertically, i see them get separated on a bump at 30km/h+, so i ditched the idea... there was also a big amount of play in the steering and the turntable itself, and they don't mount to the rc unit nicely without ruining ground clearance. Putting the turntable in front horizontally (similar to my steering in my 4 motor racer). is an option but very bulky or unstable, and ground clearance becomes a mess. very true but steering is always paired with drag. And in a straight record run i won't have to steer at all. my steering setup is not really for steering, more for damage control, maybe 1 or 2 corrections, if else i reset the run. @pagicence thanks for the input and idea's but like technicsummse already mentioned, we have been at it for a while now, maybe read up on our threads, some nice info here and there :) I have just one big question for all: Does (electrical) 3 wheeled skid steering even work? and when the 3rd front wheel is powered? .the 2 controllers option is the best weight wise, but im doubtful wether it will work or not.
  8. Soo.. it has been a while, but with better and longer days on the horizon my racing blood starts boiling again! I currently have 2 new designs: The one above is ready to go, it is a minor variation to my racer from last summer that made 39,4km/h, this one is better balanced and has a slot for the speed computer. The one beneath is still a WIP, its intention is to break the "only Lego" 40 km/h and beat the buwizz record! I am still working on the motor configuration, but this will be my most powerful creation yet. More power, more problems... and i am hoping to get some suggestions on steering this, since this has always been the biggest issue with this. Steering with the front wheel will be hard since it is motorized now, it could be done but it would be very bulky/heavy and most likely unstable. I will show you first what i came up with to start with. when steering with the controller, the small wheels will cause drag either left or right, hopefully making small adjustments in direction. (maybe i will put the wheels further out for more effect) I also thought about 3 other options: - use skid steering with a electrical swith on either side, controller by the servo on the rc unit, might be heavy and lots of wires needed - use skid steering using 2 rc controllers, set either side's rc unit on another channel, might be hard when driving on my bike.. but maybe its power will need less runway.. so no bike.. - brake the rear wheels, either left or right, directly with the servo on the rc unit, effective and light but bad for the motors and rubbing parts. I am really hoping someone has other ideas about high speed steering (better sayd: minor adjustments on a straight runway), or give other insights, before i put these parts at risk, of course any other suggestion or input is also welcomed.
  9. congratulations all! well done and great fun! Very happy with my 5th place, never expected to end that high.
  10. Here is an idea i wanted to test for a while, maybe it is not the correct place to post this, but i think technic fans might like this the most. The "air-tank" is not Lego obviously, it is a converted fire extinguisher, made to be pressurized by a bicycle pump. Don't take it too seriously, it was just something fun I had to try ;)
  11. So today i have launched this: Launched with 5,5 bar of pressure from the fire extinguisher (just like the previous plane) I will try to upload the video later today. what do you think happened? - actual gliding? - "thrown" lego? (like the previous plane) - an explosion of parts? -
  12. Motor overheat?

    i cannot see your pictures (404 error), but this might help: the buggy motor also has a thermal resitor built in, when you load it too much, by example heavy gearing or a heavy model, there might be too much current flowing through the thermistor and shutting it down for a few minutes, to not damage the motor. The Buwizz should have no issue powering 2 buggy motors it can deliver plenty of amps and this is why your buggy motor shuts itself down (my guess is you have a heavy model or geared it up too much, solution: gear down, or add another buggy motor)
  13. Did you consider using a wormgear and 8t gear? It will need higher motor speed input, but i think that this will be sturdier. Added: needs older diffs aswell... will be complex sorry...posted to early
  14. 15: 10 25: 6 3: 4 24: 3 10: 2 13: 1 Sorry no votes for decorated pull-back motors (but there were some very nice looking ones, well done!) but this is a technic forum, in my mind we needed some more mechanical functions. Great fun and well done all!
  15. ok so i tried to apply what @Davidz90 sayd, i hope i understood correctly, in the next picture you will see 2 out of place pins, the COG is now along that line, if you put the pins in from underneath you can balance the plane nicely on 2 fingers. But to make the COG shift to that point there had to be added quitte alot of bulk to the front as you can see, wich I do not really like, maybe @agrof has a nice design idea for this? I do want to mess with your design to much, but i do think the cog has to be where it is now if we want a decent shot here. i also feel it is a good idea to put the wing more to the back, further behind the bulk of the air tube, but that might mean loosing the front middle curved panel.
  16. @agrof ok i've built it, it looks very good (except for the colors, i do not own that much panels) and im pretty pleased with how the air tube was built in, please take a good look at the 3rd picture, maybe you have a better suggestion, it could be sturdier, but with the half beam as cross-brace my guess is it will hold. Maybe @Davidz90 can say something about the COG?, shown in the 4th picture, it should not be hard to shift it. If the construction holds, i have high hopes!, suggestions and other designs still welcome ofc!
  17. @agrofAh yes i did not think of bionicle, i have a box of those somewhere, i most likely have something good for it. But looking at your design, mounting the air tube might prove difficult; it has to be mounted on the 15l beams, if it is mounted directly to the panels it will tear the thing apart upon firing i think, any suggestions? (i gues that part is not in LDD..)
  18. @agrof Lovely! i dont think i have that rear wing, any other option?
  19. Very true ;) and: also very true, "Launching Lego" might be a better way to describe it. @Davidz90 I knew in advance this would not do well in terms of "flying", the way this is powered/shot means it is more like a rocket rather than a plane, asking for yet another design, fins in the rear with the COG on 1/3 of the silloutte. Perhaps i will try other designs, I had a "blast" doing this, maybe better designs can glide better and further. (a 42044 MOD springs to mind..) If anyone is interested: feel free to suggest your own (digital) design, i'd be happy to testfire them in real life, just make sure it contains
  20. to complete the topic; the video was added, you can find it in the first post.
  21. current stage, done:: Inspired by the 42065 with setting myself the goal to make it as small as possible. Does this qualify as model team style building?
  22. 19. Wind up tracked racer Inspired by TLG's tracked racer, I made a pullback-powered version of it, it has the exact same dimensions but has about twice as much parts. Wind it up, set the rear-spoilers in the direction you want to go and hit the "GO" button! The cabin opens with an other small type pullback motor for easy acces. features: - working skid steering, controlled by the rear spoilers - automated cabin opening, controlled by a button on the back - working V2 fake engine - wind up both pullbacks at once - "GO" button, releasing the ratchet Images: video: Link to my thread: