Marxpek

that is the darker grey one with the small bevel on it?

for sure it was old as it is the longer version, replaced all old u-joints for new style ones, was needed for correct geometry also. But i decided to do it the correct way with portal hubs and the extra gearing helps a lot for its performance, now i am using the 12t-20t setup. but i was wondering: can i also use 8t-24t gear setup within the portal hubs? or would an XL-motor break the 8t gear?

yeah yeah, i'm working on it ;D I like it a lot!

thanks for the reply, but: 1: not an option to me, go big or go home ;D 2: could use Lego string for that maybe, this contest is all about 100% lego, and i have 2 lego strings in displayed sets, but thats about it... already decided, my 4 y/o girl is going to be mad for a week or 2 maybe (yes i am letting her have her way with all my Lego, raising her to be a Technic fan at the price of loosing some parts) Even though the portal hubs will make it wider by 2 studs total, they will also raise the ground clearance by 2 studs, which would please me. @Zero (Zblj) the wheels are connected like that now, doesn't give any problem (yet), i think the hubs are the best solution..but maybe i can make my own (smaller) hubs, i'll try

yes i know but... i do not have them available now, i considered making something similar but that would be bulky and weak.. Ill have to break down a set my kid plays with almost daily (9398)..., which will make my kid mad/sad... but maybe if its for the greater cause, that is worth it? ;D (but already stole the v2 receiver soo..) But they will also make the entire thing wider i think, something i already did not really like in my design... I'm not sure about the quality of the broken u-joint before it broke (it is the old longer version, i always lack parts...) i might try 1 more with the same setup, if that breaks i'll make my kid sad ;D but i kind of like the way it drives now...

did some test runs and shot some video, but.... anyone had this problem and perhaps solved it?..

they are, the rear axle is one of the thing i consider to redesign, mainly because of its ground clearance at the center, however every beam is braced by either a 5 or 7L lift arm, it can survive a 0,5 meter drop without damage (most of the time..) the suspension works well and it goes like a truck. but.... i recently found some new parts/inspiration which makes me consider to ditch the entire thing, and go bigger... there are 20 days left after all..

haha, kind of yes, but didn't Lego make like 6 of those? (pure guess)

Here are 2 pictures of my WIP crawlified set, maybe someone can already recognize the set? :) still some work to be done, but getting closer!

Why didn't Porsche make this in stead of that ugly cayenne? Well done! does it perform well?

@MangaNOID wow, those pictures make me curious (again..curious person here) This thing will be unconventional making me even more curious! All those gears, i've been working on reducing the number of gears in my crawler, but you took the other way! lovely to see different approaches! Maybe i'll place a few pictures of my WIP (i rarely take pictures during the build when i am "in the zone") will be hard to cover up what set it is in the pictures, since my crawler is not the biggest around, but i will try, but the keen observer will most likely see what set it is!

@Zero (Zblj) You are making me very curious ;) and it wont discourage me, maybe even encourage me to try harder! So please do post pictures! I am only here to participate and learn, i can never compete with some of you, i need more experience and parts for that. (portal hubs please...) i'll get that in time! If you are not posting pics, can i ask which set you took?

the idea was to have both the drive motor and the steering motor/servo on the chassis, and have this rear axle free for pivoting. Having the servo on the axle itself would work (for 1 axle) but this would make the rear axle way too big and heavy, especially when i would need 2 servos for steering, 1 for the front and another for the back.. and, that way the double shaft through the turntable would be obsolete.

we still have to obey the laws of physics i'm afraid. What you are talking about is a perpetuum mobile (never ending machine) this would be the holy grail of mechanics, and even in a world without friction it would be hard to achieve (less friction in outer space with 0 gravity but pneumatics don't work well there, without air..) A engine can never provide (enough) power to feed itself, you will always need to introduce a form of energy (wind, petrol or here an pf-motor) Basically the compressor will only provide a fraction of what the motor will need, slowing it down, get a bigger compressor you say? that will need more torque and thus more air to move your motor/compressor. Not a dumb idea, a very nice idea that people all over the world try to solve, but so far no one has.. can't hurt to try tho ;D .

Here is a concept / idea which i abandoned for the crawler challenge, please look beyond the weak connections, this was a proof of concept build which failed. i have moved on to another setup, but i wanted to share this with you all, maybe anyone has an idea to fix my issue: i tried to make a pivoting rear axle that included drive and steering. Turning the u-joint will make the axles turn, turning the empty differential housing will make it steer and it pivots around that u-joint and differential axle, the old style Technic beam indicates what would fix to a machine its frame I have abandoned it for 2 reasons: 1- the drive needs a worm gear to mesh with a 8 tooth gear, they get destroyed by the torque needed, this could be fixed by increasing the size by 1 stud between the 2 turntables, but to me that's no use to figure out till problem 2 is solved... 2- when the entire unit pivots on the turntable, it will also automatically steer once the motor or servo is attached to the steering gear (differential housing will turn by pivoting as well) i do not see a way to fix this (idea's? ;D) And having so much fun making my first moc crawler! my basic setup is done, and i'm pretty happy about the result! working on fine tuning and getting the details right now (as we all know these can take the most time...)

as far as i am aware, any set we own, "crawlify" that by adding any Lego part you want. while maintaining the look and "feel" of the original set, at least.. that's what i am doing.

That's a shame... but we are going a lot off topic here, so lets go to the personal messages or move to another topic (fastest Lego car topic maybe)

Congratulations all!, this was great fun!

Ah yes i am familiar with that issue, I thought it was to get more traction on the surface we are driving on. ( 2 rubber bands in the rim work as well, gives a slight unbalanced tire, but that's no issue with low speeds, but not a lego solution)

@JJ2 You mention that foam in the tires will give more grip, could you explain why? (even though it's not allowed here) This is the first crawler i'm attempting, so i have just scratched the surface of what crawlers need. But i was always under the impression rock-crawlers and off road vehicles drive with very low tire pressures to get more grip (tire can "wrap around" a rock), why do we want to make the tires harder in Lego Technic?

@Aventador2004Even if someone would "steal" that idea (great minds think alike, perhaps someone already started on it before you did..) but it shouldn't matter i'd say. Would even be fun to see the difference in approach and execution in the end, a nice comparison! (and no, i am not using that set myself, i'll keep it a surprise until its finished, or until its requested for this event)

Thanks for the tip! But I have found a set in my inventory that i forgot about and it might work, working on it as we speak ;) Maybe i'll fail, maybe it will be ugly, but that doesn't matter to me, it's the process that is the fun!

@LXF thank you, that doesn't leave me with a lot of options though, since i only own 1 Technic car, (the 9398 crawler, but... that's no fun). I suppose i can make a crawler crane or crawler BWE? :D anyway, challenge accepted, i'll find a way or a suitable set! thanks for creating yet another fun event!

Fun idea! the idea is to take parts from just 1 set and make it a crawler? we can only use the parts provided by that the set we pick? or can we add pf and/or wheels to that? Always up for a challenge!

The hubless wheels i saw before in a slightly different setup, but your steering and suspension setup are amazing, very nice job!