Marxpek

I just looked it up, but it doesn't have damped shocks in it . Still a good idea though! Wups! that must have been a (very old) modification of mine then, do not even recall it using normal springs, but obviously it does ;)

just recalled another set: 8432 used it to choose between 2 ride heights if i recall it right.

The 8297 set used them to open the gull-wing doors, a function i always liked, since they open slowly because of the dampers.

Lovely rugged look! And erm, do i see a skid steering switch mechanism with pneumatic? I really love your "i don't have a receiver, but i will make it work, attitude" good job! Curious to see your video!

As far as i can see there is no caster, camber or toe in with this setup, you should really look into that, those can all help with a straight line and stability. Correct me if i'm wrong but this is just a straight setup which, sadly, does not want to go straight by itself. One thing i do not really like here is how the hubs are fixed, by the pictures you can already see the 1x2 crossplates want to come off, they should be braced better (try a 4 axle with end stop and a bush) this alone can cause issues. Why don't you try to use the rc front end? that has a extra return to center spring and a caster angle built in.

I don't know if this is an option to you but maybe it is an idea, remove the linear actuators and use pneumatic there and make the car lift pneumatic as well (8285 had that). That would leave you with 4 functions left for the gearbox. Nice project good luck!

Yeah but that part separate costs about 7 euros each, that 8297 set has 4, one of the reasons i only buy sets.. in the end its a way better deal.

none of the sets that contain those available used somewhere near maybe? 8297 is a fairly common and not too expensive set used, although some of the other set containing them also contain wishbones i think.

That is less then i would have guessed, but maybe wait and design first (maybe you can work in LDD?) you might need more parts, place a bigger order and save on shipping, don't rush into it. Btw: i never order parts separately, if i need parts i try to find sets that contain them and try to buy that, gives a lot more bang for your buck with all the extra parts, just takes a bit longer most of the time (i try to buy used item first)

The wishbones are great i guess, but i guess they are not cheap or easy to come by (i'm guessing) And considering the amount of parts i have destroyed with crashes at 20km/h+ i personally would not use them, i broke several 7L lift arms in the steering unit (and wheels.. and axles.. and a hand full of pins...) with crashes and to me they seem a lot more rigid than the wishbones, it's a great solution but not if you have the slightest chance of crashing, and at 20 km/h outside a small rock could cause that... I do not own these wishbones so i cannot tell you for sure, maybe anyone else has them and want to test their breaking strength compared to a 7L lift arm? I guess not ;)

At high speeds this is nearly impossible to avoid, Lego always has some play in the system and Lego was not built to go over 20 km/h (maybe the old dirt crusher rc car, but besides that nothing that i know of) even on my first record car without steering i always had a minor deviation of the route i set out, sometimes left, sometimes right, (this had no caster camber or toe in, just a axle with wheels), with speed all forces increase exponentially and connections can get loose easily. Be sure to check every connection in the car before each run to be sure, but over a 100m run i always had at least 3m of deviation ( best run was about 140m with a deviation of about 4m, which i considered a "near perfect run" they always end with a crash though :D)

@rkkm here are some pictures of my steering unit built on the RC front end. This simple but effective setup did nearly 29 km/h as you saw in my video however don't expect to be able to make a fast turn when going over 20 km/h you WILL flip your car, this was made for minor steering corrections at high speeds, but it can still be somewhat nimble at lower speeds. It has positive camber, negative caster and toe-in set wheels, all to those make your car want to go straight when used correctly. But i understand you do not have the 9L links, but there is always a way! But what exactly is your goal here? make a car fun and fast to drive? or will you try to break my record? Your goals should determine your setup i think. If you want a a car for pure speed, go with a setup similar to mine, i'm sure it can be improved! But if you want a fun car to drive, pick another setup, maybe one with suspension. And by building/trying yourself, you will learn the most! of course we are happy to help out here for tips and info!

I'm not sure i fully understand, you want details on the original set? that doesn't have much, i took out the back axle and made my own, lengthened the wheelbase to fit a turntable and motor in the front, and added the linear actuators for steering and made a new front-end. The back axle is suspended in 2 ways, the springs on top suspend the bodywork and the lower springs suspend the back axle pivoting on another turntable. Fun fact: it has exactly the same power to weight ratio as zero's crawlified Porsche, mine is just a tad faster. I do not have a digital file for it, maybe i'll make one but i do not really like to do that..

Video on my 8048 crawler is up, made a topic for it, but i'll post the video here as well since it gets a bit lost in (better) other topics. Check it out if you like, i'd really like comments on the build and/or the video itself (just started making videos and i want to improve editing skills as well, but please consider i only have my phone and a small tripod for filming..)

It performs better then i had expected with all that weight! I did a bit of math and it seems our vehicles have the exact same power to weight ratio (4000gr-800nm/s vs 1200gr - 240nm/s) which makes me think your Porsche can do even more than shown in your video! (mine is up as well in a separate topic would love some feedback!) But i can understand you do not want to risk a real drop onto rock with the costly Porsche set, and i must admit.. control with IR receivers and making good shots outside is hard with all the sunlight... Anyway, nice work and looking forward to see more pictures!

This spring can turn a XL-motor or even a L-motor? or is it just about the mount? i'm curious about the force of the springs inside..

@Doug72Yes that is the hockey spring, but i have no experience with it since i don't have one, do you recon it will work with high speeds? (solid springs inside?)

Steering at high speeds can very problematic, if you check my you tube channel you will see.. you will need a good setup (my avatar is the current speed record front-end) camber, caster, and toe-in, all help to provide stability. check this site for basic information about that http://en.intraxracing.nl/techniek/camber,-caster,-toe-intoe-out/ I have bad experience with gearing down servo's, any play on the gears will decrease steering abilities and that play we can never prevent, over 20 km/h you will surely be uncontrollable with a geared down servo. A self made return to center system could work, but it would need strong rubber bands as the forces on the wheels increase with speed and you don't want it to steer by itself.. (i do not own a hockey spring so i never tried those) Going fast is easy, but have control while going fast is harder even with a good setup you can easily flip you car with a wrong movement, good luck!

@Aventador2004 Thanks and yes.. the steering is a bit slow, but its already geared up 1:1.6667, and the motor can already stall when steering in a spot where the wheels are locked. Maybe i will try to improve it, it is slow but it works good. But first i'm working on a 2nd design. Thank you!

Hey everyone, here i present my 8048 modification for the AMS-1 contest. It's not complicated or big, but it hauls! Powered by 2 XL motors Steering by 2 linear actuators and a M-motor V2 receiver over 45 degrees of flex If this will be my final entry remains to be seen, i have a new idea and 15 days left... Check it in action here! Enjoy and please let me know what you think!

@MangaNOIDI own the 42053, but never built in the PF, but as far as i can recall there is no pressure relief, but i never had a motor stall by a compressor, more likely to pop a tube off i think. Maybe gear down the compressor motor and install a air tank? would buy you more time before the pressure gets too high and the motor would have it easier. a pressure relief could work by using the springiness of a lift arm maybe?, make it bend with a pneumatic actuator and make the actuator control a electric switch to feed to compressor motor? i hope i make sense here..

Thanks, i was not aware the LA-turntable combo is rarely used for steering, seems a good option to me, as it can help climb when a front wheel is locked behind a rock or ridge, because it is really strong, but don't expect to make a sudden turn ;) its turn circle is not that big, but we all know how fast the actuators work (geared up 1:1,667, still slow) But to be honest it was the result of not having a servo motor available, while i wanted a strong and accurate steering setup, a return to center system with m-motor would not be powerful enough and this seemed a nice solution and i like how it functions, I've also tried to mesh a worm gear with the turntable, but it was weak because bracing it was hard and not symmetrical, so I ditched that idea fast. In the meanwhile i do have a servo available, but i will not be replacing the actuators, it does stuff the servo cannot i think. The rear axle also contains a turntable, placed vertically to allow the crawler to flex over 45 degrees on the lower rear springs, but i guess that is a common used solution? Since this is the first crawler i ever built and i never do research in advance ( i think research in advance limits your own idea's, i start research when i run into issues ) i am pretty happy about the result, if all tests go well today and i am happy about the driving i will shoot video as well, if not: i will adjust. If i have time left, i might just try a 2nd crawler, i have a idea which i think will surprise everyone and will have better power to weight ratio if i get it right!

Thanks and with the portal hubs installed it is unstoppable now. But performance or looks... tough trade off, i tend to say performance, on the other hand... looks is probably what the voters want (not that i expect to have a fighting chance against the orange monster ;D)

here i will be sharing full pictures of my WIP 8048 Crawler MOD "Rune Buggy" Mainly because i would like you opinions, i am in doubt about the setup, a trade off between looks and performance, what would you do? A good looking setup, but it tends to roll over backwards when going over +/- 40 degrees incline. turned around the back axle here, lengthening the wheelbase and placing it COG more towards the front drastically increases climbing abilities, but... i do not like the looks... what would you pick? looks or performance?

i know those, thanks, ill try those if it turns out i have 4 of them ;)