Monster Truck
A monster truck with Power Puller wheels. Features 4×4 drive, three steering modes, full independent suspension, remotely controlled gearbox and lights.
Datasheet:
Completion date: 29/05/2011
Power: electric (Power Functions)
Dimensions: length 44 studs / width 28 studs / height 31 studs
Weight: 2.113 kg
Suspension: full independent
Propulsion: 2 x PF XL geared 6.5:1 (1st gear) / 1.6:1 (2nd gear)
Motors: 3 x PF Medium, 2 x PF XL, 1 x 2838
A construction I’m definitely not happy with. It doesn’t work or look exactly how I wanted, and I couldn’t make the video the way I wanted neither. The chassis of this truck has been entirely reworked three times. The first version was using 4-link floating axles suspension from my Sandrail, but it turned out unstable and it pressed strongly on the driveshaft. I then turned to the independent suspension based on the 8297 set’s suspension components, and using knob wheels instead differentials for a better off-road performance. It proved slow and it was struggling very hard to make a turn. Eventually, the third version had differentials and increased gear reduction. It drives and turns well, but the Power Puller wheels which I wanted to own and put into use for a very long time, turned out to create an amazing amount of problems.
The chassis has 4×4 drive with the differentials enclosed in 5×7 studless frames, with universal joints and CV joints – a simple solution using specialized Lego pieces, and putting these pieces at a considerable risk of getting damaged. Each wheel is suspended on three shock absorbers: two long ones and one short one, with the short one located closed to the middle of the chassis to preserve the suspension’s long travel distance. I was prepared to see some broken CV joints, and I had spares at hand, but surprisingly not a single piece got damaged. In the centre of the chassis, there is my heavy duty 2-speed gearbox controlled by a Medium motor and a single mini linear actuator. There are two XL motors attached to the gearbox, they are coupled with knob wheels and connected to a switch inside the cabin. By turning this switch off, it is possible to shut down the main drive and play with the V8 piston engine which is coupled with the drive motors. The engine is driven by a 2838 motor reaching well over 1000 RPM, and includes a fan and a fiber optics unit. It creates interesting sound effects, especially when used with the speed control remote.
Both front and rear axles are identical. Each includes a Medium motor reduced 5:1 and controlling steering, so there is no mechanical connection between the steering of front and rear axle. Instead, the rear axle’s steering motor is connected to a switch that is motorized with another Medium motor using the spring-loaded Lego connector. Thanks to the connector, the switch returns to off position when the motor is turned off, thus allowing to switch the switch remotely through three positions. This results in three steering modes: normal steering for front axle, normal steering for two axles and crab steering for two axles.
I have spent a considerable amount of time testing the chassis and getting it to perform better, and I’m disappointed with the result. Despite the fact that the truck is relatively light and driven by two XL motors, it is slow and can get stalled on large obstacles. All because of the Power Puller wheels, which are heavy, extremely wide and with very soft tires. The amount of torque required to drive these wheels at all is shocking, and they tend to tilt a little every now and then, even though the chassis is extremely rigid and the suspension is very stable. I have tested the truck with different wheels, and changing to any other wheels resulted in an instant improvement of the overall performance, at cost of the look. It seems that the reason the Power Puller wheels are rarely seen in practical use is not only because how rare and expensive they are.
Even despite my disappointment, the truck was a valuable experience on how the 8297-based suspension behaves in extreme conditions and on how durable are the pieces it requires. While the truck itself was never intended for the Truck Trial competition, I hope to make use of this experience when building my next Truck Trial vehicle. I have also used this opportunity to work on the photos a little more, e.g. by artificially re-creating the so called ‘Michael Bay flares’ 🙂
If a single motor does not provide enough torque to spin the tires, you may try two motors working together. This was demonstrated in the Lego Power Puller, few years back.
@Martin
No, it’s not possible.
hello i`m from germany and i love your monster truck and i know that i can`t buy it, but can you make a LegoDigitalDesigner modell to download. PLEASE !!!
@Lamboguy59
Well, maybe there’s nowhere to buy them at reasonable price from. That’s life.
@Sariel
No i wanted to buy them for quite a resonable price and where can i get them there not on ebay amozon or bricklink
@Lamboguy59
I don’t know. Use the power of Google.
How much for the pp wheels?
@bob
No.
i’m building your old version (from facebook) now and the 8x8x8 ginaf from emilus…
do you have some truck trial tips?
@bob
I think you could, but it wouldn’t work well because it has differentials.
can you use something like this for truck trial?
I wish i could build like you. This is a great truck! I don’t have the pieces and the know-how to build such cool creations. I’ve seen a lot of you’re creations!
@Sariel
Incredible design, however, in reality, RPM stands for revolutions per minute, as in, revolutions of an engine. Obviously, the engineers at Lego don’t know that, as they have designed the Lego Speed Computer to measure rotations per minute and label it as the RPMs. Just in case you are also unaware of what a revolution is (at least in this context), it’s one occurrence of all the pistons of the engine firing (not all at the same time of course, considering that would result in a non-constant amount of torque and rotational speed being produced by the engine). Hope this helps in the future.
@Nxt You can use bluetooth.
@caca bouze
No.
Be that you can send me the notebook of construction to download
@Hugo
What runs?
I wanted to ask the number of runs?
@Antonio
Yes, and? It’s easy to control, as you can see in the video.
@Sariel
sorry, let me explain better
When you activate the blue lever on the remote control, the wheels turn together using only the fourth lever …
@Antonio
I don’t see where’s the problem?
Fantastic…. really a super work, but… how can you control steering motor together ??
If you use Bluetooth that will work.
@Nxt
Yes, NXT is a fairly good motor. As for iPad, sorry I can’t help you.
Is a nxt motor good for a trail truck
And if u can help me i dont know how to connect nxt with my iPad ir pc
With out THE wire
@Carletto
You can attach it anywhere you like. It just has to slide it.
Ciao Sariel – can you please telle me how did you arrange the gearbox movement with the mini LA?
I have checked your gearbox instructions, but it is not showed where you attached the miniLA to activate it.
Grazie 🙂
Hello i’m new in THE trail truck world
I wanna learn more about THE suspention
And everything thing (sorry for spelling i am only 13)
Plz help me
@Zach
I don’t know about Crome, but I got chrome pieces at Bricklink.
Where did you get the Crome pecies
@jerkerhead
The easiest way to get Power Puller wheels is to get Power Puller.
hey i only recently became addicted to technic and have a few big sets but i was wondering what the easiest way is to get those power puller wheels thx
@MeCho123451
Sure, you can use bevel gears instead u-joints, but it takes more space and is more likely to snap.
is independent, steered driven suspension even possible without some form of u-joint?
@max
No, there isn’t.
Hi, is there a parts catalogue available for your creations. i am new to this. how do you find the specialist parts, thanks
@Bob
They only fit Power Puller wheels, nothing else.
I was looking at buying some of the power puller tyres and wondered if they fitted onto the rims in set 8070 or do I need bigger rims?
@MeCho123451
I don’t know any independent axle that would be good for TrTr. 99% of us uses pendular suspensions.
can you make instructions for a steered, driven, independent axle that would be good for TT? i am really stumped. all the ones from official sets normally use U-joints and don’t turn much. Thanks
I think you have done mistake in data sheet 1st gear is 6,5:1 but 2nd gear is 2,33:1. Or no? I was looking at photos and calculated this. Check it
it looks a bit short to me
@Arnau
Experience, I guess.
Very nice job! When you build a MOC, how do you know which shock absorbers to use? Every time I build something it comes out that the suspension is to hard or to weak.
@kyle m
There are plenty of Lego sets with steered independent suspension. 8297 for example.
i couldent find an independant@kyle m
@kyle m
Check the Downloads section – it’s right there waiting for you.
could you make a post on how to make a steered independant suspension for a trial truck im trying to build my first
@mindstorm addict
No, they’re not really more powerful. They have more torque than XL motors, but less speed, so there is no real difference. Also, they have inconvenient shape and require special wires to run.
Why aren’t using a mindstorm nxt, the motors of the mindstorm are more powerfull (http://www.philohome.com/motors/motorcomp.htm) . Sorry for the spelling I usualy speak french.
@technikfreak
Thank you.
very good work i think you are one of the best Lego builders in the world 🙂
Aren’t these wheels like the ones of the old red Bigfoot and the blue Future Car set’s wheels? I mean they’re soft and wide, but actually touch the ground on a little spot. Nevertheless I can imagine how hard it is to use these big wheels right. Lego didn’t offer a “motorize the Offroader” option, right? You can motorize a lot of sets, but not this one 😛
@Max K
I’ve tried live axles and I couldn’t make them stable enough. As for the differentials, they’re good as long as they’re sitting inside the 5×7 studless frames.
Excellent job, although i always wonder how do you make the 3 studs wide Diff not grind. They are extremally fragile in my point of view, but you made it run under so high torque. But i noticed one minor technical mistake – almost all monstertrucks use live axles. Im sorry for pointing it out just i am a huge off-road fanatic :D, but i think it would look awesome on live axles suspended on four link suspension maximizing the clearance of the truck and giving it the all lifted look. But i have to say that those power puller wheels look outmost awesome on this model, no smaller wheels would have given the appropriate look. And i believe there is no reason to be dissappointed because as you said this model was not built for racing but for looks, and You have achieved a wonderful truck that looks nothing less than awesome.
excellent!
Me too
@Bullet for my Valentine
A very fragile ones, perhaps.
A cool truck, can you crushed a (lego) car with that? A monster truck need cars to crush.
Awesome dude!
I totally agree with Alessandro
Sariel – you did a very good job with this Monster Truck! You do not have to be disappointed. You just realized one more time the limits of TLG system when dealing with heavy/large scale models. I am quite impressed by the functions of the model. It is great to see so many of them all packed together. Your gearbox remote controlled with mini LA is superb. Also the engine with fan and fiber optics activated by an old motor is great. The steering remote controlled in three different modes is excellent. I know, it just doesn’t perform as it should. The fact is that unfortunatelly Lego have a physical structural limit, hence as soon as you reach a certain weight it doesn’t perform optimally any more. We would need more powerful motors, but then probably we would brake u-joints and othe trasmission pieces. I think this model is very good because of the ability to put together so many functions. I agree with you on the PP tyres, great aesthetics, too much weight and therefore poor performance- The all look of the model is very good. Just a minor thing, looking at proportions I think the body is a bit too big compared to the wheels. Still I am not sure you could pack so many functions in a smaller body. One thing: if you could make building instructions of this, it would be awesome! Keep going! -Alessandro
I really like the 4×4 and the four wheel steering, but it’s a bit slow. But, as always, great job!