andythenorth

Off-topic but ha ha ha ha ha ha ha ha. There is perennial amusement watching some people complain about how everybody else is stupid, dumb, dumbed down, only capable of consuming blah blah blah. Often the people who complain most are the stupidest, because they look only through the filter of their own preconception, and they don't have the eyes to see just how smart and capable of navigating the world most other people are. And they do this whilst (in a perfect illustration of irony) elevating themselves to some kind of pedestal of above-average intelligence and insight. Not just ironic but deluded, self-serving, and sometimes dangerous. Thanks for that.

Should be an official TLG set.

It will pull my 20Kg child, on a micro-scooter, plus a bunch of other toys. Only on level ground, if it hits a bump it stalls out or tears up the chassis. The truck in the first video uses these tyres, they're huge and expensive. Smaller ones would be better for your truck http://www.bricklink.com/catalogItem.asp?P=22969c01 How about? http://www.eurobricks.com/forum/index.php?showtopic=58938

The truck in the video weighs around 2.5Kg. It will tow at least 25kg (children on ride-on toys with large wheels, on stone floor). Rolling friction of the towed load would affect towing capability. It will push a full-sized wooden kitchen chair around on a wood floor. Just for reference. You probably want to go with the wheels you have, but you might also consider these slightly larger ones http://www.bricklink....asp?P=56908c01 Larger = faster rotating without gearing up. The crane tyres are also relatively hard, and have a lower surface contact area, so more prone to slipping. The tyres I linked are quite soft and have more contact area, tend to maintain grip better. Maybe something like this? http://www.commercia...lfield-truck-vl Gear boxes are just going to annoy you, they're a hassle.

Agreed, with a few caveats :) That Rolligon thing in the video has ~1.5Kg of power puller wheels on it. If I was building an on-highway heavy haul truck I'd probably go for the 62.4 x 20 wheel, which is only 33g per wheel. And I'd build a sparse body. What I'd struggle with is building a lowboy trailer that was both lightweight, yet strong enough to hold something like the Volvo loader. Not sure that can be done. This one has 3x XL, with 2x AA battery boxes over rear axles. It will drag at least 20Kg with the difflocks in, but it's slow, and it's close to chewing up the CVs on the steering axles. And it's slow.

This may sound counter-intuitive, but power each wheel with an L motor. Why not XL? To get the XL motors to an acceptable speed, you will need inverse reduction (gearing up). You'd need to do that either: - with a long drive train, which means inefficiency, lost power, lost speed, and more chance of tearing up parts. - or in the hubs, which is hard, due to space, and same problems with inefficiency and broken parts The XL is excessively powerful and slow for your needs. Try the L This truck has 8x L motors, one per wheel, on roughly a 20:12:8:24 ratio (so slightly geared down), driven by 2 battery boxes with 7.2v of NiMH. It would put out more power on 9v. https://www.flickr.c...th/14071162377/ It's not super fast, but it's not slow either, and it has plenty of power, as the video shows. Direct drive (1:1) or 20:12 gearing would give you faster, at the expense of power, but you don't need to climb walls with your truck, right? The L motor is also easier to mount than the XL, and you can run 4 of them through one IR transmitter with no problems. With one motor per wheel you don't need diffs. I would probably build a 4 axle truck with a powered rear tridem and an unpowered front axle, but depends on how big you're building. If you have space, a powered steering axle will help you out.

A single XL motor will chew up 8t, 24t, 16t bevel, and old 16t gears trivially. Just use it on any high-reduction gear train, and stall the tyres. The XL will do this on the 7.2v put out by NiMH batteries, doesn't even need 9v. Also chews the projecting stubs off CV joints if you have a powered axle with steering. I think it would shear an x-axle too, given the right opportunity. I have seen fewer (or none) broken 12t, 20t or new style 16t gears. Have yet to break gears with an L motor, but I think it would split 8t easily if pushed.

Seriously, is anyone on this forum going to say no to this question?

Nice victory of facts over perception Would the world be a better place if there was more of this?

I am shocked that they repeated the Unimog so soon. The last one (with a a crane) was introduced in 1989, and then one before that just in 1981 (with the same snowplough + tipping bed idea). The latest one just puts the crane + snowplough idea together, and doesn't even have a tipping bed. And now we might have another Mercedes thing? I am ashamed.

I am +1 that it's inspired by Mammoet. The colours and the style are near-identical. http://sariel.pl/2009/06/kenworth-mammoet/

I think it's because an idealised 3:4:5 triangle relies on corners being at the exact endpoint of the line (I'm not great at maths, but I think strictly it also relies on an unmeasurably thin line). The Lego liftarms are not connecting at the end point, but rather some distance along (maybe about 10% from end on a a short liftarm like a 3L). Try taking a sheet of paper and drawing lines along the center-line of each beam, and you'll see how the distance between the connection points isn't 3:4:5 (I haven't done this, interested what ratio it actually is). I wondered if the gaps between the stud holes might also affect the strict 3:4:5, but I couldn't see how, they looked like a constant factor to me.

I really like the appearance of the cab

9V batteries are crap, expensive, and they don't hold charge for long enough to use in technic vehicles, or in trains that your kids want to run around around and around around But the PF battery boxes are annoying. The AA box is too tight for most NiMh batteries, I have to pry them out with a screwdriver or the battery box lid, which splits the plastic cover on the battery. The AA box is also large, sometimes trading battery life for size would be good. But the AAA box has some shortcomings. There's the stupid screw (not stupid if your toddler eats batteries) but the screw makes changing batteries a chore (I break them out and am teaching my kids to stop eating batteries). The AAA box also has no stud mounting points (adding them would make it longer, wider, or taller). For whatever reason (not sure myself), I never think of using the AAA box in technic mocs. Would be neat to have boxes holding 2xAA (total 3v) that could be ganged together, but eh, that's way too complex and won't happen.

Yeah, had them plugged into things like this http://www.ebay.co.u...u-/191420216548

Never noticed them weakening? I think sufficient excessive heating damages the coils in the armature windings, causing weakened fields. Definitely did this to at least one motor when I was a kid. Will say btw that they were often plugged into (6v-12v output) mains power supplies (either a lab supply, or computer interface board). I had a quick google to see if I was smoking crack: http://electronics.stackexchange.com/questions/104719/will-running-a-dc-motor-below-stall-current-damage-it Haven't noticed this with PF, I assume because stalling the motor draws excess current from the battery box and the overload protection kicks in. Dunno if the motor itself has current protection though.

Herp, I was trolling, but actually an RC unicorn with animated rainbows would probably sell boatloads. But still there'd be complaining if it wasn't pneumatic. Can't think where to apply a cylinder though.

I am hoping the flagship is an RC unicorn with animated rainbows

And you can stall them trivially, and afaict, there is no overload protection. Bye bye motor. Which means spur gears can drift under load (the axle deforms or the motor rocks), with no way to add beams or liftarms as bracing. Also, it was pretty common to use the motor to try...non Lego stuff, like drilling into wood. So it was pretty common to own a motor with the axle cross worn down. +1. Better or worse than the 4.5v system with the metal pins and the screw-down connectors for the wire?

Did you know that PF and 9V are (mostly) compatible? One end of the PF extension cable has 9V studs under the connector plate. This means PF battery boxes and IR receivers can power 9V components. When I tried, I couldn't get a 9V battery box to power a PF receiver though.

There's fast and there's fast. If the original poster is just looking for 'faster than with one XL using high friction knob gears', that's no way impossible.

What we all say is our opinion If you're not prepared to have an opinion challenged then the internet is the wrong place for you. I don't think the 'criticism' from Bonox is intended as criticism, it's curiosity about why you want 9V back. Also lots of people here don't have English as first language, and lots of people are technically-minded and just want to understand the reasons for something. That can sometimes cause discussions which seem abrupt or rude or confusing. So anyway what are the reasons why you want 9V back?

Way off topic, but the (real-life) monster trucks I've seen use heavy-duty axles, diffs, props, hubs, swingarms, shocks, clutches etc, either custom-made, or from severe-duty trucks and heavy equipment. They don't just stick a V8 into a mass-production vehicle. The point being that hopping up Lego with excessive power just reveals problems, - high-torque reveals the weaknesses of ABS parts (even a single XL motor will split gears and twist axles easily) - high-speed reveals the problems of a using low-melting point parts in a high-friction, unlubricated, no-bearings environment - high torque and high shock loadings show the limits of pins, axles and studs to keep parts together - high torque shows how poorly beams and liftarms resist bending moments, causing gear trains etc to come unmeshed Anyway, just my 2p

Agreed. I would suggest starting with 2x L Motors per wheel (4 in total). This is the maximum that can be practically driven from one battery pack. Based on Philo's charts (if I've read them correctly), 2x L is less efficient than one XL, but it gives more flexibility over mounting, and the motors rotate faster. The XL will need gearing up though to get an acceptable speed. Gearing up = friction losses, more space needed, and parts will break. http://www.philohome...ec/pfcurves.htm Ignore all the suggestions about gearboxes, they're not robust enough to deal with the amount of torque you need to get into that single axle. You'll have split gears, stripped gear teeth, or the clutches will slip under load (or all 3). Try the train controller to have variable speeds, I'm 100% guessing here, but I think it uses PWM, which I think means it regulates frequency rather than voltage (which means on the low setting the motor gets a brief kick at full voltage every n ms). But I'm pure guessing, and it's half my life away since I studied electrical machines, and I wasn't good then. The point being that on low speed setting the motor will get enough torque to start the vehicle without trying to apply full torque (and tearing up parts). That's my experience anyway, but it might be way off reality.

To give you a reference point, this is about 2.5Kg. 8x L Motor, 2x battery box. It's geared for pulling power not speed (it will pull at least 10x own weight). https://www.flickr.c...th/14071162377/ Apologies in advance if the flickr video doesn't play, flickr video is borked in some browsers. Sariel has made some insanely fast MOCs (can be found on this forum). Low weight is the key.