you are correct, and I understand that a normal truck with that kinda weight on it would be going slow. I just wanted the truck to move a little faster than slow. I understand that the heavy hauler LEGO truck needs the strength the pull and that means I need the torque over the speed. I just wish there was a way to have some of both. I know their are others out their that feel the same way. Do you think that a fairly large gear box would help? So that the speed slowly increases, instead of a faster start out speed. The Gearbox would work just like a transmission in a big rig. Idk, I am just rambling

Did he say he wants to pull a trailer with a 42030 on it? even trucks in real life pulling heavy machinery are aggressively slow.

The L350f is a mining front end loader, so if it were on a truck, I doubt that they would exceed 30 mph, maybe even less depending on local road laws. I've seen a couple of large trucks with smaller wheel loaders on them, and they aren't even going 45 mph on the highway.

I am not necessarily looking to go the same speeds as the true transport.

I was referring more to scaled speed as well, a 1:10 car going at 10 KPH for example would be going at 100 KPH at full scale, anyone know the scale of the 42030? i was thinking around 1:24

I am not concerned about scale at all, if I was my trailer and semi truck would have to be about half their size to be the same scale as the Loader. Can we please get back to a way to get more torque and speed out of a motor?

Can we please get back to a way to get more torque and speed out of a motor?

you're not actually listening to what is being said. The only way to do what you've asked is to overdrive the motor - in a DC motor, this will be

increasing its working voltage. You'll also have to do this without being current limited (or the voltage will fall again).

Neither of these things can be done with the factory battery box.

You'll have to plug your own battery or wall powered supply into the motor, acknowledging what everyone here has said about the risks of letting the smoke out of the motor.

Again though, all products fail at the weakest point and as countless people like Jeremy Clarkson have proved over and over is that "more power" is often not the smartest way to improve performance - thus the comments about simplifying your drivetrain, checking you don't have binding parts, ensuring you don't have competing gear ratios on different axles etc.

Aminnich, when you say it is barely crawling, how slow do you mean? Is it slower than the loader? It sounds to me like the motors may be getting bogged down by the weight. Try adding some gear reduction between the motors and axles. Technically, the gear reduction should make you model slower, but if the motors are getting bogged down, the extra torque may actually speed things up a bit.

Throw in two or three sets of 12/20 reduction on each axle and see if that helps.

Just my $.02.

Another option, assuming you are maximizing your torque is more motors. Drive every wheel you have. 4 motors and two battery boxes will improve your power to weight ratio.

Why Lego is not making another RC kit

Why Lego is not making another RC kit

Usually sets that have RC are released in the second half of the year. Hope That answers your question.

Usually sets that have RC are released in the second half of the year. Hope That answers your question.

I mean RC like the rc buggy not the PF IR system :)

I mean RC like the rc buggy not the PF IR system :)

Ahh I see what you mean. They probably stopped using it for money reasons or quality issues, I am not sure but that's my guess.

P.S. Sorry for the slight off topic

Ok now that is a suggestion of what I could do. I will try individually powering each wheel, instead of each axle.

And yes when I say crawling, It is slower than the loader. Im not 100% sure of what the ratio is, but ik it is geared down pretty good.

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.

Edited December 17, 201410 yr by andythenorth

You could just mount an XL motor to each axle and that would provide a sufficient amount of torque if they are geared down to a 3:1 or 5:1.

This may sound counter-intuitive, but power each wheel with an L motor.

..............

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?

That is impressively fast, but it is also a bare chassis. Once you put on a body which is in scale with that huge chassis, the model will be very heavy and the performance will suffer accordingly.

With only 1 amp of current to play with, there is just not that much that can be done. The only legal way around the 1 amp limit is to add more battery boxes, but battery boxes are also really heavy so this becomes diminishing returns very quickly. Even with a real R/C battery pack that can supply 100 amps, the wires can't handle it and neither can the motors, not to mention the axles and gears. Those current limits are there for a reason. They match pretty well with the strength of the parts. If you bypass the current or voltage levels built into the PF system, part destruction is likely to follow.

Once you put on a body which is in scale with that huge chassis, the model will be very heavy and the performance will suffer accordingly.

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.

Edited December 17, 201410 yr by andythenorth

The first vehicle speed would be fantastic, but it wasn't pulling weight or anything. But is there a way to power each wheel with that speed, but then be able to gear it down to be able to pull the weight?

Btw, I am using the wheels from the mobile crane (42009). As for the size, I can have as many axles, but I don't want to have to buy 10 L motors for 5 axles, that would get expensive.

So I like the speed of the L motor directly to the wheel, but if their is a way to have a gear box to gear it down, that would be cool. With this I would be able to drive truck at a nice speed, but then when the trailer is hooked up, I have to power to pull it.

I don't know if it is possible, but you guys are the pros. Thanks for all the suggestions.

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.

Edited December 17, 201410 yr by andythenorth

Wow, that truck would be very cool as a Lego, but it was not what I was thinking. I wanted to try and build a daycab 379 peterbilt like the one in the link, but black and with a third rear axle.

http://www.autopia.org/forums/the-detailers-showcase/35001-hammered-2005-peterbilt-379-daycab-ex-loggers-truck.html

I want to stick with the same tires, but are you talking about the first video? Ur saying that the truck in the first video could pull 25kg?!? If so that is what I'm going to do. If not I think if their is a way to use a gearbox, to switch to a "pull mode" I will do that

And yes when I say crawling, It is slower than the loader. Im not 100% sure of what the ratio is, but ik it is geared down pretty good.

Is your truck geared down, or are you refering to lower gear ratio in the loader?

Do you have pictures of what you are building?

The truck is geared down 1:3. The truck is a work in progress. It no built , I wanted a bunch of questions answer before I started, so I would not have to tear it all down and restart over and over. This way I will know what im doing when I start building for real.

Edited December 18, 201410 yr by aminnich

Ur saying that the truck in the first video could pull 25kg?!?

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

I am not looking to build an off road trial truck. And I want to use the wheels I have, especially if im going to be buying 6 L motors.

This is the truck that would crawl. Basically the 9397 logging truck with some modifications.

Hey guys, I did not want to start a new topic because it deals with the same thing,

Has anyone successfully made motors that have the same specifications as the power functions motors? Because I know for a fact that it would be much cheaper to make a motor work, instead of buying the power functions motors. I know I sound cheap, but I’d rather spend the money on more technic pieces (which cant be made), than spend money on the power functions.

Any thoughts?