Hydrema dump truck

[GuiliuG]

Hello everybody ! Once I saw Han's articulated hauler, I find that it's really nice BUT not built for good performances on climbing. Why? Because Han did not make the right choices. Indeed, his 3 points suspension system is nice but involve lot of weak parts. Moreover, there is no portal hub, which means that all the drive train is under high stress. Han says that he reaches lego limits but I only thing that he reaches limits not cause to lego parts but cause to his choices. I decided to build a hydrema dump truck because this firm is not well known but make excellent construction equipment. First of all, I wanted to build a 6x6 but finally I switched for a 4x4 for three reasons :

-No central differential

-I have only four big wheels of the same type

-Multi-tip ( principal reason for my choice)

Here is the model which inspired me :

And here is my lego MOC :

It owns :

-Integral propulsion powered by Xl motor ( 6:1 reduction )

-Front and rear lockable differential ( simultaneously)thanks to small pneumatic cylinders

-Front live axle

-Rotating hitch

-Articulation with two mini-las

-multi-tip ( rotating and dumping bed)

Let's take a closer look at the front axle :

I use portal axle from 8110 to good support wheels. All the reductions are on the axle to reduce stress on drive train. Everything is built strong, motor struggles and stops before one gear ( or one cv-joint) skips or breaks.

Front-axle is maintained by four points (V-link, Panhard rod and two schock absorbers)

On the photo above, you also can see the mechanicsm for the articulation ( two mini-las).From the first prototype, a better look at this function :

No reduction, La are "directly" connected to M motor).

Left switch is used to lock or unlock both differentials

differentials unlocked

differentials locked

To rotate the bed, I use the same system as the 8868 one ( pneumatic cylinder pushes or pulles rack which turns a 12T gear directly attached at the superior turn-table part.

(picture from very first prototype).

Two pneumatics cylinders are used to tip the bed. Very powerfull.

As I didn't see how to built its characteristic look with studless, I switched to studfull. I have not a lot of studfull parts so I have do my best with my inventory.

Reproduce bed form was very hard. I'm satisfied by its look, same if its shape differs from the original.

About its offroad capacites I'm happy because it performs well BUT Xl-motor suffers quickly due to lack of reduction. The problem is that I could only put more reduction before weak parts and I don't want to break them. I'm currently building a new hydrema dump truck but this time a 6*6 with rear boggy suspensions and 9:1 reduction after differentials to have a truck which performs still better.

Finally, here are the video and my brickshelf galery for additional pictures :

My brickshelf galery

My video :

Edited November 3, 2012 by GuiliuG

[Alasdair Ryan]

Very nice dumper,I saw it take shape on your Brickshelf page.

[Ramacco]

Good MOC. I like the differential lock, but don't you lose power? I can't imagine that a locked differential gives the same torque as 2 knobs or bevels.

And as you pointed out: Han's 3 bogies suspension is pretty weak (because there is not enough reduction), but you can definitely make a similar setup which can deliver good TrTr performances. I'm currently prototyping an articulated 6x6 dumper (Hydrema or Volvo) with 3 bogies suspension similar to the one from Han. But reinforced and without the differentials and of course with portal hubs. However, I'm not sure how this will turn out.

Edited July 19, 2012 by Ramacco

[GuiliuG]

Torque is influenced by the number of teeth. So knob gear changes nothing to torque, bevel gears can change something (if it's 12t/20t for instance) and differential will change torque only if there is a 3:1 reduction. When locked, it acts as if it was an axle, not a differential, so no, you don't lose any power. Also, knob gear aren't very efficient at high speed due to its only 4 teeth ( the less teeth a gear has, the less efficiency it has). But I guess you already know everything of that, so I probably don't understand what you exactly mean.

Edited July 19, 2012 by GuiliuG

[Ramacco]

I meant if the driving rings don't reduce the power between in and output. When I tried using those (only one time, because I think it's not accurate enough in TrTr, but this is probably again on of those endless discussions.) I got the problem that the driving ring sometimes pops out of the 16t gear (or the 16t got damaged). Then the power between in- and output is different. Not sure if you have this problem with the pneumatic cylinders.

Edited July 19, 2012 by Ramacco

[Jurgen Krooshoop]

Wow, very nice creation. Everything looks well thought-out.

[GuiliuG]

Thanks Jurgen !

Ramacco, as you mentionned, small pneumatic cylinders prevent driving ring from falling out of the 16t gear. If you mount chang over catch on a friction pin, then I guess that you won't have any problem with this !

Ps : for your project, you had better to choose Volvo brand because Hydrema uses boggy suspension not 3 pivoting points one.

Edited July 20, 2012 by GuiliuG

[Burf2000]

Thats looks good to me.

[allanp]

Fantastic, there's alot of functionality there

Edited July 20, 2012 by allanp

[bb15080]

good work

a lot of functions in it

Edited July 20, 2012 by bb15080

[timslegos]

Beautiful model as usual. I love the remotely locking diffs.

tim

[TimH]

Very nice dump truck.

[Phantom59]

Hello everybody ! Once I saw Han's articulated hauler, I find that it's really nice BUT not built for good performances on climbing. Why? Because Han did not make the right choices. Indeed, his 3 points suspension system is nice but involve lot of weak parts. Moreover, there is no portal hub, which means that all the drive train is under high stress. Han says that he reaches lego limits but I only thing that he reaches limits not cause to lego parts but cause to his choices. I decided to build a hydrema dump truck because this firm is not well known but make excellent construction equipment. First of all, I wanted to build a 6x6 but finally I switched for a 4x4 for three reasons :

*snip*

Looking at the basic truck chassis, you could make a Grapple skidder http://www.google.com.au/search?q=grapple+skidder&hl=en&rlz=1C2CHMO_en-gbAU489AU489&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=KyYNUOvlOe2XiAfipMjoBw&ved=0CFkQsAQ&biw=1280&bih=911

Edited July 23, 2012 by CorneliusMurdock
Shortened quote and removed pics

[Technic Gearhead]

Very nice model and interesting design! I like the original inspirational model a lot too - very unique. I think it would look even better if there was a way to eliminate the studded plates on the dumper but we are somewhat limited by parts. You could investigate a combination of 1x thickness Technic bricks, slopes and inverted slopes possibly although you have probably moved on to the next project by now. :)

All in all very nicely done! I like your work a lot.

[CorneliusMurdock]

Looking at the basic truck chassis, you could make a Grapple skidder http://www.google.com.au/search?q=grapple+skidder&hl=en&rlz=1C2CHMO_en-gbAU489AU489&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=KyYNUOvlOe2XiAfipMjoBw&ved=0CFkQsAQ&biw=1280&bih=911

Please refrain from quoting long posts with pictures in the future. There's no need for it.

[Edwin Korstanje]

Very nice Dumper truck you Build

[jacobkristensen]

What a nice dumper:thumbup:

[legomureren]

looks damn nice, would love one in my Collection. i drive one at Work pretty often. so I would love the instructions ?

[Richard Dower]

beautiful model....but with the new slanted yellow panels coming out....could they be used in the tipper section?

why not use flat tiles to cover the studs?