Hi guys,

I uploaded a video of my model to brickshelf:

http://www.brickshelf.com/gallery/Dave21/Technic/Dumptruck-8x4/dumptruck.mp4

The final pictures:

Thanks for reading/ watching.

Dave

Edited February 14, 201510 yr by Dave21

What a nice looking truck you have made there!! It looks really realistic :) Are you gonna release the LDD file?

What a nice looking truck you have made there!! It looks really realistic :) Are you gonna release the LDD file?

Thanks SimonSalomon.

I have uploaded the LDD file on my Brickshelf.

The two LA´s aren´t placed correctly, also the Servo-Motor and the L-Motor are brick build alternatives.

Dave

Looks good but you need to add dual wheels to the rear axles otherwise it looks unrealistic but other than that it looks great

Looks good but you need to add dual wheels to the rear axles otherwise it looks unrealistic but other than that it looks great

Thanks Kiwi Builder.

I know without the dual wheels it looks unrealistic, but I was not able to fit dual wheels in the narrow space in the back .

I will take inspiration from 42043 and maybe then I will "upgrade" my dump truck .

Dave

In your video the dump bed starts in the video part of the way up already, is this because is has problems with the tipping at the very start of the movement? When I build dump trucks I have the same issue

Yes, unfortunately the L-Motor struggled when the dump bed is lowered completely.

So I started the video a little bit later, when the move of the dumb bed is smooth

Dave

Yes, unfortunately the L-Motor struggled when the dump bed is lowered completely.

So I started the video a little bit later, when the move of the dumb bed is smooth

Dave

It's all a matter of leverage. It can be tricky to get an effective mechanism when the available space is limited, as in your model here. If you add suspension, there is even less room. In effect, what you want is to mount the LA/pneumatic cylinder as low in the chassis as possible, to get good vertical force. When it is too high, it more or less pushes in a horizontal line towards the pivot of the dumping bed, which is far from ideal. A trick I have used on a couple of occations is to mount the pivot for the tip low and on the very rear of the chassis, typically using 3x5 L-shaped in liftarms in the rear of the bed to get it three studs lower than the dump bed floor.

Looks good, bravo!

Looks really professional! I really like how you've managed to make the edges smooth and rounded. It could almost be a real lego set. Good job!!!

It's all a matter of leverage. It can be tricky to get an effective mechanism when the available space is limited, as in your model here. If you add suspension, there is even less room. In effect, what you want is to mount the LA/pneumatic cylinder as low in the chassis as possible, to get good vertical force. When it is too high, it more or less pushes in a horizontal line towards the pivot of the dumping bed, which is far from ideal. A trick I have used on a couple of occations is to mount the pivot for the tip low and on the very rear of the chassis, typically using 3x5 L-shaped in liftarms in the rear of the bed to get it three studs lower than the dump bed floor.

Thanks D3K for this great explanation.

I will try your suggestions in a new version of this dump truck, where I want to improve or add many things like suspension or the dump bed.

There must be enough space for this and dual wheels in the back.

Looks good, bravo!

Thanks Scapuc!

Looks really professional! I really like how you've managed to make the edges smooth and rounded. It could almost be a real lego set. Good job!!!

Thanks Olof! I took inspiration from set 8258, so I tried to make the cab in some way similar to this truck.

Dave

It's all a matter of leverage. It can be tricky to get an effective mechanism when the available space is limited, as in your model here. If you add suspension, there is even less room. In effect, what you want is to mount the LA/pneumatic cylinder as low in the chassis as possible, to get good vertical force. When it is too high, it more or less pushes in a horizontal line towards the pivot of the dumping bed, which is far from ideal. A trick I have used on a couple of occations is to mount the pivot for the tip low and on the very rear of the chassis, typically using 3x5 L-shaped in liftarms in the rear of the bed to get it three studs lower than the dump bed floor.

Thanks for that D3K, I have been having the same problem as Dave, thus I spotted what was going on. I'll have a fiddle around with my dump bed keeping that in mind when I get to that stage in my build

Thanks D3K for this great explanation.

I will try your suggestions in a new version of this dump truck, where I want to improve or add many things like suspension or the dump bed.

There must be enough space for this and dual wheels in the back.

Thanks for that D3K, I have been having the same problem as Dave, thus I spotted what was going on. I'll have a fiddle around with my dump bed keeping that in mind when I get to that stage in my build

Like I said, it's kind of tricky, but absolutely doable.

Here is how I did it on my 6x4 Dump Truck (which had live axle suspension and dual wheels):

As you can see there are 4 (or 3, depending on how you look at it) studs between the attachment of the actuators to the chassis and the pivot for the dump bed (vertically). When the bed is lowered, the point where the LAs are attached to it is in line with the pivot. That doesn't matter, in effect you want the lower part of the LA as low in the chassis as possible, and the attachment of the LA to the bed as high as possible, to create an as sharp angle as possible. This is where one can "cheat" , and manipulate the angle between the lower end of the LA, its attachment point on the bed, and to the pivot of the bed, by moving the pivot further down, thereby decreasing the angle. If that makes any sense..

At a glance I would say the angle I'm talking about is roughly 170 degrees on my model, and maybe closer to 175 on yours.

Further, to get the above pictured setup to work, I had to make certain compromises in the structural rigidity of the chassis. As you can see the rear of the chassis is 4L in height. To have enough room for the dual LA setup, I could only have one liftarm going front to rear in parts of the lower part of the chassis.

Some parts removed, but the one LBG long liftarm between the LAs is the only structure going from the front toward the rear there

Like I said, it's kind of tricky, but absolutely doable.

Here is how I did it on my 6x4 Dump Truck (which had live axle suspension and dual wheels):

As you can see there are 4 (or 3, depending on how you look at it) studs between the attachment of the actuators to the chassis and the pivot for the dump bed (vertically). When the bed is lowered, the point where the LAs are attached to it is in line with the pivot. That doesn't matter, in effect you want the lower part of the LA as low in the chassis as possible, and the attachment of the LA to the bed as high as possible, to create an as sharp angle as possible. This is where one can "cheat" , and manipulate the angle between the lower end of the LA, its attachment point on the bed, and to the pivot of the bed, by moving the pivot further down, thereby decreasing the angle. If that makes any sense..

At a glance I would say the angle I'm talking about is roughly 170 degrees on my model, and maybe closer to 175 on yours.

Further, to get the above pictured setup to work, I had to make certain compromises in the structural rigidity of the chassis. As you can see the rear of the chassis is 4L in height. To have enough room for the dual LA setup, I could only have one liftarm going front to rear in parts of the lower part of the chassis.

Some parts removed, but the one LBG long liftarm between the LAs is the only structure going from the front toward the rear there

Another big Thanks to D3K.

I will make a second version, following your great suggestions. Then it must work perfectly.

Dave