8043 Motorized Excavator is by some considered the best Technic set of this century. As the set has been out of print for over 10 years, it is now hard to find and pretty expensive. So, I've created my own version. After substantial modifications, it is built almost entirely from parts available from 42082 Rough Terrain Crane.

The result:

 

More pictures available on Flickr.

Origin of the project

A couple of months ago, I came across a comment somwhere refering to set 8043 as the best Technic set of this century. This piqued my interest. It was also one of only three Technic sets to almost make it into the "What's the best set released this millenium?" contest on Brickset. I didn't know the set, as it came out during my (very, very long) dark age. Looking the set up on Rebrickable.com showed I owned some 83% of the required parts. Color swapping the yellow to red improved that a little bit yo 85%. So, not enough to fully build it, but enough for me to give it a go. I figured I would just work around the parts I didn't have with other parts from my collection.

It took me several weeks to complete my version of the excavator. Some parts were easily replace with others, but more often I needed to create substantial modifications. Typically, creating a solution in one step created new issues in later steps. During the proces I realised I was mainly using parts from 42082. I added an additional challenge to myself: create this excavator as much as possible as an alternate build of 42082.

Of course, 42082 does not have all the necessary parts. Some are obvious and can't be built around like: additional motors, RC units, track links and sprocket wheels. Many are less obvious, but can be worked around, for example: lack of a 12L axle, to few 20 tooth bevel gears, to few 20 tooth bevel gears with pin hole, to few of of part 87408, only two large linear actuators, etc. In addition to 42082 lacking certain key parts, other parts have been superseded in the 12 years since the release of 8043. For example 50163 Technic Turntable Large Type 2 has been superseded by 18938 Technic Turntable Large Type 3 (which is of a slightly different size), 6539 Technic Driving Ring 2L has been superseded by 18947 Technic Driving Ring 3L, etc.

All of the above has required substantial modification to the original model.

Result

The result of my work can be seen in the above pictures: a red version of 8043, built almost entirely from parts available from 42082.

All functions from 8043 are re-created in this model (video):

• RC diving/turning
• RC turning the superstructure
• RC changing functions
• RC operating of the digger (arm up/down, bending the arm, tilting the bucket),

but upgraded to use PF L Motors and a clutch gear added to the function changer to protect the motor and gears.

The main aspect that I have not been able to fully achieve, is the paneling on the excavator arm. Set 42082 simply doesn't have the necessary panels to re-create this aspect of 8043. Apart from the color, this is therefore the main aesthetic difference, together with having to create a brick build digger bucket.

If you have 42082, you will only need the following additional parts to create this model:

• 88323 Technic Link Tread Wide - 76x
• 57519 Technic Tread Sprocket Wheel Large - 4x
• 99499 PF L Motor - 3x
• 58123b IR Receiver Unit - 2x
• 3673 Pin without Friction Ridges - 18x
• 42610 wheel 11mm - 6x
• 32000 Technic brick 1x2 w 2 holes - 4x
• 32187 driving ring extension - 3x
• 32905 worm gear - 1x
• 32056 beam 3x3 L shape thin - 4x (on the model I've used black, but red, LBG and DBG will also look good).

Instructions

For anyone who wants to build this version of the Motorized Excavator, I have created step-by-step PDF instructions that will allow you to build this Motorized Excavator. The instructions are available for free at Rebrickable.com:https://reb.li/m/103609

The 1242 parts are put together in 218 steps. So, you get slightly more parts per step than you do in typical LEGO instructions.

Edited March 4, 20223 yr by BrickRandom
typo's

While it looks good, have you built it from real bricks? I have a feeling those small linear actuators will struggle a slip a lot.

  On 3/4/2022 at 2:41 PM, Zerobricks said:

While it looks good, have you built it from real bricks? I have a feeling those small linear actuators will struggle a slip a lot.

Yes, I built it for real first and then created the digital version. Here's a video of the functions in action:

It does work and the small linear actuators don't seem to have a problem at all. Movement (driving and rotating the superstructure) isn't always super smooth, I think it's due to the weight and I'm wondering how well the original performed (as the original has M motors and I'm using L motors).

The original was always a bit jerky to be honest! At the time I thought of it more as a wonderful proof of concept than a smoothly functional set. Movement back/forth was jerky; changeover between the motors' two function sets often jammed, and the arm twisted around if you ran the actuators to their limits. Rebuilding it with tweaks and more recent parts has been on my optimistic to-do list for years, once I have a bit more time and a space to keep half-built models!

  On 3/4/2022 at 3:32 PM, J159753 said:

changeover between the motors' two function sets often jammed

Then that function has definately been improved in my version. The changeover now runs smoothly due to the use of smooth driving ring connector, rather than the ridged connector used by 8043. Adding a clutch gear and additional down-gearing has also eliminated the grinding of teeth on the changeover.