MOC Crawler crane

[gvo25]

Dear all,

Another year, another crane. This time it's a crane in the size range of the 42042. The crane hase the same track size and width, and shares more or less the same frame, but this time in black, also I decided for now not to motorize the tracks. The body has also more or less the same size and structure as the 42042, but I tried to make the body less wide. The crane has 4 motors, 2 L-motors for the 2 winches on top, one XL-motor for slewing and 1 angular motor for the 3rd winch. They're all housed in the body and connected to the battery box aft of the main body. The 2 ballast boxes each hold 150grams of ballast.

The building showed me it's indeed difficult to make a rugged build, due to the flexing of lego parts because of sideways movement of the crane boom. this was almost complete fixed with the installation of the 2 springs and some additionals beams for support at the front of the body. For now the crane can lift 350 grams in its highest and most comfortable position.

The cabin has an openable door and can be tilted upwards(not seen here)

I used the good old lego metal hook with 50 g of ballast stuck to it, I didn't use a turntable this time because it would make the hook too bulky and too big

Here's a view of the panels removed, you can see the placement of the motors and the winches, the winch of the hook is directly connected to the angular motor, without any gears

The last photo is for scale, in it's highest position the crane reaches 1,35 m, additional sections can offcourse be added

[Jurss]

Nice, and even without some specific frames for boom ;)

[Davidz90]

Very cool! Looks way better than the upcoming set.

 

I plan to build something similar, will definitely borrow some engineering solutions from this. What is the weakspot defining the load limit?

[Mr Jos]

17 hours ago, Davidz90 said:

Very cool! Looks way better than the upcoming set.

 

I plan to build something similar, will definitely borrow some engineering solutions from this. What is the weakspot defining the load limit?

I suppose using only 8T straps, using 4 of those on each corner when lifting, will only grant you a capacity of 24T to lift, if you keep the angle under 30° for each. Would recommend to get 10T or 15T round slings or chains.

@gvo25 nice build!

[nerdsforprez]

Wonderful job!  This build highlights some of my questions about the upcoming Liebherr model (42146).  Lego cranes, specifically in Technic, have been around for quite some time.  One can build quite sophisticated and accurate mobile, tower, and crawler cranes with extant pieces. 

What does 42146 provide that can't already be built?  Sure, there are new pieces.... but I don't really think they add anything novel or new.  Just Duplo-ed.  

Anyways, great job.  Any chance of a video showing its functions? 

Also, is that a regular jumper plate with 1x1 tile on the end of the hook block?  Or some reason they look different.  

[gvo25]

8 hours ago, nerdsforprez said:

Wonderful job!  This build highlights some of my questions about the upcoming Liebherr model (42146).  Lego cranes, specifically in Technic, have been around for quite some time.  One can build quite sophisticated and accurate mobile, tower, and crawler cranes with extant pieces. 

What does 42146 provide that can't already be built?  Sure, there are new pieces.... but I don't really think they add anything novel or new.  Just Duplo-ed.  

Anyways, great job.  Any chance of a video showing its functions? 

Also, is that a regular jumper plate with 1x1 tile on the end of the hook block?  Or some reason they look different.  

no, it's a non lego piece. It's a tungsten weight (2X25g) glued to the hook block with double sided tape (easily removed). It's to weigh the hook down to compensate for the 4 part string. With normal lego I cannot achieve such a weight. together with the small bearing balls in the ballast section, they are the only non lego items

On 7/21/2023 at 3:08 PM, Davidz90 said:

Very cool! Looks way better than the upcoming set.

 

I plan to build something similar, will definitely borrow some engineering solutions from this. What is the weakspot defining the load limit?

I find in this scale the turntable and the gearing for moving the turntable the weakest points, the main body still has to slew under load, and with a too high load the turntable is simply not strong enough and just gives too much play. In this build the upper body is supported by the liftarms just under it, and under load they give a lot of friction on the track body.