Crane Construction Part 2

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Undercarriage               about 2584 parts1 XL motor         Driving1 XL motor         Outriggers1 M motor         Steering5 M motors        Stamps Crane construction      about 854 parts1 L motor           Sliding mast1 XL motor         Slide outcounter weight1 XL motor         Mast up-down Crane mast                    about 1609 parts1 L motor           Turning mast  1 rechargeable battery4 IR receiverExtension wires short and long1 Actuator Firgelli  L12-EV3-100 Undercarriage long 1000 mm Crane height 1800 mm9 axes which 5 steerableCounterweightslide out (2x 500 gram lead grain) 70x40x35 mm
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MOC-7911

Name Crane Construction Part 2
Designer peteria
Designed 2017
Inventory 856 parts
Theme Technic

2 COMMENTS

  • 1 year, 5 months ago nigel1975 Level 24 PRO
    I'm reviewing the three parts of this MOC separately, these comments are for part-2.

    As mentioned for part-1 and -3 the LDD is fairly straight forward to follow. I made most of my own MOD's on part-2, mostly for exterior aesthetics and the routing of PF functions, to what I considered a more completed looking model.

    It was hard to tell from all the photographs originally how the PF functions were routed given very little room to work with. My own solution was to put the 2nd battery next to the one already on the undercarriage, then run a long extension up through the turntable. There are actually five functions on the upper section and boom, combined with four on the undercarriage, so 4 IR channels are not enough. I used a 2nd sbrick to control counterweight, rotation, boom extension and winch, but did not have a 3rd for the 9th function (which could increase to 10 or 11 functions depending on what I do with the optional Y section on the boom). Anyway, for boom raise/lower I decided to use a PF switch, especially as raising /lowering the boom is tricky.

    Talking of raising/lowering... the boom is heavy even without the Y section! The heavy actuator combined with brand new batteries is still not quite enough to start raising the boom. I think this is because the single L motor just does not have the power. However the boom only needs help for maybe 5-10deg of lift before the actuator can raise the boom itself (more help is needed as batteries loose power). Lowering the boom the actuator maintains control without overly stressing the individual parts - the Technic gearbox really helps here. In general its a very good actuator, but may need reworking to include an XL motor, or  better still to substitute for dual actuators using an L motor in each. The MOC owner needs to include the heavy actuator as an option and upload the parts list (I needed to order the gearbox from eBay)

    The winch and pulley system work well but have the limits. I managed to lift 1kg at short-moderate boom extension, 80deg lift and counterweight fully extended... at which point the winch pulled itself apart and I then spent 20mins untangling the strings. At smaller weights <500g the boom and winch work very well, the motorized counterweight really helps keep things balanced - a nice solution :-)

    Overall I'm very positive about this MOC, especially as there a few remaining challenges for you to make your own MODs.

    Please see my photos with additional comments.
    • 1 year, 5 months ago nigel1975 Level 24 PRO
      Update:

      I modified the structure to accommodate three winches with mechanical switching off one L motor. The two extra winches control the luffing jib. Please see new photos.

      For the counter weight I still use six D cell batteries that are contained beneath the spools. One oversight is that when the switch decouples the winch from the motor there is no locking system for the spool. One, two or all three spools can be activated at the same time. The three spools use one channel off the sbrick. Whilst not perfect the system works quite well.
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Building Instructions For Sale

This is a Premium MOC, and the instructions to build it are being sold by the designer (peteria)

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