Introduction: K'NEX Mobile Crane Truck V.4

Picture of K'NEX Mobile Crane Truck V.4

Changes made since version 3 :

+ lattice boom structure like on crawler cranes
+ string (yes, string)
+ Ackermann-like steering (almost; still needs a little human intervention to achieve)
+ stronger superstructure

So I found time and a new camera.  Here is the instructable.  There's also some photos of a 300g balance.  Yay!  I didn't bother doing a maximum testt - I wanted to see if it could carry anything at all.  Maybe you can test its maximum capacity? ;)

Inspirations to this model:

Supercar - steering and chassis
Picture of a crawler crane
Picture of a crawler crane
Crawler crane - booms
Lego Technic 8460/8431/8438 and 8421 - outriggers

Total number of pieces: 2046

Just like version 3, I made this "backward"; that is, I photographed it while I was taking it apart.  Also, pay attention to the comments in the photos.  Since there is no caption-option available (or I haven't found it), I have tagged almost every image.  If there is anything that still looks confusing, feel free to leave a comment.  As you can see, it's very lengthy, so make sure you have a lot of time.

It's kind of hybridized between a mobile truck crane and a crawler crane, since it uses the body of the truck but the crane of a crawler.  Perhaps in the next version I'll try to make it more truck-like with whatever K'NEX hydraulic technique I can come up with.


Step 1: Pieces Needed

Picture of Pieces Needed

Photos 1 and 2: You will need at least all of those pieces.
Photo 3: Piece count.
Photo 4: Rods
- 394 Green rods
- 236 White rods
- 254 Blue rods
- 60 Yellow rods
- 6 Red rods
- 1 Grey rod & 3 Black rods
Photo 5: Connectors, small gears, spacers:
- 23 Tan
- 4 ???
- 231 Grey (1 port)
- 20 Light Grey (2 ports, 45 deg)
- 55 Orange (2 ports, 180 deg)
- 62 Red (3 ports, 45, 90 deg)
- 30 Green (4 ports, 45, 90, 135 deg)
- 118 Purple Adapter (4 ports, 45, 90, 135)
- 171 Yellow (5 ports, 45, 90, 135, 180)
- 101 Blue Adapter (7 ports)
- 64 White (8 ports)
- 11 small gears (one must have notch)
- 151 Blue spacers (51 can be substituted by 17 Grey spacers)
Photo 6: Bigger gears:
- 1 Big yellow bevel gear
- 8 small pulleys
- 1 Medium bevel gear
Photo 7: Wheels
- 12 Large pulleys + Large tires
- 1 small tire
- at least 442 cm (14'6") of string

Step 2: Begin With the Chassis! the Bottom.

Picture of Begin With the Chassis! the Bottom.

Step 3: Chassis: Axles

Picture of Chassis: Axles

Step 4: Chassis: Steering Column

Picture of Chassis: Steering Column

This is the hard part.

Step 5: Chassis: After the Steering Column...

Picture of Chassis: After the Steering Column...

...we stabilize it (as best as possible)

Step 6: Outriggers: Part 1

Picture of Outriggers: Part 1

We're going to make 4 of these, or two sets of these; I'll show you the first part here.  These are for the front outriggers.  The way they work come from Lego Technic 8460/8431/8438.

Step 7: Steering (and Other Miscellaneous Stuff)

Picture of Steering (and Other Miscellaneous Stuff)

Here we put on the steering stick.  You can substitute the yellow rod for a longer one and attach a wheel if you like; I just never bothered with it since I was more concerned about creating a working crane.  Also, the steering stick doesn't do quite an adequate job at turning the wheels (another thing to keep in mind for my next design...), even with the connectors holding it in place.

Step 8: The (base of The) Superstructure

Picture of The (base of The) Superstructure

Follow those pictures and captions!

Step 9: The (base of The) Superstructure: Part 2

Picture of The (base of The) Superstructure: Part 2

Step 10: The Front.

Picture of The Front. in the part covering the front wheels.

Step 11: The Cab

Picture of The Cab where the driver sits.

Step 12: Outriggers: Part 2.

Picture of Outriggers: Part 2.

We made these before.  The outriggers themselves are exactly the same as the front ones, but their connection points to the truck are slightly different.

Step 13: The Superstructure:

Picture of The Superstructure:

And now we get to the crane part of the program.

Step 14: Strings!

Picture of Strings!

In this step, we will construct the string drums, as well as the crane cabin floor.

Step 15: The Crane Gets a Cabin! (sort Of)

Picture of The Crane Gets a Cabin! (sort Of)

Step 16: The Hook.

Picture of The Hook.

Here is the double-hook for the crane.

Step 17: The Counterweight.

Picture of The Counterweight.

Step 18: The Boom.

Picture of The Boom.

Step 19: The Final Stretch!

Picture of The Final Stretch!

Don't forget to read the notes!

Step 20: Complete!

Picture of Complete!


GeekBeam (author)2012-05-30

your method of attaching the rods so that they are fixed to each other is quite similar to how i did so with my K'nex orrery, very interesting...

xobile001 (author)GeekBeam2014-12-30

Sorry for the super late reply, but life got in the way and I haven't any new ideas pop up. I checked out your orrery (where I live, they call it a mobile; yours is probably a mechanical mobile) and I wish I had more of those orange peg pieces! It is similar; however, I don't have the central blue connector support. If you look at a tower crane, they use similar triangles. I suspect it is so that it doesn't bend easily; using purple interlocking connectors will make the connectors unlock under its own weight.

martijnb95 (author)2011-11-08

really nice, K'NEX should make this an official set
eeehm, well they better don't, because it will have lots of stupid bricks and mini-knex.....

zap8005 (author)martijnb952011-11-13

completely right,you cant even get a set from a non-online store any more, all they've done is made it more fiddly than it should be!!!!!!!!!!!!!!!!!!!!!!

xobile001 (author)zap80052014-12-30

They should bring back "Classic" sets where bricks were nonexistent, and make new sets from "classic" pieces.

Seattle Seahawks made it! (author)2014-11-16

I made it!

Nice! Looks awesome!

brainiac120 (author)2012-08-13

Not sure I have enough pieces, but this is too cool for not to at least try and make it!
Wish me luck!

itzandy (author)2012-04-23

alot of people call what youv called ??? yclips

xobile001 (author)itzandy2012-06-28

Ah. Thanks. Wasn't sure what the official name for it was. I can see why people call them y-clips. says "Standard Black Rod/Connector". Might just go with black rod "Y" connector (or 人)

legodude42901 (author)2012-06-25

i like it but it took me 5 hours really fun ........................................................................................................................................... no steering but i put my own if you want to learn how to make steering better go to building tips on watch and copy the video if not i will post on it will be posted today if not next weekend on june 30th please subscribe:)

The Chunky Sniper! (author)2011-09-25

Nice job - 4.5*

mulletman6 (author)2011-09-19

Made it - took a few hours, but tis done. Tis rather awesome, but the steering isn't as good as in the version 3.

mulletman6 (author)mulletman62011-09-19

Been thinking - how easy do you reckon it will be to change the steering in this, for that in the Version 3? Only problem i can see (at a glance) will be the front outrigger :/ - will have to look into it tomorrow

xobile001 (author)mulletman62011-09-19

Thanks for building it!

Yes, the steering sucks in this one; putting the front outrigger there probably wasn't the best idea. The reason for the steering sucking is that I was going for something a real truck might have.

mulletman6 (author)xobile0012011-09-20

Ah right. I'm going to build the chassis and steering from version 3 and then try to change it so it takes the outriggers and the rest of the body from this one :)

dr. richtofen (author)2011-09-18

great! 4.5 stars

~KGB~ (author)2011-09-18

Thats pretty impressive! =D

About This Instructable




Bio: I don't always make instructables, but when I do, I prefer to use pictures. Stay instructed, my friends.
More by xobile001:K'NEX Mobile Crane Truck v.4K'NEX Mobile Crane v. 4K'NEX Large Tower Crane
Add instructable to: