Review: 8288 - Crawler Crane

[Mithrandir]

I'm a big fan of skid-steering machines, and I even bought 3 copies of 8419 - Excavator just for the treads. I like to build custom-tank-like vehicles. So naturally, when I found out last year that Lego had re-introduced the classic chain-tread piece , I was pretty excited, since I never had any of those.

I intended to buy the wookie attack set just to get my hands on some, but unfortunately, other sets had higher priority to me, so I never got around to it. I just assumed the set would be around for 3 years like Lego had always done in the past. Unfortunately, Christmas came around and I finally decided to buy it... and I couldn't find it anywhere. The only place I could find it was open-or-expensive boxes on Bricklink. D'oh.

Lego came out with a huge Sandcrawler set with these tread links too, but I could never really wrap my mind around buying one huge set just for a particular part. I tried to justify it, but in the end, I really had no use for the metric big behind-ton of brown and sand bricks that came with that set. I almost decided to get it... but then the 2006 technic lego set pics were leaked, and behold, the answer to my dreams:

The 8288 - Crawler Crane. Technic! Tread Links! Lots of beams! Jackpot!!!

I decided to put on my waiting hat and waited patiently for 7 months for this set to become available, and a short time ago, it did. I rushed online and bought it, and waited eagerly for it to arrive, and yesterday it did just that.

I quickly built it in 90 minutes; I was anticipating a difficult build but it was a lot easier than expected. My overall impression is that it's "pretty good". Nothing absolutely groundbreaking, but well worth the cost and definitely reccomended.

The tread links were a bit of a let down, but I was kind of expecting this. They're all plastic, so they are absolutely useless on smooth surfaces, or if the structure they are supporting is light. They have a very small frictional coefficient, but work okay on more irregular surfaces. Unfortunately the links tend to decouple rather easily as well, but that's not a huge concern, because it's usually when I'm messing around with the links in the first place.

The most clever part of the design is the clicking-levers used to control the crane. I saw them way the heck back in January and quickly put together a bunch of designs emulating them for my own MOC's, so the novelty isn't as fresh in my mind right now, but they are still cool and work really well. Basically, if you haven't seen pics already, they use the rubber grommet-type double-axle joiner that came with last years Vladeks castle, attach an axle in one hole, brace the other hole with an axle-pin, attach a bionicle tooth to the axle, and lay it against a 24t-crown gear. The pieces mesh together well enough so that the tooth has enough force to remain centered on its own, but if human force is applied to the gear, it moves the tooth enough (either up or down!) so that it can turn. This holds the cranes strings in place without the need of resorting to a screw gear. It's pretty clever.

As far as the actual model goes, I like it. I have a few complaints, but these are pretty much minor and don't really detract from the set overall:

- The base is kind of simple and also wobbly due to the turntable gear being the only support for the whole superstructure

- I wish the treads were longer

- The counterweight is somewhat underwhelming, it's not nearly heavy enough in my opinion. They use 2 boat weights and I feel that 4 would have been a much better design.

- Since the counterweight is light, you cannot move the center beam past the 90-degree mark without having the model tip over, meaning that the 3rd beam is pretty useless.

- Instead of a typical technic crane hook, they opted to use a custom-made part made out of axles, pins, and lift-arms. I'm not sure why.

- The "alternate model" is simply removing the center beam and re-attaching it to the top of the first beam to create a super-tall crane. It's a cool model, but I have to take points off in the originality department.

But now the good:

- Clicking-wheel controls are very clever

- The build was a lot easier than I expected. Usually these things are super-tough because of the nature of strings, they don't illustrate well in instructions, but I didn't have a single problem.

- The whole design of the crane is well done; I found myself playing with the levers and pulleys for over an hour after I finished building it.

- 800 pieces for $50. Great value

- TONS of long beams, mostly red, white, and grey.

So overall, I'd have to give this a 9.1 out of 10.

[Hobbes]

Basically, if you haven't seen pics already, they use the rubber grommet-type double-axle joiner that came with last years Vladeks castle, attach an axle in one hole, brace the other hole with an axle-pin, attach a bionicle tooth to the axle, and lay it against a 24t-crown gear.

Uh... what? I didn't understand a single word...

:-P

I was waiting for that set, too, and reading a positive review from one of the really skilled people here is just the reason I needed to buy it ;-)

[dunamis]

I was waiting for that set, too, and reading a positive review from one of the really skilled people here is just the reason I needed to buy it ;-)

Same here. I've been eyeing this one at TRU lately and this is just the excuse I need to pick it up.

[Mithrandir]

Basically, if you haven't seen pics already, they use the rubber grommet-type double-axle joiner that came with last years Vladeks castle, attach an axle in one hole, brace the other hole with an axle-pin, attach a bionicle tooth to the axle, and lay it against a 24t-crown gear.

Uh... what? I didn't understand a single word...

Heh, okay, let me try again. I don't have a CAD program or anything, so I'll do my best with just words.

The key is this piece:

You have one of these, and an axle that goes through one of the holes, so that one stud-length of the axle is sticking out of one end, and the rest of the axle is sticking out of the other. Then you attach a blue axle-pin into the other hole, so you get a lower-case "h" shape.

Now you take lthe legs of the h and put it into a beam. You'll notice that the rubber grommet allows the axle to twist ever so slightly, and it always returns to the original position when it's done twisting.

So now you take a bionicle tooth (red):

And hang it like a flag on the h:

G_____

|.--``

|

|

|

|

===

|G|

Now you get another axle which has a string-drum on it (blue) and a 24 tooth crown gear (green)

G_____

|.--``

|G|___|

|GG-+-

|GGG|

|GG-+-

===G|

+-+-+

Two teeth of the gear overlap onto the edge of the bionicle-tooth, so now when you turn the drum-axle, the 24-t gear clicks against the bionicle tooth. The tooth moves up and down to allow the gear to turn because of the flexibility given by the grommet. If the axle with the bionicle-tooth on it were locked in place, then the 24-t gear would not be able to turn at all.

[Hobbes]

Whoa 8-

[dunamis]

That's pretty slick - neat idea.

To me, that is the draw of the Technic sets. Finding new and innovative ways to make real life devices.

[optimus-convoy]

Great review. *y*

That gear mechanism is pretty ingenious, kudos to Lego for the design. ;-)

[Mithrandir]

Okay I got antsy and rebuilt the crane with the alternate model. I kept looking at the pics and I felt like the alternate would be a much better model.

I was right. Sort of.

First off, the alternate is huge (about 3ft high). The crane actually wobbles now, which really can't be helped due to the nature that Lego really wasn't designed to make that large of a structure at scale. So I'm not going to subtract that.

They use a triple-pulley (as opposed to the double-pulleys they used for everything in the main model) for the joint inbetween the long beam and the short beam, which is cool. I think they did that because a double-pulley would have caused too much torque on the click-mechanism, but regardless, I like it even more than a double-pulley.

Now, I thought the counterweight was weak before, and now that this extends even further out, I feel that the counterweight is even less useful, which is the huge problem. You can somewhat allieviate this situation by turning the crane so that it's perpendicular to the treads. Since the treads are wider (21studs) than they are long (15studs), you get an extra 3-stud's of leeway with the center of gravity (COG). For those of you who need to brush up on your physics, if the COG extends past the base, then the structure will topple over. If you increase the base, then, you get a more stable structure (ala outriggers).

However, that didn't quite solve the problem altogether. So I got my bix-box-o-lego out and dug out my two boat weights that I already owned prior to this (I now have 4, woo), and extended the counterweight structure backwards by two studs. This was actually pretty easy to do (add 4 2x6 plates, a bushing, a 1/2 bushing, remove the pole reverser handle and replace it with a perpendicular axle joiner + 4stud axle). Not only did this double the weight of the counterweight, but it also made it slightly more effective, since it was now extended two studs further back. Again with the physics, the farther away something is from the COG, the more torque it applies on the structure. In the counterweights case, the newer rear weights "weigh more" than the older ones which are closer to the COG. It even looks better this way too, in my opinion.

So now this is noticably more effective than the old counterweights. I can extend the crane almost completely down (I can get about 60 clicks away from the fully extended position before it topples over) now. So this set really does need 4 boatweights, and not just 2. 6 would be perfect for the alternate, and I'm pretty sure 4 is perfect for the main model.

The looseness of the treads began to annoy me, so I tried removing one link from each tread. This was a little difficult to attach, and in retrospect was a bad idea, because I ended up warping the connects of one of my links. So don't do this.

Also, when building the main model, it says to cut the longest string so that it's 80cm (I think?), which is a good length for the main model, but if you plan on building the alternate model, I would suggest you cut it longer, since the alternate doesn't allow enough length for the main string to lower the hook below the bottom of the treads (which you might want to do if you have the crane working in a quarry-type environment where you lift things which are down a cliff from you). There's a ton of string, so don't worry about not having enough.

I think that's about it? I want to build it even bigger now, but unfortunately I don't have a lot of white technic beams (actually just 4 more 15stud beams), so I may buy another if I find it on sale somewhere (more treadlinks and boat weights, can't really go wrong).

[Ickelpete]

Great review

I did like the rachet mechanism it is also used on the new technic tow truck to hold the hook

Like you I had a problem with overbalancing. I had the alternate model built and a gust of wind toppled it off the cupboard where it was standing I will have to find my counter weights from the bottom of my spares box. It is a pity TLC didnt add 4 weights in to start with.

all in all I thought this was a good value for money kit

[chewie]

I picked this beast up a back in June for my birthday and loved it. I too leaned toward this set because of the technich tread link. However you get an awesome amount of treads for $80 if you buy two wookie attacks as I did.

But now for the set. I really do like this set and its a lot of fun to play with, moving the arms and hook up and down. I even motorized the most rear winch with a 9 volt motor. If you had 3 red mini motors you could easily motorize the whole crane.

The counterweight problem is definatly not good and I agree with everyone else that it topples over way to esaily.

Aside from the few niggles, the set is awesome!!

Chewie