Sunday, June 16, 2013

TBs TechReview 23 - 42004 Mini Backhoe Loader

Set reference: 42004
Set name: Mini Backhoe Loader
Theme: LEGO Technic
Release date: 2013.Jan

Number of parts: 246 (plus a few spares)

LEGO Designer: ?

Model under review: Main model
Weight: 422 g (15.94 oz)
Approximate set dimensions:
Length - 31 cm (12.2")
Width - 9 cm (3.5")
Height - 11 cm (4.3")
Approximate box dimensions:
Length - 26 cm (10.2")
Width - 19 cm (7.5")
Height - 6 cm (2.4")

Stickers: No
Building instructions: 2 booklets included
Main model (72 pages with 47 major building steps): 1/2
B-model (68 pages with 48 major building steps): 2/2
B-model: Telehandler

Recommended for ages: 8-14
Building difficulty level: Easy
Estimated building time: 1h - 2h

Price range: 20€
Price per part: 8.13 euro cents

Inventory (BrickLink): : Link
Inventory (Peeron): Link (when available)
Other user reviews (Brickset): Link

Following the apparent trend of launching "Mini" versions of previous sets (the most glaring being the 8110 Mercedes-Benz Unimog U 400/9390 Mini Tow Truck duo), after last year's 8069 Backhoe Loader, 2013 brings us its minimised version, the appropriately named 42004 Mini Backhoe Loader. It could be said that the "Mini" prefix doesn't refer just to the model's size, but also to the real machine's size. The similarly-sized wheels and the method of steering feel like a machine with a smaller calibre than its bigger, last year's brother.

As can be expected from a construction machine, the model is primarily yellow, with some black details here and there: besides the obvious tyres, there's also the centre section of the bonnet and the steering wheel. Thankfully in my opinion, there are no atickers around to complement the model.

Despite the reduction in size, the 42004 retains most of the functions present on its older brother: steering, raising and tipping the front bucket, slewing the rear digger arm, and articulating it in 2 points. Even though it's there, I don't consider the rear bucket's click hinge as a real function, as it's quite fiddly to use and, like you'll see later, not really needed for play. What is really absent is a pair of rear stabilisers, but at this price point it'd be asking too much...

The model has a shape that can instantly be recognised as of a backhoe: the large, wide loader bucket in the front, the bonnet with a chimney, the four all-terrain wheels, the digger arm in the rear. Its proportions seem right for a smaller model of backhoe; however, the front bucket seems too narrow for the tyres. Or are the tyres too wide? Anyway, speaking of the tyres, they are definitely too thin for a construction vehicle meant to go on not so forgiving ground. They almost feel like a "backhoe tuning" job! And, while the front bucket is too narrow, the rear one is too wide. Backhoes usually have a narrow rear bucket for excavation purposes; for an example, see the 8069. This can be justified by the fact that both buckets are dedicated parts instead of built from other parts: therefore, there's not a very large choice of available sizes to fit the scale of the vehicle.

The driver's compartment features a seat in the traditional Technic blue and a small, adjustable steering wheel. The steering wheel is decorative only and can't be used to steer the model.

The ground clearance, as expected for this type of machine, is high. There are no parts whatsoever below the level of the wheels' axles, except for a lone 5L beam that sticks out like a downwards-pointing thumb, which it figuratively is.

1. The package and contents

Unlike the 42002 Hovercraft reviewed earlier, I felt that the box came had the usual (low) density, being no smaller than the boxes for previous sets of the same size. However, this is a very subjective analysis and shouldn't be taken too much in account.

The front of the box shows, as usual, the main model, a smaller image showcasing its functions, the LEGO and Technic logos, the set reference and name, recommended age range, number of parts, the "2 models in 1" stamp, and, in case you forgot what a LEGO set is all about, the mention that this is a building toy. Boxes meant for other markets may vary slightly in the contents of their front.

The top shows the usual 1:1 image for scale: in the case of the 42004, it's a side shot of the front bucket.

The back of the box shows the B-model, a telehandler. The "2 in 1" stamp and the small image of the A-model convey the notion that the telehandler is built using the backhoe's parts. In the corner, the telehandler's functions are shown: steering, lifting the boom, and tilting the bucket.

As usual for sets of this size, the box is opened by tearing up one of its sides. Inside we find that the box is tightly packed with instruction booklets (unlike larger sets, instructions for both models are included), three unnumbered bags with the parts (the smaller bag is inside the larger bag), the tyres and the large bucket.

2. The new parts

Strictly speaking, there are no new parts in this set: everything has appeared on previous years. However, like other 2013 sets, it uses a new mould for an existing piece: the 8T gear is of the new variety, which is better in every way (except perhaps being a few percent heavier, but that's nit-picking) than the old one, especially in terms of robustness and not hiding away inside the holes in beams. Unfortunately this set has only two of them, but as other new sets come out this part will become more abundant.

3. The parts assortment

This being a small set with no new parts for 2013, not much is to be expected. Besides the aforementioned new 8T gears, parts of interest are the four wheels (being the same size can be an advantage for MOC's), a small turntable, and perhaps the small steering wheel and the two excavator buckets.

4. Building experience

Following the now usual "instructions on how to follow instructions" first page of the instruction booklet, I separated the parts and am now ready to start construction. That's also the opportunity to have a general idea about that types and quantities of parts in the set.

There are no particular highs or lows when building the model. Of note is the abundance of large chunks that are assembled before being integrated into the main model. Like on the previous review I wrote, the LEGO magic is at work here and the model assembles itself.

After the 47 main steps, we're done! With no stickers or printed pieces, all detail is ensured by shapes and colours.

These are the spare parts that were left. Unfortunately there's no third 8T gear for MOC's.

5. Functionality and playability

For a set this size, there is really lots of functionality! Six functions in total, although most are barely mechanised, if any at all.

First, we have the most complex function in the model: steering. The 12T gear at the top drives a vertical axle connected to another 12T, which meshes with a 20T and then into the small turntable. This results in an easy to operate steering, without being overly sensitive or lazy.

Next, we have the rear digging arm. Turning the vertical axle joiner makes a worm gear rotate, which then turns an 8T gear, and raises one part of a four-bar linkage that moves the arm's boom.

The front loader arm uses a similar worm-8T coupling to raise it. However, in this case there is no linkage, and the 8T gear drives the arm directly. Also, the axle joiner here is disguised as the backhoe's chimney. The gearing down on the mechanism (8:1) is too small for the weight of the arm, which makes it very hard to rise it. As you can see in the video, I had to hold the model with one hand while I raise the arm with the other. The worm gear should be mated to a larger gear, like a 24T instead of the 8T, to make the mechanism easier to actuate, but there would not be enough room under the bonnet for it.

Then there are the simpler functions, actuated by knobs (made using more 12T gears) directly on them. Again, the one on the rear is more complex and the one that more positively surprised me. Turning the 12T at the arm's "elbow" deforms an antiparallelogram (a kind of four-bar linkage where two of the bars are crossed). This raises and lowers the arm's jib, while simultaneously turning the bucket at the end of it for a "digging" motion. This is why manually rotating the bucket around its click hinge is actually unnecessary for play and therefore I don't consider it a function on this model.

Note that you can dig quite deep holes with this arm, as it has a considerable reach.

The front bucket can be tipped with a mechanism similar to the one found on the 8235 Front End Loader. When tipping the bucket, the linkage goes over centre, which means it can't be tipped by accident.

You can raise the front wheels off the ground by tipping the bucket when the arm is down; real-world backhoes do a less extreme version of this for stabilisation during digging operations.

A peculiarity of the tipping mechanism is that, when the arm is down, it can't maintain the bucket completely tilted up because it hits the bonnet. You can see that in the video and below. Fortunately that's not enough to force the linkage to go over centre, and so it remains stable.

Finally, the last function is a wholly manual one. Like on real backhoes, the rear digging arm can slew left or right, around two friction pieces. There is no mechanism whatsoever, apart from your hand, to accomplish this, and the range of movement is extremely small; yet, it is a very nice feature to have in a model of this scale, so there are no complaints here.

6. The B-model

The B-model is a telehandler. It features a very flat body, with rear wheel steering, driven via a Hand of God 12T gear at the top. The arm rises via a four-bar linkage actuated by a worm-8T pair like on the A-model, and the large bucket tips using a linkage also similar to the one on the A-model. Like it, there is no chance of accidentally tipping over. The asymmetrically-placed cabin features a steering wheel but no seat.

Unlike some sets I won't mention, this B-model looks quite nice. Its functions are in a much smaller number than on the A-model, but that's not because they're few; that's because they're so many on the A-model.

7. Final thoughts

This set offers a surprising amount of functions for its size. As, mechanically speaking, it would be a euphemism to call these functions "simple", an adult may find them uninteresting. But a 8-14-year-old kid, the target audience, won't mind that and will surely enjoy playing with the model, digging up piles of bricks and loading and unloading them. I'm just not sure if all 8-14-year-olds will have the skills to put together this bigger-than-smallest set. But that's what parental help is for.

The B-model, although comparatively weaker than the A-model (that's expected from a B-model, right?), appears to also be good and perhaps worth of buying a second copy of the set to have both models built and working together at a construction site.

Speaking of parental help... I must confess that I had the offstage help of one of my kids during the building, photographing and filming session. ;D

8. The Ratings

Depending on what you intend to do with the set (playing with it or using it for parts) and what is your age, you may find this set either fun or "meh". The parts selection is both very generic (mostly common beams, axles, gears and connectors) and very specialised (the two buckets) is literally a mixed bag; the wheels are also good or bad, depending on what you intend to do with them. The set, while being just another in a long dynasty of Technic backhoes and excavators, has good looks and extraordinary playability for its size (only marred by the difficult front arm mechanism).

as value for the money
for parts innovation
for set innovation
for set design
for functionality and playability

Overall rate: Good

This is first and foremost a set to be played with, not a parts pack or a mechanics lesson. For this and for its size and construction complexity, I'd say that this is the ideal 2013 Technic set for parent-child team building.

1 comment:

Aqualize said...

I just built this set last night and read the review right now.
In the beginning you mention you think "mini" in its name also means it is modelled after a smaller backhoe than the 8069.

I actually think it is the other way around. Here in Sweden we have these backhoe loaders (similar size of wheels and articulated steering, like the 42004). I would guess they be common in Denmark too.

With the 8069 I think of a JCB style backhoe, like this:

The 42004 could have been made from the "Huddig" or "Lännen" backhoe loaders, like this one:
(they are also available in yellow)

Found a picture whith the Huddig 1260 beside a JCB.

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