Wednesday, 26 September 2012

UCS AT-AT : Tricky

Last time I wrote about the UCS AT-AT build (here) I'd completed one of the AT-AT legs and started work on the remaining three. It took me longer than expected to finish them up (doesn't it always ?) but I eventually completed them as you can see below. Astonishingly, the four legs alone are made up of a total of 2,120 pieces, which means that once I'd completed them the model was more than a third finished, in terms of part count at least.

Suitably confident after having largely breezed through the first part of the build, I decided to face my demons head on and attempt the AT-AT body next. This was really the only part of the build that I'd been facing with a degree of trepidation, on account of the complexity of the structure plus designer Pete's warning that there might be mistakes in the LDD rendition of his design. Having at times struggled through the distinctly illogical LDD-generated building guide while constructing the legs, I was also wary of what the building guide would throw at me this time round given the significantly greater level of complexity that it needed to negotiate. As it turned out, I was right to be apprehensive....

Above you can see a screen grab of the LDD file for the AT-AT body (click to enlarge). It's 'only' made up of 1285 parts in total, so significantly less than the legs. Once again I had the added complication that the LDD file had been tidied up a bit by Pete after I'd sourced the parts, so some of the hidden internal pieces I'd collected were a different colour to those in the LDD file. Thankfully however this didn't turn out to be too much of a problem.

I got a hint of the challenge to come as I waited for LDD to generate the building guide for this section of the model; the operation took almost 10 minutes on my (reasonably high spec) iMac, yielding an impressive 422 building steps. First to be built were the structures to which the legs would later attach plus the large cylindrical structures slung under the body which I assume are the engines, then a bunch of greebles, and finally the floor of the body and the internal skeleton upon which everything else would ultimately hang. At time of writing I'm up to step 343 of 422, so a good way into the build, and you can see a few pictures of the build so far below (click to enlarge).

Attachment points for front legs & forward engine section.
Attachment points for back legs & rear engine section
Work in progress : Body - floor
Work in progress : Body - underside
Contruction of the body has been, to put it politely, rather tricky.... This is in large part due to the ridiculous LDD-generated building guide which I've been struggling to follow. You may recall that while building the legs I wrote about the sometimes baffling and illogical order of the building steps, plus the expectation that the builder is able to make parts float in mid-air as if by magic. Well, the building guide for the body has taken these issues to a whole new level of absurdity, and it's been a significant challenge to follow along at times. I've attached a screen grab of one page of the building guide below to try and illustrate my point; at one stage there were up to 50 Technic pins, axles, sub-assemblies and various other loose parts floating in mid-air. These are positioned in 3D space exactly where they will eventually reside when later sections of the build drop into place, but you're given no guidance on how they attach to everything around them. At the point when later sections eventually drop into place en masse, therefore, you have to figure out what on earth all these free-floating bits and pieces attach to. This isn't too much of a problem for most of the larger sub-assemblies, but for the individual free-floating parts, and particularly the Technic pins and axles, it's a huge problem because you can't actually see them when everything else is in place - they're hidden by other parts and/or located deep within the build. All you can therefore do is study the final page of the instructions in minute, painstaking detail and, skipping backwards and forwards between the final page and earlier pages, try and figure out where everything goes.  It's a colossal and totally unnecessary pain in the arse.

LDD is a superb tool, but a build of this size and complexity has seriously shown up the limitations of the building guide generator. Even so, I'm getting there, slowly but surely, and next time I post an update I should have finished the body and decided on what to tackle next. Hopefully....

<-- Building the AT-AT : Part 3                                     Building the AT-AT : Part 5 -->


  1. that looks like quote a build. looks harder than building gundams XD

  2. Anonymous27/9/12

    Eek! 442 steps for just the body... Well, there goes my plans to try to create LEGO-like instructions out of the LDD files...

    I have to admit that at the 5000+ piece mark the pile of LEGO for this thing is impressive. Now I'm off to purchase those now-rare parts from BL (due to numerous people building this thing). ;-)


  3. It certainly looks like gravity was not factored in by LDD when generating those building instructions!

    I've had a quick look through them here and it certainly doesn't look like a job for the weak willed. In fact, I may have to take a break before embarking on the build - the buy was draining alone!

    Anyway, I've about 100 bricks to go before I can start on this beast, a few straggling orders have yet to arrive.

    On a side note, I'm recommend anyone attempting to build this not to upgrade to the latest LDD version 4.3. It removes 2 bricks from the Neck file claiming that they are not placed properly, I guess it is getting a little more strict in its old age as 4.2.5 has no problem with it (and my main problem is that it doesn't have the decency to tell you what bricks it has removed!). I've reverted to 4.2.5 for the moment and will likely reinstall 4.3 once I've complete the neck.

    1. madpeon28/9/12

      The two bricks in the neck are simply two misaligned 1 x 1 dark gray round plates. If you select them all and move them out of the structure it's easy to spot where they should go.

      I'm also waiting for a few final orders, but I started construction on the head yesterday. I'm about 95% done with the bottom, front and top plates.

      Overall things went fairly smooth but there's a reason Cavegod had to leave a few pieces free floating (namely the wheels at the base of the guns, the two wedge plates behind them, and tiles around the viewport). They are a tight fit!

      Also, to help out LDD with the building instructions, I've been separating out pieces of each section as best I can. For instance the front and top plates of the head are stuck together, but if you split them at the hinges, LDD seems to use fewer floating pieces in the building instructions.

      I plan to separate the engine section from the frame when I build the body. Hopefully it'll make for more useable instructions.

  4. WOW! That's awesome!

  5. After four weeks, a multitude of BrickLink orders and over 6300 pieces of Lego, I finally have a full inventory needed to build the AT-AT.

    Once I've recovered from the buy, I'll start the build.

    1. Congratulations, Tristan! At the rate I'm going you'll probably finish before me...


  6. No new instalment yesterday, Dave. Guess we're not going to see the finished beastie at STEAM.

    1. Afraid not, Rich - that was never on the cards for this year.

      Pete (cavegod) is however planning to bring his AT-AT to STEAM, so attendees will be able to see it in all its glory ! He'll also hopefully be bringing a selection of his other UCS MOCs including Slave 1 and maybe even his massive Sandcrawler...

  7. Kevin5/10/12

    Hi Dave - It looks like our builds are progressing at about the same rate. I still have to start the body floor, which I'll do this weekend. I have a large zip bag filled with the various "floating" pins, technic liftarm assemblies, and greebles shown in the last photo on your blog post.

    I think we will run into more trouble once all of the sub-assemblies have been completed, since I don't think that the LDD instructions will show us how to put all of them together. It looks like we have a fairly large group who have taken this project on, so I'm glad we can help each other out.


  8. Working on it as well. Currently at the body too, which is quite a challenge.

    I already created building instructions for the legs. Wanted to create them for all different sections, but I can't find the time to finish them.

    I am thinking about creating a separate thread on Eurobricks, so we can join forces.

    1. Feel free to post any tips or AT-AT building advice on here; hopefully the content of the blog postings plus the comments from readers will provide a useful resource for others who are also buiding this monster ! I'm pretty much done with the body now and will post another update in due course.

  9. I got pretty confused when building the four teardrop-shaped sides of the engines, as I thought LDD instructed me to put 1 x 1 bricks against the inverted slopes facing downwards, where they were actually 1 x 1 bricks with 1 knob. The knob being invisible on the 3D instructions, I found out about my mistake much later when I needed 1 x 1 bricks for the front of the body and couldn't find any left.