Impossible LEGO

[Didumos69]

29 minutes ago, letsbuild said:

It would be pretty easy to make legal instructions. I just don't have enough dog bones to do so.

23 minutes ago, Slegengr said:

@Didumos69 I see how it is possible and can be done legally, as you can use the double-length portion of the black pins (without the collar) to slide the pins out during pre-assembly and lock them in once all pieces are assembled.  Removal of the pins is entirely a different story, as you would need to grip the revealed shaft-portion of the black pins to slide the pins back out incrementally.  The "little brother" one does require the use of another cross-axle to push the internal cross-axles out for removal.

As a mechanical engineer, I find these connections quite fun to decipher, though I do not build much in the Technic realm.  If I had the time and funding available, I probably would expand beyond just LEGO System.

That's indeed how it can be done.

@Epic Technic made instructions for both cubes in the original topic, but the link to the instructions for the bigger brother appears to point to the instructions for the small one...

[masterX244]

I just laughed my youknowwhat off on those gordian knots... thanks god i haven't built a single of those yet by accident

 

Edit: made wording clearer

Edited March 4, 2017 by masterX244

[letsbuild]

57 minutes ago, masterX244 said:

I just laughed my megablocks off on those gordian knots... thanks god i haven't built a single of those yet by accident

You can take them apart easily.

[ColletArrow]

16 hours ago, nerdsforprez said:

I have long noticed that this piece,  along with its smaller sibling,  http://www.bricklink.com/v2/catalog/catalogitem.page?P=15100#T=C

Have incredibly thick pins.  Thicker plastic than 3l pins.  Even the black, old style.  Still, with enough force, they should come apart as @Slegengr mentioned 

This has been mentioned before. I think the reason was that the part needed to have the rigidity of a standard liftarm for the hole, and the softer plastic usually used for pins wasn't up to the job. This makes the parts harder to connect and disconnect at the pin ends. Part 48989 escapes this by having no friction on its pins, so the pins are slightly smaller (I guess) and thus no connection stiffness problems.

[N-4K0]

The pin hole with a single pin (15100), while not being impossible to take apart, would certainly require some force if put together like Didumos69 showed on the previous page with the 2 pin version. I'm gonna try that with 15100 myself just to see 

[Phil B]

Didn't read the entire thread, so apologies if this has been mentioned before, but one part combination that always gets me worked up is the Tile 1x1 Round w Straight Sides in a transparent color inserted in the bottom of a Plate 1x1 in an opaque color, like in Bart's bedside lamp from 71006 or in the Christmas lights on the Winter Village Cottage. Apart from force with pliers, I know of no way to safely separate this combination.

[Lasse D]

You put them on top of a brick separator and push the top part toward the edge. That should do the trick. At least that's how I got them apart.

[DrJB]

On 2/10/2017 at 5:31 PM, Josephiah said:

I have a contender (from disassembling the 8480 sub the other day, so this is from official instructions!):

Any ideas?  Genuinely at a loss as to how to separate them.  Possibly (gently) heating them would help...

Soak them up in hot soap water

Edited March 27, 2017 by DrJB

[Erik Leppen]

What if you connect one of the round plates on the center of a 2 x 2 plate? Can you then separate one round plate? The round plate can then be separated from the 2 x 2 plate using a brick seperator.

[allanp]

Anyone tried separating these pieces in step 7 part 1 in the image below? It's from 8466.

[Tommy Styrvoky]

2 minutes ago, allanp said:

Anyone tried separating these pieces in step 7 part 1 in the image below? It's from 8466.

 

Couldn't you just use your fingernail, or a knife blade to pry them apart? As that is what I use when attaching system parts to technic pieces in that method.

[rener]

1 minute ago, Tommy Styrvoky said:

Couldn't you just use your fingernail, or a knife blade to pry them apart? As that is what I use when attaching system parts to technic pieces in that method.

Fingernails won't do, unless made of steel, in my experience. I only managed to separate the parts with help of a small knife with a very thin blade. And not without some damage to the pieces. 

Remarkably this construction was also used in 8448, but it doesn't seem really "legal" to me. At least it's not possible to separate the pieces by normal means...

[Slegengr]

@rener For connections similar to that, I have used a bar or cross-axle as a push stick through the hole and against the stud.  As long as you can get enough grip on the link beam, they should come apart with minimal damage.

[Blakbird]

32 minutes ago, allanp said:

Anyone tried separating these pieces in step 7 part 1 in the image below? It's from 8466.

Yes, I remember that as the most difficult connection to separate in any Technic set.

[masterX244]

Gordian Knot i found somwhere on Brickshelf: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=2978671

[Mantarri]

16 hours ago, masterX244 said:

Gordian Knot i found somwhere on Brickshelf: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=2978671

Just drill the 3L axles out with a small drill bit...

[nerdsforprez]

Not impossible, but there certainly are many scenarios of difficult connections with Technic....especially for those of us with out fingernails.  Little video here of a tool i found very helpful.  Much more helpful than a knife and not nearly as damaging to Lego......

 

 

[Tommy Styrvoky]

5 hours ago, nerdsforprez said:

Not impossible, but there certainly are many scenarios of difficult connections with Technic....especially for those of us with out fingernails.  Little video here of a tool i found very helpful.  Much more helpful than a knife and not nearly as damaging to Lego......

 

 

I think that's a feeler gauge, I guess it would work well, though with my experience with them, the thinner ones could be bent. That's why I prefer to use a pocket knife in very few cases, such as starting to pry apart a stack of plates, though for most other cases a butterknife works for removing tiles and separating stuff.

[nerdsforprez]

Just now, Tommy Styrvoky said:

I think that's a feeler gauge, I guess it would work well, though with my experience with them, the thinner ones could be bent. That's why I prefer to use a pocket knife in very few cases, such as starting to pry apart a stack of plates, though for most other cases a butterknife works for removing tiles and separating stuff.

Yea, as mentioned in the video it is a feeler gauge.  And I have bent mine, but only minimally.  The one used is very old and I have several so it is not a concern. Knives can also be used, but as mentioned I found it is easier on my pieces

[Tommy Styrvoky]

5 hours ago, nerdsforprez said:

Yea, as mentioned in the video it is a feeler gauge.  And I have bent mine, but only minimally.  The one used is very old and I have several so it is not a concern. Knives can also be used, but as mentioned I found it is easier on my pieces

The Ideal tool for separating parts would be something thin and strong like a feeler gauge, but covered in something soft like ABS or other soft sheath of plastic/rubber material, as the metal core would provide strength but the outer coating would minimize damage to parts. Maybe one of the tools for tearing down electronics, as they are durable, but don't scratch/damage stuff.

Potentially something like this would work effectively. 

https://www.ifixit.com/Store/Tools/iFixit-Opening-Tool/IF145-335-2

Edited March 28, 2017 by Tommy Styrvoky

[Captainowie]

2 hours ago, Tommy Styrvoky said:

Potentially something like this would work effectively. 

https://www.ifixit.com/Store/Tools/iFixit-Opening-Tool/IF145-335-2

That doesn't look like it'd do much more than back end of a brick separator.

[Jon61]

On 5/14/2016 at 4:31 PM, Didumos69 said:

Who is the first to provide legal instructions (legal as in 'not making use of slack') for this cube? It is possible .

LXF-file here.

Well I know that other have worked out how to build the larger cube, and that the instructions have already been done somewhere, but as I couldn't find them from the links quoted above I thought I'd have a go at them myself. I also didn't have enough 'dogbones' to build it for real without disassembling 2 of my 3 Technic sets, so it was also a useful 3D 'thought experiment' for my brain (assisted by MLCad, which I've only just started using, so this was good practice on that too).

In my theoretical build I used 18 blue 3L long pins  - I assume the picture above is using the same part (#6558) but in black? For MLCad I took the rather unorthodox approach of using artificial colours, as it helped me see the symmetry in the pieces. So all the pieces in practice are either #6558 (18 of, blue/black) or  #14720 (6 of, LBG) regardless of the colours in the graphic below:

 

On 3/3/2017 at 6:53 PM, Slegengr said:

@Didumos69 I see how it is possible and can be done legally, as you can use the double-length portion of the black pins (without the collar) to slide the pins out during pre-assembly and lock them in once all pieces are assembled.  Removal of the pins is entirely a different story, as you would need to grip the revealed shaft-portion of the black pins to slide the pins back out incrementally.  The "little brother" one does require the use of another cross-axle to push the internal cross-axles out for removal.

As a mechanical engineer, I find these connections quite fun to decipher, though I do not build much in the Technic realm.  If I had the time and funding available, I probably would expand beyond just LEGO System.

I think it should be much easier than suggested above to take this cube apart. You could grip the middle portion of each with pliers, but I think in practice the 'inboard' end of each pin is opposite an open pinhole in the adjacent frame, and so could be pushed out through that hole using an axle. E.g. the three pins shown in yellow (another reason to use false colours!) that are pushed up from below in step 7 of my graphic, can be pushed back down through the holes in the top frame (shown in light blue).

Without having built it, I initially thought that once assembled 'legally' as shown, it might be possible to collapse the cube further by carefully and simultaneously pushing on all 6 faces, thereby taking up the slack middle 1L in each of the 3L pins. However, thinking about it more and experimenting using MLCad, this is NOT possible, as the 5L length of each dogbone effectively keeps two of the adjacent dogbones a fixed distance apart.

Edited June 28, 2021 by Jon61
replaced Photobucket-hosted photo by Flickr

[Slegengr]

@Jon61 You are certainly correct in your observation!  The cube could be disassembled as you said, utilizing an axle as a push pin.  I overlooked the opening opposite those pins you showed in yellow.

[Didumos69]

@Jon61, great to see the instructions for the cube being redone, thanks! I'm happy this helped you to start off with MLCad.

[masterX244]

another one involving a O-Frame and a gear

lower part of the L-piece contains a red 2 long axle