TBs TechTips 18 - Don't do this at home

In fact, don’t do this anywhere.

While browsing Parax’s Brickshelf folder, I found something worth heeding for every TECHNIC inventor: examples of dead ends you won’t want to get yourself into.

There are some combinations of parts you can put together, but are nigh-impossible to take apart. Take a look at Parax’s examples (and note that he wisely didn’t use physical pieces!), to see for yourself what horrors these seemingly innocuous structures hide. As you can see, building any one of these is easy, if the axles (in grey in the first example, and red in the second) are the last pieces to be added.

But disassembling them is another story... In both examples, you would be able to disassemble the structure if somehow you could pull out the axles again. But they’re fully inserted, without any protruding bit to grab and pull, and the Angle Connectors #2 don’t allow then to be pushed to come out at the other side. Also, on the first example, if you could rotate the Axle Joiners Perpendicular free from the Pins Long with Friction, none of this would have happened. But it can’t be done without breaking either the joiners, the pins, or both.

So, if you really need to have a structure like these or similar, how can you avoid this nasty deadlock?

First of all, you can give yourself somewhere to grab and pull, by using longer axles that stick a bit out of the structure. Given the friction axleholes impose, maybe one extra stud isn’t enough, unless you use potentially damaging tools like pliers; just to be on the safe side, the best would be to use 5L axles on the first example and 4L axles on the second.

Also, on the first example you can replace the long pins with axles (properly bushed at each end), so that you can push or pull them out.

Remember “LEGO” means “I put together”, but also implies “I take apart”!

Edit:
Like it was suggested in a comment, I changed the background of all pictures to transparent for better visibility, including those made by Parax.

Meanwhile, Parax mentioned other situations that present serious complications, at cbt's Brickshelf folder. Here they are:

Both can be solved by using longer axles instead of short ones, and the second one can also be solved by replacing the long pins with axles.