Jan 24, 2008

How do you get these parts unstuck?


In my experience, the tan axle pin is the element most likely to be damaged when I'm teaching with the NXT or another Technic set.

As best I can tell, my students damage the pin tips when they are trying to remove it from another part, especially if they use their teeth (shudder).

Bent axle pins won't spin freely in a Technic hole, and they won't grip a hole well enough to stay in place.

If the axle side is stuck in a gear or a beam, you can use an axle to push it out from the other side. That's not an option with a number of Technic connectors, like the one shown in the photo above.

Sometimes, I can get a fingernail between the collar of the axle pin and the connector, but not always.

If I put something in the pin, like an antenna, I can grip the pin and pull it out easier. The antenna prevents the pin tips from getting crushed when I squeeze the pin half of the axle pin.


update:
The below picture from the building instruction of box 8842 shows how LEGO recommends to disassemble some constructions, including how to remove an axle-pin. Note how the axle-pin is first stuck in a beam to prevent the pin getting deformed by the thin antenna size insert. This insert pushes the axle-pin firmly in the beam so it will have more friction then the (old style) Technic connector.



Do any of you have another method for separating these parts?

29 comments:

Alban said...

Watch this :

http://www.hccamsterdam.nl/brickfactory/scans/08000/8842/020.jpg

TooMuchCaffeine said...

I tend to be a 'teeth' man myself, although I do have to hold a 'broken peg cull' every now and again as a result - chucking out all the mis-shapen pegs with bite marks on them!

Philo said...

A trick that worked well with old Technic pins and should be usable here: put the pin in the middle hole of a beam (or better a half beam). Insert a LEGO bar or antenna in the pin hole. This bar prevents the side clips of the pin to collapse in the middle, so the pin fits very snuggly in the beam. Pull the beam, the pin will come. Remove the bar and pull the pin from the beam.

Matthias Paul Scholz said...

What's wrong with using the teeth, though?
For apes and men, it's the natural method that comes first to mind (when it comes to mind at all). ;-)

Buckskinn92 said...

I am ashamed.....

I always use my teeth. Though, I always grab onto the gap between the wall and pin. It comes out alote easier and with very little damage to the pin.

Bu92

Anonymous said...

I use David purdue's method if a fingernail doesn't work. I use those black, flxible axle joiners. You wrap it around the pin and pull. My kids love to put those very short 3M studed axles inside LEGO pieces. I have to use a hemastat to get those out. The boys often crush the stud using their teeth.

LEGOmom

Brian Davis said...

Stop damaging your dentures - use a jar opener:

http://csne2.homestead.com/jar_openers.html

These thin rubber sheets are perfect for gripper a slippery surface - it's what they are made for, and you can generally find them for free somewhere as a promotional giveaway. They are the studless equivalent of the plate separator, and are dirt cheap. They work much better than using the 1x2 rubber piece, and they're cheaper and harder to loose as well.

--
Brian Davis

CATpit contractor said...

Two tools that I always have handy when building: Brick separators, and needle-nosed pliers. I find that if I work gently enough, I can unstick a lot of different situations, even when they are in tight positions in my robot. Needle-nosed pliers.

Rick Rhodes said...

Never thought of a jar opener--good idea.

No more needle-nosed pliers for us. (They weaken and/or break the pegs).

Rick

Brian Davis said...

I introduced several people to using the jar openers at the NXTLog Sumo event, where in the course of a day we had to build & in most cases disassemble 20+ robots. It was the only thing that saved us from bloody fingers, and made it very easy - even pulling an axle from a long series of cross holes.

--
Brian Davis

Steve said...

I use jewelers pliers. One tip will fit inside the exposed friction end of the pin and the other tip on the outside. This allows you to pull evenly without compressing the the end and shortening the life of the pin.

peter hoh said...

Thanks for the tips! Jar openers are going in all my class sets.

The scan from the 8842 set is very helpful. I wish LEGO would do an update. Or maybe there is one that I don't know about.

I need a visual guide to teach students the importance of keeping their beams parallel. This is not such a big issue when building with the studded beams, but studless beam designs often suffer from this flaw.

Borrowing from this image, I talk about happy LEGO and unhappy LEGO. This seems to make sense to the kids -- that we want to build in a way that avoids stressing the pieces.

L Giskard V0.1 said...

I use either teeth or push an axle through from the other side.

poetryinmotion said...

I use the 2 of 2M length rubber pieces and squeeze them together. sometimes i use the rubber handles of one of my can openers. I finally chipped my tooth trying to get the exact same pieces off each other. I've been thinking about designing sets of pliers and such specifically for lego with rubber tips and such.. we'll see how that goes

Jonathan Daudelin said...

When I can't pull the peg out, I find it's easy to slide the blade of a pen knife between the two pieces and wedge them apart.

-Jonathan

William Meitzler said...

I have found the Technic Brick seperator! The 'Sports Soccer Goalie Stick' (30493 on Peeron) has a good handle and a tip well adapted to pushing out stubborn pieces with a combination System wheel axle and cross-axle tip. In this case you can use Philo's tip with it, as the end tip is that diameter. Oh, and did I mention these are $0.08 apiece?

Anonymous said...

First I try philo's trick with the technic brick and bar. If it doesn't work, then I grab a pocket knife and try to wedge it in between the tan piece and the red piece.

I only use pliers when I'm trying to pull out a stubborn light sabre blade or piece of flex tubing.

My standard equipment for disassembly: A technic brick, a bar, a long technic axle, a pocket knife, pliers, and two brick separators

phil said...

I just wiggle it a little with my two thumbs and fingers. Dont squeeze it too hard not to crush it and it allways works for me on the tan, grey and blue ones. I will try these other sugestions here and see how well hey work. Phil

RDewsbery said...

Teeth??? *shudder*

I have a strip of butyl rubber, left over from when we dug a garden pond over 20 years ago - the pond has long-since gone, but I still have a couple of small strips of the rubber pond liner tucked away.

One strip lives in the kitchen, and is used to open jars with - wrapping it around the lid gives you better purchase on it, and prety much anyone can open any jar if the grip is right. I guess that your jar openers are pretty much the same idea.

The other piece lives in my Technic box. I tend to use it a lot with the studless stuff - especially to pull stubborn pins out.

I'm still appalled that we have grown-ups using their teeth. My 5-year old received her first few boxes of Lego for Christmas this year, and even she knows that teeth use is a hanging offence. (Got to train them young.)

Al459163 said...

I use a needle-nosed pliers. So far it's worked pretty good and I have yet to break a pin with it.

Talking Chimp said...

Wrap a piece of masking tape around it (the smaller one) and then twist/yank.

Parax said...

Could be worse:
http://www.brickshelf.com/cgi-bin/gallery.cgi?i=2951014

Parax.

peter hoh said...

Parax, did you figure out a solution to sticky situation?

Parax said...

Yes its a complex recipe of an X-acto knife and patience... by using the back of the point in the grove of the axle and levering against the rim of the hole millimeter at a time, scaring was minimal.

luckymonkey said...

Ok I always use teeth teeth is the best way and me and you and lego all know that BUT you have to be careful when you are using teeth there will be no damage to the parts grab the part with your 2 front teeth (never use molars)then grip it very easily and pull make sure you get it right in between the 2 parts and you should have it come out no problem

Andreya said...
This comment has been removed by a blog administrator.
Andreya said...
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SomeDude said...

I've stumbled on this problem myself, and I got a solution.

1. Place a brick inside the technic pin, an antenna or some pointy brick. It's purpose is to pressure the connector from the insize.
http://www.peeron.com/inv/parts/3957

2. Place a brick with holes outside the technic pin, a technic beam will do. It's purpose is to pressure the pin from the outside.
http://www.peeron.com/inv/parts/32278

3. Push the antenna against the beam (any direction will do), and pull the pin (and these 2 bricks) out of where the pin is stuck.

SomeDude said...

Are you insane?

Never, ever, chew on bricks!

They will be deformed, and models will not function as intended when the pin doesn't have the right amount of friction.

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