Hi,

When designing a MOC/MOD with lego technic it is very hard to change something after building it, because everything is locked in, three dimentionally.

Axles are not so bad because you can push or pull them out, the real problem is with pins, and with axles with stops blocked off.

To fix this, I could just use axles without stops when prototyping a MOC/MOD, but the problem with pins is still there.

So, I had the idea of having some custom pins without the stops, so that they can be pushed out again without having to dismantle half of the model.

Here are the pins needed:

• frictionless pin 2L with bar thru hole, without stop
• frictionless pin 3L with bar thru hole, without stop
• frictionless pin 1L with axle 2L and bar hole, without stop
• frictionless pin 2L with axle 1L and bar hole, without stop
• frictionless pin 1.5 with bar thru hole, without stop
• frictionless pin 1L with stud and bar thru hole, without stop

(frictionless can be structural like frictioned)

This would be very handy, and then when the design is finalized you just replace the prototype pins with real lego pins.

What are your thoughs on this?

Regards, Snipe

Edited August 26, 20186 yr by SNIPE

Interesting concept, and there are times when it was a momentary wish of mine.  There are 4 pins in my moc where a 4x2 lift arm was removed from the design, leaving 1/3 of the pins exposed. To disassemble and replace those 4 pins was a complete rebuild, almost all the way back to the frame.  How I wished for unstopped 3L blue pins right then.  So they are still there if you look. I decided not to care and left them for “future improvements”.

I had the same wish, but not for prototyping. I think ALL pins should have the hard stops removed because it allows for previously impossible constructions.

Also, one thing I sometimes find sometimes difficult is placing 2 beams together where there are a lot of pin connections. Have no hard stops means they can be inserted one by one. 

Also by being able to push pins out instead of having to remove beams around them would make for easier disassembly. 

Also in many cases mistakes arrise from placing 3m pins in the wrong way sometimes leading to lots of back tracking. Removing the hard stops eliminates this.

So this begs the question, why do we actually need the hard stops when the soft stops (as seen on the 3m pin) seem to work just fine?

I'd buy such parts from Shapeways if they designed them.

On 8/26/2018 at 4:17 AM, SNIPE said:

frictionless pin 2L with bar thru hole, without stop

Something like this ?

Printing parts would come up as very expensive, especially if you need many of them. it would be a more efficient solution to buy standard pins and sand down the stop rings. If you're not against damaging your parts.

23 hours ago, allanp said:

So this begs the question, why do we actually need the hard stops when the soft stops (as seen on the 3m pin) seem to work just fine?

I think the hard stops serve as aligners, to prevent pins from sticking out 0.05 stud at some end and being in the way of a nearby liftarm or gear or other object.

 

I understand the desire for stop-less pins, but I don't really have problems with the stops. I'm also afraid that parts that can be pushed in and only pushed out by axles, will genreate lots of constructions that are impossible to take apart again, becuase something is blocking the axle supposed to push out the pin that holds everything together. The fact that pins can't be pushed all the way in a build, also means they are always removable.

You could design stop-less pins with a matching tool to pull them out.

5 hours ago, Erik Leppen said:

I think the hard stops serve as aligners, to prevent pins from sticking out 0.05 stud at some end and being in the way of a nearby liftarm or gear or other object.

 

I understand the desire for stop-less pins, but I don't really have problems with the stops. I'm also afraid that parts that can be pushed in and only pushed out by axles, will genreate lots of constructions that are impossible to take apart again, becuase something is blocking the axle supposed to push out the pin that holds everything together. The fact that pins can't be pushed all the way in a build, also means they are always removable.

Very good points Erik 

but would you not have to dismantle the whole model to replace 

On 8/26/2018 at 3:17 AM, SNIPE said:

This would be very handy, and then when the design is finalized you just replace the prototype pins with real lego pins.

What are your thoughs on this?

But then you would have to dismantle the whole model to replace these frictionless pins with normal pins?  when I'm MOC'ing, I would not remember where all the parts went the second time around!

I feel like all the pins have stops, so there must be a reason for them.  I think the stops also serve as the most rigid part of the pin since it is the thickest, but I could be wrong. 

I would say that if we went down the route of having no middle stop in the pins, and imagine Lego adopting it, think of all the problems that it would also generate.  As previously mentioned, pins could be slightly out of place, causing trouble for the first-time child technic builders, but also we could end up pushing a pin into the belly of a machine, into a gearbox for example, resulting in a major strip down to retrieve it.  A life without boundaries is not always the answer, stick with the middle stop and plan your builds better!

4 hours ago, trekman said:

but also we could end up pushing a pin into the belly of a machine, into a gearbox for example, resulting in a major strip down to retrieve it.

That would be my concern. It could cause too much trouble.

Hi,

I am not talking about lego adopting it, I am talking about some third party company creating them.

When the prototype is made, you replace one pin at a time, or build another copy using the pins with stoppers.

I can't think of any 'impossible connections you can do with stopless pins. they can push an axle out, an axle can push them out and so forth.

You do need to be careful to make sure that the pins are not sticking out a tiny bit as erik said but at least there will be the two lips on each end where they snap in to the recesses of a pinhole, that will help keep it flush with the pinholes.

Why need pin with no stop when you can slide an axle instead? The Heavy Lift Helicopter uses this technique. A 5L axle with stop aligns 5 pin holes together.

Axles have more play.