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Posted

I am sure I am missing something.  But to be there seems to be a decreasing use for Technic 3/4 pins. 

32002.jpg

I mean, I know their intended use, obviously, for 1/2 lift arms.  And I know they have the exact measurement and grooves

at the end so there is a perfect connection with a 1/2 lift arm.... when one connects the 1/2 pin into a 1/2 liftarm there is a *snap*.   However, the connection never seems perfect... does it?  The connection wobbles a little bit.  Not

sure about others but I find myself using the Technic 1/2 pin

4274.jpg

More often than the 3/4 pin to make a connection into a 1/2 liftarm.  I know the connection does not provide a **snap** and therefore is not a perfect connection, but it does seem more secure.  There is no wobbling.  Anyone else have this

issue with 3/4 pins?  Do you sometimes, always, never make this switch?  If so, what is the rational?  Are there other good uses for the 3/4 pins?

 

 

Posted

I use the 3/4 pin when the half-liftarm needs to rotate. But often I also find myself just use the 1/2 pin for the same reasons. However, it seems that if you first put the short end in the half liftarm then it goes in too far, and the other long end won't snap anymore (does anyone understand this? :blush:). I'm not sure which one TLG prefers to use, but for this latter reason I would assume they'd use the 3/4 pin.

Posted

After my dark age, this was the very first part that I found to be broke. And I still don't know how or when it broke. So yep, I don't trust this part either, though I use it rarely-randomly for smaller loads.

@Ludo VisserIt's perfectly understandable, and one have to pay attention to this issue (especially when making instructions) and in cases it's better to use the 3/4 pin instead, though I can't recall any cases at the moment...

Posted

The pins are obviously made for different purposes.  The 3/4 pin is intended to connect to the 1/2 lift arm as stated while the 1/2 pin is intended for regular stud coupling in LEGO bricks.  Using one or the other just changes from a hinging joint to a clutching joint.  The wobble is due to tolerances to allow for the hinge to pivot.

@Ludo Visser The purposes also explain why the long end will not snap if the stud-end of the 1/2 pin is connected first.  Pay close attention to the collar width, which seats into the countersink on lift arms.  The 3/4 pin has a thicker collar to seat into a countersink on a lift arm on both sides while the 1/2 pin has a thinner collar to seat into only one lift arm to keep the stud even with the lift arm edge.  If the stud connection is assembled first, the collar seats into that lift arm instead of the one on the pin side, which offsets the pin connection enough to not allow the "snap".  The lip on the pin that snaps is the same depth as the 1/2 pin collar to seat into the countersink.

I hope this makes sense.

Posted (edited)

All replies make perfectly sense to me. And I also have the experience that the 1/2 pin should first be inserted with its pin side and then you can attach something to the stud-side, not the other way around.

I prefer the 1/2 pin over the 3/4 pin when I want to avoid slack, but only when the attached element is locked-up someway to avoid it from getting disconnected when it gets stressed. Here's an example:

960x450.jpg

I prefer the 3/4 pin over the 1/2 pin when I want to avoid a thin liftarm with axle holes from sliding off the axles. Here's an example:

960x450.jpg

Edited by Didumos69
Posted

To start with, well noticed @nerdsforprez and even though it is a "small" discussion I do like to add... ;-)

Most of the times I start with the 3/4 pins because of there purpose but find myself ending up with 1/2 pins instead. The later cause of there added stability. I know wishing for parts doesn't add anything, but I really hoped LEGO would have 3/4 pins with frictions too...haha... :thumbup:

Posted
1 hour ago, 2LegoOrNot2Lego... said:

I know wishing for parts doesn't add anything, but I really hoped LEGO would have 3/4 pins with frictions too...haha... :thumbup:

+1 but please not in green color..

Posted

Well there is a purpose for the 3/4 pins and in fact there are several unique uses for it.  But I also find myself just using the 1/2 pin quite a bit myself, in fact I just bought around 50 of the 1/2 pins the other day. As for the 3/4 pins I would say there more functional then the 1/2 pins for this given reason here, The 1/2 pins are like insert-able studs for thick Technic beams and bricks, while the 3/4 pins are designed for the thin lift arms to be functional just as good as a 3L pin for thick Technic beams.

Posted

Interesting, I never thought of using 1/2 pins to connect liftarms together.  Learn something new.  I use 1/2 pins mainly to connect standard system pieces to lift arms and technic bricks and various SNOT things.

I find the 3/4 provides a much stronger connection to the thin lift arms.  They work great too for connecting thin liftarms to large train wheel drivers if you MOC steam trains.

 

 

Posted
20 hours ago, Slegengr said:

The pins are obviously made for different purposes.  The 3/4 pin is intended to connect to the 1/2 lift arm as stated while the 1/2 pin is intended for regular stud coupling in LEGO bricks.  Using one or the other just changes from a hinging joint to a clutching joint.  The wobble is due to tolerances to allow for the hinge to pivot.

@Ludo Visser The purposes also explain why the long end will not snap if the stud-end of the 1/2 pin is connected first.  Pay close attention to the collar width, which seats into the countersink on lift arms.  The 3/4 pin has a thicker collar to seat into a countersink on a lift arm on both sides while the 1/2 pin has a thinner collar to seat into only one lift arm to keep the stud even with the lift arm edge.  If the stud connection is assembled first, the collar seats into that lift arm instead of the one on the pin side, which offsets the pin connection enough to not allow the "snap".  The lip on the pin that snaps is the same depth as the 1/2 pin collar to seat into the countersink.

I hope this makes sense.

This makes perfect sense! Learned something today :classic:

Posted (edited)
On 10-10-2016 at 10:48 PM, Slegengr said:

The pins are obviously made for different purposes.  The 3/4 pin is intended to connect to the 1/2 lift arm as stated while the 1/2 pin is intended for regular stud coupling in LEGO bricks.  Using one or the other just changes from a hinging joint to a clutching joint.  The wobble is due to tolerances to allow for the hinge to pivot.

@Ludo Visser The purposes also explain why the long end will not snap if the stud-end of the 1/2 pin is connected first.  Pay close attention to the collar width, which seats into the countersink on lift arms.  The 3/4 pin has a thicker collar to seat into a countersink on a lift arm on both sides while the 1/2 pin has a thinner collar to seat into only one lift arm to keep the stud even with the lift arm edge.  If the stud connection is assembled first, the collar seats into that lift arm instead of the one on the pin side, which offsets the pin connection enough to not allow the "snap".  The lip on the pin that snaps is the same depth as the 1/2 pin collar to seat into the countersink.

I hope this makes sense.

Speaking of collars. Maybe a bit off-topic, but one thing I never understood is why the 2736.png with its overly fat collar does not fully insert into a axle hole. This causing the ball to misalign with a one-stud-grid.

Edited by Didumos69
Posted

@Didumos69 That ball-and-axle piece mis-aligns because the cross-axle holes in beams have no countersink for the collar.  That piece still seems a bit off in its design, as you would never connect it in a pin hole with a countersink, thus the collar seems unnecessary.

Posted
7 hours ago, Slegengr said:

@Didumos69 That ball-and-axle piece mis-aligns because the cross-axle holes in beams have no countersink for the collar.  That piece still seems a bit off in its design, as you would never connect it in a pin hole with a countersink, thus the collar seems unnecessary.

Wasn't this part introduced together with 8880? I recall it was used together with this part to make the steering rack: 

2719.t1.png

There the collar was needed, obviously.

  • Jim changed the title to 3/4 Versus 1/2 Pins

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