Answers.Body: <p>In general, this sort of connection is illegal, but I think that it works fine with a Travis brick. Technic pins must be "in click" in a model, or the pins will be held in compression and can be damaged over time.</p>
  
  <p>Here's a slide from Jamie Barard's classic "Stressing the Elements" presentation that explain the need to have Technic pins in click:</p>
  
  <p><a href="https://i.sstatic.net/EufA6.png" rel="noreferrer"><img src="https://i.sstatic.net/EufA6.png" alt="Technic pin in click"></a></p>
  
  <p>And here's the slide that explicitly states that Technic pins should not be used to connect to System bricks:</p>
  
  <p><a href="https://i.sstatic.net/6VFjS.png" rel="noreferrer"><img src="https://i.sstatic.net/6VFjS.png" alt="System brick and Technic pin"></a></p>
  
  <p>Here's an example of a set that didn't keep Technic pins in click and the resulting damage from prolonged storage assembled:</p>
  
  <p><a href="https://i.sstatic.net/lSpSL.png" rel="noreferrer"><img src="https://i.sstatic.net/lSpSL.png" alt="Legoland Germany Promo Set"></a></p>
  
  <p>With all of that said, the four holes that run through the stud connections on the sides of a Travis brick provide ample room for a pin to click into it. This isn't an obvious connection as with a Technic brick, but the fact the pin can move freely inside the brick indicates that it isn't in compression and is simply constrained to remain inside.</p>
  
  <p>I can't speak to whether or not this type of connection would get through a design review today, but I can say with confidence that this wouldn't cause damage to elements. If this is considered "illegal" it would be for other reasons.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-09-15T20:42:37.130Z
Answers.Text: Great answer. Interesting to note is that a new macaroni was made with axle holes to account for this. Part no 25214 on Bricklink doesn't have any photos of the holes, but the instructions for 42122 Jeep Wrangler show the piece's practical use on page 167 as part of the roll cage.
Answers.UserDisplayName: Joel Mellon
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-27T21:44:18.307Z
Answers.LastActivityDate: 2018-01-27T22:08:48.600Z
Answers.LastEditDate: 2018-01-27T22:08:48.600Z
Answers.UserDisplayName: jncraton
Answers.Body: <p>TLG continued to use this technique through at least the mid-90s. The technique appeared in the Cowboy sets <a href="https://brickset.com/sets/6761-1/Bandit-s-Secret-Hide-Out" rel="nofollow noreferrer">6761: Bandit's Secret Hide-Out</a></p>
  <p><a href="https://i.sstatic.net/e7yLn.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/e7yLn.jpg" alt="enter image description here" /></a></p>
  <p>and <a href="https://brickset.com/sets/6765-1/Gold-City-Junction" rel="nofollow noreferrer">6765: Gold City Junction</a></p>
  <p><a href="https://i.sstatic.net/Pcm7h.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Pcm7h.jpg" alt="enter image description here" /></a></p>
  <p>to construct turrets.</p>
  <p><a href="https://i.sstatic.net/e9r2g.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/e9r2g.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.sstatic.net/F7vNc.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/F7vNc.png" alt="enter image description here" /></a></p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-11-19T09:23:38.653Z
Answers.Text: Hi Mark, welcome to Bricks.SE and thanks for the great answer! I took the liberty to add links and images to the referenced sets and their relevant steps from the instructions, feel free to add or correct anything else too!
Answers.UserDisplayName: zovits
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-11-18T20:47:06.947Z
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Answers.LastEditDate: 2020-11-19T09:22:22.963Z
Answers.UserDisplayName: Mark Dickerson
Answers.Body: <p>Although technically the connection is illegal, I don't think the pin is under stress. I remember this set from my childhood, and the "rotor" rotated easily, which would not have been the case if the pin was stressed.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-01-30T14:25:10.690Z
Answers.LastActivityDate: 2020-06-04T13:17:15.057Z
Answers.LastEditDate: 2020-06-04T13:17:15.057Z
Answers.UserDisplayName: Michael Verschaeve
Body: <p>Is seating a Travis brick on a Technic pin a legal connection? TLG has used this construction at least once (M-Tron Particular Ionizer's "rotor"), but that was in the early 90s. Will this connection stress the Technic pin?</p>
  
  <p>Here's an example of what I'm referring to from that set:</p>
  
  <p><a href="https://i.sstatic.net/YYvid.png" rel="noreferrer"><img src="https://i.sstatic.net/YYvid.png" alt="6923 step 17"></a></p>
  
Tags: <technic><connections>
Title: Technic Pin/Travis Brick Legal Connection?
UserDisplayName: Nobody
ThreadText: # Technic Pin/Travis Brick Legal Connection?
  
  (Asked by: username_0 on 2018-01-27)
  
  Is seating a Travis brick on a Technic pin a legal connection? TLG has used this construction at least once (M-Tron Particular Ionizer's "rotor"), but that was in the early 90s. Will this connection stress the Technic pin?
  
  Here's an example of what I'm referring to from that set:
  
  [![6923 step 17](https://i.sstatic.net/YYvid.png)](https://i.sstatic.net/YYvid.png)
  
  **Tags:** technic, connections
  
  ---
  
  ## 3 answers
  
  ### Answer by username_1 on 2018-01-27. Score: 14
  
  In general, this sort of connection is illegal, but I think that it works fine with a Travis brick. Technic pins must be "in click" in a model, or the pins will be held in compression and can be damaged over time.
  
  Here's a slide from Jamie Barard's classic "Stressing the Elements" presentation that explain the need to have Technic pins in click:
  
  [![Technic pin in click](https://i.sstatic.net/EufA6.png)](https://i.sstatic.net/EufA6.png)
  
  And here's the slide that explicitly states that Technic pins should not be used to connect to System bricks:
  
  [![System brick and Technic pin](https://i.sstatic.net/6VFjS.png)](https://i.sstatic.net/6VFjS.png)
  
  Here's an example of a set that didn't keep Technic pins in click and the resulting damage from prolonged storage assembled:
  
  [![Legoland Germany Promo Set](https://i.sstatic.net/lSpSL.png)](https://i.sstatic.net/lSpSL.png)
  
  With all of that said, the four holes that run through the stud connections on the sides of a Travis brick provide ample room for a pin to click into it. This isn't an obvious connection as with a Technic brick, but the fact the pin can move freely inside the brick indicates that it isn't in compression and is simply constrained to remain inside.
  
  I can't speak to whether or not this type of connection would get through a design review today, but I can say with confidence that this wouldn't cause damage to elements. If this is considered "illegal" it would be for other reasons.
  
  > **Comments:**
  > **username_2**: Great answer. Interesting to note is that a new macaroni was made with axle holes to account for this. Part no 25214 on Bricklink doesn't have any photos of the holes, but the instructions for 42122 Jeep Wrangler show the piece's practical use on page 167 as part of the roll cage.  
  
  ---
  
  ### Answer by username_5 on 2018-01-30. Score: 6
  
  Although technically the connection is illegal, I don't think the pin is under stress. I remember this set from my childhood, and the "rotor" rotated easily, which would not have been the case if the pin was stressed.
  
  
  ---
  
  ### Answer by username_3 on 2020-11-18. Score: 5
  
  TLG continued to use this technique through at least the mid-90s. The technique appeared in the Cowboy sets [6761: Bandit's Secret Hide-Out](https://brickset.com/sets/6761-1/Bandit-s-Secret-Hide-Out)
  
  [![enter image description here](https://i.sstatic.net/e7yLn.jpg)](https://i.sstatic.net/e7yLn.jpg)
  
  and [6765: Gold City Junction](https://brickset.com/sets/6765-1/Gold-City-Junction)
  
  [![enter image description here](https://i.sstatic.net/Pcm7h.jpg)](https://i.sstatic.net/Pcm7h.jpg)
  
  to construct turrets.
  
  [![enter image description here](https://i.sstatic.net/e9r2g.png)](https://i.sstatic.net/e9r2g.png)
  
  [![enter image description here](https://i.sstatic.net/F7vNc.png)](https://i.sstatic.net/F7vNc.png)
  
  > **Comments:**
  > **username_4**: Hi Mark, welcome to Bricks.SE and thanks for the great answer! I took the liberty to add links and images to the referenced sets and their relevant steps from the instructions, feel free to add or correct anything else too!  
  
  ---
  
  