Answers.Body: <p>Physicist Richard Feynman explains how train wheels work on <a href="http://youtu.be/y7h4OtFDnYE" rel="nofollow">this</a> Youtube video. It's not necessary to coat the wheels, applying a generous amount of coating may decrease, traction which will effect the trains performance.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-01-23T23:39:48.867Z
Answers.Text: I think the question is referring to the axle friction, not the wheel on rail smoothness :-)
Answers.UserDisplayName: Rory Alsop
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-01-24T19:21:28.937Z
Answers.Text: @RoryAlsop: I'm not quite sure what you mean by axle friction. Which particular piece are you referring to?
Answers.UserDisplayName: Ambo100
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-01-24T19:29:18.133Z
Answers.Text: See @LarsTech's final sentence. It refers to the axle, not the wheel.
Answers.UserDisplayName: Rory Alsop
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-01-25T19:15:56.123Z
Answers.Text: @RoryAlsop: I don't understand, It might help if I knew the piece or set in question.
Answers.UserDisplayName: Ambo100
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-01-27T10:38:02.170Z
Answers.Text: @RoryAlsop: You mean that the question is about the way the axle turns freely in its plastic holder (the place where you might have a bearing in a humal-scale wheel), rather than the friction between the wheel and the track?
Answers.UserDisplayName: Kramii
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-01-27T12:02:41.830Z
Answers.Text: I think so, yes. @LarsTech - can you clarify.
Answers.UserDisplayName: Rory Alsop
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-01-27T13:49:25.427Z
Answers.Text: @RoryAlsop I don't know if the friction of the axle versus the friction of the wheel to the track are mutually exclusive.  This is actually a helpful answer, because even though I was focused on the axle rods, it could be that I was focusing on the wrong thing.  When you place a Lego wagon on a track, I'm amazed (easily apparently) by how well that wagon will glide over the track, especially on straight track.  I've always attributed it to the axles, but maybe there's more going on there.  I *might* have to consider rewording my question.
Answers.UserDisplayName: LarsTech
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-01-23T21:41:44.340Z
Answers.LastActivityDate: 2012-01-23T21:41:44.340Z
Answers.UserDisplayName: Ambo100
Body: <p>After assembling a train or its companion wagons, I'm always impressed at how smoothly the wheels glide over the track.</p>
  
  <p>When putting them together, it's just a metal axle with two wheels on each end inserted into the slot of the wheel holder.</p>
  
  <p>Is there a special coating on the axle to limit friction?  What makes it so smooth?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2012-01-24T21:52:15.190Z
Comments.Text: I recall in my school CDT classes we'd make bearings by drilling a hole through solid nylon and pass a fairly tight fitting metal axle through that which would tend to spin quite freely. I also have some old trains axle bricks that are clearly made of at least 3 parts - a black outer shell, a clear base, and then red "tubes" inside that the axles locked into. It's possible that the tubes are made from a slightly different plastic with a lower CoF than standard bricks (which use friction to lock).
Comments.UserDisplayName: Zhaph - Ben Duguid
Tags: <trains>
Title: How do the train wheels turn so smoothly?
UserDisplayName: LarsTech
ThreadText: # How do the train wheels turn so smoothly?
  
  (Asked by: username_0 on 2012-01-21)
  
  After assembling a train or its companion wagons, I'm always impressed at how smoothly the wheels glide over the track.
  
  When putting them together, it's just a metal axle with two wheels on each end inserted into the slot of the wheel holder.
  
  Is there a special coating on the axle to limit friction? What makes it so smooth?
  
  **Tags:** trains
  > **Comments:**
  > **username_1**: I recall in my school CDT classes we'd make bearings by drilling a hole through solid nylon and pass a fairly tight fitting metal axle through that which would tend to spin quite freely. I also have some old trains axle bricks that are clearly made of at least 3 parts - a black outer shell, a clear base, and then red "tubes" inside that the axles locked into. It's possible that the tubes are made from a slightly different plastic with a lower CoF than standard bricks (which use friction to lock).  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2012-01-23. Score: 1 | Accepted answer
  
  Physicist Richard Feynman explains how train wheels work on [this](http://youtu.be/y7h4OtFDnYE) Youtube video. It's not necessary to coat the wheels, applying a generous amount of coating may decrease, traction which will effect the trains performance.
  
  > **Comments:**
  > **username_3**: I think the question is referring to the axle friction, not the wheel on rail smoothness :-)  
  > **username_2**: @RoryAlsop: I'm not quite sure what you mean by axle friction. Which particular piece are you referring to?  
  > **username_3**: See @LarsTech's final sentence. It refers to the axle, not the wheel.  
  > **username_2**: @RoryAlsop: I don't understand, It might help if I knew the piece or set in question.  
  > **username_4**: @RoryAlsop: You mean that the question is about the way the axle turns freely in its plastic holder (the place where you might have a bearing in a humal-scale wheel), rather than the friction between the wheel and the track?  
  > **username_3**: I think so, yes. @LarsTech - can you clarify.  
  > **username_0**: @RoryAlsop I don't know if the friction of the axle versus the friction of the wheel to the track are mutually exclusive.  This is actually a helpful answer, because even though I was focused on the axle rods, it could be that I was focusing on the wrong thing.  When you place a Lego wagon on a track, I'm amazed (easily apparently) by how well that wagon will glide over the track, especially on straight track.  I've always attributed it to the axles, but maybe there's more going on there.  I *might* have to consider rewording my question.  
  
  ---
  
  