Answers.Body: <p>I found CAD files for LEGO technic axles here: <a href="https://grabcad.com/library/lego-technic-axles-1" rel="noreferrer">https://grabcad.com/library/lego-technic-axles-1</a>
  and some gears which have holes for technic axles here: <a href="https://grabcad.com/library/lego-technic-gears-1" rel="noreferrer">https://grabcad.com/library/lego-technic-gears-1</a></p>
  <p>Using their online viewer I found the following dimensions (Which are a little inaccurate due to the limits of their online viewers tools. For more accurate and detailed dimensions download a copy of the CAD files)</p>
  <p><a href="https://i.sstatic.net/v4G9S.png" rel="noreferrer"><img src="https://i.sstatic.net/v4G9S.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.sstatic.net/vPTF8.png" rel="noreferrer"><img src="https://i.sstatic.net/vPTF8.png" alt="enter image description here" /></a></p>
  <p>This would seem to indicate (if accurate) an interference fit between the outsides of the axles and the holes (i.e. the hole is slightly smaller) which could be accurate as axles are usually tight.</p>
  <p>Someone should also probably measure actual LEGO parts with some calipers for confirmation on these dimensions.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-02-16T19:05:42.367Z
Answers.Text: my caliper says 4.68 rather than 4.78 for cross width, and 1.83 vs 1.79 for cross arm width.
Answers.UserDisplayName: jumpjack
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-11-22T22:51:21.770Z
Answers.Text: Quick measurement here with digital calipers gives me 1.80±0.01 mm for the arms and 4.71±0.02 mm for the entire axle.
Answers.UserDisplayName: Isti115
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-11-22T16:26:24.603Z
Answers.Text: This is great! Thanks.  I'm traveling for thanksgiving, and I'll take my calipers to measure some actual parts.  I'll comment with results.
Answers.UserDisplayName: BillThePlatypus
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-11-21T22:26:36.723Z
Answers.LastActivityDate: 2017-11-21T22:26:36.723Z
Answers.LastEditDate: 2020-06-18T08:28:58.637Z
Answers.UserDisplayName: Josh King
Body: <p>I'm working on a LEGO compatible motor system that will be largely 3D printed.  I want the connectors to fit standard LEGO axles, but I haven't been able to find the dimensions online, and I don't have any on me to measure.
  What are the dimensions of the cross-section of a LEGO axle. Is there a difference in size between the plus-shaped hole for and axle and the axle itself?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-20T16:05:52.867Z
Comments.Text: Do these have enough dimension details? [LEGO Technic Axles](https://www.brickowl.com/catalog/lego-parts/technic/axle)
Comments.UserDisplayName: DrZoo
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-20T17:33:13.277Z
Comments.Text: No, the length is easy to find, but I need the dimensions of the cross section
Comments.UserDisplayName: BillThePlatypus
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-20T17:34:02.317Z
Comments.Text: Specifically I need most the width of the ridges on the axle
Comments.UserDisplayName: BillThePlatypus
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-20T17:51:07.257Z
Comments.Text: Gotcha. The dimensions L x 0.4cm x 0.4cm is easy to understand, but do you have any idea what `stud dimensions : 0.33` means?
Comments.UserDisplayName: DrZoo
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-21T02:10:59.527Z
Comments.Text: It appears to be relative to a normal brick, for example the standard brick has stud dimensions 2 x 4 x 1
Comments.UserDisplayName: BillThePlatypus
Tags: <technic><gears><size><3d-printing>
Title: What are the dimensions of a technic axle?
UserDisplayName: BillThePlatypus
ThreadText: # What are the dimensions of a technic axle?
  
  (Asked by: username_0 on 2017-11-18)
  
  I'm working on a LEGO compatible motor system that will be largely 3D printed. I want the connectors to fit standard LEGO axles, but I haven't been able to find the dimensions online, and I don't have any on me to measure.
  What are the dimensions of the cross-section of a LEGO axle. Is there a difference in size between the plus-shaped hole for and axle and the axle itself?
  
  **Tags:** technic, gears, size, 3d-printing
  
  > **Comments:**
  > **username_1**: Do these have enough dimension details? [LEGO Technic Axles](https://www.brickowl.com/catalog/lego-parts/technic/axle)  
  > **username_0**: No, the length is easy to find, but I need the dimensions of the cross section  
  > **username_0**: Specifically I need most the width of the ridges on the axle  
  > **username_1**: Gotcha. The dimensions L x 0.4cm x 0.4cm is easy to understand, but do you have any idea what `stud dimensions : 0.33` means?  
  > **username_0**: It appears to be relative to a normal brick, for example the standard brick has stud dimensions 2 x 4 x 1  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2017-11-21. Score: 12 | Accepted answer
  
  I found CAD files for LEGO technic axles here: <https://grabcad.com/library/lego-technic-axles-1>
  and some gears which have holes for technic axles here: <https://grabcad.com/library/lego-technic-gears-1>
  
  Using their online viewer I found the following dimensions (Which are a little inaccurate due to the limits of their online viewers tools. For more accurate and detailed dimensions download a copy of the CAD files)
  
  [![enter image description here](https://i.sstatic.net/v4G9S.png)](https://i.sstatic.net/v4G9S.png)
  
  [![enter image description here](https://i.sstatic.net/vPTF8.png)](https://i.sstatic.net/vPTF8.png)
  
  This would seem to indicate (if accurate) an interference fit between the outsides of the axles and the holes (i.e. the hole is slightly smaller) which could be accurate as axles are usually tight.
  
  Someone should also probably measure actual LEGO parts with some calipers for confirmation on these dimensions.
  
  > **Comments:**
  > **username_0**: This is great! Thanks.  I'm traveling for thanksgiving, and I'll take my calipers to measure some actual parts.  I'll comment with results.  
  > **username_3**: my caliper says 4.68 rather than 4.78 for cross width, and 1.83 vs 1.79 for cross arm width.  
  > **username_4**: Quick measurement here with digital calipers gives me 1.80±0.01 mm for the arms and 4.71±0.02 mm for the entire axle.  
  
  ---
  
  