This page contains all the files for our swivel cap headstage design for the 3x32 EIB by Plexon. As stated in the file name for the base, the model only contains the hole for aligning the headstage with bregma. Further holes will need to be placed in the model by the experimenter in order to reach their desired brain structures. Obviously, different 3D modeling programs will have different methods of doing this.

 

Below, I will describe the steps to add new holes to the headstage base using Blender, which is a free and open-source 3D modeling program available here: http://www.blender.org

 

Basic Controls:

Right Click = Selects an object. Mouse Scroll Wheel = Zooms the camera in or out. Mouse Wheel Click (HOLD) = Used to reposition the camera. Numpad 7 = Moves the camera so it looks straight down at the top of the model (pressing 5 will toggle between Orthographic and Perspective modes).

 

Step 1: Open blender, delete the default box, and import the model by going to File --> Import --> Stl (.stl), and selecting the file. Press "N" to bring up the variables pane. Ensure that the Headstage is located at X = 0, Y = 0, Z = 0. 

 

Step 2: On the left hand side, select the Create tab, then create a Cylinder. The cylinder should be placed at X = 5, Y = 0, Z = 0, and its dimensions should be X = 0.75, Y = 0.75, Z = 10. (By default, Blender uses milimeters for all measurements.)

 

Step 3: Copy and paste (CTRL+C, CTRL+V) the cylinder. Move the cylinder to the desired AP (X axis) and ML (Y axis). You can type basic mathematical formulas in the Location fields to move objects precisely. For example: If a target region is -2.75 AP and +/- 1.75 ML from Bregma, you can type 5-2.75 on the X axis variable (remember the bregma hole is located at +5) and Blender will automatically move the cylinder to X= 2.25. 

 

Step 4: Right-click on the headstage base by selecting On the far right, select the Modifier tab (represented by a wrench), then go to Add Modifier --> Boolean (second column, third from the top). Change the Operation variable to Difference, then select Object and locate the cylinder. (NOTE: If you get a message stating "Cannot execute boolean operation" you likely selected the cylinder located at Bregma. Because the hole already exists, Blender cannot create another one. Go back to the Object menu and select a different cylinder.) Select "Apply." 

 

Step 5: Repeat Steps 3 and 4 until you have created holes for all the regions you wish to record from. Next press Tab to enter Edit Mode, then press "A" twice to select the entire model. On the left hand side select the Tools tab, then select Remove Doubles near the bottom. Next, use the commands CTRL+T and CTRL+N to triangulate faces and make normals (faces) consistent, respectively. This will help ensure the printing process goes smoothly. Press Tab again to return to Object mode.

 

Step 6: Select the headstage base, then go to File --> Export --> Stl (.stl). Name the file whatever you'd like (it is generally unwise to overwrite the original file) and confirm. (Note: If the headstage base is not selected, it will not print.) 

 

TROUBLESHOOTING: 

1. If, while performing a boolean operation, parts of the model other than the desired area disappear, or the cylinder becomes part of the headstage, an error developed in the model. The quickest way to resolve the issue is to start over.

 

2. One common mistake is to assign the boolean operation to a cylinder rather than the headstage. Be vigilant while performing these steps to avoid errors.