These are our screw titration blocks for both our swivel cap and microdrive designs. Due to the variations in printing quality and resolution, we have included these so that a researcher can find a diameter/threading combination that works best for his or her 3D printer. There are three screw types available: 0-80, 0-90, and M1. 

The 0-80 will be the most commonly needed, as it is used in the designs of the "Hug" microdrive, the swivel cap base, and the swivel cap top (for the 2x32, 3x32, and 4x32 EIB). 

The 0-90 is necessary for the 2x32 EIB, since it is smaller than the other designs. 

Lastly, the M1 screw is used in the "Lambda" and "Hex" microdrive designs.

HOW TO USE

Step 1: Print out the titration blocks using the .STL files provided. (See the "How to Print" section for more details.) Use a screw of the appropriate size (0-80, 0-90, or M1) on each of the screw holes. We've provided a key on the side of each model to help identify the ideal fit. 

Step 2: Open the .BLEND files we've provided, and select the screw model that works best for your printer by right-clicking on it. Copy (CTRL+C) the screw model, then open the .BLEND file for the model you will be using, then Paste the screw (CTRL+V). 

Step 3: Press the "N" key to bring up the information panel on the right hand side. Right-click on the screw again (make sure it is highlighted in yellow, not red) and position the object using the XYZ coordinate system on the information panel. Below are a list of coordinates for each part.

• Headstage Base/Bottom
  • X = 17.75 | Y = 0
  • X = -20.875 | Y = 0 | Z = 18.5 (ROTATE 90 degrees on the Y-Axis)​
• Headstage Top
  • For 1x16 Plexon (use M1 screw)
    • X = -3.5 | Y = -5.5
    • X = -7.75 | Y = 4
    • X = 17.75 | Y = 0
  • For 2x32 Plexon (use 0-90 screw)
    • X = -7.875 | Y = -4.375
    • X = 2.125 | Y = 5.625
    • X = 17.75 | Y = 0
  • For 3x32 Plexon (use 0-80 screw)
    • X = -3.5 | Y = -2.25
    • X = -3.5 | Y = 3.5
    • X = 17.75 | Y = 0
  • For 4x32 Plexon (use 0-80 screw)
    • X = -3.5 | Y = 9
    • X = -3.5 | Y = -9
    • X = 17.75 | Y = 0

Step 4: Right-click on the headstage base to select it. 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, select the headstage and 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: Ensure that the headstage base is selected, 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