Assemble the guide tube bundles

quipment and Supplies

Equipment needed for this job (7x & 9x bundles only):

• Stereo Microscope or similar magnifier (Fig 0A)
• Guide tube bundling die (Fig 0B) – click here for build instructions
• Spring clamp (Fig 0C)

Supplies needed for this job (4x, 7x, & 9x bundles):

• Cyanoacrylate glue (Fig. 0D)
• Guide tubes  (Fig 0E)  – click here for build instructions
• Guide tube bundle collars (Fig 0F) – click here for build instructions 
  
    9x collar: 13G, .095" OD, .071" ID, .012" Wall (McMaster-Carr 8988K32)
  
    7x collar: 16.5G, .062" OD, .052" ID, .005" Wall (McMaster-Carr 8988K36)
  
    4x collar: 17G, .058" OD, .042" ID, .008" Wall (McMaster-Carr 8988K45)

4x guide tube bundle

1. Bundle the guide tubes (Fig 1A). Pick up the 4 guide tubes that will form the bundle, and make sure they are all straight (replace any bent tubes). Hold them parallel to one another, gripping them firmly between your thumb and forefinger so that about 3 cm of tubing extends from your fingers.  
2. Slip the collar over the bundle (Fig 1B).  Fit the 17G 4x collar over the bundle of tubes. It will fit snugly and hold the tubes in a 2x2 configuration. 
3. Adjust the protrusion length (Fig 1C).  The tips of the guide tubes (on the end that will enter the brain) should protrude from the collar by ~2 mm.
4. Glue the collar to the tubes (Fig 1D).  Use a non-absorbent applicator (such as an insect pin or syringe needle) to gently place a small amount of cyanoacrylate glue around the top and bottom edges of the collar. Be VERY careful not to use too much glue, because it may flow across the tubes and clog the holes in the guide tubes. 

7x or 9x guide tube bundle

1. Stack the guide tubes (Fig 2A). Pick up the 7 guide tubes that will form the bundle, and make sure they are all straight. Stack them parallel to one another, gripping them firmly between your thumb and forefinger so that about 3 cm of tubing extends from your fingers.  
2. Bundle the stack in the die (Fig 2B).  Hold the guide tubes so that they are stacked vertically (perpendicular to the tabletop). Align the tubes lengthwise so they they run parallel with the long V-notch in the bottom of the 7x slot in the bundling die. Rest the bottom-most guide tube along the bottom of the trench in the V-notch (the tips of the tubes should only extend about 1 cm into the V-notch). With your free hand, pick up the triangular block and carefully align its grooved edge over topmost guide tube in the stack, so that the top tube is nestled into the groove. Gently rest the block into the V-notch, so that the guide tubes are shaped into a tight bundle. 
3. Inspect for gaps (Fig 2C). Upon inspection, there should be no spaces or crevices between the base of the die and the triangular block. Everything should fit snugly together. When the bundle is properly formed, the top of the triangular block should be perfectly flush with the top of the triangular bundling die along its entire length. 
4. Flush guide tube ends (Fig 2D). Using a hard flat surface (such as a knife blade or flat tweezer handle), flush the ends of the diamond by gently pushing or tapping them towards the die. Push the tubes in until their tips extend about 3 cm from the die. 
5. Inspect the tips of the bundle (Fig 2E). Under a microscope, inspect the flush ends of the tube to be sure they are tightly bundled into the desired shape (a diamond for 9x bundles, or a hexagon for 7x bundles). The ends should be flush and level, with each opening of the tubes clear of debris.  
6. Clamp the die and turn it upright (Fig 2F). Use a spring clamp to secure the triangular block into the V-notch. Do not shift the triangular piece in any way that would distort the shape of the diamond. Then turn the bundling die on its side, so that the guide tube bundle extends vertically from the top. 
7. Slip the collar over the bundle (Fig 2G). Fit the 16.5G (for 7x) or 13G (for 9x) collar over the guide tube bundle. The 7x collar will fit snugly (if it is too tight to get on, then use a dremel bit or other tool to ream out and widen the hole in the collar). The 9x collar will fit loosely for now, until is it tightened later (see below). 
8. Push down a subset of the guide tubes (Fig. 2H). Use a tool such as a very small Dremel drill bit to push down a subset of the guide tubes into the collar. For a 7x bundle, you should push down 3 of the 7 peripheral guide tubes (NOT the center tube). For a 9x bundle, you should push down 3 tubes at one of the diamond's long ends, leaving the other 6 tubes alone.  The 'down' tubes should be pushed down until they are protruding ~5 mm  from the collar. The remaining 'up' tubes should protrude at least 10-15 mm from the collar. 
9. Glue the tubes in the 'up' position (Fig. 2H). Use a tool such as a very small Dremel drill bit to push down a subset of the guide tubes into the collar. For a 7x bundle, you should push down 3 of the 7 peripheral