This is yet another bit of useful information that I found on the POG Forum. This is probably the best way to make the channels in PMI Rubber grips so that they fit on a Typhoon or Stroker. For those that don't know, channels must be made in the grips for the hoses from the 4-way valve that is underneath.

Posted by Rix on October 8, 1998 at 23:38:33

One of the simplest is to rub a #2 pencil on the hoses and the grip frame edges them press a sheet of paper down on them, ensuring that you rub against the hose(s) as well as the grip frame edges to "transfer" their location (via the #2 pencil rubbings) to the sheet of paper. Cut out the paper, place it on the grip panel to be routed, trace it and go about routing it. I suggest you go a little over on the routed channel outline as well as depth to allow a little room for hose movement. The point to remember is that the left grip panel covers the other two hoses, and quite possibly they have a little section of cut tubing acting like a "cable tie" to keep the hoses together. As that little loop moves up and down the tubes, their positioning does as well, so be mindful of it. What you wish to do is make the pattern tracing when the hoses are in their normal postion, one which does not "kink" any of them & restrict the air flow in any manner. This is not a big deal to do, just take your time and don't rush....

Rix