Cary Swoveland
06-11-2008, 4:01 AM
I just installed a ProLift. It's an impressive hunk of steel.
One accessory I bought is the guide busing adapter ("GBA"), which allows Porter Cable template guide bushings to be used. One attaches the GBA to one of three ring inserts ("RIs") that come with the ProLift, namely, the RI with the 2" hole. It is attached with three #8-32 machine screws, washers, lock nuts and possibly shims. The machine screws pass through oversize holes in the GBA, allowing the GBA to be centered relative to the router's arbor before the screws are tightened. This is shown in these two pics:
90674 90675
Centering is done by placing a provided aluminum centering cone in the router's collet and raising the router until the cone centers the GBA (with the three lock nuts tighened only loosely). Then one carefully removes the RI--so that the GBA doesn't move--and tighens the three lock nuts.
This centering procedure must be performed whenever the GBA is attached to the 2" RI. One could normally leave the GBA attached to the RI, but there would be times it would have to be removed to use that RI for a bit that is too big for the GBA, but too small for the larger RIs.
To avoid the need to use the centering cone to center the GBA, I made the following modification to the GBA:
1) Securely attach the GBA to the 2" RI as per the instructions, using the centering cone.
2) While the GBA is attached to the RI, drill two 3/16" holes through the GBA, with the drill centered in the two 1/4"-20 threaded holes in the RI. These threaded holes are provided for use with a starting pin. By using a 3/16" drill, the threads will not be touched by the drill, and therefore will not be damaged.
3) Tap the two holes just drilled for 1/4"-20 machine screws, by screwing the tap into the allready-tapped holes in the RI and then continuing the thread through the holes just drilled in the GBA. (See pics above.) Because the GBA is made of aluminum, which is relatively soft, a 3/16" hole is large enough for use with a 1/4"-20 tap, and the tap will remain centered on the threaded hole in the RI as the hole in the GBA is threaded.
4) Because the holes just drilled and tapped are 180 degrees apart, it is necessary to make alignment marks on the undersides of the RI and GBA. These marks indicate the position of the GBA relative to the RI when the holes were drilled and tapped (i.e., which of two possible alignments).
In future, the GBA can be attached to the 2" RI without use of the centering cone. This is done as follows:
1) Loosely attach the GBA to the RI with the three #8-32 machine screws, washers, lock nuts and, if necessary, shims.
2) Securely attach the GBA to the RI with two 1/4"-20 bolts, after first lining up the alignment marks on the undersides of these two parts. These bolts go through the threaded holes in the RI provided for use of a starting pin. This centers the GBA relative to router's arbor.
3) Securely tighten the lock nuts attached to the three #8-32 machine screws.
4) Remove the two 1/4"-20 bolts.
If the 1/4"-20 holes in the RI will not be used for a starting pin, the GBA can be attached to the RI with the two 1/4"-20 bolts alone (possibly with shims). Obviously, the bolts are threaded from the bottom and must not extend above the top surface of the RI.
I don't know if this tip could be adapted to any other router lifts.
Cary
One accessory I bought is the guide busing adapter ("GBA"), which allows Porter Cable template guide bushings to be used. One attaches the GBA to one of three ring inserts ("RIs") that come with the ProLift, namely, the RI with the 2" hole. It is attached with three #8-32 machine screws, washers, lock nuts and possibly shims. The machine screws pass through oversize holes in the GBA, allowing the GBA to be centered relative to the router's arbor before the screws are tightened. This is shown in these two pics:
90674 90675
Centering is done by placing a provided aluminum centering cone in the router's collet and raising the router until the cone centers the GBA (with the three lock nuts tighened only loosely). Then one carefully removes the RI--so that the GBA doesn't move--and tighens the three lock nuts.
This centering procedure must be performed whenever the GBA is attached to the 2" RI. One could normally leave the GBA attached to the RI, but there would be times it would have to be removed to use that RI for a bit that is too big for the GBA, but too small for the larger RIs.
To avoid the need to use the centering cone to center the GBA, I made the following modification to the GBA:
1) Securely attach the GBA to the 2" RI as per the instructions, using the centering cone.
2) While the GBA is attached to the RI, drill two 3/16" holes through the GBA, with the drill centered in the two 1/4"-20 threaded holes in the RI. These threaded holes are provided for use with a starting pin. By using a 3/16" drill, the threads will not be touched by the drill, and therefore will not be damaged.
3) Tap the two holes just drilled for 1/4"-20 machine screws, by screwing the tap into the allready-tapped holes in the RI and then continuing the thread through the holes just drilled in the GBA. (See pics above.) Because the GBA is made of aluminum, which is relatively soft, a 3/16" hole is large enough for use with a 1/4"-20 tap, and the tap will remain centered on the threaded hole in the RI as the hole in the GBA is threaded.
4) Because the holes just drilled and tapped are 180 degrees apart, it is necessary to make alignment marks on the undersides of the RI and GBA. These marks indicate the position of the GBA relative to the RI when the holes were drilled and tapped (i.e., which of two possible alignments).
In future, the GBA can be attached to the 2" RI without use of the centering cone. This is done as follows:
1) Loosely attach the GBA to the RI with the three #8-32 machine screws, washers, lock nuts and, if necessary, shims.
2) Securely attach the GBA to the RI with two 1/4"-20 bolts, after first lining up the alignment marks on the undersides of these two parts. These bolts go through the threaded holes in the RI provided for use of a starting pin. This centers the GBA relative to router's arbor.
3) Securely tighten the lock nuts attached to the three #8-32 machine screws.
4) Remove the two 1/4"-20 bolts.
If the 1/4"-20 holes in the RI will not be used for a starting pin, the GBA can be attached to the RI with the two 1/4"-20 bolts alone (possibly with shims). Obviously, the bolts are threaded from the bottom and must not extend above the top surface of the RI.
I don't know if this tip could be adapted to any other router lifts.
Cary