Hi Greg,
I know exactly what you mean and I don't want to imply that this task should be taken up with nothing more than an electric drill and some large felt markings. But if one has the capability to mark the positions using the jig and center punch, then drill and tap the holes on a stationary drill press it does become a standard milling operation.
I've been looking closer at the supplied jig and it is quite possible that one could be off by a millimeter either way. The jig's manufacture is fairly precise but there is enough play that could lead to some small error in placement. This would make it quite important to be as exacting as possible when mounting on a fixed armboard. As you say, measure twice (and perhaps thrice) and drill once. With pivoting armboards this tolerance is a bit more forgiving as the jig will probably get you to within a millimeter. Then the fine adjustment could be made with slight movement of the armboard much the same way as the SME slide works. While true that the pivot is traveling in an arch, in the limit of a few millimeters this should be of no consequence. This may be what Doug was referring to when he mentions measuring the distance after mounted and it would make perfect sense to do so.
But he's teasing us with his silence! Probably out fighting the mall-ites.
I know exactly what you mean and I don't want to imply that this task should be taken up with nothing more than an electric drill and some large felt markings. But if one has the capability to mark the positions using the jig and center punch, then drill and tap the holes on a stationary drill press it does become a standard milling operation.
I've been looking closer at the supplied jig and it is quite possible that one could be off by a millimeter either way. The jig's manufacture is fairly precise but there is enough play that could lead to some small error in placement. This would make it quite important to be as exacting as possible when mounting on a fixed armboard. As you say, measure twice (and perhaps thrice) and drill once. With pivoting armboards this tolerance is a bit more forgiving as the jig will probably get you to within a millimeter. Then the fine adjustment could be made with slight movement of the armboard much the same way as the SME slide works. While true that the pivot is traveling in an arch, in the limit of a few millimeters this should be of no consequence. This may be what Doug was referring to when he mentions measuring the distance after mounted and it would make perfect sense to do so.
But he's teasing us with his silence! Probably out fighting the mall-ites.