Picture of an old sled
I believe that Clint's answer would solve your problem as you need "start/stop" points on the sled for the sensor that seem to be missing from your description. I do, however, disagree with Clint about their size. The sensor needs only about an inch and three-eights to function correctly. The three and a half inch "end-piece" is only necessary if you want something to butt your board against for "stay under rollers".
I personally use these smaller end-pieces so that I have room for using screws and washers to hold the ends of my work-piece.
The two wood pieces screwed to the sled at the top and bottom of the work-piece were because I had four pieces to carve and this simply centered them in the Y direction. I do not recall why I wasted so much purpleheart, that seems so silly at this time!
Measuring the width of the sled can be done anywhere on this sled since the rails are less than 1" wide and and at 1" (Y direction) from the top rail the sensor finds a void so it goes to find the other rail. If the individual rail is 1" or more, it will simply consider the rail to be the entire sled/work-piece if it then finds a void.
As you can see, my end-pieces consist of a fixed 3/4" strip and pieces of scrap I either attached with fasteners or tape simlpy to get the necessary 1-3/8" for the sensor to see after the rollers drop off the end of the sled.
I ran across this picture while searching for one to show how I use screws and washers in a grove in the end of the work-piece be running in through my table saw. That sled is still in use but it needs to be retired because of all of the screw holes and carved places in it now.
Ken,
V-1, 2, & 3
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When the Government fears the People, there is Liberty.
- Thomas Jefferson
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