As promised in another thread I got around to giving this a try.
This is the second custom pad I have made for the Duplex linear sander and neither have ended up being done with the 'sand in' method. I investigated using the sand in for this one but came up with a more controllable method to create the small radi. I ended up making a round over pad which can also be used to sand beads.
I made the pad do double duty by using one side / edge for a 1/4" and the other for a 3/8".
To form the shapes I used my router table with a variety of bits to easily create the profiles and remove excess material. The LS130 makes an ideal push block !
Round nose bits made the radius and then a straight bit and panel raiser to remove material.
Put layout lines on the ends and transfer them to were ever needed. The lines make it easy to just eyeball the bit height and fence locations.
I cut the angles away steeper than the actual angle for the bead in order to help keep the abrasive away from the bead corner to help prevent rounding off. You can see both sets of marks in this shot.
Getting the velcro to conform on the pad takes a little work because of the tight radius. I use an appropriate diameter dowel and some other pieces to clamp the velcro in place while the adhesive set. Even though it is contact adhesive the velcro wants to pop out of the shape. Left it over night to be sure.
It came out good. Just drill or cut or a little of both to open up the DC holes.
Use a dowel to help press the abrasive into the shape. It is nearly impossible to get it to confrom to the sides and flats , but it doesn't really need to.
In use it is definitely a two hand deal when sanding beads and takes some practice to keep it from taking off the edges. But it does work quite well. Obviously round overs are easier to sand. Must use thin abrasive like Brilliant or Granat. I did not have any Granat to test with.
I have not used it except for the test sanding but it seems to do the job. I would strongly recomend practicing with this pad before using it on the real work piece.