Thickness Sander Continued

I was able to accomplish more than I had anticipated, in part because my wife and granddaughter took longer than expected to travel from Boise. The almost finished sander is pictured from the in-feed side, and you can see the simple adjustment that raises and lowers the platen. The eye-screw is threaded through an insert and pushes against a mending plate, which helps prevent the screw from digging into the MDF.

I say, "almost finished," for a couple of reasons. The drum still needs to be rounded over completely and adjusted to the platen. Viewed from the in-feed side, it is between 1/32 and 1/64th of an inch higher on the right side. I am rounding and making the adjustment by running a sheet of sandpaper attached to a piece of scrap ply through the sander as it turns. It may be quicker to back the screw out and tap up the right side of the platen, but we will see where my patience takes me.

Also, of course, once adjusted, I will need to attach the sandpaper to the drum. I have ordered adhesive back sandpaper from Amazon, and I think it will do the trick, but here again, we shall see. It hasn't arrived yet, perhaps to my benefit, because I would have been tempted to put it on before rounding and adjusting the drum. If not, I have a back-up plan for a pair of hold downs on either side of the drum, but I am hoping they will not be necessary.



A couple of problems did emerge. Pictured is the power-train for the drum. The belt runs between two pullies, the one attached to the arbor of my table saw is a one inch diameter, the one attached to the drum is a two inch. The rotational speed of the drum seems about right -- not sure what it is exactly -- but the bottom pully had to be modified to fit on my saw arbor. I had to cut away the set screw. Since it was aluminum, it cut away easily.

Also, on the right side, during the trail run, the bearing on the right side grew very hot -- literally smoking hot. The problem was a small set screw that holds the interior sleeve of the bearing firm against the arbor. It is visible in the photo. There were two on each bearing, and on the right, one of the set screws wouldn't remain set. It had backed out and was turning against the housing generating the heat. I removed it, and now things seem to be fine.

Finally, when the bearing over-heated, the drum came loose on the arbor. The two events were most likely not connected. It is held firm to the arbor by two bolts on either end which are cranked in against either end of the drum. It seems to be holding fine now, but if necessary, I will pin the drum through the arbor. Here again, I am reluctant to do so, because that too will require dis-assembly, but will do so if necessary.