Drum Sander Initial Set-up

[sehast]

This a continuation of the previous Drum Sander for the Shopsmith posts
http://www.shopsmith.com/ss_forum/viewt ... 5&p=216409
http://www.shopsmith.com/ss_forum/gener ... ml#p216413
One the first set-up tasks, at least initially, is choosing the range of sandpaper grits you will use. I found a useful document on the internet that gives the specifications for each grit.

GritsSize.pdf

(12.88 KiB) Downloaded 905 times

The particle size gives you a rough idea of how much wood you will take off in a single pass over the drum. For example I choose 40 grit for my coarsest paper with a particle size of .01665” and it takes off about .015” per pass or close to 1/64”. I choose 40, 100, 150, 220 and 320 grits for my initial start. I found that you can easily skip a number of grits as you build the surface. The 40 grit can be used for the first cut on rough stock followed by 100 and 150 to get a very workable and glue-able surface. The 220 grit puts the finest surface you will want to use before applying stain and finish. I use the 320 grit for sanding between coats of finish and after the final coat. If a finer surface is desired this is where I start wet hand sanding with 600 and 1000 grit with a little bit of water for lubrication. Maybe I will change my mind later but right now I just can’t see using the drum sander beyond 320 grit even though grits are available all the way down to 1500 grit. This is important because the drum sander is set for the finest grit of paper you plan to use. The table is set so the 320 grit paper on the drum has about .001” clearance with a straight edge setting across the opening on the table. When drum starts to spin the paper elevates and makes just enough contact with the stock to take a very small amount off. The setting does not need to be changed for coarser grits. This is a onetime setting unless later you want to use a finer than, in this case, a 320 grit paper.
I have found the best source for 3” sandpaper rolls to be Online Industrial Supply

http://www.onlineindustrialsupply.com/3indrsarohlo.html

It is not quite as good as Kligspor but it lasts a long time and fairly inexpensive. It is also one of the few places you can get 40 grit.
Next to set is the speed for use. The standalone Flatmaster sander uses a flat 1725 RPM. I have found that it is a good all-around speed but I like to go up to 2000 for fine grits like 320 and 220 and down to 1600-1700 for 40 grit. Last to set is the position of the Board Buddy rollers that keep the stock firmly pressed down on the table as it passes over the drum. I set the rollers so they contact the middle of the stock when it is up against the fence and as close to the drum opening as possible, one on the infeed side and the other on the outfeed side, but they should not be directly over the top of the drum. Use 100 grit paper to check they are set correctly. You should not get any snip on a sanding pass.
You might want to set-up several different grits on the drum. For example you could put 40 grit on the first 8 inches of the drum followed by 8 inches of 100 grit and then 8 inches of 150 grit. That way you can fully prepare rough stock without changing paper. However, after a few times of changing the paper I am able to a complete the change in less than a minute so I usually use a full drum of the same grit.
That pretty much completes the set-up.

[BuckeyeDennis]

Boy, could I use one of those for my secret-room paneling boards. I'd like to put that project on hold and build a sander before finishing. But my wife would kill me.