Drum sander woes:(

[larry merlau]

i have a delta 18x36 drum sander and had some soft maple that was planed to 13/16" and then sanded down to touch over 3/4". took small cuts with 120grt paper. wasnt dogging it down. but still got deep groves that were depressed in the surface. took and RO sanded it with 100grt and got most out but still had some left after several passes with the RO. any suggestions on how to remedy in the future. is it the machine setup or the operator? took and ran the boards threw, 3 times at the same setting to hopefuly eliminate this but it didnt work. thanks fer your input

[CPeter James]

My first thought would be that the paper was not tight on the drum. I have a Performax 25X2 and if the paper bunches up on one of the drums, this will happen. The other cause can be build up on the paper, but this usually causes burn marks. I have the Wixy set up on my Performax and I only take about .005" or less each pass. The more I use mine, the fewer problems I have. It is NOT a finish sander, but it does get things FLAT so that you can take a few strokes by hand and be really smooth. What grit of paper were you using?

CPeter

[Mitchell Andrus]

If the groves are running in line to the board, check for build up on the paper and overlaps in the windings. Also - check the back of the paper for particles and/or stray glue left over from the manufacture of the paper, and before you wind the paper on the drum, run some Scotch Bright over it to be sure it's clean. You've got to be meticulous when setting the paper up.

If the groves are running across the board, you're getting chatter. I got rid of my cantilevered sander and got a 25x2 Powermatic. No more chatter. 150 on the front drum, 180 on the rear. Not a finish surface, but pretty damned close. Everything goes through it.

Check your naked drum with a dial indicator (turn by hand) to check for out of round. You might also take the drum to a GOOD machine shop and have them check for round and balance.

Mitch

[larry merlau]

well it wasnt glue build up wernt any onthe wood and was fresh roll of 120grt. willcheck out the drum for crude under the paper. wasnt over lapped either had that happen before, so i will look at the underside of the drum tonight. as for cuts taken i dont think it was taking to much at a time had the experience before as well and i sometimes learn from my mistakes:)

[Dave Anthony]

What speed are you running at? Moving the belt to the inner pulleys runs at a higher speed & seems to work better for finer grits. Are the grooves perpendicular or parallel to the feed direction? Were they evenly spaced across the board or localized to one side?

[Mike Armstrong]

. . . I have the Wixy set up on my Performax and I only take about .005" or less each pass.

CPeter
What's a Wixy?

Mike

[Mike Goetzke]

OK I'm a newbe too with my new Performax 10-20, but, maybe can help. I was luckier than you - I just completed an 1-1/4" thick cutting board as my first project using the sander. Therefore, I had room for trial/error (and needed it).

1) I got some gouges on my first pass and I think it's because I didn't have the drum lowered enough.

2) I used 120/150/220 paper and still had noticable sanding lines in the board (may have been due to end grain sanding). Had to use the ROS more than I thought I would have to.

3) Had best results with about 1/2 max. speed.

4) Since I have the 10" machine I needed two passes. I found it's best to try to sand exactly 1/2 the width on each pass - otherwise you get a groove.

5) I did get some small burn marks once - I think when I run it through too slow.

6) My slab was 11" x 15" - any bigger and I think I'll need support tables. Performax sells them but they don't fold up.

Hope this helps and any tips you can pass my way would be appreciated.

Mike

[Mike Goetzke]

What's a Wixy?

Mike

I think he has this:

http://www.wixey.com/planer/index.html

[CPeter James]

That's it, sorry for the misspelling.

CPeter

[larry merlau]

What speed are you running at? Moving the belt to the inner pulleys runs at a higher speed & seems to work better for finer grits. Are the grooves perpendicular or parallel to the feed direction? Were they evenly spaced across the board or localized to one side?
dave i have the belt on the outside pulleys now and the groves are parrelle to the direction of feed on one side more than the other approx 3 inches worth.