I've never had a board shoot out on my drum sander, that's some scary stuff. If the conveyor belt is worn, I'd start with a new one. I know Industrial Abrasive can custom make on for you. After you get a new belt on there, I'd run two 1" strips of wood through the sander, one on the left, one on the right, and measure the thickness of each. If they don't match up, align the drums.

It's possible you were taking too much off at one time in conjunction with a worn belt. I like to feed the piece through on the conveyor while the drum is off, then lower the drum until it just about touches the surface. Each pass I lower it .005". This varies based on grit, wood type and board width, but it's a good starting point.

 

Are the drum and belt going in the correct directions. If the belt and drum are both going in the same direction, it could easily come out like a rocket. If the belt is loose or the the drive belt for the belt is loose, same thing.

Taking too deep of a cut or not deep enough can have to same effect.

May want to give Grizzly a call and see if you can get the owner's manual. I would start there.

 

I have an General which is effectively the same sander. After putting the hook and loop kit on, you're effectively making the drum wider. Mine was originally designed to use standard sandpaper rolls so I needed to adjust the pressure rollers farther down to press the material down to the feed belt a little more.

As for the feed belt, even with the rollers being adjusted right, you still might have a bad belt but as long as the rubber feels "rubbery" and not hard and cracked I would think you're still fine.

 

double post

 

I guess that you have not contacted Grizz tech services…..........................
Bill

 

I guess that you have not contacted Grizz tech services…..........................
Bill

- Bill White

I have not contacted Grizzly yet. I will definitely do that next.

I ve never had a board shoot out on my drum sander, that s some scary stuff. If the conveyor belt is worn, I d start with a new one. I know Industrial Abrasive can custom make on for you. After you get a new belt on there, I d run two 1" strips of wood through the sander, one on the left, one on the right, and measure the thickness of each. If they don t match up, align the drums.

It s possible you were taking too much off at one time in conjunction with a worn belt. I like to feed the piece through on the conveyor while the drum is off, then lower the drum until it just about touches the surface. Each pass I lower it .005". This varies based on grit, wood type and board width, but it s a good starting point.

- ClammyBallz

I did look into belts at Grizzly and they are like $375 which is almost as much as I paid for the machine so I was thinking that wasn't going to happen. I will contact Industrial abrasives and see what they would charge.

I have an General which is effectively the same sander. After putting the hook and loop kit on, you re effectively making the drum wider. Mine was originally designed to use standard sandpaper rolls so I needed to adjust the pressure rollers farther down to press the material down to the feed belt a little more.

As for the feed belt, even with the rollers being adjusted right, you still might have a bad belt but as long as the rubber feels "rubbery" and not hard and cracked I would think you re still fine.

- AZWoody

Ok I never really thought that would make enough difference but you may be right. I will adjust the rollers. As for the conveyor belt it's sorta rubbery but has some tears and it's pretty slick, not really rubbery anymore. I venture to say this machine is about 20 years old.

Are the drum and belt going in the correct directions. If the belt and drum are both going in the same direction, it could easily come out like a rocket. If the belt is loose or the the drive belt for the belt is loose, same thing.

Taking too deep of a cut or not deep enough can have to same effect.

May want to give Grizzly a call and see if you can get the owner s manual. I would start there.

- dbray45

The belt and the drum are going in the same direction however I don't believe there's a way to reverse the direction of the drum… maybe when I call Grizzly they can tell me that as well.

Thanks everyone for the responses so far.

 

Update:
I called Grizzly and after several times calling (their phone system is wacked) they were sorta helpful. Bob from Tech support didn't seem to know much about the machine he was referring only to the manual. But, he did suggest that I raise the drums or lower the feed rollers first. Too much drum and not enough feed roller can cause a pitching machine effect… He also said that I should replace at some point the conveyor but more than likely it's the feed rollers not being below the drum enough. Thank you everyone for your responses and suggestions. I love this site and everyone's willingness to help out fellow woodworkers.

 

I didn't know it had feed rollers - that makes sense

 

Shouldn't the drum and feed belt be going in opposite directions?

 

runwithscissors there are rollers to hold the material down and that's why they are ok to go in the same direction.

 

I would think that a dry-rotted substrate would not help your situation. If you're handy you might look at it and think of a cheaper alternative although rubber has gotten incredibly expensive since 2008. Not only did the political class steal our wallets they doubled the prices of damn near everything. Biggest heist in history.

As for the pressure against the stock? Why would the rollers be moving that fast that boards are shooting out the rear like hot diarrhea as they've termed it in California? It doesn't make sense to me. Those rollers should be moving the board through the drums which are already exerting the same directional push you don't want them moving that fast. It does seem that the drums should be moving in reverse. Have you tried flipping the plug around? Just kidding. I wonder what would happen if you reversed the drum motor. I would think you might get a cleaner pass with the two working against each other where it's obviously going through too fast now. Some machines you can actually control the speed of the rollers which would also be an option by putting a potentiometer on the rollers to control the speed. Not having a drum sander of my own I don't even know if there's a standard direction for the rollers vs the drums or if each company has their own setup that they think works best.

Now that I've typed all this I looked at the date. OK, so it's a bit dated but it may be helpful for someone else searching at a later date.

 

I would build a carrier sled to hold the cutting board and make it at least 3 times the length of the cutting board.

 

Adjust the sander just to where the drums barely touch the material. Run the piece through without the sanding drums running and see if the drive rollers are adjusted where the piece will go though. You should not be able to hand slide the material though, the drive rollers will be applying enough pressure to prevent this. I have the same sander and have never had this problem.

 

If it was 3 phase just switch any two wires on the cord