Drum sander problems

[Roy from Pa]

I was contacted by a guy about uneven lams coming from his drum sander.

He said they are wavy not perfectly flat.

He has seen my videos of  me running lams through and he has a grizzly sander like mine.

I gave him some suggestions and I'm seeking you guys input.

[Bowjunkie]

Was he making good lams, and then something changed, or has he been having this problem from the start?

This is going to be hard to troubleshoot without more info, and without actually being there to inspect his machine and see how he's doing it. There are just so many variables.

I'd check to make sure nothing came loose, all bearings and bushings are good, check feed rate and the amount of material he's trying to remove. He might just have to slow the feed rate and take less material off each pass. What grit paper is he using?

Also make sure the lam isn't slipping on the sled, the sled isn't slipping on the feed belt, the feed belt isn't slipping on its drive roller, and the drum drive belt isn't slipping on a pulley, etc... could be lots of things bud. I'm just throwing some things out there, I've never had wavy lams, but my machine is a little different than yours too so, maybe some of this doesn't apply, but those are the sort of things I'd be looking at first.

[Roy from Pa]

Thanks Jeff.

I'll have him jump in here.

Not sure about your first question of if he did get good lams.

I don't think he has gotten good lams.

He sent me a pm late last night and I told him to check a lot of things you listed.

[Bowjunkie]

Ok sounds good. There's others here with more lam grinding experience than me and I'm sure they'll think of some things too.

[mmattockx]

More questions - are these tapered lams or flat? Is his sled known to be true and flat?


Mark

[Roy from Pa]

Both and sled is flat.

[Flem]

I have noticed with my drum sander, which is manual feed, that if I am not smooth and consistent with my feed rate I can get wave or mid board snipe. I would have him inspect the all the mechanisms associated with the feed belt. Maybe get a dial indicator on the drum and check it for runout just incase. Some times a simple tune-up can remedy minor problems. Clean, lube, adjust if necessary.

[mmattockx]

Both and sled is flat.

Hmmm. How bad is the waviness in terms of measured thickness?


Mark

[kennym]

On my first drum sander, I was getting random spots .004 to .005  thinner, so I sold it and bought a bigger widebelt. Same same , finally when I had pulled most of my hair out I discovered the conveyor belt splice was thicker then the rest of it.  Just a thought, but possible depending on the wave...

[Shredd]

   I wonder if the feed speed is oscillating for some reason...  Maybe peek under the belt and see if there is any built up resin on the platen...  The belt could be grabbing...  Maybe clean both surfaces anyway... Or something could be wrong with the drive motor or gears...

   If there is lots of short waves the drum might not be rolling true...  Check as flem said...

   The Junk man had lots of good suggestions...

[Shredd]

Or the belt could be slipping...

[Roy from Pa]

I mentioned all you guys said above, but this morning I sent him a PM and he is in the hospital.

They had to take him in an ambulance for lung problems last night.

So we will have to wait till he gets home, thanks guy's.

[kennym]

Dang, hope he is OK!!

[Shredd]

   Oh No!! 

[Crooked Stic]

If they a wavey the feed rate is not costant. Figuring out why may take awhile.

[Roy from Pa]

Thanks Mike

[deercraver]

Roy you were talking with my father.
this is what is going on we have a brand new grizzly drum sander we will cut lams at 0.200 then run them thought the sander fast slow very small bites where it does not make any sound change a little bigger bites. the target let say is .125 it will be .125 then 4 inches down it may be .133........0.136..0.129 and so on some times i can get them perfect but i have to run the lam through 150 times.i have removed the velcro from the drum and taping on my paper..
 

[deercraver]

my father is doing ok holding him for a few days but doing ok....
thanks for the concern i will pass it on..

[Mad Max]

sounds like snipe.
measure it at 10" and 20" and see if it's good or every inch from 10-20

[deercraver]

I have measured every inch from one end to the other wavy wavy