Scorching drum sander - Help

[Jeff Cord]

I have a fairly new Jet 16-32 drum sander.
After setting it up I have adjusted the drum to be parallel.
I've been making some cutting boards from maple and purple-heart (I know, real imaginative, but...).
Anyway, I have one main problem.
I've progressed to 100grit paper.
I'm taking very light passes (I may turn the crank about 1/12th of a turn).
The board moves through the the sander and I can hear the paper contacting with the board.
I then make another pass with the same board and I don't make any changes to the height of the drum.
I hear the same sound of the paper contacting the board.
OK, I think. It's end grain so perhaps it will take a few passes at the same height to remove the scratches from the previous grit.
I then go for another pass and after about 2/3 of the pass the sander slows down and my boards scorch.
If I didn't know any better I would think that the drum is dropping on its own but that doesn't sound likely.
I'm trying to keep with very light passes, especially since it's end-grain, but even with the very light passes this still happens.
Added info: I'm using stock Jet paper and I'm cleaning the paper fairly frequently.
Help.
thanks,
Jeff

[John Durscher]

Jeff,

I just happened to have downloaded the performax manual last week to replace the feed belt so I'd just been reviewing the troubleshooting part of the manual. I copied the following from the troubleshooting section at the end of the document for your reference -

Wood Burns.

1. Abrasive strip overlapped. => Re-wrap abrasive strip.
2. Excessive depth of cut. => Reduce depth of cut.
3. Depth of cut excessive for fine grit. => Use coarser grit or reduce depth of cut.
4. Feed rate too slow. => Increase feed rate.
5. Abrasive loaded. => Clean abrasives.
6. Worn abrasives. => Replace abrasives

My guess is that you're probably feeding the stock through the machine too slowly for the amount of cut you're taking. This will heat up the board and sandpaper. If the board is really warm coming out of the sander then reduce the depth of cut and/or increase the feed rate

Good luck.

John

[Larry Edgerton]

I would agree with John. I had a Performax 22 open sided sander for a while and I found i recieved better results all the way around by speeding it up and doing more passes. It is doing the same amount of sanding in roughly the same amount of time, but is spreading out the heat.

[Jeff Cord]

I had looked at the troubleshooting also.
I'm running at the fastest speed with as light a "cut" as possible.
I'm just confused as to why, after running for 2 or 3 passes at the same height the next pass slows down and scorches when I'm still running at the same height.:confused:
Jeff

[Mike Cutler]

Jeff

Some things to check;

Is the sanding strip coming loose?
It's need to be tight, as tight as you can get it. The sanding strip loosens up after it is first installed and needs to be tightened up after a few passes.

Are you getting all of the dust you can?
Dust that collects on the surface of the material can cause burning. Dust can also collect on the feed belt and make the material ride higher. it doesn't take much. Brush the feed belt off

Is the feed belt tight? and or does it have a visible "hump" in it?

I used to set my feed rate just slightly less than 1/2 the max, and took very light passes.

[John Durscher]

Mike has a good point, check to make sure the feed belt isn't slipping. When I replaced my feed belt this week it worked at first and then started slipping.

John