Wet timesaver-when to change fine belts?

HI guys,

This may be a bozo question, but I've got a new-to-me wet 19" timesaver, running 220 grit belts.
We'd just got it up and running after a full rebuild when the shutdowns hit.
(Bought it used. "Was working when pulled". Famous last words. There wasn't one single system on that thing that wasn't hosed. The *coolant pump* was seized up for god's sake. How do you seize a coolant pump???)

Anyway, many dollars later, it's basically a new machine, and works *well*. I'm very happy with it. (Now)
Except: I have no idea how to tell when it's time to change the belt. It's cutting a little slower than it did when the belt (220 grit) was new, but it's still cutting reasonably well. I'm cutting laser cut 6061 parts, mostly to deburr the laser slag from side 1, and to unify the surface prior to tumbling before anodize. It's a high end part that has to look good coming out of ano, so it needs a solidly grained surface heading into the tumbler. So we do two passes on each side. The first belt has about 750 parts on it so far, 4 passes per part, about the size of a dinner plate, most of them. And it's still cutting, just a bit less aggressively.
So how do you tell when it's time to change a fine belt?
(I've tried calling Timesavers. I think they're down for the shutdown, or at least I haven't had any luck getting them on the phone.)

Next question: one of the major issues with this "works fine" machine was that it showed up with a 1 inch wide, by 1/2" deep gouge torn out of the main contact roller. $3000 and 6 weeks later, we have a brand new contact roller. Anybody got any idea how that might have happened the first time, and how I may be sure it doesn't happen again? I'm running large-ish flat parts with no areas that stick up or might get tweaked into a shark-fin, but just because I don't want to pay another 3 grand, I'm looking to make sure I don't do something stupid.
(Don't worry, given what I paid for it, I pretty much knew what I was getting into, so I didn't get especially screwed on the cost. I was just disappointed at exactly *how* thrashed the thing was.)

Any advice gratefully received.
Thanks,
Brian

My AEM sander had a damaged drum when I bought it. I was aware of it. My solution was to have the roller re-vulcanized and ground and finned. It was really quite reasonable- maybe $200-300 range. It's a 24" roller that might be 4" diameter. My guess is that a knot broke free from a piece of wood it was sanding and took the chunk out. rubber may have been older and harder at the time. Not quite a parallel to your machine, but perhaps some help. especially if you do damage it, get it fixed.

For me, sanding wood, I notice a decline in surface finish. when I start seeing horizontal lines, the belt is done. in a production environment, I suspect you may want to swap it more frequently as you can try to determine the cost of a belt vs the extra time you are spending running it.

Pete

HI Pete,

Yeah, I looked into getting the roll re-covered, but it was going to end up being nearly as expensive, and nearly as slow, and the company that does them has just started doing them, after the old guys went under. Quality is....iffy right now. So I popped for the new one, and put the old one aside to re-cover when/as/if I have time or $$. With all the money I was sinking into this thing, a difference of $500 or so wasn't that significant, and I wanted to get it done *right*.
Once.
The first time.
So I could get the thing into action.
Which has really saved our tails during the shutdown. Prior to this, our laser cutter was hand-deburring the parts with a crew of guys using DA's, at a few minutes per part. Even with four passes, the timesaver blows through about 150 parts an hour, with just two people (socially isolated on opposite sides of the 7 foot tall machine). I *like* this thing. The hand deburr crew can't operate now, but my wife and I *can* run the sander, and it's no big deal. Ah technology....

Thanks,
Brian

Oh yeah, I couldn't work without my sander. Speed and quality improvements. I used Finzer roller to do my project. They weren't fast, but quality was excellent and price was more than reasonable. Not sure how you got a quote for that much money!

Pete