Problems with Performax/Jet 16-32 Conveyor Belt

[Eric Meier]

I'm wondering if anyone else has experienced this problem:

Under normal circumstances, my 16-32 drum sander works perfectly, but when I lower the drum to around 3/16 or 1/8" or less, for sanding thin materials, I can hear an occasional scratching sound.

What I've found is that the conveyor belt is not perfectly taut across the entire belt, and every revolution, there's a small area that wrinkles up and touches the sanding drum.

This is causing some irritation, as the two surfaces quickly dull each other, so that there is a smooth spot with little to no gripping ability on the conveyor belt, and the sanding roll that's wrapped around the drum gets dull and burns the wood and has to be replaced.

I tried the obvious solution: to tighten the conveyor belt with the two adjustment handles that are on the outfeed side of the unit. But I tightened them relatively tight, and it didn't really make any difference. I'm afraid to over-tighten them, as the manual says this can damage the machine (probably the rollers).

I don't know if the problem is from a bad conveyor belt, or if I just don't have a clear idea as to what is "too tight" on the belt's tension. It seems like it has a lot of tension on it already. Any thoughts on this situation? I'm planning on buying a new conveyor belt, and I'd prefer to not wreck the new one too.

[John Coloccia]

It's a problem with the minimum thickness specs. They are bogus and there is no way you can go that thin stock out if the box. The only solution that I know of is to use a sled. Mine is simply a piece of MSG with sand paper glued to the front. The sled rides on the conveyor, and the work rides on the sled (actually on the sandpaper on the sled). I basically just extended the conveyor up 3/4 of an inch.

[John Coloccia]

I meant mdf, not MSG. Stupid auto correct!

[Kyle Iwamoto]

It can be done. I routinely sand to less than 1/8". That's the reason I bought it. Off hand, I'd say check the tension on the conveyor belt. I should be tight enough to not have that ripple, or maybe your belt got wet. Got manual? It tells you how much to tension it. If the belt does not run at the slowest speed, then it's way too tight. If it's tight enough, change the conveyor belt.

The other problem could be the parellelism (is there such a word?) across the sander. One side may be lower than the other. That should be easy to check. And you did say that it works other than that.

Be careful adjusting the tension. Make sure the belt stays in the center.

[John Coloccia]

It may have to do with the kind of DC you have too. I can tighten mine to the point that the conveyor is flat, but the DC sucks the conveyor right into the drum regardless. With a smaller DC this may not be as much of a problem.

[Chris Padilla]

I'm w/Kyle: I sanded mega amounts of walnut down to 1/16" and it all came out perfect although it is a slow (slow as molasses moving uphill in the winter) process.

These machines are a pain to adjust although mine is the Delta 18-36 sander. I killed an entire Saturday doing nothing but constantly fiddling with and adjusting my craigslist-purchased sander but once I understood it and dialed it in...it churned out great stuff.

[Brian Tymchak]

Eric,

Yes, I have the same problem, probably worse than you. Did you just get your sander recently?? I got mine late last year when they were on sale. (Pretty much an impulse buy..) :o Does your belt look anything like the photo below? I removed the conveyor table from the rest of the unit to try to troubleshoot the problem. This is the bubble I have with the belt adjusted to track straight.

When I set mine up, I could not tension the conveyor belt without going to extreme adjustments to keep it from crashing in to the outer table frame. I was just running the conveyor in set up, not sanding anything. There was such a bubble in the belt that it sanded the paint off the top of the base before I realized what was going on. (That's when I pulled the table off). Even with extreme adjustments that got the belt tracking straight, there is still a bubble on the inner side of the table. (see pic). To control it on the bottom a little bit, I put both of the ceramic belt guides below the table on the inner side. But it still is not good enough to sand thin materials as you are trying to do. The belt clearly has a manufacturing flaw. I haven't yet taken this up with Jet Support because others things have come up, but that is my next step. I was thinking of taking a video with my phone and sending it on to them.

Brian

[John Coloccia]

I had that problem initially. Jet had to replace the whole conveyor assembly. Now the bubbles gone but I still can't make it tight enough to keep the DC from sucking it into the roller...at least not until it's ridiculously tight. I spoke at length with the folks at jet and they told me flat out that it's a problem, and to use a sled. They also said that the minimum spec was the minimum that would go through without being shredded, not the minimum height of the drum. I wasn't at all happy to hear that.

I'm starting to think that this will be hit or miss depending on your particular unit, belt and DC setup. I do know that the conveyor has been a consistent source of grief. I do really like it now that it's all dialed in for me, though.

[Terry Hatfield]

I meant mdf, not MSG. Stupid auto correct!

Dude! I thought we were having Chinese. :D

[Mark Levitski]

You guys try simply reversing the belt (removing it, rotating it end to end, and replacing)?

DC's can do that--open another blast gate.

[Kyle Iwamoto]

Wow, now you guys got all paranoid about my DC sucking up my toneboards into the drum.......

[Eric Meier]

Well, my conveyor belt certainly doesn't look as bad as the one in the picture. It is a very subtle, almost imperceptible bulge in the belt. The only way I noticed it was to get down and look across the belt at eye level, and it's a very small amount that it lifts off the table, just for a few seconds.

I'll try reversing the belt to see if that helps, but I really like the idea of a sled. That would also mean a lot less cranking on the height adjustment if I go from thin (1/4" or less) to thick (3/4" or more) stock---since the height of the table would already be lifted off the table by 3/4" from the sled.

[Kyle Iwamoto]

When you build your sled, if you use plywood, run it through the sander to level and flatten it. Or you can use MSG. I mean MDF:), it's pretty level and flat.

Sorry, I just had to get that jab in.... LOL

[John Coloccia]

Yeah yeah, ha ha ha :p

[John Coloccia]

Wow, now you guys got all paranoid about my DC sucking up my toneboards into the drum.......

What I do now for thin stuff, like acoustic sides, is rough size them with a Wagner Saf-T planer, and then get them down to final size with the Jet. The rollers do a dandy job of holding down anything you put through. It's just the conveyor belt that's the problem...at least on mine. I've also found that different belts have different characteristics. The last one I had was a bit worse than the current one. I tried some aftermarket ones that were absolutely awful. I only buy the Jet/Performax ones now. They're a lot more consistent.

[Jeff Monson]

I recently bought a 22-44 pro unit and it has the same issue, I tightened the belt up to where I can not stop it with my hands + 1 full turn, the bulge in the belt is almost gone now. It does not cause any performance issues with mine....but I have not sanded anything beyond 1/4" yet.

BTW, these machines are a MAJOR PITA to get the drum paralel to the bed!! Once set though, I'm really liking the sander.

[Chris Padilla]

John,

I wonder if toning down your DC would help? Maybe open a second blast gate and experiment with how much it drops the suction.

[Kyle Iwamoto]

I tried some aftermarket ones that were absolutely awful. I only buy the Jet/Performax ones now. They're a lot more consistent.

Thanks for that info.... My conveyor is pretty good though. So far I haven't had problems. You pay for what you get, I guess....

[Brian Tymchak]

You guys try simply reversing the belt (removing it, rotating it end to end, and replacing)?
.


No, that thought never occurred to me for some reason.. :confused:

The bubble is so bad on my machine that I only considered replacing the belt. But, I'm going to try turning it around anyway. Thanks for the suggestion.

Brian

[Brian Tymchak]

I've also found that different belts have different characteristics. The last one I had was a bit worse than the current one. I tried some aftermarket ones that were absolutely awful. I only buy the Jet/Performax ones now. They're a lot more consistent.

Thanks John. Good info.

Brian

[John Coloccia]

Re: flattening the sled

I would reccomend flattening the sanpaper side first, attach the sandpaper, flip it over and flatten the back. This will remove and slight imperfection in drum alignment for your thin stock, which is precisely where you need perfection the most. Also, if the alignment drifts slightly, you can always just flatten the back again. Just be sure to mark the outboard edge so you don't accidentally run it through backwards.

[Don Chmielowiec]

Regarding tracking issues. I could not get my belt to track properly. After 2 hours of futile efforts I stumbled upon the following. It worked!
1. with the belt loose but still on, remove the 2 bolts on the drive roller opposite the motor. 2. press down on the end of the drive roller so that it is 1/8 or so below the platen and clamp it tight so it cannot move (use a small c clamp so the belt does not hit the clamp. Note: the bolt holes will not line up). 3. Run the conveyor belt full speed while adjusting the outfeed roller. 4. You may need to tap the drive roller up or down a skosh to obtain correct tracking. 5. Drill new holes in the bracket, while still clamped, so you can reattach the end of the drive roller to the platen frame. This technique provided good belt tension across the platen as well as prevented the belt from tracking toward the drive motor. I hope it does not wear the drive motor in the long run as it now under some tension. I purchased the 25 dollar belt from 2sand.com.

[Mark Woodmark]

I have found that the stock may slide even on sandpaper. What I use is double sided masking tape on a scrap piece with the piece you want sanded on top that and the tape between the two. It holds better than the sandpaper, but is a little more difficult to remove the sanded piece when done. I also use this method for pieces too short to run through on their own

[Andy Pratt]

I have a generic belt for my 16-32 that is similiar in defect level to brian's. I rarely sand anything below 3/4 so it isn't a big deal to me, but I start hearing rubbing anytime I am below about 3/16" so I can confirm that the belt can be the problem. If I tighten the belt to where the "bubble" goes away, it will not track correctly and would rub along the edge and tear itself apart in a matter of minutes if I let it. This leaves me with the conclusion that the belt is not perfectly cylindrical, which seems to explain the related problems. I previously had a JET brand belt on there that did not have this same problem. I figure it would be easy for a factory to mess this up, 1/8" off on the glue line on a 16" wide belt would do it. If I paid $70 for the JET brand belt I would ask for a refund, for $30 I figure I got what I paid for, and it doesn't cause a problem for the thickness of materials I typically use so I'm happy to have saved the money. If I sanded 1/4" or less regularly I would just switch to a belt with a good guarantee, which I'm guessing anything from JET/amazon would probably fit the bill for.