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Post by mike211 on Jan 20, 2015 17:06:39 GMT
For sites with the composite upgrade,
We are curious as to any issues others have encountered following the composite track/chain upgrade to the PSMs. We are frequently adjusting/tightening the chain tension by moving the bullwheel. We have moved the bullwheel approximately 5 inches since the upgrade around August of 2014. When the chain begins to stretch we are seeing tray 1 vary its position by as much as 3 SEIs (per FMPCS). We have looked into the usual SEI stability culprits (encoder, counter module, broken welds, loose tray 1 sensor/reflector, etc...), but the situation is remedied when we tighten the chain.
Can anybody share similar stories and/or advise on mitigating this issue with the composite chain?
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Post by jflores0002 on Jan 20, 2015 19:04:36 GMT
5 inches? Wow! That means your chain has stretched a total of 10 inches...
When we first got the chain in it was a pain in the ass. Breaking constantly.
Can you be more specific as to your major problems? SEIs are off, mail not landing
on right tray, varying SEIs etc, etc. There shouldn't be that much wear and tear.
Once we figured out that the PM needs to be done daily and when replacing "bones"
on chain to make sure the person replacing them is doing it correctly. We found that
most mechs don't bother with the pressure washer or replacing with incorrect washer
therefore causing chain to not be snug which was causing the chain to stretch as it
allowed slop in the chain. I would take a good look at all the links and make sure
every single link has that pressure washer underneath. It needs to be a pressure
washer not just any old washer. For those who don't know what this washer looks like,
it is a washer that appears to be warped. This holds the pin in place when cotter pin
is applied.
Are you stretching your chain because of the SEIs? Is FMPCS reporting
a wide window at tray 1?
Juan
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Post by jflores0002 on Jan 20, 2015 19:07:34 GMT
Oh BTW, we got ours in 2 years ago and it actually runs pretty good now. Hardly any noise.
We also found that the center guide wheel tends to wear down or get dust between caught
up inside the shaft. Our guy that does the PM blows these center wheels down.
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Post by Admin on Jan 20, 2015 22:44:03 GMT
Hey Mike211, We've had a similar amount of chain stretch(5 inches). It seems to loosen 1/2 inch or so at each tightening. We do have a varying INdex sensor count, as always it seems....
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Post by Admin on Jan 20, 2015 22:45:41 GMT
jflores0002
I'm wondering what you mean about a wide FMCPS window at Tray 1. Is there a monitoring thing I'm not aware for the index sensor?
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Post by jflores0002 on Jan 21, 2015 11:32:53 GMT
oh sorry...FMPCS report "tray 1 received _ SEIs from index location" is what I'm referring to. Sometimes by simplifying things I make them more complicated. @mike, I just re-read your post and saw the answer to my question that it varies by 3 SEIs. So I take it that is the reason to tighten your chain. Has anyone in your building checked if there is any play at the coupling from bullwheel to shaft encoder?
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Post by mike211 on Jan 21, 2015 13:54:19 GMT
jflores0002... we have checked the usual encoder areas for play. Broken welds, and encoder timing belt play and mounting have been ruled out. When we start to get the larger drift of the SEIs we can physically see more slop in the chain as it exits the bullwheel. It appears that the chain is physically stretching. The contractor used regular flat washers on the underside of the coupling pins, but I am not certain this has played a role in our chain wear. Admin... I'm not sure why we would buy a product that would require this amount of corrective maintenance. That said, I'm also not surprised. The previous steel chain would certainly stretch when initially replaced, but would quickly settle and then perform relatively reliably and stable under normal conditions. I would appreciate feedback on how fast others are running their composite chain (FMPCS->Main Sort Controller Menu->Configuration->Configure Sorter... speed should be somewhere around parameter #3). We are presently running at 360fpm. Does this sound about right? Thanks again everybody.
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Post by jflores0002 on Jan 21, 2015 14:32:34 GMT
Ok so Mike, just to be sure we're on the right page. The actual coupling from the bullwheel to the encoder has been checked.
Someone actually crawled on top of bullwheel and gripped the large shaft that goes up to the encoder from the bullwheel and
tried turning it with both hands for any play whatsoever. A little bit of play at the encoder itself is normal but not below at the
Bullwheel. Of course your sorter has to be down to check this. Also, our sorters run at 145 trays/min.
If you're running your sorter at 360 f/min it comes to about 160 trays/min. I think my math is correct. I don't think the
composite chain is made to run that fast. Do you use the Unico drive to control your sorters? We also have the jog speeds
Slowed down. I think I set those at 20 trays/min on slow jog and 45 trays/min fast jog. If you use the Unico can you verify
your settings please?
Juan
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Post by mike211 on Jan 21, 2015 16:48:32 GMT
jflores0002... through the years the screws securing the encoder shaft would frequently backout or break off, we eventually tack welded the encoder shaft to the center of the bullwheel. The welds are solid and have been checked numerous times. This coupling is not an issue at this time. Your calculation is correct, we are running at 160 trays/min. I am anxious to see how many other facilities are running at this speed. The settings in the Unico are as I have stated, 160 trays/min. Again today, FMPCS is showing -1 to +2 SEI adjustments (to tray 1) on any given rotation. This likely means we will have to tighten the chain again very soon... maybe this tour. We are getting parcels inducting between trays when the SEI goes too far from 0. We are also occasionally inducting onto the wrong trays. Yes, it is quieter, and yes, it is easier to replace broken links, but this composite upgrade has been a PITA, and one we did not need through peak season. Thanks everyone,
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Post by jflores0002 on Jan 21, 2015 17:37:33 GMT
Ok Mike sorry, I couldn't help. We used to run our sorters at 160 trays/min but decided to back off to 145. Seemed more mail would
get damaged at this speed. It's a lot harder to hit a target moving at 160 compared to 145. Our composite chain actually runs pretty
well. It must be at least 6 months even closer to a year since we last tightened our composites. They are not just quiet but way
cleaner to work on. Who the heck wants to get all full of molly oil! Also lighter so just 1 guy with half a brain can replace links.
I'm actually quite curious as to why the upgrade didn't downgrade your speed on your sorters...
If you get this drifting SEIs figured out, post or shoot me an email. I'm really interested in what you find.
Cheers
Juan
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Post by Admin on Jan 21, 2015 22:53:51 GMT
Hi Mike, We are currently running one sorter at 160 tpm and one at 140 tpm as a test of the slower speed. I've always advocated running at the slower speed as the tray utilization shows that there's no reason to run endless empty trays. Hopefully we'll get the other down to 140 soon. When the palstic chain was installed, the mfgr said they did not recommend any higher than 140. I'm surprised on your SEI variance that you haven't shut down. Usually the parms are set so a variance of 2 in one revolution will shut down the sorter. If your shaft welds are solid, yes, tighten the chain, But if there are still probelms, I would recommend replacing the large alum encoder gear and the belt, starting with the belt and then testing. So many times those belts look perfect, but once we replaced it everything settles down. They seem to last 6months or so for us. Good Luck!
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Post by mike211 on Jan 23, 2015 13:31:45 GMT
Not wanting to leave the issue unresolved... yesterday we swapped in another encoder and we are now more stable on our SEIs. This does not obviate my concerns about the composite chain stretch, but we will wait and see how much longer we continue to have to adjust the bullwheel.
Thanks again to jflores0002 and Admin for their input/feedback on this issue, and I hope you guys have a great weekend.
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Post by Admin on Jan 25, 2015 22:28:06 GMT
Thanks Mike211, On chain stretch: We'll actually have to remove some steel framework soon to take up more stretch, because theres not enough stretched out to remove a tray yet--improper initial installation.
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Post by Norwood on Jan 26, 2015 15:56:47 GMT
Our composite chain was installe close to 6 years ago and initially had the stretch problem but is not a problem any more. Our main problem is with worn chain it breaks easily with just an e-stop. Will break about 25% of the time. We even went so far as to replace the mechanical brake on the end of the motor with an adjustable air operated one. It is better but mgmnt is afraid to make it any softer because if anyone gets caught in the sorter it will take 3 seconds for them to die instead of one.
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Post by mike211 on Jan 26, 2015 19:06:03 GMT
Thanks Norwood. We have already broken the chain a few times. I hate to think it is going to pop more as time goes on, but at least it is easy to replace and not as slimy as the steel chain.
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