The leaking, might not stop the Felder or lessen it’s effectiveness. Thus, our previous solution may have produced a problem to solve a leak that may not be an actual issue in operation of the machine.
Emptying the felder was covered when I took Woodshop basics a few weeks ago. I was told that the yellow light comes on when it’s about full. Is that incorrect?
The yellow light means there is an issue - most likely way past the time for it to be emptied.
Before you start using any of the woodshop tools, you should check or confirm that someone else has recently checked to see if it needs to be emptied. When the shop is busy, it will not be uncommon to empty a couple of times in 24 hours [real common prior to COVID]. Verifying its state takes under a minute… and probably only 10 minutes if you need to empty it.
From above:
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we talked about putting a window into the bucket area while replacing gaskets. but my worry was that it would scratch up if we used plastic or generate static and become a wood colored window.
you could easily use thick tempered glass and rtv seal, but I don’t know how effective it would be. the bag might obscure anything you’d want to see
it’s definitely something we could try without really ruining the machine since failure means it can’t be seen through, and stays a bucket… we can/ probably should try it. it’s a fairly simple solution.
I actually do have some 3/4-in glass panels lying around my storage unit. Most are about 2x2. I think they’re tempered, but I’m not entirely sure, and don’t know how to check.
This actually depends on the teacher. Emptying the felder was taught to me in my woodshop basics class. The far bigger issue for emptying imo is teaching people how to properly dispose of that heavy bag of sawdust once you shut off the felder and open the bottom. That bag is heavy
As promised, I checked out the Felder - The window was taped over with the heavy aluminum duct/vent tape. I cut out a small piece of tape (a window within
window if you will) and found the original (I assume it was original) plastic still in place. I turned the Felder on and the plastic did not blow out. I widened the window a bit and turned the Felder on - no blow out. You can definitely see through it. The Felder was on for most of the rest of the day and nothing changed before I left. The aluminum tape is very sticky. Had the tape given way, I would have re-taped it up and come up with a mechanical fix of some type. I will monitor over the next few days to see how the tape holds up with a window cut in it. If it starts to degrade - I’ll retape and figure something else out.
It is not a perfectly clear window and the plastic bag hangs over the window on the outside - making a little difficult to see into the window - you need to raise the bag to see the window clearly.
You can see one of patrick’s fingers holding the outside of the bag up and see three of his fingers through the window on the inside of the bin.
This only solves part of the problems we have with the Felder not being emptied. I know that just because there is a window doesn’t mean people will empty the Felder. What this does is makes it easy and takes less time to see if the Felder is full - you no longer have to drop the bin, check and reseat the bin. It is difficult for me to do by myself (my foot slips holding the bin “in”) and I know it is difficult for a few other people.
I don’t have any clever ideas on how to get people to empty the Felder when it is full, but at least it’s easier to see if it is full. Hopefully, more people will check the Felder and do so more often because it is easier to do. Time will tell if they empty it when it is full.
Thanks to Patrick for his help on this.
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I have not seen a good indicator of “fullness”. I used to think the yellow light was an indicator, but the yellow light is more of a lack of suction - either too many blast gates and/or the filters are clogged with fine particles. Btw - the yellow light used to come on a lot, then the filters were changed, I haven’t seen the yellow light on since then.
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Something like this may be worth looking into:
Dust Sentry Bin Level Indicator https://www.amazon.com/dp/B00JUP1TNS/ref=cm_sw_r_apan_i_BC5XNQWZDXG15AQSHMMF
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I like that it is an all-included system How do you think an IR sensor would work in such an dust covered environment?
When measuring the level in a Powdered Milk tank, we had to resort to using a guided wave x-ray level sensor to detect through the dust. They worked fairly well - but were a bit spendy.
At the time we also had to get an FCC license for each sensor - though they’ve changed the regs and it’s no longer needed.
I suspect the electronics can distinguish between air-born dust and a state of being ‘submerged in dust’, so to speak. Or perhaps there’s some other mechanism at work. I also wonder if there’s not a ‘keep the sensor clean’ requirement of some kind. Love the idea of a sensor though with a big flashing light.
Maybe we should stop looking at the physical amount, and start judging it based on weight? I feel like rigging up a makeshift scale in the bottom of the bin would probably be easier. The trick would be figuring out the approximate weight at which the bin is full for all the various types of sawdust that will go in there
Like the idea, but wiring for this may be an issue - how to place in the bin so the bag doesn’t take out or so the bag doesn’t get stuck? Also have to think about electricity - when the bin is down it is independent of the Felder - would need some kind of cord management - telephone coil or ???
I was thinking of that, some of the problems I ran into were the lift mechanism, which means the bin weight is supported by a latch on the Felder itself, and the vacuum which sucks the bin up and will reduce the apparent weight on the bin while the Felder is on.
Perhaps a sensor between the gasket surfaces to measure how much the gasket is compressed. The heavier the bin the less compression there would be. This would also catch situations with an improper seal.
Weight generally assumes that all dust weighs the same. A bin of jointer chips will weigh significantly less than a bin of table saw dust. Doesn’t mean it wouldn’t work, just that there’s an error margin there to be accounted for.
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We could train a sensor to guess full lol. Go for the lightest weight- a bin full of chips, and store that weight. Then every time it gets emptied, store the actual weight that was emptied, whatever combination of chips and dust that is. Then over time average the actual weight measured when full and the sensor will //theoretically// become more accurate. Lol. Of course this goes back to the issue of how do you measure the weight in the first place. Especially while on.
The variability in suction would make this very difficult - not only would it be different from when it was running or not, but the number of blast gates and filter condition would impact it as well [IMHO].
Personally, if we are going to assume it won’t get checked regularly, I would put a loud buzzer that goes off [or disables the Felder] every 10 hours and resets once someone scans their badge. Scanning the badge would signify that was checked and emptied - and provides traceability.
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Adding a briquetter would allow the collection point to be open and easily observable, if heavier to dump…
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It would be pretty easy to measure the pressure (or well, vacuum) at the chip bin and account for it in the expected weight calculation.
The variability in bin weights depending on chip type is certainly problematic. Perhaps the way to look at it is ‘we want the bin emptied at xxx Lbs because if it’s any heavier the next person won’t be able to dump it’, which means we don’t really care if it’s actually full or not.
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