Finding Paper Through Steel

A DIY solution may be to place a measuring device in the system.

The difference between the current position and the maximum position will be proportional to the volume / weight.

Where and what will depend on circumstances.

Are the different containers of the same size?

What is the length of the stroke?

What does the plunger look like?

The containers are always the exact same size : (standard (reinforced) 20ft container.

The lenght of the stroke is a little less than 20ft. I don't know exactly, but it should be something between 15 and 20ft

The plunger is a steel plate of about 1/3 of the height of the container, and as wide as the inside of the container. it presses on the bottom of the container.

In fact I am searching for some kind of "stethoscoop" (the thing a doctor uses to listen to your heart and lungs) that detects if there is paper at a certain place inside the container and produces some electrical signal.

anyhow Hendrik : Thanks for your fast reply !

I suppose measuring the actual travel stroke of the hydraulic ram is not possible?

Here's a light bulb moment: Can you place a magnet on part of the ram [even if means machining a samll recess to protect/locate it?]...then when you need the position...check with a piece of steel from the outside. Better yet: Fix some pivot type steel fingers close to where the edge of the container would be then as the magnet travels past them, the fingers would rotate, indicating position. This device is now copyright protected by ME.

Is certainly worth trying ! Although I doubt if the magnetic field goes through the metal side of the container ... but if it works, we are saved ! Tanx !!!

P.S.
But thanks again, Mr. Hammer ! If we decide to use your system : I'll have a nice copper sign made with something like :

Mr. Hammer:
Inventor.

It does actually go through the metal (even Steel), but "spreads" the signal and the magnet needs to be quite strong.....

Can't you weigh it?

Al

Nope... weighing is out of the question. Even if I would build a scale for the container, I guess I'll never get a reading that is close enough, since there's all kinds of paper being dumped in that container. In other words : the weight of a full container varies too much ...

Anyhow : Thanks for your reply, Al !

So it is possible that the container is too big, too wet, or that the lift system is too small. What you're looking for is a change to one of those things, really.

<Hmmmmm. Paper container. Sounds like a good place to doss for the night.>

Yeah ! It could be a good place to doss for the night. You're welcome ! But please don't forget to switch OFF the press before you enter ...

When I was young we determined the water level in a corrugated water tank by hitting the tank and listen to the sound. (approximate result but good enough for the purpose).

Your intention seems to be to use the dampening effect of the paper on the vibrations in the wall of the container to hear where the plunger is. I don't think it would be accurate enough. The different containers may also behave differently.

Proposal.

Buy a winch (used on 4x4's) and fix it to a solid surface. attach the end of the cable to the plunger. Calibrate the cable. and measure directly.

Note that the winch must be re-winded when the plunger is reversed.

A 6m self retracting tape might also do the trick.

yeah ... Hitting the container and listen to the sound is what we do too !... But measuring the distance that the plunger travels, seems to me the best idea (till now). I'm not sure there's gonna be enough place behind, to have this "winch" system installed. I'm gonna check if there is enough place to put a distance sensor ...

thanks, Hendrik !

Can you see/measure the level of hydraulic fuil in the reservoir?

This will go down as the plunger extends...

I'm assumong the plunger can't be viewd from above else you wouldn't have a problem.

(Joke:- You could always subscribe to Sky TV...Pay per view... 'paper view' geddit...oh never mind.. .)

What a good idea! calibrate the sight glass on the fluid reservoir, you could empty the container first and send the ram to the bottom and make a mark then fill it to maximum load and put another mark, then divide the gap into % filled! Even if you can't see the reservoir you could use remote sensors! Nice thinking my feline friend!

YES !!! THIS IS IT !!! I'll make a little typo when ordering the paper view system ! (You could always subscribe to Sky TV...Pay per view... 'paper view' ) Our boss won't notice the difference. I install the "pay per view" system next to the container, a nice seat, and every hour or two I'll knock on the side of the container to listen if it is full yet. Wow ... After this system is installed I'll sign a contract to not go on retirement till I'm 80 !!!

Mr. Cat : Y o u a r e t h e B E S T !!!

Two ideas. Without knowing the limitations, this is what I can come up with. The laser would be more accurate but the ultrasonic will be cheaper.

Thanks Vulcan ! (and all the others) I guess this is gonna be the system that I will use. A distance sensor is not that expensive anymore, I'll have to clean up some "debris" in the place where the plunger moves, but I guess this is the best sollution for my problem.

Thanks again to all who contributed to the sollution of my problem. I'll promiss to try to help you guys out when you have a problem !

Wouldn't you just need an ultrasonic tape measure? This way you can keep the tape measure in your pocket & be the only measuring operative in the company.

And if he happens to go on vacation?

"Uh, hello? Can you come back to the factory, sir? We need to measure the paper compactor!"

On a more serious note, being the only guy who knows something is more of a pain than an advantage. I know because I used to be that guy .

After I trained a couple of my mates, I slept better. And I still have my job!

How about a rod, attached to the back of the plunger, parallel to the cylinder? Make it long enough for the end to be visible at the bottom of the stroke when the container is 90% full, and graduated up to the full mark (2' span). Position it so it clears obstacles on the upstroke, or make openings where required.

If this is not possible, then I'm sure a hydraulic cylinder distributor can provide you with cylinder-mounted sensors to monitor the piston position inside the cylinder. When the pre-determined positions of the sensors are not reached by the piston, the corresponding indicator lights go on (or stay on).

Could you apply X-ray scanning system? If thickness of steel container wall about 2mm the 150kV anode bias on roentgen tube will be enough. Seems to me it give your chance to see container volume that fill out by waste paper. Regards, Anton. (e-mail:tyazhev@elefot.tsu.ru)

tyazhev, you gave the best possible aid to judgement by the man who monitors.

X-ray Scan monitor needs to be further judged from the Compactor Pusher Force.

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If it is Hydraulic or Pneumatic--Instal a pressure gauge(best is Analog) by side of X-ray monitor--that will be Double Check. The PRESSURE will remain below a threshold if you are pressing a less-than-full chamber.

The Pressure will rise rapidly when you are pushing a "full" Container.

If not Hyd/Pneu--but operate direct from Motor +gearbox ,motor Amps. will tell this.

If there is a massive flywheel+Air Clutch, get a strain-gauge hooked on Ram -axially.

Don't they make some kind of portable transducers, if so you could take a reading at the place of the paper bin would be "full" when its empty and then take a reading every few days, when reading is different, its now got paper to that point, full.

This may be to simple and easy how about a yard stick that you remove when done?

Similar to the measurements done at gas stations to check the level of their tanks. If the yard stick stops that is where the paper is and a measurement in comparison to the container can be made. Cheap and replaceable and can be read by anyone.

Instead of measuring the piston depth, measure the distance of the hydrologic arm. You should be able permanently mount measuring rod on one end and the other end have a sliding sleeve. Mark on the rod when you get a full container. It is somewhat reversed on the gap between the two points but if you mark the loose end of the sleeve you would be able to mark empty, half, 3/4 full and full marks. That way you are viewing the parts of the ram that are still exposed. It is all proportional and this will still give you a good gage of how much more the container has to go.

Get a 20 ft self retracting tape measure at the local hardware store. (Cost <$5.00) Attach the nib to the pressure plate at the end of the ram. Attach the tape measure to the housing of the ram.

The tape will now run in and out with the ram and give a direct measure of the height component of the volume of the container. If the container is completely full when the ram is extended 6 ft then it will always be approximately completely full when extended 6 feet.

When the system fails - replace the tape measure.

If a digital readout - sensor type of result is needed there are more expensive laser/acoustic tape measures that can do the measurement and give a direct read in whatever convenient (and safe) location you desire.

Mr. Gee

Mr Gee,

You managed to post your comments between the time I read the threads & posted my own comment so I've just added more or less the same comment as you.

What is they say about great minds thinking alike?

I would just say that you both have it "Taped".....! Just for "good measure of course!"

A a rule I don't normally like puns but this one does ram home the point nicely.

Just another thought if you are looking for cheap & simple. In the building trade they use telescopic rules for measuring ceiling heights etc. These consist of a set of telescopic rods with a tape measure inside to read out the distance measured.

Could you simply attach the working end of a tape measure to the back of the ram & the body of the tape measure to the fixed part of the machine so you can read off the ram travel as it stops at the end of its stroke? It sounds like you don't need to be that accurate so a line of sight reading referenced to some fixed point should do. For a 20ft container a 10m self winding tape should work ok.