Dust Gate Project

@garry42

I take it there was a typo and you do not have 100 dust gates for just 10 machines. 🤨 

There are several ways to implement this, but how about this simple way. For each of your 10 machines you have a stepper motor to open and close the dust gate, a motor controller board for the stepper motor, a current sensor sensor to sense when the machine is switch on or off, and a microcontroller that can send a 'wireless signal' of your choice, but an ESP8266 can be found for a couple of $. and can be used with or without wifi to send the 'signal'.  For the dust collection vacuum, also an ESP8266 and a relay to switch it on and off.

All dust gates are shut. Switch on a machine, the current draw to that machine is sensed which triggers the ESP8266 to activate the motor controller board to open the gate, and sends a wireless signal to the ESP8266 that controls the dust collector vacuum to switch it on. And of course the reverse when the machine is switched off. (maybe after a small delay to clear the dust from the pipes).

For the communications between the machines ESP8266's and the vacuum ESP8266 you could use ESP-NOW 

I am planning something similar in due course (meaning a year or 2 😎 )for my workshop.

Yep, not 100 gates. Not sure about the current sensor as half the machines are 15 amp on 240v. 

Also one the gates will connect to portable machines on different outlets.

I was thinking about a keypad on each machine. Press a number on the pad and send a signal to close all gates and then open the local gate.
The dust extractor is on Google assistant and operates by voice control as turing off and on between moving to machines or resetting the saw is wasteful.

As I said this is my first project so I am learning as I go.

Thanks

First, before you do anything else, get a prototype of your automated blast gate working. Only then will you be able to determine the correct components needed to control the gate, and start breadboarding and testing your design. I suspect you'll need a fairly hefty stepper motor or perhaps a solenoid to reliably operate the gates. They all seem to accumulate dust in the mechanism and can require a fair amount of force to operate.

Also, I'm curious as to why you have chosen centralized control of the opening and closing. It seems to add complexity for no real benefit. Since the default state of a fully automated system is for all gates to be closed except when needed, the dust collector only needs to "know" when its services are required -- not who needs them. Nor should it ever need to proactively close any gates. And it would quickly become a PITA if you have to manually "tell" it "which" gate to open. Best to just have it turn on -- regardless of which blast gate makes the request.

It is probably better to put the "intelligence" at the source of the request, i.e. the machine(s) needing the dust collector to activate. Especially since you need some logic to control the stepper motor anyway, and it would be nice to just automatically work when the machine turns on/off. I believe you can probably find current sensors that work by just threading the woodworking machines power cord through a sensor coil.

There are other reasons to keep the intelligence local to the "requesting" machine. Ideally, the blast gate should be fully open before starting the dust collector -- otherwise the resulting suction might make it even harder for the gate to move. Also, it is a good idea to keep the gate open and the vacuum still on for 10/20 seconds after the machine is turned off to allow any sawdust to make it all the way to the collection bin and not just settle in the ductwork.

Full disclosure, this has been on my todo list for at least a decade. BUT, my current low cost / low tech solution provides most of the benefits, so this project never gets moved up from the bottom of the list. When manually opened , each of my blast gates just closes a low voltage switch (wired in parallel) which activates a relay to turn on the dust collector. Since I'm already standing at the machine anyway, it is virtually no additional time or effort to open or close the gate. Or, at least not enough to justify the effort and expense for me anyway. Even so, it seems like a fun project -- and it is still on my list. Good luck.

@garry42

If you're willing to use a keypad to denote which machine you're going to use, why not put it on/with the dust bin header. If everything uses a plug (instead of built-in wiring) you could use that panel to select all of the bins and also have a set of electrical plugs (with each machine plugged into the socket below the dust bin cover). Selecting the bin with a button or keypad could then use a stepper (or linear actuator) to open the appropriate bin lid and also use SSRs (or relays) to direct power to the same machine's power socket). 

You might find this of interest as well

My current plan is to have a keypad at each machine. When a key is pressed broadcast a signal to all gates to close, at the local gate open servo on pin 13.Thinking of NRF240L01 as the wifi and MG995 as the servo.  I like this idea

If I can keep the gates in vertical hose then the dust should be pulled by gravity and not clog in the gate. 

Dusty is controlled separately and can stay on while moving to different machines or setups. I don't like to have saws running unless they are cutting material. At times the dusty is not required when cutting one small piece of wood, eg 1mm off a piece of wood.

The dust collector is on it's own circuit as most power tools and the dusty would blow the circuit breaker if on the same circuit. I am also thinking of adding a shop vac for the 33mm hose connected to the smaller power tools as I am not certain there is enough air for the dust collector in a 33mm hose as compared to a 100mm hose..

Could have a number to open all gates, although not sure why.

There are videos with a central control but this seems inefficient. There would be a lot of walking to change gates when changing machines. For example, wood through the planner, then the thickener, and then the saw would be a few trips to the central control.

All is low voltage so an electrician is not required as it is illegal here to touch 240v without a license.

@garry42

Your video doesn't play ("An error occurred. Please try again later ..."), so I can't respond to that part of your message.

I am curious though - why would you use a keypad when all you need is a simple (cheap) pushbutton switch connected to the Arduino to indicate which machine will be in use ?

I am not sure how to code a push switch to start the close procedure.

@garry42

Here's some sample code for 1 pushbutton on pin 4. Connect pin 4 to one side of the pushbutton to pin 4 and connect the other side to GND

Define the button pin

#define  pushButton1    4

In setup() specify the button is an input and connect the internal pullup resistor

pinMode(pushButton1,INPUT_PULLUP);

Add a module to test if any pin is down. Note that the pullup resistor ties to 5V which means that the button will normally be pulled up to 5V, so if the button is pressed, then it will be a GND. This sort of reverses the logic so we have ...

bool isButtonDown(int buttonPin) {

  return ( digitalRead(buttonPin)==LOW );

}

I haven't allowed for any signal bounce for the button code here, but since you'll be shifting the bin collector lids as as soon as the button is triggered, I don't think bounce will matter.

So, in your loop you'll have something like this for every button you've declared.

if (isButtonDown1) {

  ... do whatever needs to be done for this button ...

} 

@garry42

The video you linked to doesn't use a keypad or buttons it is fully automatic?

Why stepper motors instead of servo motors?

https://iliketomakestuff.com/how-to-automate-a-dust-collection-system-arduino/
https://github.com/iliketomakestuff/iltms_automated_dust_collection

Sorry about the delay, but I lost a hard disk so no computer for a while. Do NOT TRUST Windows backup except for files that you don't want!

Thanks for the comments. The video has the perfect design for the physical opening of the gate and uses stepper motors. I assume they are stronger for the price.

The keyboard is to identify which gate is to open. Although I could connect each motor to the same pin on each Arduino so I send a signal to all Arduinos to close all motors on pin 13 on other machines and open the local gate on pin 13.

The video you linked to uses high torque “servos”, not stepper motors. Probably a better choice and easier to code. But, you should really read the comments on his web page. That project is two years old and very much a prototype. He even says it has been almost completely abandoned. Which doesn’t really surprise me. He made a lot of questionable choices on his design.

For starters, the specs on the servos he uses are very low power for the job they need to do. If the blast gates get dirty and harder to open (which they ALWAYS do) I really doubt the servos would operate them reliably. They would probably either strip gears or burn up.

Also, the way he just puts the current sensor in an electrical box with only a piece of tape to protect it is dumb and dangerous. If vibrating machinery causes any wire movement, you risk destroying your Arduino or even injury or death if the 110 volt AC touches the wrong wires.

I do realize that you are not planning on using current sensing to activate the gates, and plan to use a numpad or something to choose which gate is open, but WHY??? You aren’t really saving any time or effort if it is not fully automated, and you are adding a lot of expense and needless complication, and probably making the overall system less reliable.

As long as you are willing to do “something” at the location of the machine that needs dust collection, a much cheaper and simpler solution is to just use manual blast gates with integrated low voltage switches to control a relay to turn on/off the dust collector. Lots of people (me included) have used such systems for years.

Don’t get me wrong, I do think it is a fun and interesting project. And it is something I definitely have on my “todo” list. But automated blast gates only makes sense if the system is fully automated. Otherwise, you don’t actually save any time.

Just my two cents worth.

Thanks Steve.

I am new to Arduino and electronics in general. I want to put the gates in areas that will be hard to access, under benches and shelves, to save space. Also, I have learnt that if I have to run around closing gates and trying to remember which gates is open as it may have been a few days ago I won't bother and saw with the dusty going.

I have the dust extractor on Google Home so I can direct it to start and stop by voice. It only cost $20 and having Google Assistant in the shop has been great for so many other things, controlling the compressor, turning on lights, etc. I can be in the house and remember that I left the compressor on and turn it off without getting out of my chair or turn it on so I don't have to listen to it filling up the tank.

The gate project is just as much an excuse to play with Arduino as it is to get a worthwhile project. What I liked most about the video is the process of opening the gates. Most deal with the collector switch, and a few used current sensors, which I do not want to use on 240v, 15amp, and massive devices on the gates. 

There is also a possibly that I will have several collectors. One for the 100mm hose and a couple of shop vacs for the smaller items. There seems to be disagreement on connecting 100mm hose to a 38mm collection point and having the system work. There is also an argument that the gate should be as close to the dust collector as possible, and not at the device. I was considering a gate on each of the 3 ports from my collector and another gate at each collection point. Open the line at the collection and the gate at the machine being used and close all other gates.

I have been convinced that PVC piping is the best method as my hose is over 30 years old, not transparent and highly inflexible. Modern hose will bend into tighter shapes and save a lost of space in my workshop. I am now retired so I will be spending a lot more time there.

Again, just working through the issues.

I agree that any excuse to tinker with something new is a good one, but I also try to make sure that I’m going in the right direction as far as ease of use or saving myself time. Of course, that doesn’t always work out as I expected, LOL.

Regarding the “simple” solution I proposed, it only works if every machine has a blast gate with a switch and that is the ONLY way the DC is ever turned on. Impossible to forget and leave one open that way, but that is usually a good thing anyway. I did add a few “extender” handles to some of the hard to reach blast gates.

The system works well enough that I haven’t yet moved up to a fully automated system although the idea has always intrigued me. In fact, your post inspired me to purchase an assortment of servos and also some current sensors to play around with. Unfortunately, my “honey do” list is extremely long at the moment and it will be a while before I can do anything except experiment a little.

FYI, since you mentioned bending hose in tighter curves, most experts seem to recommend the opposite since sharp turns cut down on air flow and efficiency.