Blastgate and Dustcollection Automation With Node-red

This is my Blastgate-Project - It´s still work in Progress!

Electronic parts:

1x Raspberry Pi4

1x Powersupply 5V for Raspberry Pi (in my case - Meanwell RS25-5V, 5A)

1x Powersupply 6V for Servomotors (in my case - PoppStar Universal AC Adapter / 6-16V / 5-3.5A / YSV60-1)

1x Breakoutboard (not necessary, nice to have - GeeekPi Screw Terminal Block Breakout Board)

1x PCA9685 Servodriver

2x Current-Sensor (Iduino TC-9520256)

1x Analog/Digital converter (Adafruit ADS1115 16Bit I2C ADC)

3x Servo (Reely Standard-Servo S3003 MG Analog-Servo)

3x Blastgate (4” Aluminum Blastgate - it`s noname)

1x Relay-Module 1-pin (5V/220V 1 Channel Optocouplers Relay Shield)

1x Relay-Module 4-pin (ABB ESB25-40N)

1x lot of Different cables (lo list cause it`s so individual)

1x Dupont connectors and pins set

Cabinet - individual:

2m Din-Rails (Type IEC/EN 60715)

2m wiring channel / cable duct (Verdrahtungskanal)

12x PTS 1,5/S-TWIN (Durchgangsklemme)

Hardware that can be helpful for testing the electronic parts:

1. Multimeter
2. Voltage-tester (e.g. duspol)
3. laboratory power supply
4. Servotester (e.g. Voktta RC Servo Tester 3CH)

I`ve found a Blastgate Project thats was perfect for my requiremtns. It fits to a pipe of 100mm and is powered by a servo motor. I could imagine converting the blast gates to compressed air at some point, but I wanted to keep it as simple as possible and I used the servo perfectly for that.

https://www.thingiverse.com/thing:2573041

First I printed all the 3D parts and then mounted them to the blastgate.

After that was done, I connected the servo to a tester and carried out an initial functional test. You have to be very careful not to reverse the polarity of the servo, as this will lead to a defect.

Then i connected the various components on a breadboard and carried out initial tests. After making sure everything worked, so many wires, it was a mess!

I`ve printed out all the parts that I needed to manage the individual components in the control cabinet. I used a DIN rail to attach it to give it a kind of flexibility. Of course, this could be implemented much more easily, but if more machines are added in the future it will be much easier.

I uploaded the STL files for printing on thingiverse: www.thingiverse.com/thing:6817695

In my case i used a selfmade cabinet out of wood, of course you can also use a standard electronic cabinet that is made out of plastic.

Then I connected all the cables as you can see on the circuit diagram.

I don't have an exact list which wires you need but there were some with 0.25mm² / 0.50mm² / 0.75mm² for electronics and servos and a few 1.5mm² / 2.5mm² / 4mm² for power distribution (saw, planer and dust-collector) but that depends on the machines.

I created the circuit diagram with the "Fritzing" program, here the file is in .fzz format

->Please be careful, working with electricity can be life-threatening! If you have no experience with electrical systems, please have it done by a professional!!!

After everything was connected I did a functional test. After I had set up the first functions in nodered I was able to test the current sensor and the blastgates, as well as the relay.

I installed the control cabinet right next to my power distribution in which the circuit-breaker for the saw, planer and dust-collector are installed. I ran one phase from the saw and planner circuit-braker through the current sensors and back again.

In my case, all machines (saw, planer, dust-collector) are connected with 3 pins (heavy current with 400V) because they are large and professional machines. If you wanted to connect smaller 1-pole machines, the whole thing would be even easier. If so, you would use a 1-pole relay instead of the 4-pole one.

-> Please be careful, working with electricity can be life-threatening! If you have no experience with electrical systems, please have it done by a professional!!!

Of course, you'll find plenty of instructions on how to install a Raspberry Pi and get Node Red running on it. That's why I won't discuss the individual steps any further here.

As a overview:

1. Installing Raspbian on SD-Card with Raspbian-installer
2. Integrating the Raspberry into network and making the first adjustments (password, IP-address, etc.)
3. Installing node-red, probably easiest way via ssh access

This are the plugins/addons which i use in node red:

1. node-red-contrib-anolog-to-digital-converter-raspberry-pi (libary for communicating with A/D converter)
2. node-red-contrib-pca9685 (controlling the servos)
3. node-red-dashboard (making a dashboard fpr manual control)
4. node-red-node-pi-gpio (controlling gpios from the raspberrypi)
5. node-red-contrib-calc

Unfortunately, I'm not a professional when it comes to node-red. Although I have a flow here that a friend created for me, unfortunately some features are still missing and the flow does not yet work as desired in certain situations. As soon as the flow is finished I will share the code here.

I made a mind map showing the flow-diagram. At the moment I'm not entirely sure whether this variant will lead to the desired success. we'll see...

Problems that i run into:

1. As soon as both machines are running at the same time, all blast gates should open and the extraction system should continue to run, but that doesn't work with my flow yet.
2. As soon as I switch off the machine (saw or player) a timer starts and after 10 seconds the extraction system should also be switched off. If I switch on a machine (saw or planner) again before the 10 seconds are up, the extraction system first switches off and then switches on again.
3. The current sensor measures the current voltage in that is present. The sign of the measured value changes continuously from plus to minus. I think it's because of the alternating voltage. I have now managed to generate an amount using the calc function, now I always get a positive value.

After the flow got to the point where manual control worked, I installed the blastgates. I used a Lapp cable with 0.5mm² to connect the PCA controller (cabinet) to the blast gates. Unfortunately, I couldn't find a cable where the colors matched, so I had to be careful not to reverse the polarity of the servos motors. I made a sketch especially for this.

In order to control the system manually, I decided to connect a touch display to the Raspberry Pi. I then access the dashboard via the Chrome browser. As an extension, I installed a screensaver so that the screen switches off after a certain time. It was a bit annoying to have the HDMI and USB connection over 10 meters from the Raspberry Pi to the screen. Of course you could also use a tablet to access the website, but I found it better to have direct access to the Raspberry OS. I would also like to take the pi off the network for security reasons.