Hi. I am looking to create a project for my workshop that automates dust collection from my wood working tools. I have a system that uses 4 inch tubing and blast gates to run multiple tools. Currently I use 5 gates. I want to use current sensing on the cords of my main tools to open the needed gate, close all other gates, and turn on the dust collector itself.
There is a product that does thus made by ivaccum. They cost $140 per gate plus another part to remote turn on the collector. I can't afford to spend 800 on this and I feel arduino can really lower this cost.
I read and watched a utube video by "I like to make stuff" where he used a key pad to control which gate opens and a small 90 degree servo motor to open the gates. He was using 2.5 inch gates instead of the 4 inch gates I will use. Does anyone know if a servo is powerful enough to move that much? I know they can be expanded to move 4 inches but I do not know about power.
My thought was a small stepper motor with gear drive and a linear gear attached to the gate. These are cheap enough and wouldn't be to hard to program how many steps to move the motor to open and close.
For current sensing I found this sensor from spark fun,
Non-Invasive Current Sensor - 30A
SEN-11005
It clips over a power cord? That's how it looks. I don't want to cut open my power tool cords or make little extension breakout cords.
I feel this sensor which seems to be able to monitor amperage would easily be able to be coded to run the servo or stepper motor and a 120v relay to start the dust collector machine.
My main question is servo strength and exactly what that non invasive current sensor is capable of and if anyone knows of anyone who has already documented this project.
tjdux:
inch gates I will use. Does anyone know if a servo is powerful enough to move that much? I know they can be expanded to move 4 inches but I do not know about power.
Thanks a bunch
If the gate is of the butterfly type the forces of the air balance out and the servo will not require much power.
As far as sensing goes the simplest method may be to sense when the switch / trigger is pulled.
That requires invasive modification of your tools though which you may not want.
Hardware ie valves are the biggest cost. using a bit of 4 in drainpipe and a disc of plastic could easily work for the gates.
The seal does not have to be perfect for this as the airflow is large.
Exactly. They are standard wood working blast gates. I don't know how to attach a photo but a Google search will show you exactly what I'm talking about. They are very common in serious woodworking shops to control harmful microscopic wood dust.
I get what you are describing. Something like a baffle used in hvac systems to turn off a pope duct. That would work more or less but what I have is an off the shelf common gate.
Steppers or servos i would suggest are overkill for that.
The manual L shaped operating handle.
Stick or weld a nut to it.
Use a threaded rod , available from builders merchants in 1 M lengths to screw the valve open or shut and attach it to a cheap geared motor.
End stop sensors for closed and open positions will be required. either microswitches or opto sensors i would suggest.
The motor can be controlled either by relays or H bridge.
Its a largely mechanical problem the electronics/arduino can handle this easily.
The split core current sensor that you linked must be clipped over one lead of the power cord, not the entire cord. So, it is not so easy to use with typical unmodified equipment -- you need to get into the breaker box or outlet to isolate one of the two current carrying wires.
Used with a "burden resistor" of 10 Ohms, the current sensor will generate an AC voltage of about 0.15 V peak for 30 amperes in the lead. Follow the instructions here to wire up with an Arduino.
If you plan to put the sensor in a breaker box or outlet, a toroidal CT sensor will be cheaper. I use the CS60 series from CoilCraft. They will even give you a free sample.
I am very familiar with threaded rod and yes that with a motor should be easy to use.
Thank you board burner
Thank you for explaining how the current inducing sensor works. I really hoped it was as easy as clamping to the power cord. But alas no such luck. I will look into your suggestion jremington. Thanks again.
tjdux:
The gates I already have are not butterfly. They are linear.
And no I don't want to modify my tools.
Thanks for the input.
got a link to a linear valve ? when I was in HVAC they were expensive and very hard to find.
unless you are taking about a blast gate. much more common for exhaust.
you have a lot of ways to make this work without using any sort of microprocessor.
a simple relay that becomes energized when your motor gets powered and that powers your gate motor and also the exhaust motor.
a simple DC motor, all-thread and a tube with a nut and you can spin the motor to open the gate, till it hits a stop.
the relay changes direction and when the gate is full open, or full closed. there is no power used.
tjdux:
I really hoped it was as easy as clamping to the power cord. But alas no such luck. I will look into your suggestion jremington. Thanks again.
A Current transformer can be added to your wall receptacle, either stuff it inside the box, or add an extender.
no need to re-wire anything. just clip it over the black wire.
that does not require an Arduino as you can feed the output into a relay directly, but you would need some caps and didoes and such to make it work reliably. at $10/ea for the CT, another buck or two for the relays, and a box.... it would cost more than a power screwdriver to use to open/close the gate
Yes that would work to add inside the electrical junction box. But sometimes I use the same outlet to power a hand drill or other non dust making tools. I was really hoping for something to go over the direct tool cord.
I do beleive the break out extension cord plan may ne the cheapest route at this point. To further explain break out extension cord.... I would use an off the shelf diy female cord end and break the hot wire to go through a common arduino current sensor (all in a plastic or wood box) that then feeds into a cord with a male plug that goes into the wall.
I didn't want to go this route because it's a lot of conect ions at 120v ac for this project. Simple is better omho.
Somehow ivaccum has a way to do this. I do not know if it's a hall sensor or magnetic induction or what but it's possible. If I only had 6 years lol to get a electrical engineering degree and figure it out.
tjdux:
I didn't want to go this route because it's a lot of conect ions at 120v ac for this project. Simple is better omho.
Somehow ivaccum has a way to do this. I do not know if it's a hall sensor or magnetic induction or what but it's possible. If I only had 6 years lol to get a electrical engineering degree and figure it out.
Can you say what type of motors you have ?
Shop type vacuums are often synchronous and the sensor will have to be on a conductor for that.
Some tools however have commutated motors and the electrical noise from those can be detected with a clip on cable tool.
Its more complex and susceptible to error though.
Can you post a link to the ivacuum system , i can only find domestic cleaners.
I found these
That system clearly uses custom outlets for detection.
Not expensive either when compared to buying and building a clip on sensor.
Requires a sparkie though.
Edit
UMM the 9.96 i saw is just for 3M cable, the outlets themselves do seem pricey.
tjdux:
I did a little research into the ivaccum system and it claims to detect the magnetic field created by powering the tool from the cord.
I beleive a hall sensor may be capable of detecting such a field but I am also not very familiar with using one.
probably possible, but would take some very intricate circuitry. probably dozens of hours and multiple attempts to get it right.
could be cheaper and easier to spend the money per unit and just get it done.
if you want to make a workable system, you already have to ability,
add a second receptcle to make a quad outlet, monitor one with a CT
and add a master on/off switch.
hard wire the lot and you are done.
but, if you will only be satisfied with a clamp on your existing cord and then have that wired to your control panel, you have the link to get the ivac and you can get it all done in a brief afternoon.
I have still been researching this in my free time. I can no way afford to buy 5 ivaccum blast gates and at least there of their clamp on current dectors. At 150 or so apiece the total bill would be around a $1000.00 and that's just crazy.
It's two hall sensors on one board to detect current without breaking a wire or curing through wire insulation.
It's $18 bucks per sensor and will easily output to arduino. I can buy all I need for the price of one ivaccum current sensor.
As far as the mechanical opening of the blast gates it will be trial and error until I prototype something that is cheap and effective. I already bought a cheap servo on amazon just to play with it and see if it will serve my purpose.
I already have an arduino that I got for my bday last year and besides the book projects that are amusing I really want to put it to work in something really useful. I will make this work eventually. And make it work cheaper than 1000 dollars.
