Cheap Remote Controlled Dust Extraction

[PerryGunn]

First off, I say cheap but it's only the remote control part that's cheap - circa. £25 - you spend whatever you like on the actual dust extraction setup - but this may help anyone who needs the functionality

First... some background

I only have a small home workshop so nothing that requires large-scale chip extraction and my vacuum needs were adequately covered by an old Henry (which I modified to always start in high-power mode) and a Dust Commander cyclone with a 30L metal drum. To cut down on noise the vacuum and cyclone are in the garage which is separated from the workshop by a brick wall - the Henry power and dust tubes run through the wall and power to the Henry was from a wall switch in the workshop.

(NB This setup has now evolved to include rigid tubing, multiple outlets, blast gates, and more vacuum 'suck-pressure')


The problem...

This worked well but I got fed up with having to walk over to the switch to keep turning the vacuum on and off - more awkward than you'd think in a small workshop as the limited space means that there's often stuff in the way.

I started looking at ways of switching the vacuum on and off automatically. Intelliplugs and Vacs with power take-off are always mentioned but power take-off doesn't really work if you have the vac the other side of the wall (trailing sockets are a horrible trip hazard) and Intelliplugs need you to always plug into certain sockets - when I built the workshop, I installed lots of sockets so there would always be power where it was needed without long cords trailing all over the place.


A solution

After hunting around, I found a 240v 40A-rated 433MHz remote control relay which came with a couple of small 2-button (ON/OFF) keyfob remote controls, it was cheap enough at around £20 to take a punt so I ordered it. A bit of testing with it plugged into a mains socket and controlling power to a trailing socket confirmed that it worked as advertised so it became a permanent part of the setup. When I'm working I hang one remote control around my neck on a very short lanyard (so it can't get caught in anything) and just press the buttons to start/stop the extraction - it's manual on/off rather than automatic but, for me, it works very well.


Parts & Installation

The relay & remotes https://www.amazon.co.uk/gp/product/B07CTL3TG6 or https://www.amazon.co.uk/dp/B07SCZ8V1W they're both the same thing and are £21 at the time of writing this

The relay is single pole and only switches the live line, neutral is direct pass-through to the output (think of it like a lamp that has an in-line rocker switch on the live), you need to ensure Earth continuity around the relay (Wago connectors are good in an enclosure). The relay always defaults to the 'off' position when power is applied (even if it was 'on' when the power was switched off).

It needs to be enclosed in a suitable box as the terminals have little in the way of protection from small pointy objects/fingers and, in a workshop, it's best to keep the dust away - I used something similar to https://www.amazon.co.uk/gp/product/B07MV9Z26Q but it would fit in a double backbox with a front blanking plate.

You'll want to have a fused switched power supply to the relay so you have a 'master switch' for the vac supply. I always turn the vac power off when I finish using the workshop . I have a switched fused spur connection but a 13A mains plug in a switched socket will work just as well and avoid any Part P issues. I would recommend wall mounting the relay enclosure and ensuring you have proper strain relief on the cables in/out of the enclosure and ensuring that any surface mounted cables are properly enclosed/protected.


Wiring is very straight forward - apologies to anyone who's colour blind as I've used Red (Live), Blue (Neutral) & Green (Earth)

Hope that helps somebody

 

[DBT85]

Very useful write up. Is your vac now too powerful to just use a normal remote controlled socket?

 

[PerryGunn]

Very useful write up. Is your vac now too powerful to just use a normal remote controlled socket?

The majority of the remote control sockets / 'plug in plug' devices that I found were either intended for low power devices such as lamps or had chocolate bar type remote controls.

I wanted something that had the headroom to handle higher power devices as vacuums tend to have a high start-up draw and, because it was the other side of a brick wall, I'd modified the Henry so it started up in 'high suction' mode rather than the normal 'can't suck the skin off a rice pudding' mode. I also wanted a small remote control that could be attached to a lanyard or belt loop so it was always to hand.

There may remote control sockets/smart plugs that matched my requirements but I stopped looking once I found something that worked

(and I should say that I have an inbuilt bias towards hard-wired solutions rather than 'plug-in-plug' devices)

 

[peter-harrison]

I had the same problem about 20 years ago, before anyone had invented a remote-control switch, so I made what’s in the photo. Inside the MDF box is a standard on-off starter for a 3-bag extractor. Strings run through pulleys or bell-crank levers to each machine. It all looks very Heath Robinson but has worked well and saved many trips to the corner!

 

[petermillard]

First off, I say cheap but it's only the remote control part that's cheap - circa. £25 - you spend whatever you like on the actual dust extraction setup - but this may help anyone who needs the functionality...

Thanks. How immune are these remotes to ‘nuisance’ triggering? I had one of my vacs on a domestic remote and came in one morning to find it running. I switch off religiously now, but still.

 

[PerryGunn]

Thanks. How immune are these remotes to ‘nuisance’ triggering? I had one of my vacs on a domestic remote and came in one morning to find it running. I switch off religiously now, but still.

I don't know if these are 'fixed code' or 'rolling code' remotes - given the price, I'd think they're 'fixed code'.

The Short Answer:
It's a very small possibility but it can & does happen - I always turn off the vac power when I finish in my workshop 'just in case'

The Long Answer:
Without doing lots of research, I'll have to rely on memory and, IIRC, in this sort of application a 433Mhz remote uses 32 bits as the 'key code' plus 4 bits for the 'command'

a 32 bit code means that there's a 1 in 2^32 (just under 4.3 billion) that another random 433Mhz remote control code will match

Then you have to allow for the 4 bit command word - if I was designing the system, I'd set it so that only one 4-bit combination, say, 1111, turned the relay 'on' and all other bit combinations would change the relay to the 'off' setting but I don't know how they've designed the command word.

Worse case (from the 'stray signal' PoV) is that the 16 possible encodings of the 4 bits are split evenly between on & off states - or, more likely, as this is a bistable device, they're only checking one bit - this would mean that a stray 433Mhz signal that matches the 32-bit code would have a 50% chance of changing the operating state of the relay from on to off or vice versa

That gives a 1 in 8.6 billion chance of a stray signal making a state change - it's a very small possibility but it can & does happen as there are a lot of 433MHz devices around and lots of them use rolling codes so the transmitted key code changes after each use

Correction:
My memory's not as accurate as I hoped - it's a bugger getting older :-(

Whilst 433Mhz allows for the capability to use 32bit codes, not all 433MHz devices do - my rolling code gate opener seems to use 24-bit codes

Without pulling the relay or remote apart and looking for the manufacturer's data sheets I can't tell how many bits it uses for its key code - so all that calculating was worth nowt....

Whatever they use, it's still good advice to turn the master switch off when leaving the workshop

 

[mr rusty]

I have two devices. A master-slave plug-in adapter which starts the vac when the power tool kicks in and a cobbled together home-brew device which combines a sound activated switch, Sound Activated MiniVox Relay Switch | Quasar Electronics AS3126KT a cheap remote activated socket switch and a little device simply made from a couple of relays and capacitors which converts the continuous "high" from the sound activated switch to a "pulse" to switch the socket on and off as if momentary pressing the on/off on the remote. All housed in a little box that I strap to the tool with a bit of tape. Crude, but works, and I find the sound sensitivity adjustment can be easily set by the "noise" of the tool and ignore most background sounds.

 

[robgul]

Perhaps I'm missing something here? - I have one of these
https://www.amazon.co.uk/gp/product/B00NMD4QL6/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1with a Henry connected to it - seems to do the job and was a 10 second installation job.

 

[gcusick]

Yes, I use something very similar. The plug-in bits are rated at 3000W, so even my dual-motor Camvac extractor is OK. Also use another socket to control a (2kW) heater. Three sockets + remote cost me about £10 about 10 years ago.

 

[PerryGunn]

Perhaps I'm missing something here? - I have one of these
https://www.amazon.co.uk/gp/product/B00NMD4QL6/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1with a Henry connected to it - seems to do the job and was a 10 second installation job.

You're not missing anything as such, in common with lots of those 'plug-in-plug' remote control sockets, they have a 'chocolate bar' type remote control - so it'd either have to be in a pocket or left on a bench. The small keyfob type remotes are much easier to connect to a belt loop or lanyard.

The other thing is that I have an aversion to plug-in-plug devices and much prefer hard-wired solutions

 

[robgul]

You're not missing anything as such, in common with lots of those 'plug-in-plug' remote control sockets, they have a 'chocolate bar' type remote control - so it'd either have to be in a pocket or left on a bench. The small keyfob type remotes are much easier to connect to a belt loop or lanyard.

The other thing is that I have an aversion to plug-in-plug devices and much prefer hard-wired solutions

Hmm, a lanyard would concern me in terms of it catching in a machine or whatever.

The biggest problem I have is forgetting to switch the Henry on! . . . I have a printed label by the switch on each machine saying "Switch on vac" There's a Record air filter fixed to the ceiling above my main work area and that has two wooden "pockets" on the timber frame holding it up - the remote for dust extraction is in one and the remote to switch on the Record is in the other .... being tall it's no problem to just reach up and switch the Henry on and off.

 

[PerryGunn]

Hmm, a lanyard would concern me in terms of it catching in a machine or whatever.

As I said in my initial post - it's a very short lanyard, if I press my chin down to my chest, my chin is just above the remote control. In the unlikely event it did catch on something, it has a breakaway catch at the back

 

[Sheptonphil]

Superb solution for many applications, including HPLV vacuums, however, these solid state relays are not suitable for high current inductive loads, They aren’t going to last long running a 1.5 or 2HP induction motor even when rated at 40A. The remote controlled plug in sockets and Fostek solid state relays specify for resistive load, not inductive. I’m wiring a remote system for a high current draw motor on my dust extraction system this weekend using a transformer and relay. Will put it on a separate thread so as not to distract from this one.

 

[MikeH]

When I built my original workshop 20+ years ago I had similar issues. I got around it by having the extractor on it's own dedicated socket and I controlled it by 2 way light switches with intermediates all around the workshop mainly next to my many power sockets, I had about 10-12 of them IIRC. Needed 4 core cable between but that was easy as I wired the shop when I built it. It meant there was a hard power switch for the extractor within reach from pretty much anywhere in the shop and as with light switches you could turn on at any switch and then off at any switch. Worked brilliantly up until the day I moved.

It did have a couple of gotchas over your neat system you described here:
1. It was more expensive but back then was pretty much the only option as the auto switch kit was not around. And it was a one off investment.
2. Power rating would have been a bit lower. I think it was rated at about 10 amps, but that was ample for my extractor at the time. I had taken the precaution of making the socket on the spur a 5 amp socket so no one could plug in a 13 amp heater or anything.

 

[gmgmgm]

Very neat solution. A contactor could have been used to switch the higher-current power if you hadn't found a good 40A remote.

I use an alternative approach: I have an Alexa Echo in the workshop (playing the radio!) and a wifi switch (~£10) on the extractor. When I say "Alexa, turn on dust extractor", it turns on. Similar for off. It's amazing how well it can hear commands over the noise.

 

[Sheptonphil]

When I built my original workshop 20+ years ago I had similar issues. I got around it by having the extractor on it's own dedicated socket and I controlled it by 2 way light switches with intermediates all around the workshop mainly next to my many power sockets, I had about 10-12 of them IIRC. Needed 4 core cable between but that was easy as I wired the shop when I built it. It meant there was a hard power switch for the extractor within reach from pretty much anywhere in the shop and as with light switches you could turn on at any switch and then off at any switch. Worked brilliantly up until the day I moved.

It did have a couple of gotchas over your neat system you described here:
1. It was more expensive but back then was pretty much the only option as the auto switch kit was not around. And it was a one off investment.
2. Power rating would have been a bit lower. I think it was rated at about 10 amps, but that was ample for my extractor at the time. I had taken the precaution of making the socket on the spur a 5 amp socket so no one could plug in a 13 amp heater or anything.

This is still a very viable setup even with high power motors using light switches and intermediates by incorporating a relay at the socket end. It was one of the ways I had considered. Now I am going with a low voltage switching system using micro switches on each blast gate so the extractor will turn on as soon as a blast gate is opened, and a capacitive rated relay in a control box by the extractor.

 

[Charlie]

I too have a plug and play system, I hang the controller from the roof on a cord in the middle of my small workshop. The problem I have is that of starting the vac up. My Axminster vac has to be started at the machine in the corner of room as I don't quite know how to make it permanently 'on'. Any suggestions as to where I can find such info would be greatly appreciated!
I've been looking at automated systems on YouTube recently and found a couple that I like the look of using microswitches attached to the blast gate so that when you're at the machine and open the gate, the vac comes on. When you shut the gate, the vac shuts off, but until I can fix the vac switch, I cant use such a system.

 

[Sheptonphil]

I too have a plug and play system, I hang the controller from the roof on a cord in the middle of my small workshop. The problem I have is that of starting the vac up. My Axminster vac has to be started at the machine in the corner of room as I don't quite know how to make it permanently 'on'. Any suggestions as to where I can find such info would be greatly appreciated!
I've been looking at automated systems on YouTube recently and found a couple that I like the look of using microswitches attached to the blast gate so that when you're at the machine and open the gate, the vac comes on. When you shut the gate, the vac shuts off, but until I can fix the vac switch, I cant use such a system.

That is exactly the system I’m putting in this weekend.

What vac are you using? It seems to have a NVR switch. If it’s the latching type, you can bypass the NVR part by rewiring the switch, if it’s a cheapo push to contact held in power state by an electro magnet you would need to change the switch. It certainly doesn’t raise any safety issues bypassing NVR or replacing with non NVR as there is truly no need for a vacuum to be in a safe state after a power off, my big Jet one never had NVR from new.

 

[Charlie]

Its a Axminster Hobby FM300BC

 

[TheUnicorn]

I use an alternative approach: I have an Alexa Echo in the workshop (playing the radio!) and a wifi switch (~£10) on the extractor. When I say "Alexa, turn on dust extractor", it turns on. Similar for off. It's amazing how well it can hear commands over the noise.

Genius, although all a little bit 2001 for my liking