My latest project...

[Dr.Al]

Today I finished making two battery adaptors, one straight:

and one with a slight offset:

These allow you to use Makita 18 V LXT batteries on Makita 18 V LXT Tools!



Don't give up reading this yet - there's more to it, honestly!

Offset version (which is angled up to avoid the vacuum hose on my sander):

Standard version (which sticks out a bit less):

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Unlike most battery adaptors though, these two have got a switch on the side. That switch has no direct effect on the operation of the tool.

There's a bit more stuff in there than in your average battery adaptor:

Here it is without the wires attached for a slightly clearer view:

Starting at the bottom and working anticlockwise, we have:

1. A switch, which (when turned to "on") connects 18 V to the positive input of...
2. A switched-mode power supply, which regulates that supply down to something more usable for:
3. A hall-effect current sensor, which monitors the current flowing into the power tool and outputs it as an analogue signal, which is read by...
4. A microcontroller development board (using its built-in Analogue-to-Digital Converter), which detects when the current goes over a certain threshold and then transmits a carefully curated signal via...
5. A 433 MHz transmitter to...

One of these - a radio controlled power socket (into which is plugged a vacuum cleaner):

The net effect of all that is that when I start the power tool, the vacuum cleaner starts automatically and when I stop the power tool, there's a couple of seconds of delay (to allow the vacuum cleaner to suck up any last bits of dust) and then the vacuum cleaner stops automatically.

Video showing it in action (first run is with the adaptor thing turned off, second is with it turned on) - watch the light on the power socket in the background:

 

[Edward Teach]

Today I finished making two battery adaptors, one straight:

View attachment 334929

and one with a slight offset:

View attachment 334928

These allow you to use Makita 18 V LXT batteries on Makita 18 V LXT Tools!



Don't give up reading this yet - there's more to it, honestly!

Offset version (which is angled up to avoid the vacuum hose on my sander):

View attachment 334930

Standard version (which sticks out a bit less):

View attachment 334931e

Unlike most battery adaptors though, these two have got a switch on the side. That switch has no direct effect on the operation of the tool.

There's a bit more stuff in there than in your average battery adaptor:

View attachment 334935

Here it is without the wires attached for a slightly clearer view:

View attachment 334937

Starting at the bottom and working anticlockwise, we have:

1. A switch, which (when turned to "on") connects 18 V to the positive input of...
2. A switched-mode power supply, which regulates that supply down to something more usable for:
3. A hall-effect current sensor, which monitors the current flowing into the power tool and outputs it as an analogue signal, which is read by...
4. A microcontroller development board (using its built-in Analogue-to-Digital Converter), which detects when the current goes over a certain threshold and then transmits a carefully curated signal via...
5. A 433 MHz transmitter to...

One of these - a radio controlled power socket (into which is plugged a vacuum cleaner):

View attachment 334938

The net effect of all that is that when I start the power tool, the vacuum cleaner starts automatically and when I stop the power tool, there's a couple of seconds of delay (to allow the vacuum cleaner to suck up any last bits of dust) and then the vacuum cleaner stops automatically.

Video showing it in action (first run is with the adaptor thing turned off, second is with it turned on) - watch the light on the power socket in the background:

Brilliant,
Well engineered.

 

[Maker]

Very nice.

 

[Onoff]

I like that. I have no idea how it works and it makes my head hurt thinking about it so am retiring to the pub.

 

[ukracer]

stunning..

 

[Dr.Al]

Thanks everyone

 

[Wildefalcon]

Brilliant! Well done. Mad, but brilliant. We need more of that sort of madness in the world. Thanks for sharing.

 

[Parm]

I like that. I have no idea how it works and it makes my head hurt thinking about it so am retiring to the pub.

I went to the pub at a similar time, now I’m just back

I’m correctly set to understand this trickery ....

 

[drjim]

Very clever, just started playing with Arduino stuff, this is on my list of stuff to do. Did you have some battery shells to make the adaptor or is it all made from scratch?

 

[Dr.Al]

Very clever, just started playing with Arduino stuff, this is on my list of stuff to do. Did you have some battery shells to make the adaptor or is it all made from scratch?

I bought some empty "battery case kits" from aliexpress: that gave me the bit that connects to the tool (black bit in the pictures) as well as the PCB with the slots & the spring. The connection to the battery was mostly 3D printed but I used a spare part for a power tool for the actual connector.

The battery case kit was £6 & the spare part was about £3.50 I think, so not worth the effort of designing my own.

 

[Kayos]

Absolute genius, always a faff turning on the vacuum then going back to the tool when using cordless

If I was still self employed I would be placing an order

 

[bricol]

Very good.

I still use a very highly developed, long term tested and proven, bio-mechanical, opto-mechanical device to do something similar

 

[Onoff]

I went to the pub at a similar time, now I’m just back

I’m correctly set to understand this trickery ....

A first for me...after hospital visits and playing Dad's taxi I donned my hi-viz, beanie and head torch and set off for the pub. En route I stopped by the church where I got married. Already quite depressed with life in general, work and the week that was, I looked at my watch. 20:16hrs. I'd have been at the pub for 20:30hrs and left at 22.00hrs. Sod it I thought, not enough time to relax. So I've walked back, opened a bottle of Merlot and am playing with cows in Paint Shop Pro.

 

[Dr.Al]

Just in case anyone wants to make one of these (or wants to get a better idea of how it works), all the design details are now published here: https://www.cgtk.co.uk/woodwork/powertools/cordlessvacuumstart

 

[mtt.tr]

Today I finished making two battery adaptors, one straight:

View attachment 334929

and one with a slight offset:

View attachment 334928

These allow you to use Makita 18 V LXT batteries on Makita 18 V LXT Tools!



Don't give up reading this yet - there's more to it, honestly!

Offset version (which is angled up to avoid the vacuum hose on my sander):

View attachment 334930

Standard version (which sticks out a bit less):

View attachment 334931e

Unlike most battery adaptors though, these two have got a switch on the side. That switch has no direct effect on the operation of the tool.

There's a bit more stuff in there than in your average battery adaptor:

View attachment 334935

Here it is without the wires attached for a slightly clearer view:

View attachment 334937

Starting at the bottom and working anticlockwise, we have:

1. A switch, which (when turned to "on") connects 18 V to the positive input of...
2. A switched-mode power supply, which regulates that supply down to something more usable for:
3. A hall-effect current sensor, which monitors the current flowing into the power tool and outputs it as an analogue signal, which is read by...
4. A microcontroller development board (using its built-in Analogue-to-Digital Converter), which detects when the current goes over a certain threshold and then transmits a carefully curated signal via...
5. A 433 MHz transmitter to...

One of these - a radio controlled power socket (into which is plugged a vacuum cleaner):

View attachment 334938

The net effect of all that is that when I start the power tool, the vacuum cleaner starts automatically and when I stop the power tool, there's a couple of seconds of delay (to allow the vacuum cleaner to suck up any last bits of dust) and then the vacuum cleaner stops automatically.

Video showing it in action (first run is with the adaptor thing turned off, second is with it turned on) - watch the light on the power socket in the background:

brilliant