• Author Author: manojroy123
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Building safety system for PCB cutting machine

Table of contents

Building safety system for PCB cutting machine

Abstract

We have already build a PCB cutting machine for at least 1.5 years back for cutting PCB. The problem with it is it used to get over heated and I wasn't aware about it that it got over heated. Having no intimation about its heating may lead to failure of the DC motor that was used for cutting PCB(Printed circuit boad)

I have already build a PCB cutter for at lest 1.5 years back for cutting PCB. More often or no the DC motor used to get hot after 1 hour of use. I was looking for way to protect the DC motor that I am using in the PCB cutter. I decided to build and implement safety system for the PCB cutter. Temperature measurement and indication of motor over heating is also one of the requirement I need to satisfy. For a motor to be safe to use it's temperature should not go beyond 50'c. If it goes you should get an indication about it. bellow is the image that display how we have attached RTD temperature sensor to the DC motor.

image   

The RTD is glued to the motor using Kapton tape. So that the RTD can measure the motor temperature and send that information to the mkr Wifi 1010 development board. The mkr Wifi 1010 board checks for temperature weather it is above 45'c and bellow 50'c give a 5 beep indication and if the temperaure is above 50'c it gives 1 long beep indication. bellow is the image of how we have fitted the mkr Wfi 1010 to the paper box.

image

After fitting the mkr wifi 1010 board in the box. We have assembled the entire system in the PCB cutter. which is shown bellow.

image

Bellow is the video that is showing buzzer response when the dc motor gets over heated.

Category : Projects
  • in reply to manojroy123

    Something slightly more powerful than what you have would be good, but I'd strongly advise not to go to extremes for this DIY project. You shouldn't need more than 50W or so for that size blade anyway (I think mine is probably about 35-50W (I could check), and has a slightly larger blade, and cuts thin material extremely quickly - with a more coarse blade).

    And the build quality is critical (it's extremely easy to cut yourself, poke out eyes with flying material and so on, even with many of the models with more safety features built in). Table saws are one of the more dangerous tools compared to other electric saws; check some online articles or videos on the subject if you're not convinced.

  • in reply to shabaz

    I am looking for various other motor as well. As I have a huge requirement for this table saw for every know and than use. more powerfull motor something above 500 watt.

  • in reply to manojroy123

    I watched the video again, that's much clearer thanks.

    The motor is underpowered, it should slice through the wood very quickly. Also, your saw blade is quite fine, if you can find one that has much coarser teeth, it will likely work better. The fine-tooth blades are usually for cutting metal  (which is dangerous anyway with a table saw). 

    I looked on AliExpress and saw this, which might be more suitable:

    image

    Or, probably better but more than twice the price:

    image

    The second example will have more suitable bearings, plus may have a better speed to match the saw blades (the saw blade isn't included in that price though).

    I have a small circular saw that is ancient and has been playing up recently, so I took the rear panel off to examine it, and noticed it too uses a belt drive. Mine has a coarse blade which is ideal for wood and PCB material (although I don't often cut PCB material with it).

  • in reply to shabaz

    processing engine of element14 is still suppressing the loudness of audio.

  • in reply to shabaz

    I have updated the video and have cut it to five minutes with more louder audio.

  • Hi,

    The video is really long and nothing happens. I watched for several minutes, and didn't hear any temperature alert. Might be better to shrink the entire video to say just 1 minute, and put some text overlay mentioning when the motor has overheated.

    Your implementation is a table saw, it's well worth reading up on safety for such devices, I appreciate the motor is very underpowered, but it could still cause harm when you least expect it, e.g. throwing offcuts into your direction (wear glasses, and try not to have fingers so close). Table saws are really unfriendly tools, although I admit I use one too, but would probably buy a different saw in future (e.g. bandsaw) since most table saws are an accident waiting to happen at a moments lapse of concentration.

    Also, well worth using it outside rather than indoors, to get rid of the dust (which can be harmful). There are other options to cut PCB too, although I can see why a table saw is convenient too.

  • in reply to balajivan1995

    Hi, I have updated the video on the project. Hope it get available soon.

  • in reply to balajivan1995

    Sure I will be editing the video tommorow.

  • Can you please edit the video so that we can focus on the important moments? It's quite jarring watching the video when the audio is mostly buzzer and the rotating blade.

  • Please let me know if I am missing anything to add to it before deadline.