Safety Switch

admin

Here's a handy one.  But technically not a welding project -  - but it is attached to one!A long time ago in a galaxy far far away … [1975 ... and about 3 miles!] worked part time in a wood shop.  Had a great 3hp Delta Unisaw, mag start.  Got a piece of plywood caught crooked to the blade and the kick was so hard it almost knocked me over.  The mag start was mounted at knee level front left, BUT, both the red and green buttons were in a little protective channel.     Could NOT turn it off without bending and reaching – but couldn’t reach it and hold on to the wood!!!  Although it wasn’t my saw, I decided to ‘fix’ it.  Cut the channel off above and below the red button, and glued a 2” square of red plexiglas to the red stop button.  Pic#1.Voila!  The Jerry Rigged Safety Switch was born!  I know I probably wasn’t the first, but I was surprised how good it felt to be able to turn off the saw with a knee while desperately wishing for a couple extra hands to hold down the emergency above!  And with continued routine use, the knee-off reaction became automatic – no need to think – especially helpful in an emergency.So how about one for the other tools?  Band saw, drill press @ forehead level, another table saw knee high, a router table, anything less than 1hp @ 115v or 2hp @ 230v.  Wait!  Can't afford mag start for all those, so ... workaround.  Pic#2 - Found a double pole 20a Decora switch. $10. Pic#3 – Cut 3”x4.5” pieces of red plexiglas and drilled 1-5/16” hole in each.  Foam taped it to a 3” piece of 1” piano hinge, pop riveted it to a galv Decora cover for a 4” square box.  Drilled out a double switch cover 7/8” for cable clamps for in/out cords.  Another version [right] had hole/clamp for cord in and switched duplex outlet for router.Pic#4 – 1.5” extender ring for 4” box bolted to tapped holes in bandsaw base.  3/16x1-1/4 Black strap needed for stiffness.Pic#5 – Finished.  Yellow cord 12-3 from wall, black to motor.  Knee level, turn off with a bump!  Turns on by pushing the white switch rocker thru the hole.    A lot of new tools come with switches like this now, but they’re not $20! WOW!  Just noticed the date on the last pic!    Time flyz!  Thanks for lookin! Attached ImagesLast edited by Fabn4Fun; 11-23-2011 at 11:19 PM.
Reply:I wondered if that was a home made shut off when I first saw your bandsaw project. Nice work..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:@DSWThanks!  Meant to post it [hahaha - write an article] in Fine WoodWorking magazine decades ago but never got around to it.  It's SO much easier here [online] and now [2011]!
Reply:Personally, I think all shops should have an emergency kill switch for the power going to machines. A few years ago, Son-n-law was working as a welder in a production style shop,,, He had been using this welder for hours (building a dump bed for a truck),  he stopped to take a break for a minute, so he removed his hood and gloves.. right before he put he gear back on, he decided the welder needed to be pulled a little closer to the work, since this was an industrial size machine, the Son-n-law needed to pull the welder with one hand, and grab the truck bed as the welder weighed as much as the SNL. Anyway, as soon as he did this, electric was coming out of his arm pit and running down his arm to the bed of the truck. His co-workers were all wearing hoods, ear protection, etc., not that SNL could yell or do anything anyway.... SNL already had decided he was dead, then he came to and was laying on the floor.... to this day, he has no idea who or how his life  was saved. He was off work for a while, went thru lots of medical test, but no permenant damage appears to have been done.Come to find out, the welder (machine) broke down during first shift, and one of the workers "Fixed it" by taking a broken ground wire inside the machine and attaching it to a new location (he basically, made the entire welding machine a ground), when SNL grabbed pull handle of welder, then touched the grounded truck bed, he became the ground.Qualified & experienced at welding scrap metal
Reply:I have a floor button on my small drill press.  I rigged it on a length of cord and it is plugged in between the drill press cord and wall socket.  It makes things fast and safe. Same principle as a dead man's switch.
Reply:Originally Posted by little JeepPersonally, I think all shops should have an emergency kill switch for the power going to machines. A few years ago, Son-n-law was working as a welder in a production style shop,,, He had been using this welder for hours (building a dump bed for a truck),  he stopped to take a break for a minute, so he removed his hood and gloves.. right before he put he gear back on, he decided the welder needed to be pulled a little closer to the work, since this was an industrial size machine, the Son-n-law needed to pull the welder with one hand, and grab the truck bed as the welder weighed as much as the SNL. Anyway, as soon as he did this, electric was coming out of his arm pit and running down his arm to the bed of the truck. His co-workers were all wearing hoods, ear protection, etc., not that SNL could yell or do anything anyway.... SNL already had decided he was dead, then he came to and was laying on the floor.... to this day, he has no idea who or how his life  was saved. He was off work for a while, went thru lots of medical test, but no permenant damage appears to have been done.Come to find out, the welder (machine) broke down during first shift, and one of the workers "Fixed it" by taking a broken ground wire inside the machine and attaching it to a new location (he basically, made the entire welding machine a ground), when SNL grabbed pull handle of welder, then touched the grounded truck bed, he became the ground.
Reply:Originally Posted by David HillmanI don't understand how an emergency kill switch would've helped your son-in-law?  Wasn't the problem a half-assed repair to the welder?
Reply:My machines are all on foot pedals.  That way i can hold everything yet still turn the stuff off.Syncrowave 350Coolmate 3Millermatic 251Spoolmatic 30A
Reply:They make the emergency stop buttons that aren't too bad on price. $20.00 or so for a simple one. They can be installed as a knee switch or forehead switch depending how your equipment is shaped. Only about 1 in 100 chance of it doing any good in a real tangle up emergency but that's 1 chance you don't have without one. I shouldn't talk, the only thing with one in my shop is the one drill press."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Originally Posted by little JeepI'm sorry, I didn't finish the story, of course if you are in a one man shop, the emergency kill switch probably isn't going to help you. In my SNL situation, part of the problem was once the co-workers realized what was going on, the problem became how to free him without the person coming to his rescue also being electrocuted.
Reply:Originally Posted by DSWThat's why equipment is supposed to be hooked up with plugs or have disconnect switches. On one job I was on where there was an electrical issue, one guy simply threw the main on the sub panel and killed everything rather than waste time guessing. There were a lot of pissed off people, but he solved what could have been a major issue instantly.We had one guy on base who got badly electrocuted. He was in a tight electrical closet on board ship working on some thing minor when he got a minor shock and stepped back out of reflex. He backed up into the live panel however and got grabbed by the DC. He threw himself forward to break the contact only to throw himself into the forward panel causing the same thing. This repeated itself several times until one of the other guys tossed a dry fire hose over him and dragged him out. It's part of the training on how to deal with these sort of emergencies. Most people never give any thought in advance about how to deal with emergency issues until it's too late. It's why the military and so on stress emergency training. You don't have to stop and think about what needs to be done. You react automatically with the right solution to the issue at hand.I can think of half a dozen good responses to the issue with your example. Everything from pulling the plug, hitting the disconnect, hitting the off button with your boot,  or using some non-conductive item to separate him from the vehicle/machine ( say a pallet, strap/rope or piece of dunage).