replacing a bench drill power switch

Hi all ,

The power switch on my asian built bench drill has finally given up the ghost and i need to replace it .

A new switch will cost around $30 AU and considering i never liked it anyway i would like to look at another option and i would like to draw on the experience of other forum users .

I want an emergency cut out switch either way as this unit didn't come with one .

My options are :

Make a new switch up using a rocker switch in series with the emergency switch or:

Make a switch up using momentary on / off switches with a relay so the relay latches in and have the emergency in series with the relay coil or:

Set up a foot switch system ( i would still have the emergency mounted on the drill head also) I could drop the voltage down to 12v for the pendulum for safety and use a relay mounted behind the emergency switch to switch the mains for the motor .

I have used a foot control for punch and shear machines and found them very handy but what about a drill ?

I'm sure i have read about using foot controls on a bench drill some where before - maybe it was in MEW or ME ?

What sayeth ye ?

Ian

Long time ago, when I was at school, the plllar drills were all fitted with foot operated stop switches - a hinged plate on the front of the base casting.

Very convenient.

Push switches for on and off plus contactor/relay. You can have as many emergency stops as you like then and it all shuts down and stays off if the power drops out. Floor mount knock off switch is very usefull as it allows you to turn off with your foot without letting go of anything. It's more involved but really is the proper way of doing things.

regards Martin

Many times I have contemplated having a foot switch for my drilling machine but have just not got round to doing it yet! Minly because I have not found the right pedal

I fitted a VFD and (apart from the the main power switch) have fitted a small fwd/stop/rev toggle switch and speed pot both within reach of my fingers whilst holding the quill advance lever.

Most people think very negatively about running a VFD/motor at low speeds (motor overheating problems etc) but I find the reduced torque perfect for tapping operations/ I regularly use M2.5 taps held in the not overtightened normal chuck. Ideally I would like a foot switch that worked like an accelerator but in both directions

Ian P

Hi Guys

See HERE . Good idea but not cheap!

Norman

I also have fitted a VFD to my drilling machine, wired it much the same as Ian above and made a digital read out following an article in MEW.The foot switch is very good especially when drilling thin metal which if not well restrained is liable to rotate in a dangerous manner. I have fitted VFDs to my Super 7 and bench top milling machine all pre owned as the car saleman says, and wired a push switch to give jog usedful when setting up. I also fitted a relay, wired to give no volt release.Never had any problems with motors over heating, I am aware of the reasons for possible over heating and when I first fitted the VFDs I did often check the motors when on slow speed.As I said there was a good article in MEW regarding digital read out using VW car ABS braking sensor which counts the teeth on the lathe bull wheel. I made a 60 slot wheel for the milling machine out of some printed circuit board, it works slightly differently. Regarding the foot switch working like an accelerator, what about a sprung loaded linear slide switch, must look in RS, only one direction though.Got me thinking Ted.

Thanks for the replies all.

That is another thing the mechanical switch won't do and that is switch off if the power goes out so a contactor set up may do although the spring loaded foot switch would do the same as it cuts power until you stick your foot in it and push down .

My machine is single phase so no speed control of the motor .

I was thinking of the foot switch being purely to start the machine when i commence drilling and not as a sefety cut out although lifting your foot off the swich will cause it to stop and i would also have the standard red button style emergency cut off mounted on the drill head as a back up should the foot switch ever jam .

What if you modified an old foot switch from a sewing machine to get your speed control ?

You would have to rip out the Nichrome wire and make up something to mount a slider pot in there and you could mount a micro switch to turn the motor on /off .

It would be finnicky to make but possible .

Looks like i have found another new project to distract me !

Ian