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Drill press - variable speed foot pedal


#1

I have an 8" Delta drill press, model 11-950. Do you know if I can
without damage to the motor install a variable speed foot pedal
between the drill press and the wall outlet so I can have hands-free,
variable speed operation of the drill press? (Delta technicians
didn’t seem to know what a variable speed foot pedal such as that
used with a Foredom flex shaft machine was!) Many thanks.


#2
   I have an 8" Delta drill press, model 11-950.  Do you know if I
can without damage to the motor install a variable speed foot pedal
between the drill press and the wall outlet so I can have
hands-free, variable speed operation of the drill press?  (Delta
technicians didn't seem to know what a variable speed foot pedal
such as that used with a Foredom flex shaft machine was!) Many
thanks. 

Depends on the type of motor. Many tools of that type have a
typical induction (brushless) motor intended to run on 110 volts AC,
at a specified constant rpm, like washing machine motors, or buffing
motors. These things don’t work with variable speed controllers. If
the motor is a brush type, then it will work. Routers, hand drills,
flex shaft motors, and the like, are brush type motors, and can be
speed controlled. It’s pretty easy to tell the difference.
Induction motors are pretty quiet. Brush types, you can hear the
brushes against the commutator. Induction motors are usually marked
with a specific RPM, most commonly either 1725, or 3450 rpm.

Peter


#3
     I have an 8" Delta drill press, model 11-950.  Do you know if
I can without damage to the motor install a variable speed foot
pedal between the drill press and the wall outlet so I can have
hands-free, variable speed operation of the drill press? 

Louis, That would be nice, but unfortunately it won’t work. Trying
this will likely damage the foot pedal and very possibly the motor,
depending upon how hard you try. :slight_smile:

Ignoring details for the sake of simplicity, a Foredoom type speed
control varies motor speed by changing the voltage to the motor. This
works because a flex shaft machine uses a “universal” type motor. The
name “universal” is derived from the fact that this sort of motor
will operate on either AC or DC power sources. It’s most obvious
characteristic is that it has brushes.

Most drill presses use “induction” motors. Induction motors are
strictly AC machines. They do not have brushes and will not operate
on DC (they will sit there and quietly burn up!). The speed of an
induction motor will not vary with voltage, and is fixed by the
frequency (60 Hz in the USA, 50 Hz in most of Europe) of the power
supplied to it and the physical construction of the motor. That is
why motors generally have odd numbers for their speeds like 1725 RPM
and 3450 RPM. That is also why most drill presses have step pulleys
to vary spindle speed.

If you wish to have infinitely variable motor speeds, you can get an
inverter (often called a “variable speed drive” or “VSD”) which
takes in 60 Hz power, and converts it to a 120 Volt output with a
variable frequency, which you control with a knob (or foot pedal).
These are not terribly inexpensive (maybe $180 and up, depending upon
just what you need) but are a great way to go if you have the cash
and really need the capability.

Hope that helps.

AL


#4

Hi,

 I have an 8" Delta drill press, model 11-950.  Do you know if I
can without damage to the motor install a variable speed foot pedal
between the drill press and the wall outlet so I can have
hands-free, variable speed operation of the drill press?  

The quick answer is “NO”, you can’t add a variable speed control to
your drill press.

There are only two ways to vary the speed (without changing the
motor) one by changing the pulleys the belt runs on, using a
mechanical variable speed drive or transmission. Motors used on most
shop tools are usually single speed, sometimes 2 speed motors. In
order to have a variable speed motor it’s necessary to use a motor
designed for variable speeds.

There are a number of considerations to take into account when
selecting a variable speed motor drive, power required at slow & full
speed, input voltage, method of speed control, etc.

Generally controlling motor speed for larger machines can get
involved & expensive.

Dave


#5

Nope, you cannot use a variable speed foot pedal on you drill press.
The motor on your drill press is an induction motor, and the little
motor on a Foredom is a brush-type motor.

Jack Reisland


#6
    I have an 8" Delta drill press, model 11-950.  Do you know if
I can without damage to the motor install a variable speed foot
pedal between the drill press and the wall outlet so I can have
hands-free, variable speed operation of the drill press?  (Delta
technicians didn't seem to know what a variable speed foot pedal
such as that used with a Foredom flex shaft machine was!) Many
thanks. 

No you can’t use a variable speed foot pedal with that type motor.
It is built to run at only one speed that is governed by the line
AC frequency . 60 cycles most places and 50 cycles in Europe and
some other places. Jesse


#7
 Do you know if I can without damage to the motor install a
variable speed foot pedal between the drill press and the wall
outlet so I can have hands-free, variable speed operation of the
drill press? -- 

G’day Miles; Do you REALLY need continuously variable speeds for a
drill press? I’ve had my press for very many years, and it has, like
most drill presses, a belt and pulley system that, by flipping a belt
across, gives three distinct speeds. I find the fast, medium and slow
speeds sufficient to use 12mm drills in steel and 50mm hole saws in
wood at the slow speed. The medium and fast speeds I use for smaller
drills in copper, wood and aluminium, according to the size of the
drill.

However, I bought a robust ‘push-on’ 'push-off ‘switch’ which I
mounted on a small box which has a lead with the usual outlet plug on
the end, and a flush mounted power socket. I plug the ‘male’ power
plug from the box into the mains outlet, and the male plug from
the drill press into the flush socket on the box. The box goes on the
floor. Thus, pressing the button switches the press on and off
again using my foot, leaving both hands free to guide the job…
Very simple and effective. And cheap!

Not sure how to wire it up? email me off-list.

Cheers for now,
John Burgess; @John_Burgess2 of Mapua, Nelson NZ