Variable Speed Drills

[BDFan1981]

Is it true that on variable-speed drills with a dial to lock in the desired speed, the drill runs at whatever speed is so "dialed" in the moment I pull the trigger? Thus, if I adjust the speed to the fullest, then the drill will likely run at full speed as soon as I pull the trigger (as if being a single-speed drill), no? On electronically-controlled VS drills this becomes a huge problem on machines without a dial on the trigger.

I have a Black & Decker 7190 Type 1 3/8" variable speed reversible drill that I bought as a Christmas present in 1994, good for up to 1200 RPM. B&D/DeWalt does/did make numerous similar drills, but few with the dial-in speed feature. One drill even has numbers on the dial to cater to specific bit sizes.

But what I want to ask you all is whether or not regardless of where I "dial" the speed, shouldn't the drill motor start out slow (10 RPM) and get to the point where I dialed it (say up to 300 RPM)?

~Ben

 

[Nor'Easter]

I would say that depends on the drill. I have some that can be varied just by the position of the trigger, then some that are full bore on the lightest press of the trigger. Being an older drill you can probably do the first.

To answer your question in a basic way, yes. There will be a very small amount of time in which the drill speeds up, it is not an instant movement. Even if it's 1/10th sec., it's still acceleration.

 

[redmondjp]

My drills that have this feature (small dial built into the trigger) still have the variable speed as you depress the trigger (which operates a potentiometer), and the dial simply acts as a mechanical stop for how far the trigger can be depressed. These are drills from the 1980s.

 

[BDFan1981]

I decided to give my 7190 another test to be sure the trigger didn't reach full speed when pressed lightly, and it still works!

UPDATE: Video now added!

~Ben