Portable Drill Design Question

[Jack Olsen]

The basic form factor of the hand-held drill has stayed the same for a long time, as far as I can tell, with cordless models only modifying the pistol design by adding a lump of weight to the bottom of the handle.

This bugs me a little. When I'm drilling through metal or using an impact-driver to drive fasteners, the pressure I'm applying is offset rather than symmetrical. Press too hard and the bit bows as it turns -- or the fastener collapses to one side.

It's not the end of the world. But it's the slow part of the holiday weekend, and the kids aren't attacking each other as the moment. So I'm wondering: has anyone ever designed a drill that applies uniform/symmetrical pressure? I know there are additional handles added to something like a Hole Hawg. And it's possible that the limitation of a small pistol-type drill is also a benefit, in terms of limiting how much pressure is applied to material or fastener.

But maybe there's something out there I've just never seen?

 

[neophyte]

Milwaukee used to manufacture cordless drills with the traditional L-shape normally found on cordless drills. I believe Dewalt did as well. I believe both companies were the last, or close to the last, to drop the design from their lineups.

Milwaukee also used to manufacture a D-handle drill that was similar to their Sawzall's in shape.

Makita manufactures a 3/8" cordless angle drill with threaded holes to mount a handle similar to the way the handle is mounted on an angle grinder.

http://www.makitatools.com/en-us/Modules/Tools/ToolDetails.aspx?Name=XAD01Z

They also manufacture a corded version.

http://www.makitatools.com/en-us/Modules/Tools/ToolDetails.aspx?Name=DA3010F


Triton Tools from Australia used to manufacture a drill with what a guide that worked similar to the base on a plunge router, for drilling more accurately. Model TDC-100. I believe it's been discontinued.

http://www.woodmagazine.com/woodwor...-would-you-ever-need-a-plunge-drill-find-out/

 

[larry_g]

You may be running under the assumption that drilling one handed is proper. Using two hands is a better way. One hand to pull the trigger and apply anti-rotational force, the second hand to apply pressure directly inline with the spindle.

If you study the corded drill motors you will see the grip goes behind the rear bearing allowing you to grip with the web of your hand between the thumb and index finger near the centerline of the spindle and the trigger actuated with the middle finger. Most of the newer battery drills don't allow this so it takes a second or a really good wrist.

lg
no neat sig line

 

[the gypsy]

The drill design you are talking about is typically American and Canadian design. If you take a European drill the handle is usually shorter and designed in such a way that you can only use the drill if you put your hand right over the motor and use your last two fingers to press the trigger. I do not have my Holz Her drill here with me but when I do I will take a picture to show what I mean.
Thus the position of the hand is more in line with the chuck. This will certainly require a picture to fully appreciate what I am trying to describe.

 

[theoldwizard1]

They used to make "D handle" drills. Yep, a big "D" inline with bit.

More likely to twist your wrist if the bit "bites" a bit hard.

 

[rsanter]

Yes, they have made drills that had the handle on the back so the pressure is more in line with the chuck. The problem is that when one of them torques you have less leverage to stop it so that is a key reason the pistol grip type drill took over

Bob

 

[Fretters]

This type of thing is the older D handle style. I have an old CP knocking about somewhere of similar design. I'll take a photo later of that too, if I can find it.

Leading on from rsanter's post, they were affectionately termed as wrist breakers for good reason though. As someone else mentioned, you ought be using two hands wherever possible with any drill though; one on the handle and one around the body near the spindle. You'll always get flop if you're drilling one handed, no matter what the drill style.

 

[finn]

The offset handle better enables you to counteract the torque developed by the drill motor by giving your hand and wrist a moment arm to work with.

I'd say that the manufacturers are ahead of you on this one.

Sketch out a vector diagram and you will see what I mean.

 

[ChevyEFI]

This bugs me a little:

When I'm drilling through metal or using an impact-driver to drive fasteners, the pressure I'm applying is offset rather than symmetrical. Press too hard and the bit bows as it turns -- or the fastener collapses to one side.

The plan should be to have a properly sharpened bit that will do the cutting in due time without much pressing from the worker.

In fairness, if it's not a precision job and my bits are dull ( ) I'll walk it around in a slight circle to let the face of the bit catch a new angle against the material and cut into fresh metal.

And getting downright honest, I could really use a Drill Doctor, and anymore, I generally keep the thread-in handle installed on my Milwaukee 1/2" drill all the time so I can use two hands.

And who doesn't need a DD and a nice set of Norseman bits?

 

[neophyte]

Always remember to use proper drill safety procedures.


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