Since I had to strip one of my hand drill down to the last pins, figured may as well share what I know about these little beast.
A little history
The form that we know today, an American invention, did not existed until about 1870.
In their first incarnation on the continent (Europe) they had a totally different configuration.
Both are part of the family of Bevel gears hand drills
Could not find a good picture to use, so made a quick doodle.
This is the general arrangement they first used.
The way the side gear was attached to the frame gave rise to the name cage drill.
They were mostly bigger than today's hand drills, due to their construction.
Sort of like a brace with a side handle.
Some were quite ornate during the Victorian era
.
The American form, was not invented by Millers Falls (as they once claim in their publicity), but they, more than anyone else, popularized the style and made some of the world's best.
The American form, took advantage of a flat casting to mount the gear (s) and attach on one side a flatten driving gear wheel. Making for a much more compact size, the tool became easier to make in smaller form.
Example Millers Falls No 1 1878-1880
This is a small size hand drill.
It normally reside inside my carving tool box.
I used it for pierced carving or fret work
A flat open casting hold the driving wheel.
The small driven gear is not attached to the frame but rather...
Red arrows point to the pins (2) securing the gear to the shaft
and the drilling shaft restrained to the frame.
Blue arrow show direction of pressure, cross pin sticking out equally
on both side of shaft do not rub against casting, there is some play.
Blue arrow also point to next logical evolution, put in a thrust bearing were it count
The one driven gear style suffer the most from uneven loading on the meshing gears.
That is the jerky motion you experienced probably using a cheap one or a gummed up good one.
This is where the two major style of construction differ, in how to secured both gears.
The Millers Falls above used an open casting, while a much cheaper construction style would be using a long solid shaft.
It does not get any much cheaper than this :-(
And that is a Breast drill...
Moving the gear(s) inside the cast frame ensure more rigidity
but we still have to deal with flexing the gear wheel, since it is unsupported at the other non driven end.
Solutions varies from keeping the driving wheel size relatively small (at the cost of higher gear ratio possible), making the wheel quite beefy and stout, while loosing weight by an open spoke design
Another innovative design idea was to counter the tendency of the gear to unmesh slightly by using a wiper or roller to keep them down.
Best illustrated by the
Millers Falls No 2, a brilliant design that spin like a champ. Very, very smooth operator. I am talking about the earlier version of this tool, later they abandoned the design and went with two gears instead. :-(
One smooth operator.
Best ever design in my book
Strangely (patents??) no one else ever took on this idea. The closest was one of their renown competitor Goodell Pratt who came out with a fix wiper instead. They would later be acquired by MF who still made this tool, along with other GP products
The casting looks like the MF No 1 with the gear now enclosed inside the frame
Goodell Pratt No 655
Pics are in as found condition
Another solution was to used an idler gear to support the other end of the wheel.
That introduced another problem, more drag, since we are now turning three gears simultaneously.
The major reason why the No 2 is so smooth.
There are many variety of this design, but one of the better one is the ubiquitous MF No 5.
They are everywhere... back in the days before power tools, this was the handy man drill of choice.
There was one in practically every house (kitchen drawer, garage or basement shop) before being slowly replaced by the corded electric drill, which is being replaced by the cordless battery operated drills. Meet the original cordless drills
Millers Falls No 5
Two gears design, the addition of an idler wheel
Look how thick the wheel casting appears.
Compare that with the No 2 wheel.
Making it lighter by open spoke design and thinned out center.
Make for a nice flywheel effect for its diminutive size
A similar, but not as good design from Stanley No 624
Bigger, solid driven wheel
Pic in as found condition
Of course there is also the same cost saving idea with the two gear style, no casting, solid shaft
Stanley No 626
Pic in as found condition
The driving rotational speed is of course set by the gear ratio between the wheel gear and the driven spindle gear. In the original Continental cage drill, the gear ratio was at first 1 to 1 and peaked around 3 to 1.
In the American cast frame variety much higher gear ratios are possible, since we do not have the same size constraint, starting in a much more compact package.
Generally a higher speed would be found more useful for drilling small holes in metal or most domestic wood species. While a slower speed would be useful for driving large bits or drilling tough exotic wood species. Hence for general wood working a No 2 or No 5 are a great all around drilling implement. Others favorite solid performers would be from Goodell Pratt (designs were later produced by MF) or North Bros (designs were later produced by Stanley)
And yes, they made fancy two speed models (more later)
WHAT TO LOOK FOR
In order to operate as it should, the gears and mechanism should turn smoothly. As found in the wild, they are often gummy or sticky, which is OK, a good and sometimes repeated drench in WD-40 will restore it.
If you look at the above pics of my as found examples, it should give you some ideas of how much rust is OK. In any cases when I pick up a tool for purchase, my first question running thru my mind is always: Can I put it back to work? If NO, I'll pass, unless I need some parts from it.
That GO-NOGO decision should be based on your level of willingness to get dirty, add to your Spring's work clothes wardrobe collection and if you feel comfortable doing the work.
In most case you will rarely find broken casting, mostly rusted and gummed up mechanism.
But in most severe case, or for optimal tuning, you will need to drive the pins out securing the driving shaft and gears.
Driving shaft with chuck still attached, separate from frame and driving gear.
Cross drill hole for the securing pin is used with a nail to unscrew the chuck.
Caution, always separate parts over a container to catch small parts with a mind of their own.
Think small ball bearings, springs and such
Notice the small bearings and both plates to sandwich them.
That is the later introduced thrust bearing on most MF drills.
Anything that reduced operating drag is a good thing
Pic from
Wiktor site That guy takes it to the next level, better than new
In order to do so, you need a solid metal surface. The open jaws of a mechanic vise makes a good solid support surface. I was at first using my transfer punch to drive them out but it is a bad idea, too soft metal, too long, easily bent DAMHIKT.
Damn if I could find my proper pin punch so used a finish nail, works great
Resting the frame over the opened jaws of the vise.
DO NOT clamp the frame by the wheel post.
It is simply resting over.
Size of removed pins shown.
My pack of 160 punches, should be enough to remove a few pins.
Laying down besides it are two slightly bent transfer punches :-)
If the drill was stiff, chances are some gorilla damaged the gears. They will show up as thinned out uneven teeth. If you find uneven worn or broken gears, passed. There are millions of them out there.
A more common ailment is with the wooden parts, the top handle and side handle (if present).
Look for a tell tale screw in opening for a side handle if none attached. They don't always had one, but if there is threaded hole, it's a given it is missing.
If your hand drill look like this,
you have a missing side handle that screws in
On MF drills anyways, the thread seems to be standard, all my MF drills that sport an handle are interchangeable.
Besides the ubiquitous paint droppings and other finish ailments on the wood parts, they are sometimes found loose or broken. and the metal ferrule are often split. That was caused by work hardening of the brass cold, later they eliminated that problem.
Neither of those conditions are deal breakers, handles can be refinished, re-glued, turned new ones and yes, those broken ferrule's can also be replaced. Some used copper plumbing fittings, that would work, but you can also
buy new ones that fit from Lee Valley.
Example of copper fitting used as a ferrule
MF No 5 with a broken taped handle
They have a large variety of styles and sizes
The one I picked fit just right.
They are brass and could easily be plated for an authentic look
How found attached in this later manufactured MF No 5 circa 1935 or so.
In some cases they are in addition pinned with a cross hole and pin.
That one was not.
The No 1980 handle was threaded on the shaft then cross drilled and pinned
The formerly wobbly, taped one is now serviceable again
Some, but not all had a removable screw cap on the end to store drilling bits.
A complete set was 8 bits, often MIA, broken or replaced by nails or modern twist drill bits.
The original were first spear points bits, then fluted bits
Half a set in this one, 4 out of 8.
The smallest sizes were often destroyed thru the years :-(
This is what a full complement looks like.
1/16 to 11/64 by 1/64 in increments
An earlier form, the spear point.
That one is a brace bit, but you get the idea
A nail tip work just fine to drill small holes
Another common ailments are problems on the wood finish. From paint splatters, to flaking finishes.
In most case a good wash down with
Murphy oil soap cleaned them pretty good. If they are paint splatters I would scrape them first, then finished with my
Howard products. Refinisher and wax.
I have yet to try my
Tru oil finish on them, but that is what I want to experiment with next.
Typical crumbling film finishes on handles
Early on they used exotic wood such as Cocobolo, Rosewood which had only an oil finish on them.
Later on they started coating with lacquer then varnishes. These would be the ones causing the flaking. Easily repaired in some cases by melting the old to blend with the new using appropriate solvent. But in most cases they are pretty well beyond salvaging. Strip, sand and refinish are your best choices.
Typical crazed finish on "newer" tools.
You don't really see it much until you cleaned them,
then it really shows :-)
A bigger problem I have yet to figured out how to fix, is the flaking paint finish
This Stanley one seems to sport more flaking chips out every time it comes out to play.
I'm thinking a complete strip and repaint or stain?? Any idea on how to best replicate original thick finish? Open to suggestions
Finally I should mentioned that the side handle if present, has changed shapes thru the years on MF hand drills. So if missing and you want to acquire or turn a new one, find out which vintage you have and which shape is appropriate
First of the races was the
Tear drop handle
sort of an elongated pear shape
Late 1800s to approx 1909
Mushroom shaped handle.
The one you are most likely going to run into the most
1910-1934
Mushroom side handle from my No 2
Showing typical split ferrule, no big deal
Leave it alone or if weaken connection, replace.
Chef hat handle
1935- until end of production
These rarely suffer split ferrule, the problem being well understood by then
Chef hat side handle from my No 5A
Pic in as found condition
Currently soaking in Evaporust
This is getting a bit long winded, to be continued after my soaking examples are out.
A suivre...
Next out of the bath to tuning
Bob, where apparently the grass has grown lately and need to be mow, who knew ? :-)
