Sunday, March 6, 2011

The Turn of the Screw, Part One.

How to Operate a Screwdriver.

Almost everyone has used a screwdriver at some point in their life. 

As simple as the tool seems to be, many find it difficult and awkward to use, and many fail to rotate the recalcitrant screw without bloodshed. 

So this article is dedicated to those who approach this simplest of tools with fear and loathing.

Consider the tool itself.  It is far younger than the axe and hammer in Man the Tool Maker’s inventory by several hundred thousand years.

It has but three parts, the handle, the shaft, and the tip, or blade.  There are no moving parts aside from the tool itself.  It is pretty obvious which end to grasp, and the other end will be as far from the grasping hand as the shaft will allow.

Before getting into the intricacies of the handle, let us first discuss how the tool works, the physics involved and some of the engineering considerations for this tool.

There is a blade, a shaft, and the handle.  The blade comes in many shapes and sizes, but for now let us consider the ordinary flat bladed screwdriver.  The wider the blade the more twisting power the screwdriver has because in effect the blade is two levers, each the length of half the diameter of the screw slot which is used to turn the screw.

Therefore if the only screwdriver available is less than the total width of the slot, place it so that one side of the blade is at the end of the slot.  That way the screwdriver will be powering the screw at its maximum torque on the one side.

The best choice is a blade the same width as the slot.  It should fit the slot tightly.  Most blade problems come from the condition of the blade.  If the blade tip is rounded and eroded (the usual condition), file it flat on both sides, and square across the tip so its edges are sharp.

A second problem is the hardness of the blade. Soft steel erodes and the blades wear into blunt instruments suited only for damaging the rims of paint cans. Chromium and vanadium added in tiny quantities makes steel hard and tough. Look for those words on the shaft of the tool, or the name of a famous maker that sells tools with a lifetime warranty. Avoid chrome plated tools, the chrome is too hard to file and often flakes off, it usually hides an inferior grade of steel.

Choosing the correct shaft.  Square shafts are really cool because a wrench can be used on the shaft to help turn the screw if it is really stuck. The longer the shaft, the easier the tool gets to use.

When you twist the screwdriver, your hand keeps making tiny errors of position as it tries to maintain the blade in a vertical position in the slot of the screw.  Short shafts translate these tiny errors into big changes of angle, whereas long shafts make the angle errors smallest.  Use the longest shaft you can for the job.

Handles are also important because through the handle, your hand applies the twist.  The fatter the handle the greater the turning power your hand has, because it is all about that radius as a lever principle again.
For comfort, the handle should have a smooth flat end that fits your palm.  From my experience of fifty years, smooth almost cylindrical handles are best. 

The worst handles have serrated rubber grips that become irritants, and domed tops that injure the palm when heavy pressure is applied.

Proper use means pressing down with the handle while twisting the thing at the same time.  If that handle tapers to the shaft, your fingers have less torque, and they tend to slide down.  The flat top allows maximum pressure with comfort, while a long straight cylinder gives best grip for the fingers.  Two handed is easy if the handle is big. 

One hand on the top for position and pressure, the other on the handle for turning.  If you need more grip, put on a pair of rubber kitchen gloves.

Most of the operation of a screwdriver needs little power, so usually I press lightly with the top and use my other hand=s fingers to spin the shaft.  No wrist fatigue, faster spinning. 
Turning it one handed, press lightly at the top, and spin the handle with your fingers until you need to apply more torque and begin using your wrist.

About paint in the slot and other problems like partly worn grooves. 

With your sharp ended screwdriver right at the end of the slot, angle it slightly and tap with a small hammer on the side of the blade to drive the paint from the groove. 

This sliding the blade into the slot from the side gives a good fit and better turning due to the tighter fit in the slot. Badly worn screws can be cut with a hacksaw blade to make a fresh groove to turn with. If you do this do not make much of a cut because you are also weakening the already compromised head.

Another trick once the screwdriver is correctly positioned in the slot is to give a sharp rap on top of the handle. this shocks the screw threads in the holding material and frequently makes the removal easier. 

It is not illegal to use WD40 on a screw overnight if it is very resistant.

It soon becomes obvious that a completely equipped person has a multitude of screwdrivers.  Long shaft, short shaft, medium shaft.  Robertson, Phillips, Torx, Star, Flat blade, and more esoteric designs abound. 

Not to mention broken screw extractors, small hacksaw blades, and so forth.

For those handy types that like to shop for, buy and use tools B this is a good thing.

For the rest? 

Hire a handyman B or marry one. 

For the right woman, I can be had.

Next post?  

All about the screws these things turn. And the slots in them that help or hinder the worker.

Here is a picture of three of my stock of screwdrivers. One is an antique from the 1930's the other two are new with a capacity for quickly changing the tip to match the screw to be rotated. Note that all have fairly long shafts for the size of the tip.

Sunday, February 27, 2011

The bandsaw died.

Perhaps you were expecting an update about the bartered woman syndrome?
The paint has to dry first. Actually it has to be applied first. So the pics will have to wait, and the story will continue later.

Meanwhile back at the ranch, the bandsaw stopped starting.
At first it was thought to be a problem with the switch.
The saw is twenty um years old and the switch was maybe getting tired?

So we took it apart and saw that it was literally choked with decades of fine dust and the lever arms could no longer travel far enough for the contacts to meet and pass electricity.

The air compressor took care of the dust problem, and the switch was reassembled.

But it was installed in  an inconvenient location so we decided to put it up where it was easier to find and switch off if needed.

Here is the tale of relocating the switch from the lower stand to the back of the casting that holds the upper wheel.

Phase one was to acquire an electrical box to hold the switch. And step two was to drill and tap a couple of holes in the cast iron frame to hold the surface mount box.  Look at the pretty picture and see the tap. Click on it for a bigger image.

I used a # 10 by 24 thread machine screw with 5/64 drill to tap the threads.
Here is the box installed.

You can see the box has plenty of holes and cracks to let dust in, so the next phase was a bit of sealing with a hot glue gun.

Here is the gun. A cheap one but it does the job.

After sealing around all the cracks and extra holes with nylon glue, the whole box was covered with silvery duct tape.

Next the wire from the motor was lead through the stand and shielded with a plastic fitting so it wouldn't chafe.
I rewired the switch and assembled the interior by attaching the ground wires first.

When I connect wires I try to arrange the stripping and sconnectors so that there is no naked wire available to make accidental contact.

After testing the switch, the final assembly proceeds, sealing the cracks with duct tape on top of the glue seals.

And there it is. A relocated switch that is safer because the machine operator does not have to seek at belt level for the thing is he or she wants to switch off quickly.

Saturday, February 26, 2011

Barter Building

So in the actual construction of the vague drawing, there are a few steps that are obvious.
First - make the measurements of the location for installation,  and determine critical dimensions.
Then figure out a way to make the item in such a way that it can be easily transported to the job site and erected with little difficulty.

Make a cutting list of all the materials needed to be assembled. Figure out how to assemble it at the job site while making allowances for the uneven floor, and the baseboards, the existing pipes, the queer angles and assorted randomness of the job site.
Preview the available stock and decide which bits to cut from which stock lengths.
The idea is to avoid waste, make the best stuff the most visible bits, cut the knots out and use the clear, straight bits to maximum advantage.

Amazingly enough, this takes time. I have learned to charge this time at the same rate as the other time I spend doing work like shopping, cutting, assembling, transporting and installing. At the end of the day - all I sell is my valuable time. And my time is valuable according to my education, skill, and experience in doing what I do.

So here is a picture of the trial assembly of the bathroom vanity concept: It is a trial assembly held together with a few clamps to see if the assembly theory will work, and to see it in three D for the first time.

Click on the image to get a bigger picture.

And the three quarter view

It looks mostly white because the wood is pale, and the picture is over exposed.

Check back for pics of the completed install and other cool stuff.

Friday, February 25, 2011

Sensible Spending Spruce Up

The first thing we discussed was the eternal and infernal choices between wallpaper and paint for low budget renovating.
Paint is almost always cheaper because of this:
Wallpaper needs a good flat surface to show well, and also takes a lot of skilled labor to hang in spaces where the walls are not flat and the corners are awry. Lumps underneath have to be smoothed, and the walls need to be clean enough for the glue to stick. Wallpaper in bathrooms is always challenged by a steamy warm humid atmosphere. (Sorta what commercial wallpaper removers do to get the stuff to fall off the walls.)

Next we discussed the obsession over smooth flat surfaces in relation to several of my years' experience renovating in France where the 200 year old village houses I mostly worked on never had plumb, flat walls that met at right angles.

Paint goes on any texture of finished wall.
Paint is cheap.
There is no need to have only one wall color in a single room.
You can even do stripes, shadow effects, murals, abstract, and more wild ideas like trompe l'oeil art effects.
A primer coat solves most difficulties.
Even large cracks and dents, and holes can be filled easily with several quick setting compounds.

So after I let her off the floor and released the choke hold she agreed that paint would be used rather than wallpaper.

So we raced off to the Home Depot for supplies.

Where she got Shocker Number Two:

There was nuttin' in the flat pack industry that would accept the (non returnable) sink she already had at a price she wanted to afford, and in a style that went with the existing mashup of style in her rented space.

So I drew her a picture of something I could build her for the same price as one of the upscale flatpacks. So we scored the materials for the counter, the repair of the walls and paint for the room at under a hundred bucks.

Here is the drawing:

We bought a four foot piece of counter top and six pieces of knotty pine 1x4 which I was allowed to pick over and arrive at six pieces of pretty well clear pine for the frame of the sink counter, and I had some recyclable panels for the rest back at the shop I hauled in from the trash pile at our loading dock.

Here is the first trial fit of the sink in the counter top:

Tune in tomorrow as we continue the adventure.

Thursday, February 24, 2011

Barter Bathroom Bettering

So - here was the problem.  My barter partner has this bathroom she wanted to refresh and it had some really bad problems. Plus she did a Bad Thing.

On impulse she purchased this gorgeous multicolored made in Mexico bathroom sink. Without considering how it would be inserted into the bathroom at minimal cost.

The bathroom had the following 'features':

An uneven hardwood floor with several very old coats of paint on its wavy, cupped board surface.
The walls did not meet at right angles.
The floor was neither flat nor level.
There were a multitude of serious cracks in the plaster (not sheet rock) walls which had a sort of horsehair layer under the plaster against the lath.
That plus a large number of nails and other fasteners in the material that had held other decorations over the years.
The full size claw foot bath tub with a shower curtain surrounding it was OK but the sink, a relic from the original construction was well past eighty years old. The enamel in its cast iron bowl was mostly worn through, the replacement faucet handles were scummy beyond repair, and the under sink pipes were a hodgepodge of replacements from galvanized originals to copper replacements - all still in place.

And now a nice shiny new ceramic sink intended for a counter drop in type of installation and the original install being a Harvey Wall Hanger. Made me want to bang a few walls and have a Harvey Wall Banger to boot.

And a really tight budget plus she is talking WALLPAPER and an off the shelf el cheapo melamine flatpack counter to hold the sink off the floor...

What to do?

Tune in tomorrow and see how your guesses match what I counseled and later implemented for a refreshing low budget improvement.

Wednesday, February 23, 2011

Barter Mania

So - I confess its been a while, but I have been busy expanding my hobby operation to a small studio in the Mile End part of the Plateau area in Montreal.

And all that activity has me in need of the occasional massage for therapeutic purposes.

And that in turn brought my attention to a great masseuse who is an addict of the barter system who was advertising on Craig's List - a source of many goodies..

So we struck a deal.
She buys the materials. I do the work, and barter the work value I do for the massage value she does.

Her rented studio is a couple blocks from mine and needed a substantial makeover from the shabbily neglected apartment it used to be. A first focus was the kitchen which it seemed had not been touched or visited by the landlord since before World War Two.

Check out the before pictures to get a look at the state of affairs with the kitchen counter. Yes a new top, but under the counter successive paint jobs had prevented drawers from closing, and two doors were now missing, the openings covered by really gross red cloth.

So I did a quick measure and used some recycled wood hanging around along with some used plywood from a packing crate to make some quick n dirty reproductions of the original doors.  The middle door had jammed inside the casing, and had not been opened in two years until I applied my magic. See what was in there in the picture.

I also used a trick of the trade and shifted one of the original doors to the end of the three and inserted the new door into the space between. Subtle differences become less apparent using this method. The doors are actually plywood with thin pine glued to the surface to simulate the look of the original panel doors. A bit of gyprock mud simulates several coats of paint in the inside edges, fills gaps and softens the look.

I then recycled the old hinges and hardware to mount the new doors, and viola, after a coat of paint and removing some of the excess paint from decades past - a sorta retro look refurbished kitchen will appear.

Check back in a couple weeks to see the stuff all painted retro white and when the top bit to hide the too big sink is placed into position. The sink actually overhangs the door under it.

Does this mean I am getting Bartered Woman Syndrome?

Sunday, November 29, 2009

Putting it all Together

The primary problem to making the sewing machine work was getting a motor control connected and the barrier was a lack of the specialty plug that connects the speed control to the machine. That power source also powers the light.

The trick is that the power to the motor is modulated to vary the speed from zero to max, whereas the power to the light is constant at max.

So I whipped the plug receiver off and took a look.

Definitely not rocket science.

I made a simple plywood cover for the hole to re-use the existing screws that threaded into the machine case. Next I used two different colored wires to identify the motor from the light power, and wired the junction box appropriately using a specialty plug receptacle and plug with one lug at ninety degrees to normal. After color coding the plug end to wire color, and assuring the wrong plug cannot be inserted in to the wrong socket by putting a bit of glue in the slot, the junction box can only be connected one way without the willful assistance of a hammer.

If you do manage to plug it in backwards you get a foot control on the light and a full speed ahead motor. But no electrocution.