Re: [MedievalSawdust] Re: New, and with ignorance aplenty, and with a sketch Q
- On Sun, October 10, 2010 7:14 am, frode_kettilsson wrote:
> I posted a sketch in a album named "Frode's musings" of simple benchCouldn't make the sketch come up, but many examples are in the books.
> with a strap holding the work piece. Is this a correct interpretation of
> the description below? Thanks,
> --- In firstname.lastname@example.org, conradh@... wrote:
> ...A primitive possible shave horse
>> ancestor is a simple bench, straddled by the worker like a shave horse.
>> leather strap or rope has a stirrup-style loop at each end, and goes
>> over the work. The work is pinned down to the bench in front of the
>> worker by his feet in the loops. Add a raised platform for the work in
>> front of the operator, which is easy and obviously useful, and only the
>> foot lever has to be added to invent the shave horse...
There are some major weaknesses to the technique in practice, which
probably led to the development of foot levers and wedging systems.
In particular, if you try this you'll discover that basic trigonometry and
vectors are of more than theoretical interest. The strap's holding power
depends on a workpiece that either sticks up a fair ways above the bench,
or is close to but narrower than the bench's width. File cutters were one
craft that traditionally used this holding system, but they had a raised
block of lead, a soft anvil, that ran down the middle of the bench. The
lead block was only a little wider than the file blank they were chiseling
teeth on, and thick enough that the strap had an effective angle of pull.
(The lead protected the just-cut teeth of the first side when they turned
the file over to cut the second side.)
The strap also won't hold anything wider than the bench very well. (It
still holds stuff down, but the work can slop around from side to side.)
In some woods, you can even break unsupported edges off the workpiece from
the pressure of the strap.
Advantages are mostly that it's cheap, it has a quick clamping action, and
that within its size and shape limitations it can hold oddly shaped
pieces. It's probably at its best as an accessory for some bench you
already have and use for other purposes, or for repetitive production work
such as the file makers did--where you can make a block or jig that takes
a single size of workpiece and optimizes the strap's holding power.
I've been saying "strap" here, but a rope can often be used as well. ISTR
some Japanese workers have used a light-duty version where the workpiece
is on a block in front of a sitting worker, whose big toes pull loops in
the ends of a cord over the work.
And if you want to go the investigative route in the shop, you can always pick up a device called Kill-a-watt. It’s a device you plug into the wall outlet and then plug your electronic device into it and it will tell you what it’s drawing. More or less. I see them at radio shack personally. $100 bucks is a lot agreed.
Not to throw in a 'me too'. But ... yeah, I can't see how a little shop
work could add $100 to an electric bill. My computers eat up more
power than an hour+ in the shop does. And that's with 220V tablesaw,
220v dust collector, and who knows what else running semi-constantly.