How a Slide Rule works - basic.
- Thread starter Fordman
- Start date
In my younger days I spent quite a few hours operating one of those. Was a big step up from the Tee & Set Squares I was using before I got to College.
Yep, very familiar. I was always amazed by the quality of these. The smoothness of the movement, the positive detent when you released the lock lever, and it had an angle vernier! If I had the space a proper old skool drafting table would find its way here.
There's nothing wrong with the trusty 30/60 and 45 set squares. If you know what you're doing you can produce 15º increments and get around board very quickly with a pair. And you still needed a 4mm parallel line scribed onto the 45 to do sectioning anyway. I'm never far away from a pair of No10 Kents.
Agree but a drawing board just makes it so much faster, a bit like CAD has today.
You should have asked a year ago Schlitz. I sent a German drafting machine to the tip. A year before I sent the stand and board.
I still have a couple of properly made ebony edged drawing boards for my heirs to dispose of together with cedar T squares with real ebony edges and some large 45 degree straight edged set squares. The 30/60 ones seem to be hiding.
I always found a tee square and set squares on a level board much quicker than the vertical board and machine favoured by mechanical draftsmen. Some preferred a plastic edged parallel rule that ran up the level board on wires and pulleys, but the ordinary square is as good if you don't mind hanging on to it with your left hand. I think I have a parallel rule somewhere in the junk.
The speed of CAD can be debated. I wrote early CAD code and used it, so am familiar with it. I think architectural and structural draftsmen are quicker on the board by hand, unless the drawing has a lot of repetition. 3D CAD for this work is quite slow compared to plan and elevation style 2D.
I still have a couple of properly made ebony edged drawing boards for my heirs to dispose of together with cedar T squares with real ebony edges and some large 45 degree straight edged set squares. The 30/60 ones seem to be hiding.
I always found a tee square and set squares on a level board much quicker than the vertical board and machine favoured by mechanical draftsmen. Some preferred a plastic edged parallel rule that ran up the level board on wires and pulleys, but the ordinary square is as good if you don't mind hanging on to it with your left hand. I think I have a parallel rule somewhere in the junk.
The speed of CAD can be debated. I wrote early CAD code and used it, so am familiar with it. I think architectural and structural draftsmen are quicker on the board by hand, unless the drawing has a lot of repetition. 3D CAD for this work is quite slow compared to plan and elevation style 2D.
One of these though the old style board was made from separate pieces screwed to a frame, and the rule was wood. We put a plastic backing cloth layer over the woodwork, usually green. Some preferred heavy paper. Wires ran around the edges to keep the motion parallel. You had to be careful not to run over fresh ink.
Hehehe. Yep. I remember my mom being very frustrated with low quality ink that took a few seconds to dry compared to the likes of Rotring that would dry instantly. That was too long a time for a professional doing their job. I had a few oopses doing projects at uni.
I think Rotring still had a similar cable and pulley board in their lineup until a few years ago. I had a look at one but the model was too small (A3) and I wasn't very confident with the parallelism of the movement. A heavy duty old Kinex was built like the machines of the time and probably weighed as much.
There are lots of tricks with set squares and parallel rules to keep things true and set certain angles, but it makes everything a bit harder.
I think Rotring still had a similar cable and pulley board in their lineup until a few years ago. I had a look at one but the model was too small (A3) and I wasn't very confident with the parallelism of the movement. A heavy duty old Kinex was built like the machines of the time and probably weighed as much.
There are lots of tricks with set squares and parallel rules to keep things true and set certain angles, but it makes everything a bit harder.
Let's debate. If you were to compete with say
Engineering Design
or every other company you would not last 1 week in business
From sketches these guys create in CAD to do
Floor and Ceiling Plans
Roof framing plans and details
Structural elevations and cross sections
Detailed wall sections
Foundation plans and details
Bill of materials schedules
Need a change, make it 2m wider. Press the button everything is redrawn and recalculated
Drawing boards are dead I feel
It's those alterations and repetitions that make CAD economical in a drawing office and now universal for most activities. Some of them actually cost a lot of time to draft if you want to then create perspectives, bills of quantities etc. Interestingly you refer to 2D CAD as used in the building industry.
If you could somehow in a perfect world have no alterations or adjustments, and no adaptions for the next job, a pencil draftsman would be lots quicker - that little competition was common in the 1980s when CAD was slowly introduced into this field. Unfortunately perfection isn't common and CAD has won.
Somebody has to code much of that. Once it was me. For design work the board is far from dead.
If you could somehow in a perfect world have no alterations or adjustments, and no adaptions for the next job, a pencil draftsman would be lots quicker - that little competition was common in the 1980s when CAD was slowly introduced into this field. Unfortunately perfection isn't common and CAD has won.
Somebody has to code much of that. Once it was me. For design work the board is far from dead.
My ACAD is now years out of date and runs on Windows. The costs of both are compelling reasons not to update either. My now occasional needs can be met by LibreCAD, an open source (free) version of 2D Autocad. It runs on Linux with ports to Windows and OSX.
Autocad (1980s) predates Windows and ran on Linux workstations a long way back, but they later got into bed with Microsoft and started to rely on aspects of Windows OS, making it a non-portable application. It was a shame, because those workstations had better graphics. Fortunately Lisp code for drawing was still interpreted. I prefer using a digitiser for the menus, not the mouse, but those things are dying now.
Autocad (1980s) predates Windows and ran on Linux workstations a long way back, but they later got into bed with Microsoft and started to rely on aspects of Windows OS, making it a non-portable application. It was a shame, because those workstations had better graphics. Fortunately Lisp code for drawing was still interpreted. I prefer using a digitiser for the menus, not the mouse, but those things are dying now.
Get an Autodesk “hobbyist” license then.
A photo of some of my ”slide rules”. On the left is a Stanley Fuller cylindrical slide rule from 1884. In the centre is a Thacher from early 1920’s and on the right is a home made complex number calculator. They all operate on the same principle as the traditional linear slide rule. The Stanley has an effective length of nearly 13m and the Thacher of almost 22m, giving them an accuracy of up to 5 significant figures. So much more tactile and impressive than a pocket calculator.
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