Rapidograph, technical drawing

[user079622]

In the past was enginners/students draw directly with rapidograph or first with mechanical pencil and after that redraw everything with rapidograph?
Is rapidograph good for writing or he works only in vertical position?

Why rapidograph if we have ozalid machines?

 

[Baluncore]

Why rapidograph if we have ozalid machines?

The original drawing was finished with ink pens such as Rapidograph.
The original was then copied onto ozalid paper for distribution to the worksite.
That was the origin of "blueprints".

 

[user079622]

The original drawing was finished with ink pens such as Rapidograph.
The original was then copied onto ozalid paper for distribution to the worksite.
That was the origin of "blueprints".

Why finish with rapidograph if you can put original work with mechanical pencil into ozalid and make a copy?

 

[Baluncore]

Why finish with rapidograph if you can put original work with mechanical pencil into ozalid and make a copy?

Pencil lines do not have a specified regular width.
The UV light must pass through the original paper, but be blocked by the ink.

 

[user079622]

Pencil lines do not have a specified regular width.
The UV light must pass through the original paper, but be blocked by the ink.

But mechanical pencil have also more width, 0.2, 0.3, 0.5 ,0.7 1.0 etc

Is rapidograh good for writing?

 

[Baluncore]

Is rapidograh good for writing?

No. Rapiodograph have a tubular 'nib' that must be held at close to 90° to the paper. If you use them for handwriting, they must be for a very thin line, then they will wear unevenly, and will tend to scratch the paper as your hand pressure changes.

 

[user079622]

No. Rapiodograph have a tubular 'nib' that must be held at close to 90° to the paper. If you use them for handwriting, they must be for a very thin line, then they will wear unevenly, and will tend to scratch the paper as your hand pressure changes.

Best pen for fast and fluid writing is fountain pen?

 

[Frabjous]

You might try reading this article on choosing a pen
https://arkanabar.tripod.com/pens.html

 

[Baluncore]

Best pen for fast and fluid writing is fountain pen?

That will depend on the style of writing.
A fountain pen can get very messy.
Sometimes a calligraphy brush is better.

 

[user079622]

That will depend on the style of writing.
A fountain pen can get very messy.
Sometimes a calligraphy brush is better.

Style is fast ugly cursive.

 

[DaveE]

I drew schematics with normal pencils on vellum then made blueprints back in the dark ages. Nothing special required, but you did have to roll up the original and protect it from abuse.

I never used a blueprint machine that didn't require fiddling with the exposure to get good copies, but the original vellum was seldom the problem. I suppose someone had one, but we didn't. If there was a faint line on the vellum you could just overwrite it.

A good eraser (Staedtler) was precious though!

 

[Lnewqban]

Style is fast ugly cursive.

I would recommend gel ink roller pens, not Rapidograph type.

Why finish with rapidograph if you can put original work with mechanical pencil into ozalid and make a copy?

The paper was very erosive on the graphite, which made the process slow via endless sharpening of wood pencils.
Using drafting tables with protractor head, ink could be used directly on paper in a quicker and more productive way.
Tilting the table made easier the perpendicular positioning of the pens to the paper.

Please, see:
https://en.wikipedia.org/wiki/Drafting_machine

 

[user079622]

I would recommend gel ink roller pens, not Rapidograph type.


The paper was very erosive on the graphite, which made the process slow via endless sharpening of wood pencils.
Using drafting tables with protractor head, ink could be used directly on paper in a quicker and more productive way.
Tilting the table made easier the perpendicular positioning of the pens to the paper.

Please, see:
https://en.wikipedia.org/wiki/Drafting_machine

View attachment 342907

This engineers on your picture use rapidograph directly on paper, if yes, when they make mistake how they erase ink?

I drew schematics with normal pencils on vellum then made blueprints back in the dark ages.

So ozalid works with graphite lines as well?

 

[Lnewqban]

This engineers on your picture use rapidograph directly on paper, if yes, when they make mistake how they erase ink?

Sharp knife and alcohol.
Even when using pencil as a guide, errors and ink spills were regular occurrences that required corrections.

 

[user079622]

Sharp knife and alcohol.

I always thought that in drafting engineers use first mechanical pencil...

 

[Lnewqban]

I always thought that in drafting engineers use first mechanical pencil...

I was drafting at the time prior to mechanical pencils.
There was seldom a good reason to draw straight lines and circles and fonts over pencil.
Complex assemblies, yes.
The main reason was time saving (drawing in pencil, and then erasing the pencil marks from around the ink traces).
With enough practice, using ink directly was almost free of errors.

 

[DaveE]

So ozalid works with graphite lines as well?

Anything dark that blocks light. This is why we used vellum and not paper. Light can go through the vellum. The original is a photographic positive.

 

[user079622]

I was drafting at the time prior to mechanical pencils.

?
Mechanical pencil exist since 1822..

 

[Lnewqban]

?
Mechanical pencil exist since 1822..

Not available in my country, to me and my colleagues at least.

 

[DaveE]

The paper was very erosive on the graphite, which made the process slow via endless sharpening of wood pencils.

Things you could have found at our drafting tables back in the day:

 

[user079622]

There was seldom a good reason to draw straight lines and circles and fonts over pencil.

But ozalid machine works with pencil line as well(as Dave state) and vellum paper is smooth, it is easy on graphite, so to me seems that using ink is useless.

 

[DaveE]

But ozalid machine works with pencil line as well(as Dave state) and vellum paper is smooth, it is easy on graphite, so to me seems that using ink is useless.

Ink is needed if you want the original to be rugged. Penciled vellums can't used forever because of smearing and such. I never had to make more than 10-20 copies.

Also some mechanical drawings require more precision than schematics. I really didn't care too much if the traces on my drawings had a consistent width, as long as you could see them.

 

[Lnewqban]

But ozalid machine works with pencil line as well(as Dave state) and vellum paper is smooth, it is easy on graphite, so to me seems that using ink is useless.

Again, Vellum we did not have back then, only Albanene® plotter paper.

As @Baluncore explained above, widths of regulatory lines were 0.2, 0.4, 0.6, 0.8. 1.0 and 1.2 mm for different types.

It is very difficult to create such lines, uniformly dark and wide, using only pencil.
Much more difficult to achieve on curved lines and circles.

 

[DaveE]

BTW, it's ancient history now, draftsman don't really exist AFAIK. But you could always tell if the drawing was from a design engineer or a draftsman by the lettering. Theirs was perfect, mine was just readable. OTOH, my schematic layouts made sense to other EEs, theirs seemed like a random assortment of components and traces often laid out for uniform component density. They didn't know one amplifier from the next, mine were grouped by function.

PS: I really wish I'd kept one from back them. But (unlike some current politicians), I might have been put in jail, LOL.

 

[Lnewqban]