Lets Talk about Engine Drawings

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The other method that was used was to apply a water colour wash, this could be done from a printed out image, an example from my ever growing "to buld" list may be possible by using very light tones of colour for the various parts and applying model shadow.

The other option for the cover of your build manual would be to take a photo of the finished model and use a sepia or B&W filter, this is a Heinrici I scratch built but gave it a weathered paint finish. There are filters that will make it look like a worm old photo to further add the effect that it is an old original engine

This is another filter that would make it look like an old catalogue image
I always liked the watercolor shading. The photo idea sounds cool as well.
Being a draftsman or working with drawings for most of my adult life I would like clarify a few things. I have read every post and the consensus is that the 3d drawings and shading makes wonderful drawings. I have to agree only because I also know how to read drawings.
All skilled trades, electricians, machinists and engineers to name just a few are taught through vocational or apprenticeship schools to read, draw and understand drawings or schematics. Can you imagine an electrical engineer making a schematic and saying "I'll just leave out that symbol because I don't know what it means?" Drawings are meant to convey the proper information for the end user. The end user also has to be able tr read and comprehend what the drawing means.
3D CAD programs (like Solidworks) will produce a 2D drawing from the part model but that doesn't make it a correct drawing. The drawing needs to be adjusted to meet drafting standards. Sure a person that knows how to read a drawing will understand it but for others it might be a struggle to understand what is being presented. Some have stated that adding an isometric view or 3d model to a drawing makes it easier to understand what the part is. That's because the person doesn't know how to read or understand a properly made drawing.
Having come from 'the drafting board' and at one time a subscriber to Live Steam magazine I like others was in awe of the drafting work that Kozo Hiroaka did, and without a computer I might add.
Most of the drawings that we as model engineers work with are very simple presentations, generally a 3 view part with dimensions. If drafting standards aren't met we can still understand what the intent of the drawing is and can make it. Fair enough. When I worked for a large auto company as a pattern designer/draftsman we worked with drawings that were made for engine blocks, cylinder heads, manifolds etc. These drawings were many feet in length and the drawings had section views, projected views. shape blends to locus points, geometric tolerancing etc. etc. etc. Without the training to read a create a drawing properly these drawings would incomprehensible.
When we as builders or modelers complete a project we want to do the best we can which means accuracy, fit and finish. If we want those attributes for our projects then why shouldn't we also want the same quality for making drawings. Be proud of producing the best you can!
Quality and mediocrity don't go hand in hand!
I came from the manual drafting world, where "using a computer" meant punching cards for an IBM mainframe, to run a FORTRAN program, with a results printout on a line printer.

Things have changed a LOT since the 80's, that much is for sure.

3D modeling and the associated analysis programs have revolutionized the design world, and in my opinion are as significant as the creation of the paper and pencil.

You can now design parts in 3D, assemble them virtually, run the engine and test for faults, diagnose the mass and vibration when the engine is running, check on the flow of molten metal during casting, the cooling rate of various parts in the mold, etc. etc.

In otherwords, you can simulate the entire process of engine design, assembly, running/testing/machining, casting; all without ever leaving your computer.

You can have Xray vision with a 3D program, and see through the walls of the engine, even when the engine is running.
There is no 2D analogy to this, and no 2D drawing substitute for the clarity that this can provide.

It is a phenomenal and shocking change from when I started drawing with pencil and modern vellum seemingly just a few years ago.

I think focusing on how the 2D drawings look (which is very critical to be sure), sort of misses the big picture of what 3D modeling and associated programs can do.

Ultimately the 2D drawings will be used to machine parts (unless you are into CNC), but 2D drawings that are based on a poor design are poor drawings, regardless of how well they are drawn.

The heart of the matter is the design.
The rest is pretty much gravy, I think.

Some have stated that adding an isometric view or 3d model to a drawing makes it easier to understand what the part is. That's because the person doesn't know how to read or understand a properly made drawing.
Can I read and understand a drawing? Yes I can
Can I draw a drawing properly? Not yet .
But I'd love someone to add a 3D model to their plan
I haven't actually created a design and sold them - the exception being the diesel plan - for a couple of reasons.
My question is : How many formally trained people like you are on this forum or elsewhere ?
A lot of members on this forum don't have professional knowledge or they have expertise in other industries or... so why not add a 3D model to the design so they have a more visual view. ???
Adding a 3D model to a plan doesn't mean that the person designing the plan doesn't have any specialized training in design, they just want to give other people - non-professionals/amateurs - an overview of a project or a part that they will process and I think that's good.
Make something simpler , easier to understand .. for everyone why not ? .
That is what I mentioned when Julius's drawings first came up. There are people coming into the hobby now who have little or no engineering back ground so they will not find it as easy as a person that had technical drawing and metalwork classes when at school and then went on to serve an apprenticeship to understand traditional drawings. Many beginners in the UK at least find it hard enough to understand fractions and imperial threads let alone whatever else is shown on the drawings.

It is people like that who Benifit from the 3D views of the more complex components not to mention sub assemblies and general arrangement drawings as otherwise they would have little idea of how the parts go together let alone how to make out what each part drawing is actually conveying.

The clients I design furniture for generally all find it hard to visualise what the finished item will look like but show them a rendered 3D image or an interactive 3D pdf where they can move the view point about, zoom in & out etc and they can get a far better idea of what they are paying for. This is little different to anyone else with no technical background so if the hobby is to continue then things like this will bring in new blood.

Will there come a time where a STEP file is included with a set of drawings so builders can 3D print a model first to make themselves familiar with the parts or to allow some parts to be made by CNC without the need for them to be redrawn by each builder. I've certainly shared a few STEP files of assembled engine that have been built from those so maybe we won't need traditional drawings at all! Even the engines I build I don't do a set of 2D drawings for, mostly I'll just take what dimensions I need off a 3D model and build to that, the CNC parts I don't even need to take dimensions off except to know the size of the piece of stock.

The way things are made now has changed so "drawings" need to as well
There may be some hesitancy without an NDA, but at a minimum, a dumb solid is necessary for most CNC shops. That is something younger people will be used to. With extra effort, animations (youtube) may be added as well for timing and rigging. Those creating castings have the advantage that hardly anyone will be able to copy and sell their exact design.

The younger crowd might benefit from a 3D model they can measure. If they are new to machining and only have engine assembly experience, then the learning curve will always be high. They may prefer a demo youtube video over a 3D model.

The real goldmine to the younger audience is having someone like Joe Pie walk through the machining process as he's done for some PM stuff. I was scratching my head a little with my Sherline lathe threading attachment installation instructions, until I watched the video they posted.

This video has 1.1 million views. It is an older one with nothing fancy. My guess is business at PM research is doing well!
Some of these drawings vary the line width on curved surfaces, and vary the line spacing with a constant width line for flat surfaces.

There is a lot going on in some of these drawings, and one has to look carefully to see how they achieved the 3D affect.

Other surfaces solid, or blank.

Edges typically very bold, with the closer edges more bold tan the ones further away in some cases.

Such as this one, for example.

It is all just flat lines on a flat sheet of paper, but looks very much 3D in appearance.

View attachment 146955
The methods of creating the original drawings were a good fit with the methods of reproducing them in their day. When blueprints were required for technical use, the high density of inked lines were needed to prevent exposure of the sensitized paper under the carbon arc lamps, and later fluorescent lamps.

For commercial publication and catalog work, visually attractive results were desired. These were achieved by the use of varying line weights, as printing processes of the day could only print solid ink, or no ink. Photolithographic halftones were not readily available, so the artwork was generated by artists skilled in the techniques.

US currency is still produced by intaglio from engraved metal plates, the same technique used for this early commercial printing. Text was set by hand or machine and illustrations were printed as "plates" on better quality coated paper.

The advent of photographic halftone techniques using equally spaced dots of varying size (percent coverage) allowed the creation of shading effects, eliminating the need for the highly skilled engravers. Artwork could now be generated by any means desired; drawn in ink, pencil, charcoal, watercolor, etc. Photographs could be faithfully reproduced or extensively retouched by mechanical or airbrush techniques. Artistic skill now moved a little farther from the technical expertise previously required.

Halftones were created on process cameras with high contrast lithographic film using glass crosslines screens and later contact screens. Eventually electronic scanning and halftone generation replaced the big hardware and wet darkroom equipment.

We had one of the biggest cameras and processing equipment facilities in the NY metro area. 48" wide film and automatic processors. A camera with a 48" (1200mm), f/11 lens, 6' x 8' backlit copy board, 6000w pulsed xenon front illumination, etc.

All that, and buggy whips, all gone now.

Rutherford, NJ
We had one of the biggest cameras and processing equipment facilities in the NY metro area. 48" wide film and automatic processors. A camera with a 48" (1200mm), f/11 lens, 6' x 8' backlit copy board, 6000w pulsed xenon front illumination, etc.

Wow, that is a BIG camera !

Interesting technology info.

When I started working, everyone had one of those big drafting tables.
I guess they were 60" or 72" long, and about 48" deep, and a good wood table was about $400.00 as I recall.
Metal tables were more expensive.

When computers/CAD came along, many kept their drafting tables, but it did not take too long before the cubicle and workstation came along, and the engineering firms had fire sales on tables. I purchased two nice oak drafting tables for $20.00 each.
I ended up cutting them lengthwise in half, and making some nice shelves out of them.

I don't use a drafting table anymore.
I use to keep one "just in case", but eventually it became clear that drafting tables were out, and computers were in, permanently.

Scanners have come way down in price, and they do a superb job of scanning drawings, with 600 dpi, black/white, gray scale, or color.
My scanner is 48" wide, and it does a great job.
Generally I only use my scanner to scan old drawings, or if I create a large format marked-up drawing with color markers, and need to capture that image and send it to someone.


When I was in school, my girlfriend and I were both EE's, and we hung out with another couple, who were also both EE's.

We kept up with the other couple after we graduated, and they moved out west.
The girl went to work I think for Boeing, or some simlar company, and she use to tell us "I am working on a system with a bunch of satellites, to make a space-based internet system".
I recall at the time sort of rolling my eyes, and thinking "yea right, they will never get something like that to work".

So now we have Starlink, and perhaps other systems.

Her husband worked on the space station design.

My wife and I use to double-date with this couple from school, and sometimes we would run into folks from school.
People would ask us one at a time "What is your major in school", and we would respond one at a time "EE, EE, EE, EE".
Then we would ask them what their major was, and they would say something like "Art", "Theater", or "Business".
We would say "You mean you are NOT an EE ? What were you thinking when you signed up ! ".
All in good jest of course.


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