Draw a Perfect Circle...Freehand

That was cute! I can draw mathematical curves pretty decently, and had some professors who could do better, but not usually as good as this demo. However, much of his circle was of forearm radius; could he do as well with smaller circles? A set of concentric circles would be a greater test; or better yet, osculating circles.

Shoot! I can't even get a perfect circle printed out from an Excel drawing... I don't have CAD, and occasionally as a chemist I have to communicate a piping modification to the maintenance and/or engineering staff, who apparently cannot read between the lines of my simple sketches. But there again, I also suspect they want to put all my stuff on the back burner, while they polish the knobs on their lawn mowers.

Cool that it closes perfectly.
I think the ability to put ideas down on paper by hand is a great gift. I also think a good deal of it can be taught. Too many kids today never see a pencil and paper... and they aren't taught how to observe and compare size angle parallelism etc. The old thing with the artist holding the brush or pencil up in front ... who many people actually realize what he's doing? (me Sir me Sir I know!)

And don't preach CAD to me... garbage in garbage out. CAD is great but it's the ideas that matter, and if you can get them down free hand so much the better.

Del

Agreed.

I had 4 CAD designers when we built modular PWB process equipment.

So, I asked two of then to make a quick hand sketch of some fitting locations for a filter for a customer before the equipment shipped later that day.

It seemed simple enough to me. Rough outline of the modules, some dimensions and angles showing the approximate relative locations. Much of our stuff was customized for specific customers.

They were lost. No mouse, keyboard, fitting library................................just a pencil and a sheet of paper. Finally, they got something "close enough".

Sounds very similar to todays "automotive technicians" versus a true automotive mechanic who could tell you what was wrong by actually listening to a vehicle run. Valuable skills are being lost with all the modern technology these days.

Cool, but can you do one 1/3 that size please......... Seriously, my free hand is quite shaking...... Always has been.

I do recall, one of my grade school friends could draw a perfect freehand circle of different sizes.... (On standard tablet paper) which he said was easy,..... I was always impressed which he later told me he practiced a lot.

I never recall him doing a large circle though, but I was still impressed.

Got to watching the suggestions videos on this....... Unbelievable ...... Came across "Amazing People compilation 2012" good find

I always used the "French's" engineering manual method which was to lay off ticks 45° apart; then connecting the ticks by hand.

My grandaughter (now almost 4) can draw circles so nice that they look perfect to all in the family. She started doing this at 2 and blew all the minds in the family. The rest of us have poor handwriting and struggle with drawing anything. Her drawings are much better than her brother, 6 years older, but his has a lot more imagination. Hers are very blocky.

Well I can't draw a perfect circle free hand, but when I was in college majoring in Industrial Arts, I had a course in "Mechanical Drawing" that was one of the most difficult I've ever taken! The prof was an old guy that was meticulous and he graded on weight of lines, spacing and length of dotted lines, as well as accuracy of the drawing itself. Of course this was all waaayy before CAD systems. I still have my drafting tools,and just used them to draw the basic plans for a shed I'm having built. The building inspector kept complimenting me on what a great job I did on the Building Application. I asked him what he usually got and he showed me some of the "sketches" he receives...including some with stick-figures! They were pretty awful and required him to ask many questions...he approved mine immediately, no questions asked except, "Where did I learn to draw like that?"!

Nice story, I like it when stuff we learned years ago suddenly becomes useful.

I did some back of an envelope geometry the other day and was rather enjoyed it.

In case anyone wants a coffee time puzzle here it is.
You are making a bow (as in bow and arrow) starting with a (perfectly cylindrical ) log.

You want to know what diameter log to start with.
The cross section of the bow is to be a segment of a circle.
The back of the bow will be the outer surface of the log, the belly will be flat. The max thickness from belly to back is 1/2" and the limb width is 2".

So to sumarize, log diameter x. Sector 2" wide 1/2" deep

What diameter log (x) do you need start with?
Del

I have needed to make that calculation a number of times. The first time (long before the internet), it took me hours to figure out the formula by myself. I now keep it as an Excel spreadsheet.

I love CAD! I can correct my many mistakes with no sign of an erasure! My mind goes so much faster than my fingers, that I'm constantly changing what I write or draw.

Yup, that's right, you can have a gold star but I did with just a pencil and paper all long hand.

Del

Nice to hear... I still have instruments as well (unused in twenty years) and some pens etc... ...Got rid of the drawing board a while back though, for lack of space.

I am amused that some people seem to think that engineering drawing was not possible before CAD.

it's unbelievable what was accomplished without cad..... lines of drafting tables where typical....

And what they were able to produce..... I believe there were two planes in WWII that did not have prototypes. It when from drawing to manufacturing.

The B-25 (Pre-WWII), and the B-29.... not simply feat.

In high school (over 45 years ago?!), my geometry teacher could draw a perfect circle like that. It always amazed us. What really blew my mind was his ability to show 3-dimensions on the blackboard. He could draw a plane intersecting a cone (conic sections) or just about any 3-D shape and it looked like a photograph! He really enjoyed how amazed we were. I think he practiced a lot. It's funny the stuff we remember.

I still remember my TA101 instructor at IIT/Kanpur/India way back in 1967.First thing he told us was to forget Rulers,Set-Squares & French Curves.These are for draftsmen. An engineer is supposed to communicate his idea to a draftsman or to a fabricator directly. He will do the rest.

Although I never became good at Freehand drawing the idea still persists. I present my ideas more visually by hand drawings.

Thank you instructor(I don't remember his name!)

Yes, but if you are a draftsman as well, you can get a chance at an engineering job when engineers aren't in demand. When I first came out of school as an EE in the early 70's, engineers were a bit over abundant. Fortunately PSU made all engineering students take 2 drafting courses, and my great uncle Tony, as draftsman for the USN, gave me his tools when he retired. My first job was at a consulting engineering firm on the drawing board. Don't know what I would have done had I not had the drafting skills. Well, yes I do - I also had an offer as a repairman for arcade games, which I turned down.

Drawing sketches to put across the ideas is the language of an engineer.

Engineer is also a visionary and drawing sketches helps.

I still use it as the master weapon.

Back in college, we had to take a drafting course in our first semester. I remember how perfectly our professor could print letters. He taught us that the letter o should be made by making a right 1/2 circle and a left 1/2 circle. To this day, when I need to print very clearly, I do the same thing. I've been told that my printing is excellent - the credit goes to my drafting professor.

I took 4 years of drafting in high school, and vaguely remember prior classes in penmanship. My hands are much steadier than those of most people in their 70s, yet I have never been anything beyond barely acceptable in freehand drawing, including letters. I can't even read it myself when I try to write in script, so I print everything except my signature, and even that isn't readable any more.

I'm totally grateful for computers that let me correct most of my mistakes, both in writing and in drawing, with no sign of erasures.

I believe I made 6 or 7 corrections just while writing the above two paragraphs...

I used to practice my lettering for hours and hours. I also used to tip my head back and spin my circle template on my nose when I got bored. Two triangles to prevent ink from wicking under the bottom one. Orthographic projections and isometric views by hand. Thinking about drawing layout. Rotating the pencil as I drew across the sheet. Electric eraser almost setting my vellum on fire. Developing prints with a tube, a dish of ammonia and a stopwatch. Running my manuals off on a Gestetner. Cut and paste meant cut and paste.

Now, anyone with 3D CAD can call themselves a Designer. Just not true.

"Developing prints with a tube, a dish of ammonia and a stopwatch."

Wow! I had completely forgotten about that!

In my college course we had to do a "Project Drawing" to be graded as our final exam.

I did a cut-away of a V8 engine as if sliced through from side to side...whew! Wish I had kept that one!

Ammonia...sheesh...I don't know how many times I got a snootful of that stuff! Just about knocked me over every time.

My final project in my 1982 Machine Drafting course was to build something, from drawings that I made, that used machined components. I made a wooden cube, cut two eye holes in one side and a slot on an adjacent side. I mounted a prism on that side and inserted a hand crafted mini mirror ball through the bottom. A small motor and pulleys turned the mirror ball slowly. The idea was to shine a light through the prism and watch the pretty colors reflect off the mirror ball. I got a B- on that one, but my weed smoking classmates gave me an A+.

Now, anyone with 3D CAD can call themselves a Designer. Just not true.

There are people that takes a ('a' as in singular) course in CAD, and then calls themselves an engineer......

One also had a "bartenders license" to go with his engineer label.

I started my career back in the 50's in shipbuilding. Back then, drawings were done on vellum with pencil; then traced in ink. Drawings for a battleship would be numbered in the 10's of thousands. Modifying those drawings was time consuming. Thank God for CAD. We didn't have Xerox, only mimeograph. We sharpened pencils with a pocket knife. We used parallel straight edges and T-squares. The T-squares glided along the stomach edge of the drafting board, as drawings could be 10 or more feet in length. A large triangle glided from top-to-bottom for L-R lines. Lettering was done with Leroy lettering guides. Everyone had to sharpen their ruling pens on a small stone. Everyone was dressed in a white shirt and tie with their sleeves rolled up. There was NO talking in the drafting room, unless it was job related. We punched a time clock. There was no air conditioning. How things have changed. I still did pencil drawing as late as 1995. I think some big companies still do pencil work because of old drawings that are still in use. Most have been digitized by now. I speak only of the shipbuilding area, as that is the only area I've ever worked in. Shipbuilding was the last to modernize their drawing needs. Aircraft and automotive were the first to switch to CAD/CAM.

If I recall, one of the first CAD system was for McDonald Douglas... They used it for piping.... I think they called it McCad? :/ :)

It's funny you mention 1995. The last time I worked on a board was 1992. I had dropped out finished university 2 years prior and worked only on the board until then. I got my first computer in 93-94 and it was a Pentium 486...with Turbo!! There was a little button you pushed to crank the speed from 8Ghz to 16Ghz LOL! I had a massive 340 MB (yes Megabyte!!) hard drive. The software I was using was Mirco Cadam. It was nothing more than a 2D drafting program.

I looked through a box of my old drafting tools the other day. I haven't seen this stuff in over 20 years.

In electric eraser,...... I always wanted one of those,......... back then....

In a couple of years, when the antiques road show comes to town, it still probably would bring much because a lot of us will still have our old drafting tools.....

Where's your sandpaper pad for sharpening pencils?

My artist wife has cabbaged onto the French curves and templates, but in high school I made a felt-lined tool case with partitions for triangles, pens, compasses, dividers, beam compass, slide rule, T-square, desk brush, etc. The drawing board served as the lid, held in by aluminum pins in copper tube ferrules.

It's a cute relic, supplanted by AutoCAD in the early 1990s.

Sandpaper pad? Nah, I was hi-tech back then. My sharpener was that thing you see the pencil sticking out of.

Whippersnapper!