How did they make old drafting tools?

Looking at old drafting sets, I'm particularly curious about how they might have made the spring bow tools, like this old German Schoenner 2 1/2" ink compass.



They made them in large numbers to a pretty high standard. Did they start with a stamping? Didn't it bother them to lose all the material in the middle. Everything appears cut, maybe with a fine saw, then smoothed, polished and plated. AFAICT, nothing is joined, it's all one piece. It's a good spring, so must have been heat treated. On similar dividers, the arms are round and were not separate pieces. Turned? And how did they hold the thing to machine it? The collective mind here seems to know most everything, so can anybody enlighten me on this? (If I had to make one it would take me three weeks and I'd have to charge $2000.)

Conrad Hoffman said:

Looking at old drafting sets, I'm particularly curious about how they might have made the spring bow tools, like this old German Schoenner 2 1/2" ink compass.

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They made them in large numbers to a pretty high standard. Did they start with a stamping? Didn't it bother them to lose all the material in the middle. Everything appears cut, maybe with a fine saw, then smoothed, polished and plated. AFAICT, nothing is joined, it's all one piece. It's a good spring, so must have been heat treated. On similar dividers, the arms are round and were not separate pieces. Turned? And how did they hold the thing to machine it? The collective mind here seems to know most everything, so can anybody enlighten me on this? (If I had to make one it would take me three weeks and I'd have to charge $2000.)

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You don't have forge or anvil then, do yah? Not all that sort of "blacksmith" work was heavy nor crude., decent box-joint pliers but one example.

car2 said:

mastering ink ruling-pens must've taken a lot of practice.

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A lot of mistakes, rather, but they happened in the first DAY, usually. Then it got obvious.

Line width is adjustable, but ink flow is not 100% co-operative, all widths, Tilt along the line-axis is survivable, tilt either side is not. Applying just enough ink to complete a line and not so much it shat took easily as much practice as the proper holding of them even so, Once mastered they weren't half bad, nor as slow as might seem. We DID still use a lot of tracings. GOOD Vellum was wanted, these don't DO fuzzy-papers well if at all. The sharp tips are actually scoring parallel lines as become a "fence" to surface tension. They wear. They must be stoned.

Dad's "Engineering Drawing" textbook, 1920's had been Written by French. By the 1950's our JR HS used French & Vierk. I got permission to save the cost of a book and use the old one. Care and feeding of those pens was well covered.

The Rapidograph clan first got their foothold on single-stroke Gothic lettering, then took over. Those had sets of different tips for different fixed line widths, managed corners and curves waaay better and managed the ink VERY well.

Those, we soon started skipping the tracings and went directly brain to vellum, relied on "Snowpake" and or heated wax tables for corrections. "Camera ready" art, 105 mm negatives, black-line Ozalid had replaced blueprints. Same change saw lettering go to typewriters, then 'puters, then the rest of the drawing went into the 'puter as well and most of us hung up our pens of any kind, perhaps kept a"T1" lead in a mechanical pencil.

I think I still have mine (Dad's, actually. Bought used 1926). Awkward-looking but much easier to clean, sharpen, be making lines with sooner than modern "bucket and tube" ones.

Curves? Were not easy.

When Rapidographs came out, everyone in that era also wanted one in their SHIRT pocket - ELSE an "Osmiroid" - to sign stuff with, much as "Sharpies" are seen today.

Signing your name with these old pens? Just try it!

I suspect "EVE" was the last person as did not have a problem with that.

Not in my shirt pocket, the Rapidographs had a tendency to leak.

Tom

Funny you should mention ruling pens and Rapidographs. Dragging my poor thread OT, here's a panel I labeled directly with a Leroy guide. I later added straight lines with a ruling pen- nothing else worked worth a darn.





It works rather well if you use the right ink. Much easier with black on white, the way we used to do it 40 years ago back in the electronic prototype shop. After this thing dries a day or two, I'll give it a protective clear coat.

TDegenhart said:

Not in my shirt pocket, the Rapidographs had a tendency to leak.

Tom

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Youngster back then eh?

The "older guys" had experience with ummmh "rubber goods"? ...and soon found a miniaturized counterpart. Shirts were dear then. Few had many of them. Not that we were "square". Just not well-funded. White shirts sorta helped hide the fact that one had rather few of them.

Wimmin' were pragmatic. Gal liked you "a lot", she'd brand you with the gift of a nice distinctive shirt. Had to keep those sorted by situation ...unless one had a death-wish!
DAMHIKT!

I still have the original set of drafting tools that I used in my drafting class in High School. They are still complete and in good condition in their felt-lined case, even after being used many times. I always wondered how they made them.

Later on I was the administrator in an aerospace company where I purchased supplies for a staff of something like 120 draftsmen who did board art. We went through Rapidographs, Vellum, X-Actor blades and handles at an alarming rate.

They told me that they used them up but I suspected that lots of them went home with the staff.

A few years later, the whole lot of them, myself included, was replaced by three people with a main frame computer. LOL

I did some work doing mapping...acad and microstation.

I learned to make good maps from the guy supporting legacy mapping with these tools.
That man was an artist.
Twitter

MEMORY LANE!

I learned drafting back in the 60s and have used everything seen here. I may still have some of it, but I don't know where.

You have no idea how happy I was when I got my first CAD program. Well, it was really just a drawing program but it was vector based so I could make accurate drawings with it on my good old PC Junior. I did a lot of work with that.

EPAIII said:

MEMORY LANE!

I learned drafting back in the 60s and have used everything seen here. I may still have some of it, but I don't know where.

You have no idea how happy I was when I got my first CAD program. Well, it was really just a drawing program but it was vector based so I could make accurate drawings with it on my good old PC Junior. I did a lot of work with that.

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Took me all of a week to confirm that without CAM and CNC machine tools, CAD was but a time-wasting parasite.

Went back to ink. Or pencil. Still have no CAM or CNC. Still faster with pencil.
Mostly don't do drawings at all until I have a finished part to take measurements off of. That's the way we did it.

If visualization was not "natural"? You were not in the Tool and Die shop atall. You were out in the Machine hall using our tooling to "make stuff", one identical part after another, else sitting at a station on the production line we tooled-up.

Conrad Hoffman said:

(If I had to make one it would take me three weeks and I'd have to charge $2000.)

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If you had to charge $2000 for the one you showed, how much would you have to charge for the articulating compass at the left (sorry for the shadows)? A detail of this Original Prazision Lotter is in the second attachment.

Speculation about soldering is addressed by the Dietzgen compass on the right since it's made from aluminum. It actually feels a little weird to use since it is much lighter than every other compass I've ever used.

opscimc said:

Speculation about soldering is addressed by the Dietzgen compass on the right since it's made from aluminum.

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Soldering probably not, but what's that got to do with Aluminium?

thermite said:

Soldering probably not, but what's that got to do with Aluminium?

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car2 said:

it's barely evident this was machined in two parts, soldered or brazed together,

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The original question was about making such instruments, and soldering was mentioned in a subsequent post. The thread then wandered off into nostalgia about use of drafting instruments. Getting back on topic, I posted the the aluminum compass since it shows such complicated precision devices could be made without soldering. The original poster may find this relevant as he looks for answers to his question.

opscimc said:

The original question was about making such instruments, and soldering was mentioned in a subsequent post. The thread then wandered off into nostalgia about use of drafting instruments. Getting back on topic, I posted the the aluminum compass since it shows such complicated precision devices could be made without soldering. The original poster may find this relevant as he looks for answers to his question.

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Ah, so.. I thot you meant to imply aluminium was difficult to solder.

"Different", yes. Difficult, not so much.

thermite said:

...GOOD Vellum was wanted, these don't DO fuzzy-papers well if at all.

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Absolutely! Trying to use these on most paper usually led to a nice linear tear that crumpled as you went along.

Oddly enough, I just sold my drawing board on ebay last Saturday. Had it for 30yrs, but used maybe half a dozen times in the last 12 yrs.
Chap drove 600 miles down from Inverness to get it, and I ended up giving him my old Isograph pens too. Though I kept the slide rule for nostalgia.

Peter Neill said:

Though I kept the slide rule for nostalgia.

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Actually took a Mannheim K&E Log-Log-Duplex Decitrig to 'nam with me to make sure I hadn't screwed the pooch with the big books of log tables I switched over to in Jr HS.

Annoying to be always one or two significant figures shy of the need, even on 66-inches worth of - what were those? "Thatcher" cylindricals?

Commodore brought out that first "affordable' desk calc, I took one into a night class in Accounting. Smug prof wanders over said I could not use it. I stood up, wraped up, said:

"Sir, I cannnot use this? You are just as surely FIRED as any of my staff I catch doing calculations manually at an hourly rate. Subject is advanced accounting. Not Arithmetic."

The big advantage evening students already in executive slots have?

Deans listen.

He grumbled it was not "fair" to students who could not afford a calculator.

My response? "FAIR? And you are in the finance department? "Fair" is for phys ed!"

Ha! Back in high school we had one of the first HP programmable "calculators". It was big floor-standing thing I wasn't smart enough to use.

That articulated compass is pretty neat.

IMO, you can always learn something by studying old techniques. If I look at my small ink compass, it looks like the area under the top is filed. There's no evidence of any type of joint and I'd guess it would fail unless very well done. OTOH, plating can hide a lot. Looking at the slight tool marks remaining, I can imagine some kind of filing machine being used to refine the shape, though the ruling pen slot looks tough to do regardless. Not sure how they did the bevels and finger reliefs you find on the larger compasses in the sets. Times were different- labor was cheap and you could have more people doing manual finishing for longer than anything today. There was probably a higher level of skill applied to manual operations than today, heck, few even want that sort of work anymore. I think we call the remaining ones with those skills, gunsmiths.

I first encountered slide rules in high school physics. The teacher tried to prepare us for college and warned us that we'd have to be working a lot faster in engineering college exams. Those using Post slide rules (laminated bamboo) would be using asbestos gloves while the Pickett folks (alum) could just have water buckets by the chair for intermittent cooling.

FWIW I still have the drawing set and slide rule from college. The drawing set got used for many years in design. The slide rule was gratefully retired when the first hand calculators came out. The HP RPN and short keystroke programming were a godsend for repetitive draft calculations and other tasks.

TGTool said:

I first encountered slide rules in high school physics. The teacher tried to prepare us for college and warned us that we'd have to be working a lot faster in engineering college exams. Those using Post slide rules (laminated bamboo) would be using asbestos gloves while the Pickett folks (alum) could just have water buckets by the chair for intermittent cooling.

FWIW I still have the drawing set and slide rule from college. The drawing set got used for many years in design. The slide rule was gratefully retired when the first hand calculators came out. The HP RPN and short keystroke programming were a godsend for repetitive draft calculations and other tasks.

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My first 10" (25 cm, actually) Mannheim-style K&E had been Dad's at College, 1920's.

Lovely to behold, it was stark white, easy-to-read, and never yellowing Nitrate plastic over old-harvest Mahogany core. Eventually, it de-laminated and a "high tech" solid plastic one half its length and in a belt-holster replaced it - same significant figure count by virtual of finer ruling work, nearly invisible line-width, higher precision manufacture, and a now very necessary magnifier in the cursor.

Our first "desk" calc at the office had orange nixie-tech tubes, cost the Earth, was a shared resource Engineering staff had to "pre book" any significant time on. It was waaay faster than the Marchant and Monroe-matic mechanicals my Dad's Corp of Engineers field office used.

Not many remember those ever even existed. I had leaned to repair their innards, much as I had his beloved "Shakespeare" fishing-reels. I have never see anything made by the hand of man the least bit more complex for the tight space those occupied. A "Curta Calculator" AKA "Coffee mill" of similar era was deceptively simple by comparison.

The "deceptive" part was that a Curta required a seriously high degree of precision that was NOT at all "in your face". ISTR "Alpina" was the only successful copier of that.

Enter "dirty beach sand". Game over.

some are cast parts of zamak, babbit, etc. some made in metal mold like you would make fishing lead sinkers or printing press type. pewter spoons or silverware was common long ago. most were not made from silver but cheaper alloys
.
of course most was trade secrets. that is you did not publish methods if there no money in it. if anything you had to worry about your paid workers learn you methods and then leave and go into business for themselves