1 - I think is the horizontal brake. It should be connected to a rod that goes all the way to the top and operates a toggle to bring a rubber pad into contact with the main track. I'd guess the rubber is either gone, worn out, or most likely as hard as a rock and was left engaged so it has a track-shaped dent where the elasticity used to be. It is spring applied. As you mention for #11 if this design used some "string" and that failed then that could also be a problem. The ones I used that lever was in a fixed location; maybe this design travels with the drafting head.
2 - not sure
3 - Similar to the horizontal brake, for the vertical direction. Probably was not left in the locked position and, because it is not spring applied, one can lean on it to make it work even if the rubber has hardened.
4 - not sure
5 - this is to lock the rotation in any orientation. It is a direct acting clamp. There should be no rubber involved. There usually was a vernier to get to tenths of a degree.
6, 7 - not sure
8 - I recall that if it is pressed and pushed up or down it would either a) allow free rotation, b) latch into detents at useful angles.
9 - not sure, but I doubt it's a memory device. At least I don't recall ever thinking such a thing was required.
10 - me neither
11 - On the ones I used there was an eccentric axle for one of the wheels opposed by a spring loaded wheel that was adjusted to set the vertical travel to be perpendicular to the horizontal travel.

It's been 30 years since one of these was a daily driver for me.

Thanks for the reply Dave.

Piece 1 contains a bushing on a sliding rod, screwed to a sliding plate. A second sliding plate can also be seen. The holes in the plates are tapped/threaded. I don't see how this could be useful, so I think there is a missing piece.

Here is piece 1:

I've still got an old drafting machine from when I was working in Michigan. Just before we got our first CAD/CAM system in 1977, they decided to replace/upgrade all the drafting machines in the design office. They let us buy the old ones from the company for something like $10. They replaced our drafting stools as well and I bought my old one for $5, which I still use at my workbench in my garage.



I've also got a set of scales (12 inch and 18 inch) but haven't used it years (my drafting table is now being used to hold any old shortwave radio:

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

https://books.google.com/books?id=qdtJDEPZrrkC&...

Have not used one in many years. I prefered the track machine over the arm machine. Either one way better than protracter and sliding triangles.

Ted

Yes, they replaced our arm machines with the track ones.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

wow, this brings back memories of my early first career. "on the board"

those early days of visualizing in 3-D, and doing lots and lots of trig, really paid off later in my engineering career.

I actually used one of those Mutoh track machines. After using the Vemco arm machines.

I drafted for a structural in the summers during university, it was the late 70's.
Started with square and triangles.
He bought some used arm machines, I rebuilt a few of them and used those for a couple of summers.
I drafted on track machines in some classes.
I prefer the arm machines but don't own either. I didn't grab any when they were being phased out.

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P.E. Metallurgy

Tom,

On the right of the Mutoh grip, there is a toggle switch to hit with your thumb (8). What's that intended to do?

RPMG - I seem to recall a red plastic toggle control on the Mutoh, sort of with two short arms at 120°, almost like a bell crank? I seem to remember operating that a number of times a day. But this was around 1972 and further details escape me. sorry.

RPMG, You could post a thread like this to the Eng with hobbies forum.
Maybe when you get to your next steps.

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P.E. Metallurgy

As talent required to orientate a piece of paper and operate pencil and pen becomes lost art,
a website devoted to Obsolete Drafting Technology is a humorous reminder of the tools and human [skill sets] we once relied upon.

https://www.moodt.org/

John

Ah yes, the Leroy Lettering set. Thank you John for the link...

In addition to my old drafting machine and the couple of scales that I still have, I also still have my original drafting set from high school and of course, my Slide Rule. Even my drawing table brush, that I use on my workbench in the garage. I've got a couple of eraser shields and several circle and ellipse templates. When I was working as a draftsman and later as an machine designer on the board (before CAD), at least once a year, the chief draftsman would arrange for someone to come in from our local drafting supply company and he would give each of us a modest amount of credit toward buying supplies, maybe $20 or so, but this was back in the 60's and 70's, so for $20, you could stock up on a lot of stuff. Now the company provided all of our consumables like ink, drawing pencils and lead for our mechanical pencils, erasers and such, but anything that was a tool, we were responsible for supplying ourselves. Now the company provided the design office with a couple of Friden calculators but we all had our own slide rules. When handheld calculators came out, at first they bought a couple for people to share, but that didn't last long as most of us eventually got our own as the prices started to drop (I waited until I was able to get a Texas Instrument for under $100).

For those of us who can remember living through the transition from the drawing board to the CAD station (it's like the old adage that if you remember the 60's, you weren't actually there) you might enjoy this marketing film which shows you what CAD was like back in 1977 when the company I worked for bought their first system, and yes, the system you see in the film was the one we bought. Please note the hair styles and the less than PC nature of the portrayal of the 'draftsperson' (sorry about the quality of the video as it was converted from a 36 year old 16mm marketing film that was found when they were cleaning out a storage closet at work and I managed to snag it before it was tossed).

https://www.youtube.com/watch?v=s9F5zIKuLBw

I hope you enjoyed it.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

When I moved to Maryland from Florida ~11 years ago, I frowned deeply and tossed my drafting table, swivel chair, and T-square in the dumpster. I really hated to get rid of it, but moving (and living) space was becoming a premium. I did manage to hang onto all of the other equipment, though... triangles & french curves (both for inking), Ko-I-Noor technical pen sets (can't remember exact sizes, but it was two complete sets, 14 pens, that ranged from ~000-7?), my father's original Dietzgen toolset (various pencil/inking compasses, dividers, etc.) in a wooden box, Leroy inking character sets, three different tri-scales (mechanical, architectural, and standard) in a felt pouch (made by my loving mother as I transitioned into high school), and so on. I continued to use my Koh-I-Noor pens for artistic drawing until around the same time, but I have no doubt they're in need of a serious sonic cleaning and a new bottle of ink.

I definitely miss the days of hand-based drafting, and even now I may do some basic floor planning of my PCB designs using a ruler, pencil, and paper before it ever touches the computer.

Dan - Owner
http://www.Hi-TecDesigns.com

My Dad was an elementary school principal. He wanted things to look professional but hated paying people to do stuff. He managed to buy a Leroy set (actually 4 sets) and guides for lettering from 1/4" up through 3" or 4". He an I would go in on Sat and make signs for things. He actually had other schools in the system hire him to make signs in exchange for hard to get supplies.
Sigh, I wish that I had that set today.

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P.E. Metallurgy

I, actually, do a lot of hand drafting and issuing of sketches as a structural engineer, but on 11x17 sheets with 1/8" grids. Scanners don't pick up light grids or 3mm pencils, so I'm not accustomed to using triangles or other tools other than a straight edge and scale. And no one wants this "lettering" you speak of.

I'm really loving this Unigraphics video. It's going to take me a week to get through it though.

working abroad, sometime far away from the city or with facilities not available, I was used to bring with me a portable drafting device for drawing review (and still I have in very good conditions)

Roby, that is neat. I would take one of those kits.

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P.E. Metallurgy

In its day, this would be to the draftsman, what a laptop would be to a CAD user today.

And I forgot to mention earlier that I've still got my T-Square and triangles from when I was in school and before I got a job that had a drafting machine.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

I still have my father's t-square and french curves, but dumped almost all the mechanical pencils and ink pens.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

I still have all my drafting stuff, after working as a draftsman starting 42 years ago. Since then I got my BS degree, but still enjoy drafting
I have been working on NX (Unigraphics) the last 33 years, and I hope to go at least another 10 years.
Check craigslist for the drafting machines, they are still around.

Jerry J.
UGV5-NX1884

I made it 38 years on UG/NX (when I started in 1977 they didn't have version numbers, just a date on the tape, and when I retired, I was using NX 11.0).

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

In my industry, the pencil has not fallen to UniGraphics or CAD. Contractors, actually, want it hand drawn. Of all the people, contractors are the most dismissive of computer generated details and calculations. They want someone to look at it and think about it, instead of filling inputs into a program. I could do everything that I do in CAD, myself, just as quick, but we get the response "No CAD" or "We're not paying for CAD." And I understand that. I deal a lot with existing structures, and the existing detailing is much better than today's standard. CAD, by some, is seen as low quality and added expense. I don't personally subscribe to that thought, but I like using a pencil.

Also, the thumb toggle (8) sets the angle to 30 and 45 when you loosen the rotation (6). During the COVID pandemic, my table is seeing a lot more use, both as a drafting table and an art studio by my 4 and 6 year old girls.

If all you were talking about was a replacement for hand-drawn drawings, I might agree with you, however, in today's world, CAD is so much more than that. Granted, my views are based on the 38 years (and the four years since I've retired) that I've personally seen as CAD's impact on what we called discreet manufacturing, which covers virtually everything from industrial machinery (my background) to automotive & aerospace, medical equipment & consumer products and dozens of other industry segments which have been completely transformed by CAD and it's ancillary technologies of CAE and CAM. In the industry segments that I mentioned above, the pure CAD, as in Computer Aided DRAFTING, is rarely the intended 'output', and for many industries, Drawings themselves have long been moved OFF the critical-path from inception to production to the delivery of the final product to the end-user. So please, don't sell 'CAD' short, at least not when it comes to the rest of the world.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without