Drafting Machine (pre Sketchup!)

[scholar]

I do not have any pretensions of draftsmanship skills and having toyed with Sketchup, I know I just don’t have the will to master this, much as I would like to. I do, however, frequently draw out plans of my projects, whether woodworking or room layouts etc. I have been using a (plastic) Rotring A3 drawing board, but inspired by an idea in the instructions for one of my Black & Decker Workmate 2000’s (see here Temporary workbench recommendations (Saw horses + 2x4 or otherwise)), I thought I could improve on this.

Here is the extract from the Workmate document:

So I impetuously looked on eBay for a parallel drawing mechanism as shown - and I chanced on something that unbelievably was in the next village - it was cheap and whilst it needed a good overhaul, looked very similar - turns out it was a bit bigger - it had belonged to the seller’s father who had been a draftsman for various large Coventry engineering companies.

I now know this is called a “Drafting Machine” - I have basically dismantled it, cleaned and regreased all the little ballraces and scrubbed the rusty chrome, so it is now functioning smoothly and is very satisfying to operate.

It was attached to an old, but nicely made, professional drawing board - the drafting machine looks like it didn’t originally belong on this board (the board has an inset spline on one side of ebony(?) that was evidently for running a T-square against and also there is evidence of other fixing holes for some different fitting). The board has been cleaned up and sealed/waxed (it‘s full of holes on the front - drawing pins, not woodworm!)

Anyway, it turns out that the board and drafting machine make quite a nice setup that works nicely when propped on my Workmate.

I have one query on the drafting machine - branded “Allbrit” that was a grand British brand of a company called WF Stanley: the tensioning mechanism consists of a spring and cable which is secured at the top end by what looks like a bathroom chain hooked into a slot on a post at the top - evidently the original tensioning mechanism would have involved something different - the chain works, but it is not elegant. I have googled and googled, but I have failed to find any similar examples online (most drafting machines having completely different tensioning mechanisms. Does anyone have any idea how this one should be?

A couple of pictures:

Anyway, this may just be of interest - but if anyone has any additional insight, that would be very interesting to me.

Cheers

 

[Phill05]

Hi, I used to have one it looks like the spring has been changed mine had a full length spring with a tension screw at the top peg, no chain.
You need the spring on to to balance it stop the arm from wandering down on it own.

 

[scholar]

Thanks @Phill05 - my guess is that the spring could well be original, but that the top end comprised another length of wire cable and some kind of spool and lock off mechanism on that top post (the post has a wire-sized slot and three little machined faces on the little chromed top that swivels. It would be great to find a picture of a complete one!

Cheers

 

[pe2dave]

I've an A0 board, with 'crossed behind' mechanism for the ruler.
Current use? Jigsaws! Just too good to throw away!

 

[Jacob]

I gave up on draughting machines and went back to plain A1 drawing board and T square.
Draughting machine come into their own for bigger drawings than A1 but also need to be good quality in very good condition, ideally brand new.
Parallel rule mech would be a good compromise for bigger drawings than A1, but wasted on smaller, and they are both large bits of office furniture. An A1 board can be tucked away behind a cupboard or in a drawer if you have a plan chest too.

 

[Pedronicus]

I started my working life drafting on a A0 board with T-square & set squares then got upgraded to a parallel motion board to compliment the set squares. The next job move I had a posh drafting machine which, TBH, I could never get on with. Final move before becoming self-employed I went back to parallel motion which I eventually bought from the company and set up on my own. Then came CAD! I could produce drawings manually far quicker than using that. One could always tell a CAD produced drawing as the dimensions were SO accurate i.e. 1502mm instead of 1500mm. Trying to get the old pipe fitters to cut a length of 6" steel pipe to an accuracy of =/- 2mm was somewhat of a challenge!!

 

[pe2dave]

Hard to break ingrained habits. Tech drawing at school, I was always happy with a drawing board and T square.
Then I had a job with electronic, mechanical and software groups all wanting drawings. Autocad bought (rev 1.0).
Yep, took some getting used to! 40 years on I can still use those commands on Qcad, a fraction of the price,
almost as good as ACAD. I know which I prefer now, eraser over select/del.

 

[Jameshow]

I started my working life drafting on a A0 board with T-square & set squares then got upgraded to a parallel motion board to compliment the set squares. The next job move I had a posh drafting machine which, TBH, I could never get on with. Final move before becoming self-employed I went back to parallel motion which I eventually bought from the company and set up on my own. Then came CAD! I could produce drawings manually far quicker than using that. One could always tell a CAD produced drawing as the dimensions were SO accurate i.e. 1502mm instead of 1500mm. Trying to get the old pipe fitters to cut a length of 6" steel pipe to an accuracy of =/- 2mm was somewhat of a challenge!!

Where did you work? my Dad worked all his working life at Foster Wheeler petrochemicals..

 

[Pedronicus]

Where did you work? my Dad worked all his working life at Foster Wheeler petrochemicals..

My 6" steel pipes were involved in the mechanical services industry primarily heating and domestic services to RAF stations, new tower blocks and centralised boiler plants serving new council estates all back in the late 60s & the 70s. I only flew a drawing board though not a welding torch.

 

[Jameshow]

My 6" steel pipes were involved in the mechanical services industry primarily heating and domestic services to RAF stations, new tower blocks and centralised boiler plants serving new council estates all back in the late 60s & the 70s. I only flew a drawing board though not a welding torch.

Just sounded very much like his work that's all!

 

[BCS1980UK]

I may be late now for a reply…
Back in the 80s my father had one of those at home on a huge A0 desk (both parents engineers may explain why I am an architect myself).
The mechanism worked with the springs tensioning thick nylon threads, not chains.

Edit: Fun fact, these were called ‘tecnigrafo’ in Portuguese

 

[pe2dave]

I still have one - stands atop a desk though. A0, same framework. Just gathering dust if there are any takers.