Folding rule ChristMads tips

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Blog entry by mafe posted 12-19-2012 10:50 PM 7860 reads 8 times favorited 34 comments Add to Favorites Watch

Folding rule ChristMads tips
Folding the rules, not bending…

Hi guys and girls, I have been quite a lot off line lately…
The X put my daughter and me on the street with one weeks’ notice (no I did not cheat on her, smiles).
But that meant chaos in my life, and my beloved daughter Mathildes also.
Now we are landed, living more or less in the workshop, but have got a wonderful apartment from February so we are both full of bright light for the future and the new apartment is so cool that I almost can’t wait to get there.
So yes, even chaos has been the name of the game, smile has slowly returned to my face an so I want to send you all some of this good feeling I have inside.

So I will share with you a page from my little book, or more precise two pages and a blog showing what I mean, needed? Yes, since the text is written in Danish.

So here are the pages from my sketchbook.
Those of you who know all the trick can go and make coffee now and come back to my next blog…

The folding rule or even tape measure hold secrets helped by mathematics and some clever peoples thoughts.
Need is the mother of invention they say.

There are many types of folding rules wood, metal and plastic are some of the materials they can be made of, they are usually promised a tolerance of app. 1mm for each two meters or 1/8 in six feet US.


Trick one is a way to set precise circle degrees when you have only a ruler.
Mark up the number 57,3 cm or 57 5/16 inch on the ruler.
(You might want to use half inches if you don’t want too big a radius, then the number will be 28 5/8 inch, then each 1/2 inch will equal 1 degree on the circle).

Drill a hole in the center.

Now you are able to put a nail through the hole and hammer it onto a board that are longer than the 57,3 cm.

Now hold a pencil tight to the end of the rule and draw the circle section needed on the board.

Then make a line from the nail and to the circle.

If you are alone hammer in another nail here.
(The thickness of the ruler behind the circle).

Then you can hold the ruler against the nail and bend the ruler at the same time.

And even set marks with the pencil.
Here I mark 10 cm and this equals 10 degrees.

Now I draw a line from the center to the 10 degree mark.

Get the point?
I think this is brilliant.
Learned it more than 20 years ago from some old concrete workers when we had to make a staircase concrete form.

And yes! You can make holes in the tape measure too and this will work the same.


Easy way to divide into equal parts without having to calculate.
This board measures app. 33,7 cm, a bad number when I want to divide in three parts…

So instead I take the nearest integer numbers that are easy to divide in three.
Here 60 cm and mark up for each 20 cm.

Like this.

Then I hold the rule up to the point and hold firmly on the rule with my left as I draw with the right and move the ruler towards me.

Like so!

And the same for the next line.

That’s it!
Divided in three.

PERPENDICULAR or a perfect 90 degree

This one we usually thanks Pythagoras (app. 550 BC) for, but actually the trick was known as long back as 1800 BC in Babylon and probably even before that and the magic numbers are 3-4-5.
We need three boards (I make a model here).

Now mark up the 3, here I go for 30 cm, but it could be any number as long as the ratio stays the same.

Then 40 cm.

Finally 50 cm.

Mark carefully.

Now fix the 3-4 over each other at the end marks.

Hold it together with nails, screws or as here just glue, but so that it is still movable.

Like so.

Now add the 5 and place this on top so that the outside is the 5.
I mark up for glue now.

And time to fixture.

Clamping for the glue in my small version.

Now I add the numbers for you guys, do you get it?

Clamps of.


It really is 90 degree!
And yes it is quite so.

So ready to work.

Nerd stuff:
a² + b² = c²
3² + 4² = 5²
9 + 16 = 25
25 = 25
Job done!
(Laughs and thanks David, edit done).


Just one more trick.
If you have no star for the Christmas tree.
The folding rule star is the rescue.
Smiles and merry ChristMads to all of you.

My wonderful old nutcracker is in the shop now.

A pallet becomes fire and this keeps us wonderful cozy and warm.

Even made a ChristMads decoration for the shop window.

Lights and all in front of the shop.

Finally I say goodbye with this picture of the lovely evening light in Copenhagen where my shop is located.

Hope some of the tricks was new to you or at least they could bring some inspiration.

Best thoughts,


-- MAD F, the fanatical rhykenologist and vintage architect. Democraticwoodworking.

34 comments so far

View Bagtown's profile


1739 posts in 3758 days

#1 posted 12-19-2012 11:03 PM


Those are brilliant.
Thank you.
Sorry you’re in the shop, but looking on the bright side, you’ll have another great story to tell about when the world was supposed to end how you and your daughter were ready for it living in your shop. :)

Really like the first trick a lot.

Merry Christmas from Canada.


-- Mike - In Fort McMurray Alberta

View TopamaxSurvivor's profile


18291 posts in 3703 days

#2 posted 12-19-2012 11:07 PM

Merry Christmas Mads. Glad you are back inside, warm and dry! Interesting post as usual.

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View Jim Rowe's profile

Jim Rowe

1041 posts in 2340 days

#3 posted 12-19-2012 11:07 PM

MaFe, Sorry to hear about your “chaos”. I’m sure you will find the light at the end of the tunnel. Thank you for this post.

-- It always looks better when it's finished!

View lew's profile


12102 posts in 3783 days

#4 posted 12-19-2012 11:15 PM

Thanks for the photo essay, Mads.
Sorry to read of your family problems. I know you and Mathildes will over come them and the new year will be bring happier times.
Merry Christmas to you and your daughter.

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

View grizzman's profile


7836 posts in 3331 days

#5 posted 12-19-2012 11:20 PM

well you have survived it and had a place to go, oh no i was sent to the shop, do i have to go..maybe we need a new sign that says ban me to the shop…your Christmas cheer is warm and funny, but yet in my heart i know that you had sorrow , and im sorry for that, but i can see as a cat you landed on your feet and will be fine…the fire in the stove is warm and inviting…is it any good at cooking pancakes…lol…cheers..

-- GRIZZMAN ...[''''']

View patron's profile


13609 posts in 3369 days

#6 posted 12-19-2012 11:22 PM

4×4 = 16
not 14

9 + 14 = 23

not 25

might want to edit mads

thanks mads

helpful as always

merry mads and mathilde
and a better new year

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

View Don W's profile

Don W

18754 posts in 2595 days

#7 posted 12-19-2012 11:23 PM

Merry Xmas Made. Hope the new year is prosperous.

-- - Collecting is an investment in the past, and the future.

View Jim Jakosh's profile

Jim Jakosh

20600 posts in 3133 days

#8 posted 12-19-2012 11:24 PM

Those are some slick methods, Mads. It is amazing – you can do all that without a calculator or computer.

Best of luck to you, my friend!!.........................Jim
This too shall pass!!!!!!!!!!!!

Merry Christmads and a Happy New You!!!!!!!!!!!!!!!!!!!!!!!!!!!!

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

View twokidsnosleep's profile


1106 posts in 3001 days

#9 posted 12-19-2012 11:37 PM

2013 is a fresh start for you now
Wishing you and your daughter well until you settle in
You could come to Canada for a visit and some skiing while waiting for February to arrive:)
All the best in the New Year,

-- Scott "Some days you are the big dog, some days you are the fire hydrant"

View Tim Dahn's profile

Tim Dahn

1567 posts in 3593 days

#10 posted 12-19-2012 11:54 PM

Merry Christmas to you Mads, great pictures too.

-- Good judgement comes from experience and experience comes from poor judgement.

View Dennisgrosen's profile


10880 posts in 3143 days

#11 posted 12-20-2012 12:08 AM

it breaks my hart to hear this happened for you and Mathilde

thanks for the toturial , I have heard about this degree trick but never
learned how it was done ….. now I do know :-)
but I wont recoment bending a wooden ruler …. one in plastic is alot more flexiple

wish you the best


View patron's profile


13609 posts in 3369 days

#12 posted 12-20-2012 12:15 AM

thanks for the edit mads

there is one difference
in our measuring system
from the metric

we drink our beer by the ounce
seems you drink yours
by the liter

maybe why it is so hard to measure
over there

and keep tract of the numbers

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

View Dez's profile


1166 posts in 4105 days

#13 posted 12-20-2012 12:28 AM

Sorry to hear about the X Factor – (pun), glad you still have access to the shop and soon a new apartment! Thank you for the tips and tricks! I always enjoy your postings.

-- Folly ever comes cloaked in opportunity!

View Roger's profile


20929 posts in 2832 days

#14 posted 12-20-2012 12:51 AM

You are a wood wizard my friend.

-- Roger from KY. Work/Play/Travel Safe. Keep your dust collector fed.

View balidoug's profile


485 posts in 2506 days

#15 posted 12-20-2012 01:00 AM

Many thanks, Mads. Always happy to learn a new trick.

-- From such crooked wood as that which man is made of, nothing straight can be fashioned. Immanuel Kant

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