A Card Level is versatile low cost easily made level that can indicate accurate level and any and all angles from level.
How to Make
- Take a rectangular piece of card. The rectangularness must be accurate, freehand cut card is no use.
- Measure and mark a point half way along the top. Again this must be very accurately placed.
- Push a pin (drawing pin, map pin etc) through the card a few mm below the top at this halfway point.
- Wiggle the pin in all directions until the pin sits in the hole with absolutely no friction.
How to use
When held only by the pin, the top of the card indicates the horizontal accurately.
Either push the pin into the workpiece, or hold it against the workpiece.
Ensure you're not touching the card when taking level.
A perfectly symmetrical rectangular card indicates vertical as well as horizontal.
The simplest way to find card with accurate angles is to use a whole sheet of card of any kind from a stationer's. Perhaps surprisingly I've yet to find a piece of such card that is not cut with accurate angles all round.
There are 2 ways to indicate any other angle.
- Mark lines at the desired angles on the card
- Cut the card at the desired angles. Whatever angles you cut, the card must remain perfectly symmetrical and all angles must be cut accurately.
It is even possible to cut a card with 4 sides that give 4 different angles, but excessive maths skill would be needed to design such a thing.
- Can be made on the spot almost anywhere
- Indicates any and every angle you want it to
- Costs nothing
- Reduces total weight & bulk of portable tool kit
- More versatile than spirit levels
- Susceptible to wind
- Not robust, though its not hard to make a robust plastic version
- Careless manufacture could result in inaccurate level indication
- Items to be levelled can not be pressed against the level in use. It is easy to put them very close and equalise the gap by eye, but not quite as quick as a spirit level.