https://youtu.be/YoY1ErzMBZU
Printable View
It's very refreshing to see someone who appreciates the metric system for its lack of those infernal fractions found in the inferial system (i.e., the USA corruption of the Imperial system). Combining that with the use of a calculator in the shop raises your tip to five star status.
I love the metric system—I'd happily switch if there were a push for it. The only time it gets tricky is when dividing something into equal sections. Instead of clean halves or thirds, you often end up with long decimals, which aren’t much better than fractions. I guess no system is perfect.
A millimeter is only about 0.040 inches, less than a sixteenth of an inch (0.063). I doubt that you can subdivide BY EYE a millimeter better than a quarter which suggests an error of only about ten thousandths which seems more than accurate enough for wood working.Quote:
Originally Posted by Make Things
Set your calculator display to show only one digit to the right of the decimal. Mentally round that fraction to the nearest quarter millimeter. Personally, I don't think I can split a millimeter better than half by eye so I would just round that digit to the nearest half.
=================================
One of the most infuriating things about the inferial mess in the USA is the use of three systems - fractional, number, letter - for designating drill size. Number is counterintuitive with smaller numbers for larger drills, letter is not open ended; and neither of them tells you directly the size of the hole the drill will make. Fractional tells you the size hole but requires mental number skills to solve puzzles like what size drill is just smaller than a 7/16 ?
The ubiquitous Starrett pocket card relates all these squirrelly notations to a rational decimal size but leaves out all the metric drills which can fill gaps in the inferial mess.
Fortunately, the Amtek corporation has put together a downloadable pdf that ties all of them together. You can find it here...
http://websales.amteksteel.com/Asset...imal-Chart.pdf
Amazon will even sell you a drill gauge that incorporates all four nomenclatures up to `5/16"...
https://www.amazon.com/Holistic-Dril...3-024fb5d9a430
Even when I worked in countries that were quote unquote exclusively on the metric system 90% of all tape measures found in the stores were dual measurement with both metric and inches. When dividing things into equal parts especially when an odd number with a non-equally divisible total dimension. I would find guys flipping their tapes around to read from the infernal side most would just count the number of lines since they had no idea what 1/4 or 1/16th was. When doing multiple hole layouts on metal with scribe lines, I cautioned them whenever possible to always use a zero-point start. this would prevent an escalation or accumulating total error. usually retaining a .010" or .25mm total error.
Watching whiteboard demonstrations using Imperial dimensions becomes too cluttered to make any sense. I dont know how I managed as a young manual draughtsman back in the day.Quote:
Originally Posted by Make Things
I still occasionally use fractions though with the metric system, putting a 3 as a denominator under a metric size can simplify equations but I can't remember the last time I had to.
Congratulations Make Things - your compilation of marking and measuring tips is the Tool Tip of the Month for February 2025!
This is a helpful collection of tips for anyone doing any type of work in their shop.
Some more good tool tips from February:
Blind Hole Center Marking by Gadgeteer
Perfect Miter Clamping Aid by Make Things
Beat the Bandsaw's Limit by Make Things
Rotary Table Tips by Mook
Fixing Bandsaw Drift by Make Things
Straps to Eliminate Board Stretching by Make Things
Wood Bending by Make Things
Make Things - we've added your Tool Tip to our All Tool Tips of the Month winners post. And, you'll be receiving a $100 prize, in your choice of Amazon, PayPal, or bitcoin. Please PM me your current email address and prize choice and I'll get it sent over right away.
Congrats again :thumbsup: