I picked one up at the BORG when I was trying to figure out how to throw up a peaked roof on my shed build. I paid about $39 for the "Construction Master 5"

It was handy. I could have done it using CAD or a trig formula book but I wanted to try it this way.

But it has since migrated into the shop and I gotta say I really, really, really like the thing.

I can convert back and forth from all systems of measurement CM MM Inch Decimal whatever.

I think in Decimal and prefer inch standard but my tapes are all in fractions.  And once in a while I'm dealing with metric and it gets crazy. This thing sorts it all out for me. I hit the convert button and then the measurement standard I want to see the dimension in and I get it.

I keep finding new uses for this thing. A while ago I built a sine plate. Two hunks of ply with a piano hinge. I built if as a drill press tool. But have found that the set up is a bit tricky. For those who don't know a Sine plate is just that two plates with some type of hinge and two round bars down a specific distance away from the center of the hinge.

You do the Trig and figure how what size gauge blocks to put in between the bars to get a dead on accurate angle.

Set up was a bit tricky until today, when I grabbed the calculator and entered 10" hit RUN and then entered the 22.5 and hit PITCH. Then I pressed the RISE key and lo I knew exactly how far apart the ply boards needed to be at the 10" mark to give me precisely 22.5 Degrees.

If you hate math but love complex design you might think about picking up this calculator.

You are so right, Cliff! I have the "III" version from many years ago. They were really expensive back then but as you indicated, money well spent. My favorite operation is being able to enter and do math in fractions. Your newer version probably has functions this old one doesn't. For the price, I may have to think about replacing mine. 

 

 

I've been using one of those for a long time. They do have one problem, after a while they make you forget how to do it any other way.

I've had the III model for quite a while, and it's extremely useful. As for Richard's observation...I forgot how to do a lot of this stuff long before I had the CM III

I don't use that one but may have to look at it. I have an app on my phone I use in the shop all the time and it really helps with the conversations and math.

Great review Cliff!