Shop Math: How to Calculate and Cut a Fitted Angle
Kevin is calculating how he needs to lay out a fountain he has been commissioned to make. He's using pipes as spacers between the water feature's eight dishes. The pipes need to be just the right height so that, when he gets everything put together, the fountain is 40" tall.
He first figures out how deep each dish is and how long each pipe needs to be, and don't forget to put the angle on each pipe! It requires a lot of math. "I hate math," he admits.
Once he figured out how tall the bottom dish is - 6" - he was able to start spacing out the other seven dishes within 40" and figure out the height of each pipe. They're going to end up being about 3-1/4" to about 3-1/2" long. But then there's that pesky angle .....
Kevin shows the pipe that will hold the next dish. There's a big gap between the bottom of the pipe and the bottom dish, so now it's time to calculate the angle so the pipe is flush to the metal dish. That brings us back to that darn math again.
A steel protractor is the perfect tool. He has one that was his brother's that must be at least 30 years old, and it still works fine. He places the protractor's straight-edged base across where he wants to weld the pipe, then adjusts the tool's lever until it's vertical.
He knows it's vertical because he uses his level to check it. Once the level's bubble indicates it's correct, he looks at the protractor to see how many degrees the angle is. Kevin shows how he measures the number of degrees from 90, which is straight up, to the notch. This time the notch is at 22 degrees.
He sets his Ellis 1800 horizontal bandsaw by loosening up the cutting attachment and pivoting it to 22 degrees, then locks it back into place. He puts the pipe in place and clamps it in. Then Kevin checks the bandsaw's throat - you want to set your guide just far enough to miss whatever you are cutting. If you set it too wide, the blade can twist and wobble, giving you uneven cuts.
Kevin puts on his safety glasses and fires up the machine, which cuts through the steel pipe easily. When it's finished cutting, Kevin releases the metal pipe from the clamp and walks back over to his workbench.
To check his work, he places the pipe in place on the dish and puts his level up against it. The bubble is just right. He then checks it the other way vertically, then both ways horizontally across the top of the pipe. He turns it a bit to level it, then again checks it the other way. It's dead on.
Each dish must be level, or each one thereafter will be at an angle, which will throw off the flow of the water. That would be fatal!
Next he'll weld the pipe to the bottom of the next dish, then flip it over and weld it onto this dish. Then he continues with each subsequent dish.
There's lots of math and lots of brainpower, so Kevin is going to go back to what he's doing.
Well, you might want to take one more moment to hear Kevin indulge in his love of sound ....
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