Now, we can answer these questions with a simple yardstick measurement. Sometimes I'm curious what the transition radius truly is. But, I do understand the feeling and effects of riding different sized transitions, as any skateboarder does. I don't really understand the math completely. Now most people probably don't think that skateboarders are smart enough to understand the math behind what makes these curves. Now we have a way to figure that out, thanks to Mike Spevy. Often you might hear us ask, "What's the tranny in this bowl?" We call them trannies, Mathematicians call them radius. As I mention in the plans a 6' 10" transition works well.Bowls and ramps have curved surfaces that are large or small. Since the funbox is 2' high and the plywood is 4' wide, you need to measure your stopping point (another way is to cut the plywood in half the long way (hot dog way), then make two pieces out of each half).
MINI RAMP TRANSITION RADIUS HOW TO
8' Halfpipe: In the plans I show a picture of how to align two pieces of plywood needed for each side of the ramp, use those measurements.Since you are starting from the ground you can afford to start less than 18" into the plywood and still fit two sides in each piece of plywood, this way the sides will have a larger flat top on them. 4' Quarterpipe: The quarterpipe transitions to the ground, so you start the transition from the ground instead of 6" up.So now you should know exactly how to draw the transition if you were to make a 3'6" high halfpipe with a 6" flatbottom, some tips for the other ramps on this site. Use the piece you cut out to trace the second rather than drawing both using this method. You are just about done, if you haven't already, draw a line from your point 5.5" off the ground to the ground, Then use a jig saw to cut the transition you have drawn. VERY SLOWLY draw the transition, trying your best to keep a constant amount of tension on the string and keeping the pencil at a 90 degree angle with the plywood.
Now the String and Pencil does the work for you. Take your time doing this so that the pencil is lined up with the point you made 5.5" off the ground. Here I use fishing wire (2 lb test line), Any string with minimal give/stretch will work.Īt the other end of the string connect a pencil (I use a marker for video purposes only).
Now measure 6' 10" along the 2圆 from the point you just drew and put a screw into the side of the 2圆 there, attach a string to the screw. You will start the transition 5.5" off the ground because for this halfpipe there will be a flatbottom that is 5.5" high. Next, draw a point along the 2圆 that is 5.5" off the ground (marked incorrectly as 6" in picture above). NOTE: In the picture above where it says 6" it should day 5.5", I forgot that 2圆's were actually only 1.5" by 5.5". Use the line you drew to make sure the 2圆 is completely vertical.Īgain, the 2圆 goes 18" into the plywood, which was pre-calculated so that two cuts could be made from one sheet of plywood.
Next, attach a 2圆 (or a 2x4 or just anything that is at least 7' and straight) to the (3/4)" sheet of plywood. When you are making a ramp, you should only draw the transition once, then cut out the piece and use it to trace the rest of the transitions.įirst, draw a line (or just two points), that go along the width of the plywood that are 18" into the plywood. I draw the transition twice to demonstrate that you can cut two sides from one sheet of plywood. The following is directions for cutting the transition for a 3 feet and 6 inches tall halfpipe, using a transition radius of 6' 10", see the bottom of the page for how the transition differs for other ramps.Ī couple of notes on this video: I used a platform instead of just a 4x8 sheet of plywood so that I could stand it vertical for the video, when you are drawing the transition you can just lay the plywood flat on the ground. These factors will depend on the ramp you are building. So, to draw the transition, you just need to figure out how large of a radius you want for your curve and where to start/end the transition. Here's how it works, when cutting a transition, the curve always follows that of a perfect circle (unless you want an irregular ramp). The String and Compass method can be used to draw smooth and precise transitions. Check out the Xtreme Skater Ramp Tool for calculating the transition cuts.