SpudFiles

I was asked for help on making our schools physics department an air cannon for launching model rockets and doing physic-ee stuff with it.

One of the things I haven't quite decided on, is adjustable angles. They want to be able to shoot it at different angles, and holding the gun and guessing doesn't work too well for college physics. I was thinking an adjustable length bipod, and using math to figure out the angles for different length legs.

Now for the question: Do they make these in Tee fittings? That would make it really easy to make an adjustable length bipod.

Yes they do. My local hardware store sells them. Check McMasters.

Maybe think about designing something that has notches and can be moved up and down like those layback chairs...As you said, accuracy is probably a key thing in your design, and if you do it like this, its rather constant... Just get two support beams like this:



leading from your barrel down to wherever your "bar" is...Same basic idea as JSR's

why reinvent the wheel.



You can easily make your own clinometer attached to the barrel with a plumb line to indicate angle of elevation (as different bipod leg lengths could be inaccurate on uneven ground)

Make a wooden frame for a base and mount one of those cheap car jacks on it. Allow the gun to hinge on an axis near the back and place the jack where you can get the desired elevation.

It'll take a bit of component hacking/duct taping (or the equivalent), but I'm sure you can figure something out.

if you made a bipod and then somehow attached an angle finder to it youll know what angle your at every time. like <a href="http://img232.imageshack.us/img232/2571 ... g">This</a>

The mortar mount is a good idea, lets you set the launch angle in small increments. But, mortar mounts don't usually have a very large inclination range. (Mortars are not usually fired at inclinations less than 45 degrees or so.)

An inclinometer, home made or the one Trae08 posted, is a great idea.

HaiThar's idea, kind of like the attached. You'll have to come up with a way to stabilize it laterally. A hinge at the butt of the gun is not needed if you build a u-shaped butt stop (only a simple butt stop is shown in the drawing).

BTW Moderx, us po foks with dial up connections really hate one megabyte image files!