Re: How to change angle of shooter?
 

Here is a vid of our first test run on the chassis. Frisbee shooter works fine and the elevation adjustment runs off of a jack screw powered by a window motor. Used a couple of basic door hinges so that the angle of the motor and screw can change freely.

Doug

http://youtu.be/fuEmQBhBpnw

Re: How to change angle of shooter?
 

We're using a single air cylinder mounted on the side of the shooter to switch between being level (loading angle) or shooting angle, probably around 35 degrees. To fine tune the shooting angle we're using a magnet on the cylinder to adjust the stoke length.

A fairly simple solution :)

Re: How to change angle of shooter?
 

Could someone please explain how a magnet can be used to adjust the stroke length of a pneumatic piston?
Thanks

Re: How to change angle of shooter?
 

How did you connect the lead screw to the window motor?

Re: How to change angle of shooter?
 

I believe there are different kinds of switches that can be used to adjust the stroke of an air cylinder. The method that I was referring to uses a sensor that can be adjusted along the body of the air cylinder.

This works because the sensor detects a magnet on the inside of the cylinder, once the rod has extended to the desired position the sensor will send a signal which will limit the stroke to that postion.

More information can be found here :

http://www.bimba.com/products-and-ca...?searchRef=yes

Re: How to change angle of shooter?
 

I know for a fact our team is mounting the front end of our shooter on a bar as the pivot point and then the back end will be sitting on a CAM. Which will allow us to change our angle.

Re: How to change angle of shooter?
 

We have a lead screw being used to adjust our shooter mechanism, which for the most part, is working like a charm. I cant believe the 1st banebot gearbox ratio we chose was the best one.
Initially after the shooter was built, we mounted it to a varying angle extruded aluminum frame to match the height where we designed the shooter to be. From there we determined the optimal angle range of the shooter head. Thus, the decision to design a varying angle shooter using the lead screw was determined.

Re: How to change angle of shooter?
 

I'd suggest a cam. Basically an offset disc to transform rotational to linear motion. It's compact, and works smoothly.

Re: How to change angle of shooter?
 

you could use a screw attached to an encoder to change angle. I would only use pneumatic if you are using pneumatics for something else on your robot because they are very heavy.

Re: How to change angle of shooter?
 

We took the black plastic splined connector that came with the motor and glued in the jack screw using JB weld. Took some attention to keep the joint symetrical. The window motor seems to be geared just right for this application.

Doug

Re: How to change angle of shooter?
 

Thanks for the quick reply.

How do you keep the black connector on the window motor?

Re: How to change angle of shooter?
 

Last year we did something very similar with a window motor. We used a screw through the plastic connector and into the window motor shaft. However, you have to be careful because last year we had continual problem with pulling the metal cover off of the window motor because it's only crimped on and we were pulling with the screw.

Re: How to change angle of shooter?
 

We use the force of gravity. The shooting platform weighs enough to hold it down. We had thought about using a bungee but that wasn't necessary.

Doug

Re: How to change angle of shooter?
 

Not entirely true. I spent last weekend testing the plausibility of pneumatic angling. By using a dual solenoid, and 1 spike controlling it, im able to get infinite variation with no lack of strength.

The solenoids two red leads go to M+ and M- of the spike, the black going into a splice on the ground side of the spike. By setting the the spike to full forward (12 volts on both pins, 0 pot. difference) the cylinder hold position due to equal pressures. I can then simply set the spike to forward or reverse to raise and lower the piston, having it default back to holding. On a 1"" bore bimba piston, i cant move the shaft at all. Flow control valves on the piston allow me to control how fast it moves up and down.

I may link a video if i get the chance on sunday...

Re: How to change angle of shooter?
 

What did you use to get the motor onto the end of the screw of the car jack?