Quote from: Swapnil on November 24, 2015, 07:13:17 AM

Quote from: rockmania.89 on November 23, 2015, 11:49:02 PM
My family is in Kopri. I am in Germany since some time now.

You are in Germany and want to gift a German guy a cannon! Is it just me who finds this funny?
I'm not being a douche. I know you want to gift your professor, which is really great. It's just that the wacky center of my brain finds it funny giving a german guy a cannon! Aren't those guys all born tank commanders?   

haha no , not at all. Germans are really nice. They are just a bit different when it comes to opening up to people. I live with two German guys here and they are one of the coolest roomies I found so far.

The spinning wheels for the throwing mechanism would also be feasible. By varying inclination and speed projection of the projectile can be changed!

Quote from: Himadri Roy on November 24, 2015, 11:06:24 PM

The spinning wheels for the throwing mechanism would also be feasible. By varying inclination and speed projection of the projectile can be changed!

this looks cool. I will try this.

So, for now I think i will go ahead with the suggestion from Himadri. I managed to hook the arduino up to the RC motors and get a controlled spool using a potentiometer.
Here is the video ...



If my calculations are not wrong then, a motor of a diameter of 3 cm when spooled at max rpm ie 1000kv at 11 V will have a linear velocity of approximately 16m/s viz 58 kmph at any point on the diameter of the motor!

Now if i add a wheel of diameter of 5 cm my numbers almost double and should get a max speed of 100kmph!!! And the best part is, I just need a max speed of 14 m/s at a launch angle of 38.66 degrees to have a max reach of 20m, My classroom is half that size. Thus so far, this sounds really promising.

I already see some other related problems that might arise, but for now I am happy with this and will work them out later.

Quote from: miginstruments on November 24, 2015, 07:45:12 PM
Hi Rock. Quite Tedious but interesting project. I came up with one solution in my mind. maybe it ll help you out. But if this concept works then your loading and firing mechanism ll be quite simple. All you need to do is to find a high torque or say high pressure solenoid coil. Connect the Solenoid at one end of the barrel. Once you power it the shaft of the solenoid coil will move with a kick, and the kick produced will be good enough to shoot your snicker. Provided you ve to search for such a solenoid that should produce enough torque to kick the snicker out of the barrel upto a certain distance. More distance can be covered by adjusting the angle of the barrel. The loading mechanism is more simple, as it works on Gravity Feed. You need to design a Magazine similar to that of a Rifle Magazine, wherein the Snickers are going to be your bullets. cut a hole into the barrel similar to the size of the magazine. fill the magazine with snickers and place it onto the hole of the barrel such that the last snicker has to be inside the barrel. Once the solenoid shoots the snicker inside the barrel, the snicker residing over the last snicker will take its place. This seems a bit simple, but it ll be a tricky job in itself, coz the precision level has to be very high. But I guess this ll work out if carried out properly. And for the Barrel rotation mechanism its better to use Stepper motors, coz you can set precise angles. Also keep updating the process. Thanks.

This sounds like a lot of work and will demand precision ! I have heavy hands! But thanks for the suggestion and your time.

Gentlemen,

I worked over actuating the joints over the weekend and made this work.

here is the video:


the servo in the elevation actuating joint is barely keeping up with the load, I therefore am gonna support it with an identical one on the other arm. But this is how it works so far with the arduino.

wxPython is still in the pipeline which will power my front end.

thanks for the attention and support. I hope it remains a continuous process.

Excellent!   

hi rockmania, where do you source these gears from

Excellent indeed! 

Now you need to work on countering the recoil. Considering the weight of a 'Snickers' bar is 50 grams on average and the range required is greater than 4 meters, a large impulse will be generated.

The aiming and reloading parts are easy. First, you must do tests with various propulsion mechanisms.

Quote from: roby on November 30, 2015, 10:48:52 AM
hi rockmania, where do you source these gears from

hey Roby, these i found a year ago in some heap of abandoned stuff. I just liked it and decided to keep.
You can also use main rotor gears from an RC heli in case you want to do something similar. The gear ratio is 8:1 and the azimuthal servo is a CR servo.
hope that helps.

Thank you guys

Quote from: Swapnil on November 30, 2015, 01:52:41 PM
Excellent indeed! 

Now you need to work on countering the recoil. Considering the weight of a 'Snickers' bar is 50 grams on average and the range required is greater than 4 meters, a large impulse will be generated.

The aiming and reloading parts are easy. First, you must do tests with various propulsion mechanisms.

I will be using a traditional tennis ball launcher mechanism for this. Have mentioned the details in an earlier posts in this thread.

Hello Folks,

So this time I made a prototype of the launching mechanism. It is no longer controlled by a potentiometer but is now controlled straight from my computer. I am firing foam darts to save my apartment from damage.
Here is the video of the same.



Also I will be modifying the frame altogether to a new design. The sketch is as below.

Wow that's so cool. Awesome