Archive: 15 posts

---

Hiya, I am trying to create a cannon that will fire a cannonball at several targets. It is easy enough to adjust the angle of the cannon by using a wobble bolt and three way switch. Can any think of a clever way to vary the force applied to the cannonball. My suspicion is that this would need to be done mechanically but I have tried for some time and can't think of a solution. Thanks, Mark

2010-10-20 08:42:00 Author: sparkle80 Posts: 27

---

The only easy way I ever came up with for varying the force of a projectile was by firing it with a rocket that smacks into the backside of it. The speed (power) of the rocket can be varied by a mag key/switch combo set to speed and simply vary the placement of the key depending on the needed speed. Or you can attach the key to a piston if you want to make a sort of timing challenge out of it.

2010-10-20 09:31:00 Author: Trader Sam Posts: 92

---

That's a really good idea. I might try that with the piston, but instead of being random connect the piston to a 3 way switch to adjust the position. The distance between the key and switch relating to the speed of the rocket. Thank you, good idea!

2010-10-20 10:38:00 Author: sparkle80 Posts: 27

---

Another method is to create a catapult of sorts, using a piston and a flipper winch. You have to "charge" the catapult by extending the piston (set to directional) and then trigger the flipper winch at a given point. As the flipper flips in almost instantly, the velocity of the projectile is based upon the distance that the piston has extended. So the longer you charge the system for, the more powerful the projectile.

2010-10-20 12:03:00 Author: rtm223 Posts: 6497

---

I did try toying with a winch and piston for a while but had no joy doing it this way. Sounds like it might be more elegant than a rocket. How would I need to set the strength of the winch and piston? Thanks

2010-10-20 17:06:00 Author: sparkle80 Posts: 27

---

Check out the CC11 finalist video (http://www.youtube.com/watch?v=48a_fBUlsdM) (Contraption Challenge 11) for some inspiration

2010-10-20 17:17:00 Author: Weretigr Posts: 2105

---

With the winch set to flipper, strength becomes a non issue, a flipper winch will always overpower a non-flipper piston. At a guess i'd say your previous efforts were using directional for both. The problem there is that the winch speed is fixed with directional, but with a flipper the winch speed is proportional to the distance travelled. Post back if you have any issues and i'll see if i can help :-)

2010-10-20 17:29:00 Author: rtm223 Posts: 6497

---

Hi, I've managed to sort of get it working, but it is very flaky. If the piston is only pulled out a short distance then the winch doesn't fire. Also the piston will sometimes only reach part way and stop. I have set the winch to flipper and control it with a push button switch. The piston is set to directional and controlled with a 3-way switch to adjust position. Can you think what I'm doing wrong? Thanks, Mark

2010-10-21 11:25:00 Author: sparkle80 Posts: 27

---

Can you jot down all of the tweak settings for the piston and winch for me and I'll think about it over lunch.

2010-10-21 11:51:00 Author: rtm223 Posts: 6497

---

OK here we go, Piston Max length: 25 Min length: 0 Strength: 10 Flipper: no Awesomely awesome wench Max length: 30 Min length: 5 Strength: 10 Timing: 0.2s Pause: 0s Sync: 0s Flipper: yes (out) Thanks for your help, muchly appreciated

2010-10-21 12:42:00 Author: sparkle80 Posts: 27

---

Ok make sure the piston and the winch have the same minimum distance for a start. That will fix the not firing at short distances issue. As for the piston stopping I can't see anything in the tweak settings that would cause that. Are you sure the object on the piston is not rubbing on anything, and that the piston is stiff?

2010-10-21 13:28:00 Author: rtm223 Posts: 6497

---

Hi, Yes I'm sure it isn't rubbing against anything, there is a clear separation between the walls of the "cannon" and the plate connected to the piston. And the piston is definitely set to stiff. However, curiously I started from scratch with the exact same arrangement and so far it seems to be working! Now I just need something to aim at! Thanks, Mark

2010-10-21 15:16:00 Author: sparkle80 Posts: 27

---

I have just published my test level for this - called Cannon Test. I would be grateful to anyone who has the time to look and tell me what they think. Particularly what could be improved. Just search for my user-name @sparkle80. Thanks

2010-10-21 20:30:00 Author: sparkle80 Posts: 27

---

I tested your cannon and I will mention two things: For one, it doesn't seem to fire at all unless it's pulled back by about halfway. I'm not sure if that's intentional, but due to the structure of the device it's basically impossible to really adjust shot strength because of the small window in which the cannon will actually fire when you press the button. You could slow down the speed at which you can adjust the piston to help compensate for that (or redesign it). The other thing is about the emitter. I strongly recommend adding a manual reload because it's annoying to have the emitter going automatically the way it is. This way you could add a switch (set to one-shot) for the emitter to immediately spawn a cannonball. With the lifetime set to infinite and the max emitted at once set to 1 your currently-existing cannonball will disappear when the new one is spawned but the one that currently exists will never disappear on its own. Hope this helps On a side note, how did you make a three-way switch interface with the grab switches? Some kind of logic device? Very clever either way, I like.

2010-10-25 04:51:00 Author: Unknown User

---

Hi, Thanks for the feedback it is much appreciated. Yes, I haven't got the emitter to work properly yet. I think I might set up a sensor on the ground that will force the emitter to create a new "cannonball" if the target is missed. As for the grab switches it is relatively simple. I have a three way switch connected to some dark matter and a winch connected to each side. The grab switches are connected to the winches which then pull the three way switch. You can do the same thing with buttons and sensor switches too. PS the cannon test level should be copyable so you can have a look if you want!

2010-10-26 00:26:00 Author: sparkle80 Posts: 27

Posts: 1077139    Threads: 69970    Members: 9661    Archive-Date: 2019-01-19

Aus dem Archiv wurden alle persönlichen Daten wie Name, Anschrift, Email etc. - aber auch sämtliche Inhalte wie z.B. persönliche Nachrichten - entfernt.
Die Nutzung dieser Webseite erfolgt ohne Speicherung personenbezogener Daten. Es werden keinerlei Cookies, Logs, 3rd-Party-Plugins etc. verwendet.