My team built a prototype linear puncher using a 60 tooth slip gear, with 20 teeth removed. It works pretty well for a first iteration, and we are looking for suggestions on how to improve it. Here is a video of it.
Thanks in advance!
Edit: Fixed the link.
Link says removed by user.
Thanks for the heads up. We are working on it right now. I will fix it when we do.
Edit: There we go, should be fixed now.
Definitely keep those standoffs that the ball rests on really tight. Loctite is a good idea on those screws because they are absolutely critical to accuracy.
You might want to try increasing the distance that the puncher is in contact with the ball (try moving those standoffs back a hole or two). I’ve noticed that there is a point where less contact gives less range. I’m guessing this is because ball compression prevents all of the shooter’s velocity from being transferred to the ball.
Thanks for the tips. We’ll definitely try moving the standoffs back (your logic makes sense, but it also probably has to do with F = ma * v/t, as t decreases, v decreases) and putting Loctite on the holder screws. Also, we’ve found that the launcher has a LOT of recoil when we shoot it, but since it’s not mounted on a robot yet, we haven’t tried to find a way to absorb that recoil. Any ideas?
Use some sort of cushion for your stops to hit.
Like a rubber link? We’ll have to try that tomorrow when we get to work again.
That is what I have used. I cut one screw end of the link off and mount it at a right angle within the slide rail.
Anyone have any tips for a stop? I’ve had problems with the puncher being to powerful and destroying any stop I use.
I had the same problem until I started to use pulley rope as a stop.
This is 2R’s robot:
Thanks, but I’ve having a hard time understanding how the pulley stop mechanism works.
After thinking about its a little more, is it the string that acts as the ‘hard stop’? I can seem to see any other mechanism attached to the string.
The string is the stop. it isn’t attached to any mechanisms other than the launcher.
Thanks! I’ll try this on my robot tomorrow.
We can score in the high goal from midcourt. Our pullback is 9 inches. We are still trying to improve it, and would love any tips
I tried the pulley method, but the c-channel that I mounted the string on kept on cutting the string after 20 or so shots. I’m not sure what to do to fix this.
we have put three lengths of the string together and that solved our problem.
I was thinking of using string for a stop but I was worried it would loosen over time, allowing the puncher to contact the ball longer and affect the shot. Have you had any problems with this? If not how did you secure the string?
we did not use string instead we attached small plastic spacers on the bottom before the slider and they hit a small black spacer up ahead absorbing the impact. This allows the slider not to get damaged. In the past when we didn’t have the spacers we used the sliders which broke from the impact.