When designing our power cube intake, we wanted the arms to be able to square the cube in our holder automatically. Our first prototype did that very well, but when we found that the surgical tubing did not have enough strength to hold the cube when lifted off the ground, we switched to pneumatics. We are debating whether or not to leave them how they are on prototype #2 because we can simply re-open the arms and close them again which proved to work or keep trying different ways to have the cube always get pulled in and end up squared. Any suggestions?
It looks pretty good!
Did you try driving your prototype frame forward at all while intakeing the cube? It seems you are moving just a little but maybe running forward a few feet can help orient the cube.
Edit: also it seemed like you could definitely add more tension to the surgical tubing, that could help
Looks good guys!
Looks great! Have you tried varying the working pressure? Less pressure will make your arms more spring-y, so it’ll behave more like the surgical tubing…you can find the perfect pressure with enough testing and tweaking.
Thanks for the feedback! We have tried a couple different pressures and 50 psi seemed to work the best, I would like to try having the bar in the back come farther up and see how that affects the cube when pulled in diagonally. Right now the main problem is that one corner is on the front wheel while the other is in the space between the wheels. I will post a video tonight if it works. Another thing we were going to try is having the pistons able to switch between 2 pressures, one lighter pressure to help suck in the cube and square it (40-50 psi probably) and a higher psi which would force the compliant wheels into the geometry of the milk crate afterward.
How well does this work with the vertical 11" cube orientation?
I think you need to add a spacer in front of the 1x2 back bumper or shorten the arms by about 1.5"::ouch::
That is what I was thinking about doing, moving the backstop up a bit to see if that will help the cube get squared. right now the piston stroke is just enough so that when the pistons are fully extended and retracted, the wheels will not run into the bumper.
That was one of our main concerns. We want to be able to grab the cube fast from any orientation so we don’t have to spend more time lining up, we are currently messing around with the spacer sizes to grab the cube from both orientations. At the moment though, the wheels can pull in the cube in the vertical orientation, but it does not hold it very well when lifted up.
Here is the video I made of what we did, basically we added Delrin guides for the belt so if the corner of the cube gets caught in between the wheels, the belt will grab the corner of the cube and bring it to the next wheel. We also added an inch to the backstop. We are still working on grabbing the cube from the vertical position. Thanks for the suggestions!
Looks good, the second prototype looks a lot like ours. We had the same issue of getting stuck; so hopefully 50 psi will change that!