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Post RIDE Discussion

Started by Louis L, April 09, 2017, 02:24:54 PM

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Louis L

Please post things we'll be doing to the robot post-RIDE in preparation for the post-season

Louis L

We spent a decent amount of time talking about how to improve the gear mechanism. The goal is get as near 100% success on depositing a gear onto the Lift. Issues we addressed include:

  • The closer to the Airship we can drive the robot, the further in we are pushing the gear. This makes it more stable since it is further away from the tip of the Lift. And since our gear will rotate as it settles, this movement can disturb the gear and it may fall off. In order to push this in as far as possible, we need to allow the Lift to through the entire Gear area and into the hopper. We should, at a minimum, cut a hole in the hopper to allow this to happen.
  • If the Gear is hit by the Lift or if the robot is jarred at the wrong time, the bottom of the Gear can slide forward and the gear ends up tilted at an angle that makes it very hard (if not impossible) to deposit onto the Lift. The upper 60% of the Gear is not supported at the read of the Gear and that's a problem. We need to better control this game piece by having it sit snugly. Options include adding a gate at the front/bottom to keep the gear from sliding out, adding a mechanism that deploys after a gear is loaded and pushes the upper part of the gear so that it sits vertically. In this scenario, this mechanism can be further used to push the gear out at the top of the gear, in conjunction with the pusher at the bottom. A third option is to go back to cradling the gear from both sides firmly so that it can't move at all.
  • The shelf where the Gear sits was lowered a little bit at RIDE. Can we / should we lower it more? The Pixy sits beneath the gear but we can gain some space if we replace the ring light with something that takes less space.
  • Other areas we touched on include the rotating doors (should they be replaced?), the pusher (should we use another method of pushing?), re-designing the whole thing vs. fixing what we have.

Louis L

Contacted AndyMark about the wear on the swerve drives and the lack of a key in the CIM keyway. Turns out the slit in the shaft extension is made to hold a 2mm key so we install those and lock the CIM to the extension. I'll be ordering replacement / repair parts soon.

Ed B

Gear update... Ryan and Ed worked out a mechanism to hold the gear vertical after loading it and then pushing both the top and bottom at the same time when pushing onto the spring. The new mechanism is powered by a 24 rpm seat motor mounted on the side of the gear unit. The motor has a built in hall effect encoder, but we need to work out the electrical interface*. Also it generates a single square wave, not a quadrature pair,  so it will only be reliably usable in one direction, requiring a switch for re-zeroing at the starting position.   It may be possible to use this mechanism for both the top and bottom push, or we can  keep the existing servo for the bottom. We have the motor and a 5/16" shaft milled to couple with it.

*spec on WPI web site https://s3.amazonaws.com/screensteps_live/attachment_assets/assets/000/276/722/original/2016-12-21_spec_sheet_-_Bosch_FRC_motor_6_004_.pdf?1482352535 shows motor pin 2 going to analog in with a 200 ohm pullup to 5 volts and pin 4 going to ground.