DEWBOT XI Intake System
- Pulling/guiding RCs into the robot lift
- Stabilizing RCs for transport once acquired
- Pulling/guiding totes into the robot
- Aligning totes on the floor to lift position
- Preventing first Human Player Station tote from landing its side
- Aligning first Human Player Station tote to lift position
- Aiding correct alignment of subsequent totes loaded from the human player station
- Correcting any subsequent tote misalignments which may occur
- Stabilizing the tote/RC stack during transport and scoring
The system is comprised of the following components:
- A pair of Intake Arms with Intake Wheels
- A robot floor shaped to align totes drawn into the robot for lifting
- A pair of fiberglass rods anchored to the robot floor and passing through holes in the lift positioned to prevent totes from sliding too far back for correct lift alignment
The 1/2" keyed 7075 Al Pivot axle provides both a pivot point for intake arm articulation and provides the drive power for intake wheel rotation. At the axle's top, it is hard coupled to the driveshaft of a BaneBot P60 64:1 gearbox (driven by an AndyMark 9015 motor). The BaneBot gearbox is rigidly mounted to the robot's chassis. The pivot axle's bottom end is supported by a 1/2" flanged bearing mounted in the robot floor (flange side down). The bottom terminus of the pivot axle is bored and tapped to accept a 10-32 screw; a screw and oversized washer prevents the axle from disengaging from the bearing in the robot floor.
The wheel axle was made from 1/2" 2024 Al Hex stock, with the lower end turned down to 3/8" Diam and keyed. Top and bottom are bored and tapped 8-32 to prevent axle shift and loss of wheel. The original wheel axle (used at Hatboro was short and accommodated only a single BaneBot wheel (2-3/8" or 2-7/8"). By Seneca this had been replaced with a 12" long wheel axle with a lower Radio-Control car wheel and an upper tennis ball. The wheel drove totes into and out of the robot. The tennis balls performed several functions:
- With the arms closed while feeding in the first tote from the human player station, the tennis balls served as a sort of ramp, preventing the tote from landing on its side (unrecoverable) and reducing the probability of it landing on end (recoverable, but a waste of time).
- With the arms closed while feeding totes after the first tote, the tennis balls prevented significant side-to-side misalignment of the fed tote relative to the first tote.
- If the (not-first) fed tote is misaligned relative to the first tote, the intake wheels can drive the bottom two totes out and in to correct the alignment.
The bottom ends of the forward two 80/20 lift guides are cut away to allow free articulation of the intake arms.
Internally, we call this the Andrew floor, after its designer: alumnus mentor Andrew Weissman (also our lead CAD mentor).
The robot floor is a 1/4" thick sheet of polycarbonate. It is structurally connected to the robot by bolts to:
- the 1" x 1" lower rear transverse chassis frame weldment element;
- the bottom ends of the rear (2) 80/20 lift guides via tapped center holes on those 80/20 guides; and
- the bottom surfaces of the lifts' Toughbox Nano gearboxes.
In addition, the robot floor houses the 1/2" flanged bearings supporting the bottom ends of the Intake Arm drive shafts.
The center of the robot floor is open and shaped to position a tote on the floor so that it is in the precisely correct position to be engaged by the stacker. The forward end of the floor is more open than the rear, to act as a funnel in the guidance of tote which are not initially well aligned. The rear of the floor's open area is tightly constrained to accurately align totes.
The fiberglass rods serve to prevent totes (particularly totes fed onto the first tote) from sliding too far back. They limit tote misalignment to a point where the spring steel clips on the stacker bottom are able to resolve any remaining misalignment.