Hopper Capper Project ME490B

SUMMARY

Aaron Nickovich1, Anton Medrano2, Lyle Cobb3

HOPPER

CAP SORTER AND ORIENTATION SENSOR

Abstract: To improve the cycle speed of BioSero’s HopperCapper. This machine is a commercial product designed to automate the process of capping a standard-sized forty eight vial rack used by lab scientists and researchers.

Project Goals:•Design a new, faster hopper and cap sorter

•Improve the speed of the capping mechanism

•The product cannot go above eighteen inches tall.

•Have a prototype unit built and show-ready before February 2015 for the tradeshow (SLAS). Show-ready does not mean “optimized”.

Results:•The speed increased from 30 [min/rack] to 10 [min/rack]. Not an ideal 5 [min/rack], but closer!

•New hopper works much faster, but is limited to a range of cap colors until a better sensor is used.

•Spring loaded vial grippers is counter-productive. The cams fight against the springs to open it, but the springs needs to be strong to hold the vials.

VIAL GRIPS

1Mechanical Engineering; SDSU, 2Engineering Intern; BioSero, 3Product Engineering Manager; BioSero

APPROACH

• The new design iteration was conceptually sketched out first

• New components were drafted in CAD and tested it as a 3D printed part before quoting machined parts.

• Structural parts were machined early in the prototyping stage due to material properties not met by plastic parts.

• Most analysis done using hand calcs and/or• iterative changes

Initial Design Final Design

First iterative hopper prototypes:•Attempted to use a tangent channel with pocketed spinning disk. Design issues:•Design uses sharp corners as the mechanism for separation and feeding caps which will often bind the system.•Slanted design can’t be filled too high or caps will fall into the channel.

Final design:•Tube design uses gravity and radial force to feed caps.•One perpendicular hole minimizes binding.•Tube design increases the total cap capacity of the hopper.

Cap in Cap out

Cap flipper

CarouselCap orientation

sensor

Position sensors

Chute

HU HD

∆H = 5.2 [mm] to 5.35 [mm]

Up depth (HU)

Sensor

Down depth(HD)

Sensor

Cap

-0.014-0.035-0.030-0.030-0.036-0.026-0.030-0.063-0.033

Transition slope: [mm/Volt]

AVG

Matte Dark Blue (Starstedt)Matte Orange (Starstedt)

Matte Green (Starstedt)

Matte Black (Starstedt)

White rubber seal (VC24)

Shiny Black (VC24)

Matte White (Starstedt)Silver / chrome

To work properly:VHu > 3[V]VHd < 3[V]

Cap

Thru-beam sensors

Solenoid

Proposed sensor method:

FEA analysis on the gripper deflection:•To understand if the bar deflection has any significant impact on the uneven grip among the eight vials.Result:•±0.04[mm] is not enough to explain why some vials grip more than others.

±0.04[mm]

Current sensor method: