1. 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
1
Mechanical Engineering; SDSU, 2
Engineering Intern; BioSero, 3
Product 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
Carousel
Cap 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: