P14006Bath Tub Lift

Phase V ReviewAmos BaptisteJeremy CzeczulinAndrew HughesRichard Prilenski

IntroductionsName Major/Role

Amos Baptiste Industrial & Systems Engineer/Team Leader

Jeremy Czeczulin Mechanical Engineer

Andrew Hughes Mechanical Engineer

Richard Prilenski Mechanical Engineer

Agenda• Phase IV Overview

• Problem Definition• Action Items

• Refined Drawings• Prototype• Materials• Actuator and System• Stress Analysis• Customer/Engineering Requirement• Risk Assessment• MSD II Plan• Questions

Problem Statement• Bathtub lift – a device that provides assistance to an individual with

physical disabilities, including limited balance, coordination, or mobility

• Can reduce the difficulties of raising and/or lowering an individual into the tub by utilizing a powered seat and a simple control module

• As population grows the number of aged individuals will greatly increase making demand for assist devices increase

• Project motivation – Theresa Loce• Improve the current design• Current device does not meet her needs• Powered lift that is sturdy, comfortable, easy to use/clean, makes

minimal noise, and takes into account physical limitations of user• Ultimate goal – user maintains autonomy and privacy

Deliverables• Effectively assist the user for bathing purposes• Device is easy to access from starting position• Minimized operating time• Provide a comfortable and supportive seating area• Accessible to 10th-70th percentile for both genders, regardless

of age• Reasonably lightweight and portable, able to be transported

Current and Desired State

Current

• Unstable• Out of production• Damaged• Difficult access• Obstructions prevent full

use

Desired

• Easy use• Easy access• Portable• Lightweight

Stakeholder(s)• Primary Customer: Theresa Loce • Contact: 585-647-2329

• Secondary Customer (s): Wheel chair users/handicap public & Elizabeth DeBartalo, Hospitals (RGH), Nursing Homes, suppliers/vendors, individuals recovering from knee surgeries, Linak, & Acrylix. • Contact: eademe@rit.edu

• Faculty Guide: Art North• Contact: ajnddm@rit.edu

• Sponsor (financial support): RIT & Theresa Loce

Issues to Address from Phase IV• Include actuator on CAD design• Free body diagram of the Actuator• Putting locking mechanism for rotation and lateral movement• Make controller longer and wider• Limitations of actuator• Reorganize risk assessment to importance & severity ratings

Action Items from Phase IVAction Item Owner Issue(s) to AddressInclude actuator in the CAD design and perform FBD

Andrew & Jeremy • Stresses on the actuator• Length of the rod needed to

ensure seat about bath tub

Refine a design and prototype for controller

Amos & Jeremy • Controller being too small having ability to slip out of hand.

Refine CAD design Andrew • Ensure the chair fits the target percentile

• Determine location of bearing and pins

• Locking mechanism

Conduct stress analysis Richard • Stress from bending with materials chosen

• Stresses on pins and bearings

Refine BOM Amos • Ensure material is waterproof and is strong for safety reasons.

Contact Linak Sales Manager Jeremy • Specific model code of actuator to order

• Limitation of actuator

Function Diagram

User uses controller

Actuator Scissor lift rises

Chair rises to maximum height

User turns the seat and sits on it

Pull lever to lift pin to slide chair

laterally

User uses controller Actuator Scissor lift lowers Chair lowers to minimum height

Pull lever to lift pin to rotate chair on

bearing.

Pull lever to lift pin to rotate chair on

bearing.

Pull lever to lift pin to slide chair

laterally

Pin must lock

Pin must lock

Remove Case from Actuator

Remove battery and plug It into the wall mounted charger

Remove battery from charger and

place back into acutator

Seal actuator in case

4 hrs

Refined CAD Model

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Prototype

Controller• Consist of:• Power button• Directional pads to

move the chair• Home button

HB60 Handset

IPX Ratings

LA31 Careline Linear Actuator• Provided by Linak• 6,000N (1350lb) max push, 4,000N (900lb) pull• IPX6 protection class• Emergency lowering/retraction• 24V DC magnet motor, 2.25m cable• Custom stroke length

BAJ1 Battery Pack• Compact design• 40 lifts per charge• 4hr charge time• Low battery indicator• Up to 6000N thrust• IPX5 Protection

CHJ2 Wall Charger• Charges in 4 hrs• Indicator light for

charging status• Compact• IPX5 rating

MBJ & MBJ2 Mounts• Mounting brackets

for controller and charger (2)

MBJ

MBJ2

CBJ2 Control box• Combines actuator,

controls, battery, and charger into one system• Central hub

• IPX5 rating• 7 different parts

overall

MaterialsMaterial Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive?

1 Fiberglass 2.49 20500 No2 Gel coated Fiber Glass 2.49 20500 No3 Acryllic Optic Grade 1.2 5510-13000 No4 Polyamides5

Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive?1 Carbon fiber 1.6 15954 No2 Aluminum 2.69 40000 No3 Acryllic Optic Grade 1.2 5510-13000 No45

Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive?1 Fiberglass 2.49 20500 No2 Carbon Fiber 1.6 15954 No3 4140 Carbon Alloy Steel (Annealed) 7.85 60200 No4 Polyurethane Alloy 0.970-1.40 1740-9720 4930-76905 Acryllic Optic Grade 1.2 5510-13000 No

Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive?1 A36 Steel 7.85 36300 Yes2 4140 Carbon Alloy Steel (Annealed) 7.85 60200 No3 Stainless Steel 0.19-9.01 11200-46000 6150-348000 No4 Medium Carbon Steel 7.75 65300-396000 No5 Acryllic Optic Grade 1.2 5510-13000 No

Chair (Seating Material)

Chair (Frame)

Base (excluding steel fixture for extendable pillar and sunction cups)

Scissor Legs

Materials

Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive?1 Gel Coated Fiber Glass 2.49 20500 No2 Polyamides3 Acryllic Optic Grade 1.2 5510-13000 No45

Material Name Weight (per cc^3) Elastic Modulus(ksi) Tensile Strength (Psi) Shear Strength (psi) Corrosive?1 A36 Steel 7.85 36300 Yes2 4140 Carbon Alloy Steel (Annealed) 7.85 60200 No3 Stainless Steel 0.19-9.01 11200-46000 6150-348000 No4 Medium Carbon Steel 7.75 65300-396000 No5 Acryllic Optic Grade 1.2 5510-13000 No

Arm Rest

Extendable Arm

Actuator $ 500.00

Total $ 1,357.00

Total with 30% increase $ 1,764.10

Amount Left with 30% increase $ 1,264.10

Material LayoutAcrylic Plastic Optical Grade

Color: Beige

Acrylic Plastic Optical Grade

Track: Acrylic plastic Optical GradeRollers: Steel

Acrylic Plastic Optical Grade

Acrylic Plastic Optical Grade

Color: White

Medium Carbon Steel

LA 31 ActuatorColor: Black

Industrial Suction Cups

Acrylic Plastic Optical Grade

Acrylic Optical Grade

Acrylic Plastic Optical Grade

Medium Carbon Steel

Pin: Medium Carbon Steel

Medium Carbon Steel

Waterproof memory foam padding

Stress Analysis

Stress Analysis – Zoomed in

Recorded stress values are 6.7 – 15.2 ksi. The limit for acrylic is 10 ksi. Therefore the scissor supports will be thickened.

Displacement (in)

Factor of Safety

Recorded values ranged from 1.9 – 5 where appropriate

Updated Customer Requirements

Updated Engineering Requirements

Updated Engineering Matrix

Risk AssessmentID Risk Item Cause Effect Likelihood Severity Importance Actions to Minimize Owner

1Actuator being damaged

Water getting inside while the actuator extends and retracts

Actuator lifespan decreasing and being damaged

2 3 6

Apply a protective housing that can extend and retract with the actuator

Team

2Electric power supply inconsistent

Charge from battery may not be sufficient to operate device when running low

User may experience longer operation times or may become trapped in tub

2 3 6Apply a warning system/visual indicator that the battery is low.

Team

3 Fixture dimensions

Measurement errors of the bath tub and the device. Not considering thickness of materials in specs.

Device not able to fit in the tub. Customer not being able to use the device.

2 3 6

Have multiple team members measure the dimension of the tub and for every step of the process, re-measure to verify meeting constraints

Team

4

User hand getting injured in the process of using the seat

Exposed folding mechanism and/or seat lowering to quickly

Hand chopped off 2 3 6

Ensure through the proof of concept the device will not lower quickly or collapse. In addition, make a safe folding mechanism.

Team

5

Not being able to meet deadlines/milestones

Not having a well developed project plan and keeping it updated

Product delay which may lost customers trust

2 2 4

Have daily or weekly updates on assignments and if help is needed

Team

6

Not being able to fulfill requirements of broad user base (height/weight differences)

Not conducting an ergonomics study on the stature of the users percentile and their reach

User may be too big or too small for device. User may get injured due to lack of space or not being able to reach certain items. Customer dissatisfaction

2 2 4Conducting ergonomic experiments on the target percentile range

Amos

Risk Assessment7

User injury due to falling/slipping off device

No adding arm rails. Combination of material, water and human skin not having enough friction causing user to slip.

Minor to severe injury to the customer/user

1 3 3Implement a safety device and use high friction materials

Team

8 Shocking the userExposed electrical components

User may be shocked by direct contact with device or through water

1 3 3

Design electrical components to be isolated/sealed from rest of device.

Team

9Device weight capacity

Device not able to lift well over the minimum requirement

Device fails under heavy loading, trapping and possibly injuring user

1 3 3Through testing device must lift >150 lbs

Team

10Safety of user’s legs

When fixture is lowering it does not allow enough room for legs

Minor to sever injury to the customer/users legs

1 3 3

Apply a foot rest at the base of the device so the user can place their feet before operating

Team

11Transfer from starting position to the device

Unsafe transition from starting position to the device

Possible falling injury 1 3 3

Option1: Having the device being able to slide out the tub for the user to access. Option 2: Ensure that the device can rotate out of the tub and is stable for users that can stand to use as a support.

Team

12Device tipping over

Sunction cup failure or the device not properly secured to the base of the tub.

Minor to sever injury to the customer 1 3 3

Reinforce sunction cup base and have a back up plan in the case the sunction cups fail.

Team

13All team members not being able to meet

Miscommunication or lack of communication between team members

Team members missing meetings or not being active in their roles

2 1 2

Communicate with team verbal and text/email when and where will meetings will take place.

Amos

14 Going over budgetNot keeping track of budget or knowing what the budget is

Having to ask for more or falling short on supplies to develop the product.

1 1 1Schedule to audit budget every 2 weeks.

Team

Company Bathmaster Sonaris Bellavita Orca Portable Water Power P14006Type Battery Battery Battery Hydraulic Battery

Number of Lifts 8 to 10 N/A 12 Infinite 40Time to charge 3 hours N/A 6 hours 0 hours <= 4 hours

Weight Capacity 308 lbs 300 lbs 400 lbs 200 lbs 350 lbsWeight of device 15.75 lbs 20.5 lbs 35 lbs 19 lbs 20-30 lbs

Arm rest No No No Yes YesPortable Yes Yes Yes Yes Yes

Recline angle 40 degrees 50 degrees 0 degrees 0 degrees 40-90 degreesRotate angle 0 degrees 0 degrees 0 degrees 360 degrees >=180 degreesLifting Height 3"-18" 2.3"-18.8" 17" 2"-21" 17"

Back rest dimensions 24" x 14" 25.1" H x12.5"-14.1"W 26" x 27" 15" x 15" 15" x 15"Seat dimensions 20" x 15"; 27" with flaps 22.4"L x 12.7"W;27.5" with flaps 14.75"W x 19"D N/A 15"L x 13W"

Plan for MSD II

Questions?