Embedded Files
Design Proposal
Introduction
The project is Retractable Hot Tub Stairs. The purpose is to make hot tub access safer and easier. Currently there are hot tub stairs that you can buy, however, they are two steps high and can get really expensive. Only 4 out of 9 major brands(Caldera Spas, Hot Spring Spas, ThermoSpas, and Bullfrog Spas) even offer these stairs. The intended audience is hot tub users, mainly senior citizens or injured users. 1 in 4 seniors over 65 will have a fall while getting in or out of a hot tub(poolfencediy.com). The goal of this project is to lower those numbers and make hot tubs safer and more accessible. The original hot tub steps are too short and cause difficulty and unsafe conditions for people. The goal of these steps is to make hot tub access easier and safer. In order for the project to be fully functioning the stairs need pull out all the way, lock in place, and remain stable until they are done being used, the railings must do the same. The real project would generally be the height of the hot tub, about 38”, each step would be 10” x 27”, and when pulled out the entire staircase would come about 60” out from the hot tub. The prototype will be scaled down to a smaller cabinet, along with other smaller parts. To make the project the cabinet and stairs will need to be built and put together with the drawer rails, and then the railing will be built and added to the stairs.
Objectives
To make the stairs safer and more accessible they retract into a cabinet to stay stored away and avoid taking up too much space. Stairs include rubber padding, for slip prevention; railings for grip and balance assistance; and no large drop between stairs and the hot tub. For testing the weight limit should be the same, but the cabinet may not be able to support the same amount of weight as the stairs. Some constraints would include: during construction and testing(trying to figure out how durable/safe it is may be difficult or hazardous), and staying within regulations for aboveground/onground residential swimming pools(phta.org) in the case I need to make modifications to the dimensions of the project.
Design Strategy
To begin visualizing, the prototype will be made of cardboard and relatively small. Next, the real prototype can be put into construction using real materials, and then tested once completed. The project may undergo multiple tests to achieve the safest, most durable, conditions. Potential risks may include abrasion hazards due to unsanded/sharp materials, or low durability from the steps or cabinet during testing.
Box Diagram:
Plan of Action
Make a key(this part of the cardboard prototype=this part of the real prototype): Helps to visualize what the prototype will look like
Build cardboard prototype
Start construction for real prototype
Prototype testing: Make sure the prototype is functioning properly
Redesigning/reconstruction: fixing any problems/mistakes
Safety Testing 2: Make sure all problems were solved/ no new problems
redesigning/reconstruction 2: fix any new problems
Finished product: final design is fully functional and complete
Verification:
Prototype Testing Questions:
Can the project hold enough weight?
Does the project wear out too much overtime?
Are there any abrasion hazards?
Could someone slip when the steps are wet?
Does the project meet all requirements/regulations?(phta.org)
Tread depth: 4” min
Riser height: 7” min, 12” max
Width: 19” min
Handhold O.D.: 1” min, 1.9” max
Do the stairs unfold smoothly?
Do the stairs lock in place and not move?
Are the railings functioning and usable?
Tolerance Analysis:
The parameters that most affect my project are how much weight it can hold, how well the drawer rails can support the stairs, and how well the railings function. Later, these will be tested using bodyweight(up to 230lbs) and making the project function(turning the railings/pulling the stairs out).
Cost and Schedule
Cost Analysis
Materials Cost:
5 step retractable staircase(200lbs max): $59.99 or 5 step retractable staircase(250lbs max): $85.25
Rubber Stair Treads(5 pack): $19.95
Drawer Rails(2 pack, 244lbs max): $120.13
Bars for railings: approx. $94.36
Hinges for railings 2: $53.98
Estimated total cost: $348.41
(with more expensive stairs: $373.67)
Estimated Labor Cost:
34 days x 1.5 hours per day = 51 hours
$20.00 x 1.5 hours per day = $1,020.00
Schedule Timetable:
Date Completed: Step(s) Completed:
10.5.24 List/Key, Buy Parts
10.7.24 Cardboard Prototype
10.14.24 Construction
10.18.24 Testing
10.25.24 Redesigning/Reconstruction
10.30.24 Testing 2
11.6.24 Redesign/Reconstruction 2
11.7.24 Finished Product
Bibliography
American National Standard for Aboveground/Onground Residential Swimming Pools. (2024). Pool and Hot Tub Alliance.https://www.phta.org/pub/?id=b497e5d6-a5f7-1463-0101-fe52e011ee65
30 Hot Tub facts & Statistics [Your 15 Questions Answered] (2024, January 24). Manny Brambila. https://epichottubs.com/blog/hot-tub-facts/#:~:text=49%25%20of%20owners%20use%20the.needed%20provide%20pain%20relief
Hot Tub Danger for Older Adults. (2022, June 30). Unknown. https://www.poolfencediy.com/blogs/blog/hot-tub-danger-for-older-adults?_pos=16&_sid=0b23f4e71&_ss=r
Hot Tub Steps Stair Accessories.Accessories. (2024). Unknown. https://www.calderaspas.com/hot-tub-accessories/hot-tub-steps
Steps. (2024). Unknown. https://online.thermospas.com/Cabinets-s/55.htm
Construction
Prototype 1
Prototype 2
Page updated
Google Sites
Report abuse