When buying groceries, sometimes the final yards to get them inside your front door can cause major headaches, especially if you don't live on the ground floor. Getting heavier items up the stairs can be a strenuous activity in general, but it becomes an even greater challenge for people with disabilities or limited physical strength.
We wrote this Instructable to document the process of building an assistive device to help people get groceries up the stairs while minimizing physical strain. This device was created as part of a class at MIT called Principles and Practices of Assistance Technology where we built an assistive device to help a client, that is a little person, get her groceries up the stairs easier. This is the Instructable on how to replicate her device.
Steps 1-5 detail how to modify the stairclimbing cart to make it more user-friendly. This includes adding a zipper-secured port to the front of the cart to have quick access to groceries as well as lowering the height of the cart for shorter users. The height adjustment steps can be changed to suit the height of the user. Steps 6-8 explain how to attach and set up an automatic winch to pull the cart up the stairs for you. Installing the winch is more expensive and requires a small fixture being drilled into the wall at the top of the stairs, however, the winch will eliminate physical effort to pull groceries up the stairs.
The bill of materials and list of tools are attached to this page.
Step 1: Lowering the Height of the Cart Frame/hande
1A) Hacksaw off the top of the metal cart frame until it is your desired height (For our project we cut 8.5" off)
1B) File down the hacksawed edges with a metal hand file until there are no sharp burrs
Step 2: Lowering the Height of the Cart Bag
2A) With scissors, cut the material off the top of the cloth cart bag until the bag is your desired height (For our project we cut 4.5" of cloth off).
2B) With scissors, cut the lid off of the cloth bag, as close to the seam as possible. This lid will be sewed back on to the cart later.
2C) Thread the sewing machine with the heavy duty black thread.
2D) Clip the lid onto the back of the shortened cloth bag, using either mini-clamps, pins, binder clips, or clothespins. Make sure to match like sides together. Take care to make sure it is centered and parallel to the vertical sides of the cart.
2E) Sew the lid back onto the shortened cloth bag.
2F) Take 48 inches of 3/4-inch-wide twill tape and iron it in half lengthwise.
2G) Secure the twill tape onto the newly exposed top edge of the cart bag, using mini-clamps. Make sure that the twill tape is folded in half lengthwise when secured. In securing the twill tape, make sure the top 3/8-inch of the top edge of the bag is folded over (see diagram for details). This step protects the newly exposed edge of the top of the bag and makes sure the twill tape is secured firmly.
2H) Sew the twill tape on 1/4 inches from the top edge of the bag.
Step 3: Create an Accessible Port at the Bottom of the Cart
3A) Use a silver sharpie to mark the boundaries of the accessibility port (see diagram for details).
3B) Cut along the red line (see diagram for details).
3C) Cut ~0.5 inches off both ends of the two-way zipper (see diagram)
3D) Take one tassel off and reattach it to the other end of the zipper (now the space between the two tassels should be open space).
3E) Use hand sewing to secure the end of the zipper tightly. Once the needle is inserted as shown in the picture, sew the thread around the zipper multiple times to tightly bind the two zipper locks together. This prevents the tassels from falling off. Repeat for the other end of the zipper.
3F) Secure one side of the zipper to the outside edge of the newly exposed hole (see diagram for details). You can use pins to prevent shifting. Make sure that like sides match.
3G) Sew on one side of the zipper, leaving around 1/4 inches for seam allowance.
3H) Turn the bag inside out.
3I) Secure the other side of the zipper onto the newly exposed hole. Only secure the vertical sides, leaving the horizontal top unsecured.
3J) Sew the zipper onto these two vertical lines. We will be adding more cloth to the top of the flap because the inside circumference of the zipper is smaller than the outside circumference, so more cloth is needed.
3K) Cut a 2" by 10" piece from your leftover cloth.
3L) Sew on the 2" by 10" piece to the top (flap) of the port-covering cloth. With the extra cloth in place, now we can finish attaching the zipper to the flap
3M) Secure the new flap to the zipper with pins and sew on
3N) Hand sew the ends of the zipper onto the cart so that the ends of the zipper don't detach.
Step 4: Add Velcro to the Cart
4A) Cut a 3" by 0.75" piece of Velcro and place it horizontally on the front of the cart 2.75" from the top of the cart
4B) Cut a 3" by 0.75" piece of Velcro and place it horizontally on the top lid of the cart, 0.25" from the edge near the handle
4C) Sew around the periphery of the Velcro so that it can be secured for long-term use
Step 5: 3D Print and Assemble a New Handle
5B) You can also design your own personalized handle on CAD software and 3D print it instead of the provided handle
5C) To assemble the 4-Part Handle, put two M3 screws internally to attach parallel pieces and convert the handle into two halves. Place the two halves around the two exposed poles of the metal cart frame, then use two M3 screws through the top holes to attach the two halves together. Finally, put four M3 screws in the holes on sides of the handle so the handle assembly hugs the cart frame tightly (see diagram for details).
5D) To assemble the 2-Part Handle, place the two halves around the two exposed poles of metal cart frame and put four M3 screws in the holes on sides of the handle so the handle assembly hugs the cart frame tightly.
Additional Links to CAD files:
Step 6: Install the Wall Fixture
6A) Use a stud finder to locate a wood stud in the wall at the top of the staircase (approximately 1ft above the floor). Preferably, the stud will be in the wall perpendicular to the top of the stars and within the width of the stairs. (The wall can be parallel to the stairs if that is the only option) Make sure to find and mark the center of the stud.
6B) Place the fixture flush with the wall at the center of the wood stud and use a pencil to mark the bolt holes. It is very important that the bolt holes are aligned with the center of the stud
6C) Drill pilot holes into the center of the stud where you marked the holes for the fixture using a 1/4" drill bit
6D) Place washer on lag bolt and screw in to top pilot hole using a ratchet or a socket adapter for the power drill. Do not tighten completely.
6E) Line up bottom hole of fixture with lower pilot hole. Place washer on second lag bolt and screw in to bottom pilot hole using a ratchet or a socket adapter for the power drill.
6F) Tighten both bolts
Step 7: Attach the Automatic Winch
7A) Purchase an automatic winch (we recommend the following types:)
7B) Use the securement hook on the back of the automatic winch to attach the winch to the fixture on the wall. The winch should rest at the edge of the top stair. You may need to extend the securement hook via a cable or strap so the winch can be both attached to the wall and rest at the edge of the stair. The winch will want to slide forward when pulling weight up the stairs so make sure the connection between the fixture and winch is taut before attempting to pull weight.
Step 8: Bring Groceries Up the Stairs
8A) After securing the winch to the fixture, pull the winch cable to the bottom of the stairs. Follow the instructions for your specific winch model on how to do this properly.
8B) Secure the winch cable hook to the middle bar on the back of the stair-climbing cart
8C) Return to the top of the stairs. Make sure the connection between the wall fixture and winch is taut before you operate the winch so that the winch cannot fall down the stairs.
8D) Operate your automatic winch according to the instructions from the winch manufacturer. Keep your fingers clear of the automatic pulling mechanism and make sure to follow all of the winch manufacturer's safety instructions. Do not try to pull more than 50lbs up the stairs using this stairclimbing cart method.
8E) When you have successfully brought your cart full of groceries to the top of the stairs, you can detach the cart from the winch. You can then detach the winch from the wall and put it away for storage.