Introduction: Ambrosia: a DIY Children Walking Aid

This project is part of my bachelor thesis. As an industrial design student I went to Bolivia to support occupational therapists during their work and help local students during the design process of walking aid for the local children.

Due to the pandemic, my internship in Bolivia was canceled after 1 day and I went to Belgium, where I spent several weeks designing and prototyping a walking aid that could be easily produced in Bolivia.

My goal was to design a walking aid that is easy to make, requires not a lot of tools and uses materials commonly found in Bolivia, and I managed to fulfill this goal... more or less.

The walking aid is made for children that need a low amount of support: support of the hands, arms and/or back. Ambrosia is adjustable in height and width, has multiple wheel setups and can be equipped with armrests.

ps: Any feedback is greatly appreciated!

I need to give notice that this walking aid is NOT stable. I noticed this with my last test a few days ago. Therefore, I do not recommend this walking aid to children that need a lot of support but more for children that just want something to grab.



-3 meter, 40mm pvc pipe 3mm thick

-3 meter, 32mm pvc pipe 3mm thick

-4 90°, 40mm pvc fittings

-2 T-style, 40 mm pvc fittings

-4 90°, 32mm pvc fittings

-2 T-style, 32mm fittings

-8 pipe clamps range 25-40mm

-2 castor wheels (1 hole attachment) OR 2 fixed castor wheels (1 hole attachement). (I used wheels of 75mm, these were a bit small so bigger is better)

-2 (old) tennis balls

-3 65mm M8 bolts

-1 nail minimum 65mm long

-Electric tape (or other thick tape)

-Eva foam

-120 grid sanding paper


-Metal hack saw

-Measuring tools

-Wrench or pliers


Step 1: Cutting the Pvc Pipes

After my first test, I noticed that it is hard to cut a pvc pipe straight with just a hacksaw. This problem can easily be overcome with the use of a hose clamp. Simply tighten the hose clamp at the right length and cut the pipe using the hose clamp as a guide.

There are 2 sizes that you can make, depending on the size of your kid. Look in the pictures for the dimensions.

There are 11 different lengths you'll need for this project, I numbered them to keep them apart.

40 mm pipes:

1: 2 pieces of 490mm

2: 2 pieces of 300mm

3: 1 piece of 200mm

4: 2 pieces of 192mm

5: 2 pieces of 150mm

6: 4 pieces of 60mm

32mm pipes:

7: 2 pieces of 390

8: 4 pieces of 300mm

9: 1 piece of 225mm

10: 2 pieces of 125mm

11: 2 pieces of 60mm

It's no problem if the pipes differ a bit from this, but make all the same pipes with the same number the same length.

Step 2: More Cutting!

To prepare for the adjustment system the pipes 2, 3, 5 and 6 (just 2 of 6) need some extra cuts.

Place a hose clamp about 25mm under the top of the pipe and cut 4 times as shown in the pictures, creating 8 sawlines in total.

Pipe number 3 needs these cuts on both sides, the pipes 2,5 and 6 only at the top.

Step 3: Sanding the Pipes

If you thought that the cutting was messy, prepare for the sanding.

I start with sanding all the outsides first by holding the sanding paper in 1 hand and twisting the pipe with my other hand.

Next, I sand the insides with a small strip of sanding paper.

Step 4: Preparing the Adjustment System

The 32mm will slide in the 40mm pipes to adjust. To be able to fix the 32mm pipes, they need to be a bit wider. This is why I used some electrical tape to make the pipes wider.

Tape pipe number 9 (black) completely but leave about 25mm pipe open on the pipes 8 (red) and 10 (yellow), this is to be able to attach the pipes in the fittings later on.

Step 5: Making the Bottom Frame

Now it is time to make our frame together. I glued a few pipes and the rest I attached with screws, this is needed to be able to change parts etc.

To drive in the screws, first hit it with a hammer or something heavy. This will help for driving it in. Use at least 3 screws per hole for a good and tight fit.

Read how to use your glue on the bottle, every kind has a different way of doing it so I'm not going to explain it.

I wrote numbers (the encircled ones) on the connectors to indicate in which order to attach them. Start off with the 40 mm pipes, which are going to make the underside of the walking aid. Use a flat surface, this helps a lot with alignment.

1. Attach pipes 1, 2 and 6 with screws like shown in the picture.

2. Glue numbers 4, 5 and 6 on a T connection piece like in the picture.

3. Put number 4 in the remaining hole and let pipe number 5 stick up vertical. Secure with screws.

4. Repeat for the other side but make sure the left and right parts have number 5 facing inwards.

Step 6: Making the Top Frame

Next, we will assemble top frame, made with 32mm pipes.

1. Attach the pipes 7 and 10 (yellow) on their T connection piece like in the picture.

2. Attach 2 pipes of number 8 on a 90° fitting and place an 11 on one of these as well.

3. Place the 3 parts in the top frame like in the pictures. Repeat for the other side and use pipe number 3 before securing with screws.

Step 7: Installing the Height and Width Adjustment

The height and width adjustment is possible thanks to the 32mm pipes that slide into the 40 mm pipes. The 32mm pipes can be fixed on the appropriate height and width with the use of hose clamps.

1. Take the top frame out of the bottom frame.

2. Place the hose clamps (loosely) around all the pipes where you created the extra sawlines.

3. Assembly the walking aid back together and tighten the hose clamps to fix the inner tubes.

Step 8: Installing the Wheels

For the installing of the wheels, you have to make holes. If you own a drill, just use this to make the holes. For the ones that don't have a drill, you can use this method:

If you just want to use 2 wheels, only make holes in the front.

Please do this outside and clean up afterward.

1. Heat up a nail using a gas burner or make a fire and lay it in there. Use pliers to not burn yourself.

2. When the nail is hot, make 4 holes in the appropriate places as straight as possible. You will have to reheat the nail a few times.

3. Take a bolt and heat this one up.

4. Press it on the holes you made with the nail until it goes through.

5. Sand the holes you just made.

6. Put the caster wheels in the front with the setup bolt-washer-wheel-washer-nut-washer-pvc-nut.

7. Put the fixed wheels in the back with the setup bolt-wheel-nut-pvc-nut and place them as straight as possible before tightening.

8. Roll away!

Step 9: Installing the Tennis Ball

You can use 2 old tennis balls for this, or new ones. They will need replacement every now and then, depending on the ground and frequency they are used.

1. Take a 90° fitting and a 40mm pvc pipe, 60mm long and glue/screw these 2 together.

2. Use a 40mm pvc pipe to mark out a circle on the ball.

3. Use a sharp knife to cut out this circle.

4. Make 4 little cuts.

5. Force the tennis ball over the back of the walking aid.

Step 10: Wheel Setup Options

There are 3 combinations for your wheel setup, all with different benefits. The combinations can be made with 2 kinds of wheels and a piece of PVC that acts as a holder for a tennis ball.

The decision on which one is the best depends on the user, every user will require something else.

Option 1: Caster wheel in the front and tennis ball in the back.

This wheel setup gives a lot of maneuverability. Corners are no problem while walking.

This wheel setup gives the child security when standing still. The tennis balls prevent the walking aid from moving backward when leaning against it. The caster wheels don't prevent the walking aid from moving to the sides, which can be scary for the kid.

Option 2: Fixed wheel in the front and tennis ball in the back.

This wheel setup limits maneuverability. Corners can take extra effort because the walking aid has to be lifted a bit to make turns.

This wheel setup gives the most stability to children. The walking aid will not move backward or to the sides, giving the kid a lot of security when using the walking aid while standing still.

Option 3: Caster wheel in the front and fixed wheels in the back.

This wheel setup gives the most maneuverability but at the cost of stability. Even while walking, the walking aid can feel unsafe for the user, especially for unstable children.

While standing still, the walking aid gives little support because it can roll to almost all sides.

(I do not recommend option 3).

Step 11: Softer Back Rest

Pipe number 3 can be used by the kid to lean against. To make it more comfortable I wrapped a piece of eva foam around it.

1. Cut the eva foam to size (about 12.5cm for the 40mm pipe).

2. Make cutouts for the pipe clams.

3. Apply double sided tape to the pipe.

4. Wrap the eva foam around the pipe.

There are different ways of doing this, depending on the available materials you have.

-Eva foam + rubber bands: Wrap a sheet of eva foam around the pipe and attach it with some rubber bands.

-Eva foam + velcro: Attach 2 pieces of velcro to a sheet of eva foam with contact cement and wrap it around.

-Neoprene + velcro: Sew 2 pieces of velcro to a piece of neoprene.

-Bike tire: Cut an old bike tire to make 1 long strip and wrap this strip around the pipe.

-Fabric: Wrap a piece fabric a few times around the pipe and secure with rubber bands, tape or glue.

Step 12: Decorating the Walking Aid

This step can be done in many different ways. I believe the most fun way it to do this with the child that is going to use the walking aid.

It is important to completely cover the PVC pipes. Otherwise UV light (from the sun) can weaken the PVC.

I used a soft colored spraypaint as a ground layer and proceeded with spreading drops of spraypaint in another color. I will explain how to spraypaint in another instructable.

Inspiration for decoration:

-Eva foam shapes

-Spray paint (use plastic primer)

-Wrap in leather

-Wrap in fabric



-Colorful tape


Step 13: Making a Arm Rest

In case your kid needs more support, the walking aid can be equipped with an armrest.

For this, you will need a few extra materials:

-2 T-style, 32mm fittings

-2 32mmx200mm PVC pipes

-2 40mmx150mm PCV pipes

-2 150mm long, 80mm diameter PVC pipes

-Eva foam

-Thick glue (glue gun or silicon glue)

1. Cut the 80mm pipe in 2 lengthwise. Glue these 2 parts inside each other so you have a thicker, half pipe.

2. Place the half pipe on the 40mm piece and secure with 2 screws.

3. Place a bit of thick glue between the half pipe and the 40mm pipe (To have a sturdier armrest).

4. Spraypaint this before proceeding (I forgot this so I needed to mask the eva foam before spraying)

5. Place in a piece of eva foam in the half pipe and cut off so that you have a +-10mm overlap on each side.

6. Glue the eva foam in place so that all edges are covered.

7. Make little cuts to gets the screws visible again. Unscrew the screws.

8. Remove the front 32mm, 90° fitting and slide the 40mm pipe over number 7, drive the 2 screws back in to secure.

9. Place a 32mm T fitting where the 90° fitting was. PLace the 200mmx32mm pipe on top of this.

Step 14: Installing the Arm Rests

To install the arm rest, you need to take apart the walking aid a bit.

1. Remove the 32mm, 90° fitting on the front of the walking aid.

2. Take the screws out of the armrest and place the armrest over the 32mm pipe (number 7).

3. Place a 32mm T fitting on the place where the 90° fitting was and secure with screws.

4. Place the 32mm, 200mm long PVC pipe on top of the T connection piece.

5. Secure the arm rest by driving the screws back in.

The distance between the arm rest and handle depends on your kid.