Simple DIY Conversion of a Hoverboard Into a Pottery Wheel

Warning

This project reuses a hoverboard, a product which contains a lithium ion battery. Opening a hoverboard and removing the battery should only be undertaken if you are fully aware of the potential hazards (fire, explosion) associated with these batteries, particularly if used beyond their original purpose, and especially when charging (never charge unattended, or where a subsequent fire/explosion would restrict your egress).

Do not follow this Instructable unless you are satisfied you undertand the risks associated with lithium ion batteries, and are confident you have the knowlege and skills to mitigate these risks.

Background The advantages of this Potters Wheel are: Simple and quick to build, VERY cheap, wide and controllable speed range, plenty of power to centre 5 kg 10 lb of clay, parts readily available, not need for special tooling, lightweight and small size means it can be stored in a cupboard between use.

The main improvement over the earlier Instructable (Simple Electric Pottery Wheel) is the fact that the hoverboard gyroscope sensors and brushless motor power circuits are used to provide controllable power delivery to the pottery wheel motor, rather than use bespoke ebike speed controllers and a separate footpedal. And as long as the battery on the donor hoverboard still works (they usually die because the battery's BMS charging circuit fails rather than the lithium cells) the battery can be used to power the pottery wheel for adequate amount of time (e.g. make 10 pots). This reduces the build cost enormously. Also, if any component ever fails, you can just source another donor hoverboard and fit the necessary parts. This design requires only simple tools that a DIY enthusiast probably owns already, the most high tech tool being a jigsaw for cutting the circle of plywood for the wheelhead. Since all the electrical components are sourced directly from the donor hoverboard, the total cost can be kept to around £30. 

Overview  The build process involves fixing one of the powerful brushless motor hoverboard wheels vertically on a wooden base. This is then located inside a plastic storage box which acts as a splashpan to catch the messy clay slip. After use, the main wheel assembly can be lifted out of the splashpan for easy cleaning of the water clay slip left inside.

The hoverboard control electronics (motherboard and two sensor boards) and the second wheel are all located inside a second smaller plastic food storage box which doubles up as the footpedal for controlling the pottery wheel speed. The hoverboard battery can power the system for hours before recharging, or the 36 V supply can be provided by a 36 VDC switching mains transformer and the wheel can run indefinitely.

A quick summary video of the main components are here (copy and paste this link in your browser); https://youtu.be/-PV44UnJOzU

Electrics

1 used but working Hoverboard (24v, 36v better) - online auctions/marketplace £0 – 20.

2.8 mm multi-pin connectors (6 pin and 3 pin) Auto electrics shop or online auction.

Eight 2m lengths of 1.5mm multistrand (flexible) electrical copper wire, or alternatively three 2m lengths of 3-core mains cable (gives you 9 wires, 1 is redundant as only need 8)

 3mm heatshrink tubing or PVC insulation tape

Other

Square Storage box (350mm x 350mm) e.g IKEA Vessla storage box or similar £5

Various pieces of MDF, plywood (waterproof showerboard best if available), CLS timber, screws etc (£5)

Food Storage splashproof container (lunch box) to house the electrics (note this must be large enough to hold the width of the second hoverboard wheel, most likely the wheel shaft will need to stick through a hole cut in the lid in order to keep the size of the box to a minimum.

Silicone Bathroom Sealant Tools Drill, jigsaw, soldering iron, adjustable spanner, screwdrivers, wood saw, combination square, Hex Allen keys 

Open the hoverboard casing by removing all screws including any hiding under labels. Disconnect the yellow XT60 electrical connector from the battery and cut cable ties etc in order to safely remove the battery. Next remove all wiring harnesses, but first mark each plug and socket so you know how to reconnect them later, then remove the motherboard (largest circuit board), the two identical sensor circuit boards, charger socket, on/off switch. All LED leads and lights can be discarded. Finally, remove the 4 Allen head bolts that clamp each wheel motor shaft to the chassis and lift out wheel motors. After saving one of the four soft black rubber foot pad triggers (photo), dispose of the remaining hoverboard chassis and casings.

It is necessary to extend the wires on the main motor so it can be positioned up to a metre away from the speed control electronics when using the pottery wheel. This so that you can sit comfortably with the wheel between your forearms and the control electronics (motherboard) which act as a footpedal for speed control, located down by your foot.

1.      Extending the Motor Wires

The wheel has 2 sets of wires (photo). The first set comprises the three individual thick power wires (usually yellow, green and blue) each with a bullet connector. The second set of 5 thinner wires, red, black, yellow, green, blue (the Hall sensor wires) is usually terminated with a small single multi-pin connector plug. So in total there are 8 wires to extend, 5 for speed control and 3 for motor power.

You must extend each of the eight wires by about 2 metres so that the wheel and the footpedal can be positioned comfortably apart from each other when in use (i.e. ergonomic reasons). Depending on which wire type you are using (see Electrics) this will involve different preparation. If using mains cable you need to strip the outer plastic so that 3 cm of individual wires is exposed. The insulation on all wires should be stripped back 3mm and the core tinned with solder. Then after cutting off the original plugs from the wheel wires, solder on the 2m extension wires using heatshrink or PVC tape to insulate each wire. Then wrap the bundle of wires with pvc tape to provide water proofing. Now crimp or solder a 2.8mm auto electric multi pin connector pin to the end each wire. TIP: Because it is critical that each wheel wire connects to the matching wire on the motherboard it is vital that you mark each wire with a code to tell you whether it was a motor power wire (x3) or a motor Hall wire (x5), and designate the colour. So use paper labels to mark with PY, PG, PB for the three power wires (yellow/green/blue), and HR, HK, HY, HG, HB for the 5 Hall wires (red/black/yellow/green/Blue). A volt meter on continuity setting may help to confirm the start and end of each wire is as expected.

2.      Extrending the Motherboard Wires

We are using multipin connectors so that the wheel and footpedal can be easily disconnected for storage, and therefore must extend the 3 motor wires and 5 Hall wires on the motherboard in a similar way so that these can also be terminated with a 5-pin and 3-pin connector. Depending on the make and model of the hoverboard the motherboard wires may be long enough to reach outside the Storage box where the 5-pin and 3-pin connectors are simply soldered on. If too short then just extend each wire with an appropriate additional length before putting on the multipin connector.

WARNING !! the position of each wire within the male multipin connectors (from wheel) must match the position of the same colour wire within the female multipin connectors (from motherboard) so that the joined connectors keep the continuity of each coloured wire all the way from the wheel to the motherboard. I.e. the yellow Hall wire from the wheel (set of 5 wires) must track all the way through the extrension wires and connector plugs so it links to the yellow Hall wire on the motherboard (5 Hall wires). Take extra care NEVER TO CONFUSE a yellow Hall wire with a Yellow Power wire etc.

Other Wiring

In addition to the Power and Hall sensor wires and plugs, you can make good use of the on/off switch and charging plug by mounting them on the side wall of the food container (photo). Also mount the battery XT60 connector plug in the side wall using hot glue (photo).

First glue or screw a length of 50mm x 50mm wood across bottom of the food container (mid way along) to act as the footpedal pivot (photo). Rounding the bottom edges as shown is not essential. Full description is given in Step 5.

Although only one wheel is required for the actual pottery wheel motor, the second wheel MUST be attached to the motherboard in order for the firmware to function properly and not report an absent/broken wheel with error beeping. The simplest way to achieve this is by mounting the spare wheel in the bottom of the food container that we use as the footpedal, fixing it there with a few spots of hot glue, and attaching the original 5-wire Hall sensor plug (photo in Step 2) to the motherboard (same way as it was in the hoverboard). You must NOT connect the motherboard power wires to the spare wheel as it must NOT turn, and photo shows the Y/G/B power wires have actually been cut off as they are not used (photo), its better to tape up the cut ends rather than leave them bare as shown. You will also need to cut a hole in the food container lid to accommodate the spare wheel shaft which is too long to fit inside (photo). Bend the spare wheel wires back inside the hole and tape up the unused power wires (3 bullet connectors), tucking them out of the way.

Next, mount the motherboard in the food container in a convenient way with cable ties and resting one end on the rubber wheel (photo) and fixing with hot glue. Finally, mount the two sensor boards in the food container, lay them on top of the spare wheel and hot glue in place, so they will activate the wheel when the box is tilted back with your foot (photo, and diagram later). Do some initial tests before gluing in place to determine which end of the sensor board must face to the toe-end of the food container and achieve the clockwise or anticlockwise rotation you desire (we are only concerned about the sensor board that is connected to the side of the motherboard that provides the 3 power leads going to the wheel motor). For most potters, an anticlockwise* rotation of the wheel is preferred, so determine which end the sensor board achieves this when tipped downward and fit accordingly in the food container (see Foot Pedal Section below). Ideally you want the spare wheel to be located at the toe end of the container to counter the pressure you apply tipping the food container with your foot. If the main wheel goes clockwise when the box is tilted down at the heel end, rotate the sensor board 180 degrees (switch ends). Always ensure that the long length of the sensor board aligns with the long length of the food container. When wheel rotation and food container tilt direction are correct, hot glue sensor board in place on top of the spare wheel (keeping it horizontal to the box lid) with the two black U shape components (photo) facing upwards and then wedge/ glue a piece of the soft black rubber tab (see photo in Step 1, originally taken from the underside of the hoverboard foot pad), between the uprights of ONE of the four U-shaped components (Photo). These U-shaped components are the on/off switches, and the black tab activates on mode. we only need one of them to have the black rubber inserted in order to set the pottery wheel to ON soon as the on/off button is pressed (press button again to switch off). 

You should mount the on/off button and the charging plug in the side wall of the food container just above the wooden pivot and connect their leads to the motherboard plugs they were originally connected to (photo does not show the charging port as it had not been fitted at the time).

• some people prefer clockwise rotation (e.g. left handed people)

Motor Mount and attaching motor

.....a fuller explanation of this part of the build is given on my previous Instructable "Simple Electric Pottery Wheel"

1.      Cut Square Base

The motor mount (photo) consists of a 335mm square of 17mm chipboard (plywood better) with its corners removed to allow it to fit tightly into the plastic splashpan (IKEA Vessla storage box). If you use a different box measure the internal width at a point 60mm above its base and cut the square 20mm wider in order for it to fit tightly as you don't want any movement between the base and wall when you throw pots. The corners of the plywood/MDF base MUST be cut back about 50mm 2inch as the corner will not bend at all, unlike the side walls.

2.      Make Motor Mount

Join together two 240mm lengths of 90mm x 38mm CLS timber with 60mm wood screws and cut a perpendicular groove centrally in the 76mm side (photo) using a hand saw. The groove is 10 - 12mm wide and about 3 - 5 mm deep, use the combination square to ensure it is perpendicular. Screw this motor mount to the base from the underside (60mm wood screws) so that the groove aligns with a 20 - 30mm hole cut in the centre of the square base. This centralises the wheel and helps drainage.

3.      Add Feet

 Cut 4 short lengths of 38mm CLS timber and screw to the underside of the square base to act as feet (photo) keeping the base above the pool of water and clay slip that accumulates when throwing.

4.      Fix Motor to the Motor Mount

Finally, using four 60mm coach bolts or large wood screws, attach the motor to the bracket using the square metal plate that originally held the motor onto the hoverboard chassis placing the curved face of the motor shaft against the wood and the flat face against the metal bracket (photo).

5.      Prepare Wheelhead

Cut out a 280mm diameter circle of 18mm exterior grade plywood (waterproof showerboard better) and mark a 145mm diameter circle centrally, and then drill 5 or 6 holes approx equally spaced along this circle (photo). Before drilling check that 145mm is right for your wheel ( the fixing screw will hit rubber not metal). Carefully centralize the wheelhead on top of the motor using some Silicone Sealant to stick it down, and when set overnight attach permanently with wood screws along the 145mm diam circle into the rubber tyre. These dimensions work for a 6.5 inch hoverboard wheel. 

When you mounted the motherboard and sensor boards in the food container you actually created the pottery wheel footpedal. The only remaining steps are to add a pivot bar on the underside so the food container rocks like a see-saw with the toe end slightly heavier. Ideally a 50mm square timber is hot glued to the bottom of the food container somewhere around the balance point but always so the toe end is heavier than the heel end. (Photo).

Finally, you must create an adjustable leg on the toe end of the food container so that the exact horizontal resting position (motor stops running when sensor is horizontal) can be set precisely. Fix a “furniture levelling foot” (photo) into a length of wood or into a tube and attach this to the toe-end (heavy end) of the food container. Screw the furniture levelling foot in or out so that the tread adjustments allow you to find true horizontal at which point the motor stops.

To operate the footpedal you can either rest your whole food on the top of the food box (Diagram 1) and apply heel downward pressure to start the wheel (works OK but is unnatural) or you can place another box/object of similar height behind the food container to take the main weight of your foot and rest your toe on the back edge of the food container lid to apply downward tipping pressure (more natural, like a car accelerator pedal)(Diagram 2). Or if you want exceptionally precise slow speed control you can attach an extension rod (e.g. short length of wood) to the top of the food container and push your toe down on the end of that rod (Diagram3). Diagram 2 format is probably best.

Operating the Wheel.

It was not mentioned earlier, but the top of the wheelhead must be positioned about 20 mm below the top edge of the splashpan in order to stop slip spinning everywhere and creating a right ol mess! The timber dimensions stated earlier achieve the correct height with the Vessla Storage box, but you can adjust the height easily by changing the size of the 4 blocks of wood that act as feet. One of the advantages of this wheel is the small size and light weight that allows discrete storage at home, but this has the disadvantage that the wheel is not a 100kg lump that you sit on comfortably. So operation in a seated position is most easily achieved by placing the wheel on the ground and using a very low stool to sit (squat) on. Alternatively you can position the wheel on a table, chair, etc and use a suitable stool. Either way you must be able to brace your forearms on the top edge of the splashpan to steady your hands for centering of clay and achieve accurate lifting and turning techniques. Higher seating heights will probably give a more natural foot position to operate the food container foot pedal so may be better. An alternative operating position is to place the wheel on a low table and just stand in position but in this case your footpedal leg cannot take an equal share of your body weight. Experiment to see what's best for you.

If you do build a wheel please drop a comment on the Instructable, and if you get stuck go to comments at the end and i will respond. Happy Potting.