Steampunk Horse and Cart

Steampunk Horse and Cart is a skin made to fit the Basic Walker and turn it into a walking iron horse combined with a cart with wheels turning on print-in-place bearings.

Video: 

The Steampunk Horse and Cart brings home the harvest.

Requirements.

In addition to the printed parts you will require:

•    A working Basic Walker model including batteries.   Remove the power switch, you will replace it with Iron Horse's own switch.
• A 13mm x 8mm x 33 mm single pole toggle switch.
     This is a common size of panel switch and is available from many sources.

You will also need basic soldering equipment or some alternative hookup method.

Print and check the parts.

All parts are designed to print in PLA.

All prototypes illustrated were printed on a Prusa i3 Mk3 with a 0.4mm nozzle.

Print everything at 0.2mm layer height. You will need some elephants foot compensation, 0.2mm should be enough. Supports are not needed, a pair of small supports are already designed into the model.

Post Print Part Preparation:

If your extrusion is correct there may be a few tiny, almost invisible tags of filament on the upper surface in some places where the nozzle finally lifted away, you will feel them as slight prickles; a few seconds with some fine abrasive paper will remove them.

This project includes 3D printed screws. DO NOT FORCE them. They are strong enough for this project but not as strong as metal screws. If one is reluctant to turn coax it, turn it backwards and forwards, going a little further each time ... there is probably a small blob or string in the thread which will quickly wear away.

Remove the two narrow supports from under the cab. Smooth any rough remnants.

Connect a wire to the on/off switch. Secure the switch in the socket provided, it will be a tight fit.  Connect the other end to the Basic Walker power circuit.

Fitting:

Remove the screws from the battery box of the Basic Walker.  Align the Iron horse body with the battery box and screw both together to the top of the Basic Walker.

Use the seven sided skin fitting screws to secure the tow hook to the rear of the Iron Horse.

Switch on and watch the Iron Horse go...

OK?  Now assemble the Cart.

All the wheel bearings will have printed seized, DO NOT FORCE THEM to turn, they are designed to be freed one roller at a time.
These are similar to the bearings you have already freed when assembling the Basic Walker.

Take either a stout needle, a fine screwdriver or an allen key and push it all the way through the hole in each roller in turn, wiggle it gently to and fro to break the seizure and then move it sideways by a few millimetres. It may be necessary to go round twice. Once this is done the bearing should turn but it will be rough. Exercise it for a few minutes until it spins freely.

Screw each wheel onto the cart, drop the linkage over the two two hooks and all is ready.

Troubleshooting:

Apart from broken parts, print replacements; the commonest problem is:

Iron Horse walks backwards
   The motor is connected the wrong way around, reverse the connection and Iron Horse will walk forwards.
   Why?  Because DC motors work either way depending on which way around they are connected.