SmartJointer - parts and assembly instructions

Note: SmartMini boards are available from Wordcraft International.

SmartJointer provides an excellent example of QUS SmartMini boards in action.

SmartJointer-related pages:


There are two versions of SmartJointer:

Both versions shares common components.

Manual version


9mm birch ply (good quality):

  • 1 off: 400mm x 137mm - back.
  • 1 off: 400mm x 137mm - base.
  • 1 off: 205mm x 137mm - work holder back.
  • 1 off: 52mm x 137mm - work holder side.
  • 4 off: 100mm x 33mm - supports for cylindrical rails.
  • 1 off: 35mm x 35mm - secures timing belt to back of work holder.


Tools and glue

Please see our article about a toolkit for Arduino and SmartMini development.

Electro-mechanical parts

Click on an item for a link to a source.

Assembly instructions


Speeded up video showing timber assembly.


Plywood parts cut, drilled and countersunk. Rail supports glued together. Work holder side glued to work holder back.


Laying out ready to start assembly.


Placing the rails and supports into position.


Supports held in place with clamps.


Flipped over ready to drill pilot holes for 3.5mm screws.


The stepper motor is attached to a back plate to make it easy to adjust belt tension. A drawing of the plate is included with the plans and the acrylic version, shown here, is available from QUS. The same plate is used on the pusher part of the automatic version of SmartJointer.

The pin for the free-running pulley can be 5mm dowel or, in this case, a cut-off 5mm bolt.

The micro switch is mounted on riser, shown here in acrylic, to ensure that the switch makes contact with one of the liner bearings when the work holder is in the home position.

The cable wrap is used to cover the cables from the stepper motor and micro switch leading to SmartMini-SA or SmartMini-MA.

The photos below show the drive belt which is 750mm long and has two holes punched in each end for screwing to its fitting block. For clean holes it is best to use a hole punch.

We will post more as soon as possible.


SmartMini-PS linked to SmartMini-SA via the EPort ready to drive the manual version of SmartJointer.


QUS supplies PCBs which you assemble yourself. QUS cannot accept responsibility for any damage done as a result of mis-assembly. Over the years we have blown up enough stuff to know that things sometimes go wrong - so. take care!

You will have spent time and care soldering up your SmartMini so board it makes sense not to blow it up at the first opportunity.

You will blow up your Pro Mini, and your stepper motor drivers, if:

  • You wire things up with the power supply connected - make sure the battery or mains adapter is disconnected.
  • You insert the EPort bridge the wrong way round - the "1" is in the top left corner - check, check and check again.
  • You insert the EPort bridge with the pins offset - check, check and check again.
  • You use an external power supply for the motors and it reaches the 5V digital supply - check the jumper settings - then check again.
  • For other ways to blow up an Arduino try a Google search for "how to destroy an Arduino".

The rule is simple: wire everything up, and double check everything, before connecting the source of power.

Symptoms of a dead Pro Mini:

  • It is rare for things to explode or burn - but it can happen with excessive voltages.
  • It may seem to program OK - but that proves nothing.
  • It may have corrupt flash memory - this may show up if you use verify after programming.
  • The contents of EEPROM are corrupted or cannot be programmed or read back reliably.

We will post more as soon as possible.