Gina

Removed the glass plate and set up the "mesh grid" to give suitable points for the "mesh grid compensation" which is the very fine control for bed levelling.  Marked the probe points on the aluminium sheet, put the glass plate back and stuck pieces of copper foil at the probe points.  "Mesh grid compensation" is now working with the glass plate.  The aluminium sheet is not perfectly flat and needs the glass plate clamped down to hold the aluminium sheet between glass plate and the bed frame.  I shall 3D print the clamps.

Still to do :-

1. Filament feed tube from filament reel in the bottom to extruder.
2. Support for the umbilical to hold it up clear of the workings.
3. Front panel to complete the box and stiffen the top - cut from a length of solid timber.

Thank you ?  I guess it isn't too bad considering...

Y endstop wired up and ribbon cable stuck to box.  X, Y and Z homing all now working fine.

I've considered using "Stall detection and sensorless homing" in the stepper motor instead of using endstops but it seems complicated and also not very reliable so I think I'll stick with microswitches.

With hotend thermistor working, hotend heated up and when hot, extruder motor ran.  X homing works.  Y endstop needs connecting...

Attached connectors the the umbilical wires and connected to the Duet board.  Applied power but no WiFi connection so something wrong.  Unplugged connectors and tried again - WiFi OK.  Added hotend thermistor - WiFi still OK but thermistor wiring is faulty - intermittent connection.  I'll now work through the connections in turn.

1. All motors connected - OK
2. X endstop - problem
3. Z probe - OK

X endstop problem solved - connections wrong.  Think the hotend thermistor was connection onto board which I think is fixed by removing and replacing connector (maybe dirt on pin or socket).  Can now run more tests.

Connected thermistor in bed heater and now have bed heating working.  Aluminium plate heats up rapidly but the 4mm glass plate will take longer as was to be expected. One more small step...

Applied mains power with kettle lead and been testing.  Duet board receiving power and Z drive working fine - other things need wires connecting up.  Bed travel at 100mm in 20s - adequate.

Top view.

Rear umbilical clamps.  Now, apart from connecting everything up, I need to sort out a way of holding the umbilical up so that it doesn't catch on the print or get jammed under the nozzle.

Sorted out holding the umbilical onto the X carriage and now printing clamps to hold it onto the back of the box to connect to the control board.

Attached the silicone heater pad to the aluminium sheet for my heated bed, removed the plastic coating and added the glass plate on top.  All the bed needs now is clamps to hold all the parts together and keep the aluminium flat.  The heater wires are already connected to mains neutral and the SSR - just needs the thermistor plugged into the Duet board.

Mains wiring finished and covered up.

Wiring on back of mains connector.

Slight adjustments needed to the design of the mains wiring cover.

Mains wiring cover design - CAD screenshots.

That is just what I thought - thank you. ?

Anyone know any reason I shouldn't use solder connections to these rather than the illustrated crimp connectors?

Inside.  OK so it's a very rough hole but it will be covered up by a 3D printed shield that will cover all mains connections.

Mains input socket and switch fitted into box.

Mains input connector arrived today so I've designed a plate to mount it on the box.  Also made a hole in the side of the box to take it.

Decided to put the X endstop on the X carriage where the wires can simply go in the umbilical.  So to provide somewhere to attach this plus the umbilical I have redesigned the X carriage front plate.  Now printing it in red PETG.

THIS combined socket, fuseholder and switch looks a good option.  Probably use an 8A fuse.

SSR for bed heater added.

Seems logical to put the PSU beside the Duet control board to keep high current connections as short as possible.  Then there's the question of the mains input and ON/OFF switch.  In some ways I would like the switch near the front but I had it near the back on the Titan on a printed plate together with a "kettle socket" beside it.  I feel inclined to do the same with this printer (except that it would be near the top on this one whereas it was at the bottom on the Titan).  This would keep mains wiring short as well and I could use any "Kettle lead" for the mains input.  All mains connections could be shielded from errant fingers with one cover with this arrangement.