Two endstops found for the X and Y axes (the Z uses the Z probe which I also have) so I'm ready to print brackets for them.  The other main component required is the X carriage.  I think I shall just design a single extruder one for the time being - I can make a new one for a dual extruder arrangement later.

I've had a look at the X carriage off the Pilot printer (now dismantled) and I could probably put that straight on the Giant with a few minor mods.  The wires are just about long enough and certainly would be if I reduced the height capability a bit.  I won't be building any very large items on it until I buy a Volcano hot end for it.  There will be a considerable number of wired going from the Z carriage and XY frame up to the controller.

1. Extruder motor - 4 - XC
2. Hotend heater - 2 - XC
3. Fan - 2 - XC
4. Thermistor - 2 - XC
5. A motor - 4 - F
6. B motor - 4 - F
7. X endstop - 3 - YC
8. Y endstop - 3 - F
9. Z probe - 3 - XC

Total :- 27.  Those they will be in two or three groups - X carriage, Y carriage, Frame - 13, 3, 11.  The Y carriage (X endstop) and frame could be combined giving a bundle of 13 from the X carriage (Extruder) and 14 from the frame.  Maybe some flat multi-way cable but thicker than what I've got ATM which is too small to carry 2.4A with low enough volt drop.

Ordered some heavy duty ribbon cable for the motors - the other wires (except perhaps the hotend heater) can be handled by the light duty ribbon cable I already have.

Ribbon Cable - 4A - 3D Printer Stepper Motors - Heavy Duty 4Amp Wire - 20AWG

The items have arrived from ooznest including the 700mm long rails for the main frame which I've started installing.  Shouldn't be long before I get the frame re-built and the Z drive installed.  Then I have two rails to cut to make up the new size Z carriage (aka XY frame).  Taking things relatively steadily today after an exhausting day yesterday

Done the main frame complete with Z drive axle, bearing blocks, motor, gears and pulley blocks.  Only thing is that I seem to have run out of pulleys...

Well, I shouldn't be - 12 bought and 11 needed by my counting up! 

Later :- Found one

Since I added 130mm to X but only 30mm to Y when increasing the main frame size,  I am changing the Z carriage (XY frame) arrangement to maximise the Y axis - adding 40mm to Y and taking 40mm off X resulting in increasing X by 90mm and Y by 70mm over the previous design.  I don't expect to print on the whole 500x500mm bed as the edge is bound to be a bit cooler than the area with the heater but the border can be used for probing and allowing for two nozzles.  Here are two diagrams showing the old and new arrangement of the frame corners and wheels.

I have cut the spare extrusion pieces I have to the right length for the Z carriage and assembled the latter.  I still have the piece for the Y carriage to cut to length.

Having assembled the Z carriage and tested it, it seems insufficiently rigid for three cords to be sufficient to keep it level with the moving weight of the X carriage assembly.  I shall therefore change to a four cord system like I have with the Mini printer.  This just means printing another pulley block and finding the 12th pulley.

Printing new Y carriages and 4th pulley block for Z drive.  Should be ready the attach the cords shortly.

Y carriages printed and attached to the X rail and the wheels fit the Y rails perfectly   Can't thread up until I add the X carriage.  I think I'll test the operation with the X carriage from my "Pilot" printer first - I can attach the cords to it fairly easily but will probably design and print a new X carriage later.

Handling printer parts this size is not easy, for instance the Z carriage is 700mm x 610mm (27.5" x 24" or  2ft 3½in x 2ft).

The Z carriage when populated by the drive motors, Y carriage and X carriage with extruder, motor and hotend etc. also weighs quite a lot!  I now have it strung from the cross-bar axle on the top of the printer.  I takes a lot of power to hoist it up.  I think I shall need a higher gear ratio than the 4:1 I have ATM.  I took quite a lot of finger power to wind the Z carriage (XY frame) up from the bottom to the top.  I can easily design and print new gear to give a higher ratio.  Of course, it is very much lighter the the print bed.  ATM the weight will just about drive the motor with no drive current - with a higher gear ratio that won't happen and it will stay put even without power.

Here's a photo of the top part of the printer with Z drive and Z carriage.

Looking at calibration values for the Duet WiFi now :- XY motor drums are 20mm diameter and motors are 200steps/revolution.  Circumference = 20xPi so steps/mm = 200/(20xPi).  Or in micro-steps is 200x16/(20xPi) = 160/Pi = 50.93.  For the Z drive shaft diameter is 10mm so µsteps/mm = 101.86xR, where R is the gear ratio.

4A ribbon cable has arrived

Printed a 60t 120mm diameter Z drive gear in ABS and now printing an 8t motor pinion in TPU giving a gear ratio of 7.5:1 so Z µsteps/mm = 101.86x7.5 = 763.95.

Duet WiFi control board set up ready for wiring up.

Modified the X carriage from my "Pilot" printer with a Volcano hot end, all metal heat break, 1.2mm Volcano nozzle and newer version heatsink.  Cartridge heater, thermistor and fan have been retained to save re-wiring.  This is a 12v 40W heater and a 12v fan.  Later I shall probably upgrade to 24v 60W heater plus larger 24v fan and 3D printed air duct.

Decided to go for 24v straightaway so will be putting the 24v 60W cartridge in the heat block and have a new 24v radial fan and 3D printed air-duct/bracket to clip onto the filament cooler to provide the better cooling needed with the higher power heater.

Have started the wiring up.

I shall want to add a part cooling fan and air duct for printing PLA since this would considerably reduce heating costs for objects where PLA would be adequate.

I'm looking at what Thingiverse has to offer and if I don't find anything I shall design my own.

Later...  Think I've found one that will do the job   I think it will need a new X carriage though - I shall print one based on the design for my Mini printer.

Yes, seems fine. 

Been looking into a number of options for this printer.  I might try Bowden feed again, it wasn't successful with my home made extruder but may be better with the E3D Titan Extruder.  I'm considering putting the extruder on the middle of the back of the Z carriage (XY frame) which not only makes for much less weight to move in the XY plane but also better balances the weight distribution on the Z carriage.

Here are a couple of photos showing roughly the arrangement of hotend, cooler with fan and part cooler fan and air duct.  You have to imagine the X carriage frame

Been playing around with the bits and it is possible to arrange all the parts with direct drive and having the extruder mounted on the X carriage though I still think there are advantages to Bowden feed.  I have ordered a couple of 1.75mm Bowden adapters for the E3d Titan Extruder (I shall want two when I do a dual hotend arrangement).

With the extruder motor weighing in at 300g I can save a lot of weight on the X carriage by going for Bowden feed.  I think I nay go for 3mm filament as I have considerable stocks of this size mostly in ABS but also PLA and other types and this size makes for a simpler hotend cooling block if I go for water cooling.  I'm also thinking of making my own hotend heater block with higher power and filament melting capability to reduce printing times, which are very significant for this size of printer - I'm thinking of maybe 2 x 60W heaters giving a massive 120W which would almost certainly need water cooling.  I'm also thinking of a much bigger nozzle size than the maximum or 1.2mm of the Volcano hot end, maybe 2mm.