Gina

Here is a diagram of the heatsink and water blocks.

This diagram shows the Z carriage and how it runs on the corner uprights of the frame. Only the slots used for the Z carriage wheels are shown in the corner uprights.

Postman :- extra long drill bits and 5mm grub screws for 3D printer construction. Courier :- 3 books about painting portraits in watercolour plus 4 A3 size frames for my paintings from Amazon

Thank you both. Well found 5A is just enough for a pair of 24v 60W heaters I was hoping to use on my Giant printer with custom made 30mm long heatblock and 25mm long 2mm nozzle

Wire frame diagram below shows location of rails required for the MK2. Rails required = 19. Mainly but not exclusively 20x20x500mm. Rails on current printer = 3. Spare 20x20x500mm rails in stock = 6. Also have 20x40x500mm and 20x20x550mm rails. Overall, nearly half the number required I have already and may be able to use the other two. But before ordering new rails I need to work out exactly how everything will fit together - some rails may be a little shorter and want cutting to exact length.

Does anyone have the current rating for the Duet hotend heaters? I mean how much current can the Duet control with its power MOSFETs. I know the bed heater rating but I can't find the spec for the hotend heaters. The Duet forum are not accepting new members at present.

Here is the new power wiring diagram for the Mk2. The ATX PSU is used to control main power and uses the +5v Stand-By to power the Duet WiFi control board in standby mode. The Duet switches the main power via the PS-ON control line of the ATX PSU. The standard +5v line from the ATX PSU operates a Solid State Relay to switch on the main 24v PSU for the Duet board and thereby all the stepper motors and the hotend heater and various fans. A second (higher current) SSR is used to switch the mains to the 240v bed heater and is controlled by the bed heater output from the Duet. Advantage is taken of the ATX PSU having a 12v output to power the fume extraction fan which is 12v. It may seem odd to use a relatively high power PSU for the 5v standby supply but I have lots of these ATX supplies recovered from old PCs and it has a built in control of the main power lines. The main +5v line provides control voltage for the SSRs.

Latest upgrade was to change from 12v to 24v operation with the Duet WiFi control board. This has produced a remarkable improvement - greatly reduced noise and much increased Z speed. There is still some noise from the pulleys and vibration of the print bed so a major rebuild is planned. In view of this I think I shall call the new build "GinaRep Titan Mk2". This will not only have a completely new frame instead of the acrylic and wood box construction (together with new Z drive and CoreXY) but also a new X carriage with interchangeable hotends. Some parts of the original Titan will be re-used - the X and Y rails which are the right length for the new version and the acrylic sheets will provide a fume cabinet. I shall probably need to re-design and print new side and top parts to hold the acrylic sheets. The Y carriages can probably be reused but it would be no problem to design new ones if necessary. I shall use all the motors and the "E3D Titan Extruder" (the name is pure coincidence - I named my printer before E3D sold their extruder). The rebuild will also be an appropriate time to change the print bed heater to the mains version with over twice the power. The 24V 300W bed heater takes 4-5 minutes to heat the bed to ABS/ASA/PETG temperature and the new heater should reduce this to below 2m. The 24v 60W hotend heater takes only around a minute to heat the hotend so the bed heating is looking dreadfully slow.

I've decided to go for interchangeable hotends rather than a double nozzle jobbie. This will provide for upgrades/experiments without a major rebuild of the X carriage every time.

What size air duct I need will depend on whether I go for a single or double hotend. Haven't quite decided yet. I guess a single would be easier to start with. Also, not sure whether to go for a dual hotend or interchangeable hotends.

Yes, I gave up on debayering ages ago.

The increased size might be enough (120%) but I'm now printing an even bigger one at 140%. The 120% one will go on my Titan printer.

Now seeing what wants to go on the X carriage. A lot less since getting rid of extruders and replacing with Bowden feed. Heater block will be bigger to accommodate two 24v 120W cartridge heaters. Then there's the Z probe and the part cooler fan and duct. I'm now about to print an increased size part cooler air duct.

I can balance the Z carriage by moving one of the XY drive motors. Two diagrams - first showing standard CoreXY layout with drive motors at the front and second showing one motor moved to the back to balance the carriage.

Absolutely Dave I would like to remove the XY motors from the carriage but I think that would be too complicated - that's if it's possible.

Another idea (maybe more usual) would be to have the extruders at the top of the printer near the middle. That would remove the weight of extruder motors from the Z carriage and also make the Bowden run straighter. Maybe I could rearrange the XY motors and cord runs to balance the carriage better. The water cooling pump and reservoir will also probably go on the top so with all that going at the top I think I shall make use of a piece of plywood.

Been working on the design again. I'm going to use twin Bowden feeds to hotend with nozzles for 3mm and 1.75mm filament. These will be fed from two E3D Titan extruders mounted on the XY frame (Z carriage). To equalise tensions in the support cords the extruders with their stepper motors will go on the opposite side from the XY motors. Now since I shall want to get to the extruders easily they will need to be at the front - so the XY motors will have to go at the back. I can't see this being a problem. I can simply attach the frame the other way round with the cords crossed over across the front (unless I can arrange both the drive motors and pulleys at the back).

Have drill stand but my mains electric drill is in hiding and can't find it Bench drill press is out in the shed protected by loads of snow!

Aluminium billet for heatsink - to be cut down to 40mm to match water block (or maybe a bit longer to take screws for a clamp for the water block) plus 3mm and 1.75mm Bowden feeds.

Here is a photo of the water block and 12v pump. Cooler part of hotend will be clamped to the water block with thermal grease between. The tubing is silicone rubber and very flexible. The water block is 40mm x 40mm x 12mm and although made of copper only weighs a little over 100g - much less than a direct feed extruder with motor.

Interesting

That wire retaining chain looks ingenious

This printer has a number of minor faults though seems to print well enough. The print bed is not really well supported - it still wobbles a bit. It could do with having the same arrangement as my Mini printer with a rectangular framework with wheels running on the four uprights. It also could do with the pulleys replacing with better ones as I think they are the main cause of the noise. I may consider rebuilding it after I've finished the Giant printer. I have a number of pieces of 500mm long V-Slot extrusion which I can use. I might also change to CoreXY for simpler construction.

Had to reduce speeds a bit to 30mm/s and 100mm/s. Also, increased temperatures. Seems to be printing alright now after 8 attempts

Increased the bed temperature and it's sticking fine now. First layer speed of 40mm/s subsequent layers at 120mm/s. It is NOT quiet!! But it's working