Gina

Captured on 21 Nov 2021 with my triple imaging rig, 200mm f4 Asahi Pentax Super Takumar lenses. Astrodon 3nm filters, 83 x 120s Ha subs, 97 x120 OIII and 8 x 900s + 1 x 1200s SII. Captured with KStars/Ekos/INDI and RPi image capture. Cameras ASI 294MM Pro, 2 x ASI 1600MM-Cool. Processed in PixInsight.

Piezo body altered to allow screwing to the X carriage including a third screw. Heatsink and Volcano hotend added. Attached to front plate of X carriage. Several changes of X carriage have occurred in getting to this design. Parts cooler airduct added. Angle view of CAD assembly.

Standard direct feed piezo sensor. The " groovemount" at the top fits in the extruder. This is the sensor board :- The probe consists of the two body halves bolted together to hold the top of the heatsink (called "groovemount") then the sensor and finally the top which clamps the sensor onto the body.

The hotend for Bowden coupling has a longer top part as compared with direct feed. This has meant the "groovemount" top won't fit the PrecisionPiezo body. Won't fit!! Answer to this was to design and print my own piezo body. This has the two webs (top and bottom) that hold the moving part. The latter has been made higher to take the taller "groovemount" and the fixed outer casing to match.

Taking a cue from my Creality Ender printers I have reconsidered Bowden feed for the filament. The only disadvantage I can see with Bowden feed is with soft/flexible filament. I've used this in the past but see no need for it in my Giant printer. Indeed I expect to keep to PLA. Also, I shall be using 2.85mm filament as I have a significant stock of that size. Mainly PLA but also a lesser amount of PETG and some ABS though whether I actually use the ABS is doubtful. Using Bowden feed reduces the mass of the X carriage considerably and also reduces the cables. Additionally, it moves the extruder to a more convenient location. As a result I ordered an E3D Volcano hotend with Bowden coupling as I didn't have a Bowden type nor one for 2.85mm filament. Otherwise I have my own hotend build designed for large nozzles and super-fast printing. My current needs for the Giant printer don't go this far and suit a smaller nozzle.

Z probing both for normal operation and automatic bed level compensation will make use of a piezoelectric probe attached to the nozzle. This works be allowing the nozzle to move minutely with respect to the X carriage. The bed is moved slowly up to the nozzle and a signal generated when bed and nozzle touch. I'm talking about a minute fraction of a millimetre. See this link :- https://www.precisionpiezo.co.uk/

With the Giant printer being done, I do rather wonder about a roundabout type automaton on the top that comes out and goes round on the hour!! Stopppitt Gina ... you're getting carried away!!! 🤣 🤣 🤣

Thinks... a horseshoe instead of a gong - well, I wonder 🤣

I have a design for the clock for striking the hours (1 to 12) which I plan to incorporate. Chiming the quarters is a tad more difficult!! Though designing cams in CAD isn't too bad! And printing. Much easier than filing them out of brass.

With the weather so bad for anything astro I'm considering getting back to this.

With the very long timing belt needed to connect the 3 Z rods and stepper motor plus the problem of where it would run, I've decided to go for 3 separate motors.

The design needs modifying to include a path for cables via the rotation axes viz. turret, DEC and RA. This shows a new design of the horseshoe to provide a gap between that and the DEC arc where cables might pass. Now if the smaller hole in the horseshoe is changed to a larger one with a slimline ball bearing the cables have a possible path. The "axle" can be printed as part of the DEC arc.

The design so far has one serious deficiency! Communications and power cables. Even if I could arrange all the electronics on the turret and use WiFi there is still the need for power. So arrangements have to be made for cables to connect from the outside world to the turret.

This is a home built 3D printer designed for printing very large objects. Things like a micro sized observatory, garden ornaments, chandelier with steam-punk theme. The outside measurements of the "box" are 740mm x 660mm x 1m high. I was using ABS when I first designed it so the box consists of an extruded aluminium frame with clear acrylic panels for use as a fume cabinet. Now I use only PLA and fume control is no longer an issue. The bed is a 500mm x 500mm x 5mm aluminium plate with a mains powered 1200W heater pad stuck to the underside. I expect printing volume to be 290mm x 290mm x 700mm high. I'm planning to have the bed moving up and down for the Z axis. In one of my earlier versions I had a moving XY carriage and fixed bed but that proved impractical. The Z drive will consist of three trapezoidal threaded rods with 1mm pitch driven in unison by one stepper motor, 3 timing pulleys and timing belt. Adjusters will be provided on the nuts for rough bed levelling and fine bed levelling will be automatic using the software in the Duet 2 WiFi control electronics.