Gina

Having had the ASC outdoors a bit I have been having thoughts about the lens cover. So far I have been bringing the rig in when it rains then going outdoors to see if it's stopped and then putting the rig back out if it has. Replace the "moving the rig" with the opaque lens cover and the same problem remains - ie. when to open the cover. So I have another idea - replace the opaque cover with a transparent dome OK so no dark frame provision but the hot pixels don't change so taking one dark will be sufficient. This could be done by just covering the lens during testing at night. The dome would only need to be off when there are nuisances like moon or flood light causing reflections in the dome. There would be no worries of running the ASC overnight unattended with the dome on. This could give me the best of both worlds.

The NEMA 8 stepper motor has arrived and it's certainly very small, as expected. It would be nice for the lens cover but not sure it would be strong enough - I'll have to experiment and see how much torque I can get. At least for that it doesn't need microstepping so the full power is available. With 16x microstepping I reckon it would be inadequate for focussing. But there was only one available anyway. I have a NEMA 11 on order for that.

I think I pretty much have the design of this printer worked out and have ordered the parts from ooznest. I have found enough V-slot wheels and spacers etc. Front & back top frame rails Side rail - I already have one so only one more required Right angle NEMA 17 motor mount. 2 used, have one so one more required. 10mm diameter x 500mm long smooth rod for Z drive. 3 turns per 100mm so 15 turns for full Z range. Cord is 0.48mm wide so about 7.5mm to wind onto rod. 5mm ID, 16mm OD, 22mm long to try for XY drums. Also ordered a print melting tool for general use with 3D prints (not just this project).

Here's a photo of the XY frame (or it could be called "Z carriage") with the current Y carriages and pulleys, except that there is only one V-slot wheel to run on the corner uprights because that's all I have ATM - it will need three more. It will also need replacements for the XY frame members as these were previously members of the main frame. I was at first thinking I could get away with using just the Y rails rather than a full frame but I think this would be asking for trouble - a full frame is more rigid and the extra two aluminium extrusions don't add much to the weight compared with the three stepper motors, extruder, etc. And this will only be a fraction of the print bed weight.

On looking into all the measurements, I would seem I have two choices, either replace several frame members with longer ones or sacrifice a few mm of printing space. In fact to cover 395mm or even 390mm instead of 400mm in one direction hardly seems that important. I'm saying to myself "is the hassle (and possible cost) of increasing the frame size by replacing extrusion members, worth it to gain a few mm of extra printing space?" and I'm thinking - probably not.

Seems I'm virtually working on two printers at the same time

Still to do :- Make XY drums and fit. String up XY cords. Print spool holder. Print electronics box and bracket with cooling provision as appropriate. Wiring. Testing.

I think I'll just print the XY drums on my Titan printer so that I can test all operations even though there may be some inaccuracy.

Ah yes, I understand now, thank you The older type connectors for RAMPS will fit the Duet but the connections may be in the wrong order. I think I shall be using the Duet on the new Mini printer leaving my Titan working. I could try it on my Pilot printer which works but has gone out of calibration.

I'll see what the surface of the aluminium plate is like but if it's badly scratched or the filament doesn't stick very well I could use LokBuild Same supplier as the extrusion and wheels etc. so I'll wait before ordering to save on carriage. Actually, LokBuild looks very interesting and I'm considering trying it on my Titan printer or maybe the new Mini as that would be cheaper. If it works as well as they say it would be a minor miracle

I've ordered some smaller pulleys :- V625ZZ 16x5mm 5mm V Groove Sealed Guide Pulley Rail Ball Bearing 625VV These are designed for use with fishing line, which I'm using. The ones I have ATM are 25mm diameter and 8mm ID whereas the new ones are only 16mm OD and 5mm ID so both smaller and easier to mount. Should let me reduce the length of the Y carriages.

I can imagine!! Doesn't matter much about the old mast as I'm going to replace it anyway - just means I no longer have a wind vane and anemometer to look at until I get the new ones up.

Um... What do you mean by "duponts"?

The wind has finally destroyed my old weather station mast!

My Duet Wi-Fi has arrived Looks very nice

Another interesting thing I noticed in the videos is that he's using the same little V pulleys that I'm using in my Titan printer in addition to the same cord. I might change my Giant pulleys to those to make things easier than the bigger ones I'm using. I reckon if they're good enough for the hang printer, they're good enough for my Giant one

If I reduce the length of the Y carriages by 15mm I can achieve 400mm Y range and move the frame members shown in blue inwards to form a proper corner. This can be seen in the first diagram below. Further "fiddling about" and I think I might be able to use the original frame dimensions with just a 1mm gap (easily achieved) in the side members as shown in the second diagram.

I'm posting about my Giant printer in the appropriate blog :- "GinaRep Giant Mk 2" 3D Printer

Just been removing parts that are in the wrong places for the new Z axis arrangement. I hope to take some photos soon. Now looking into the XY plane components and arrangement of wheels that run on the corner upright rails. It would seem that to retain the full coverage of the print bed, the main frame will have to be extended by around 40mm in the X direction. First diagram shows the corner uprights in green moved out from the corners between the front, back and side members. A little more than 2x20mm would ensure clearance between Y rails and uprights as shown in more detail and with one of the running wheels, in the second diagram.

Ah, I have the benefit of living on my own and being able to do as I like (well mostly - can't shop when they're closed etc.). Spent the time 3D printing and building electronics Apart from a couple of visits to the neighbours but I enjoyed that.

I decided to make the frame from V-Slot aluminium extrusion from Ooznest and the other frame parts and V-Slot wheels from the same source. The frame is 1m high and has 1m x 20mm x 20mm extrusion for the corner uprights. Front and back are 570mm x 20mm x 20mm rails and the sides are 500mm x 20mm x 20mm. These are all joined together with aluminium corner plates giving a very rigid structure.

This is the bed heater 40x40CM 1200W220V Huge Cube 3D Printer Heatedbed Build Plate Silicone Heater Pad The aluminium plate has been much more difficult and it seems that 400mm square is only available to special order, cut to size, and expensive. I have found a source of 500mm square x 5mm thick which I think should work. The outer 50mm of the aluminium plate could be insulated to reduce cooling and help with getting an even temperature out to the edge of the heater pad. With the print bed fixed at the bottom of the printer, the weight is less important and there's plenty of power available to heat this much aluminium. I might be able to could cut this plate down to 400mm square using a aluminium cutting wheel on my bench mitre saw.

I've long since abandoned my plans for a Giant 3D printer that was a metre square and 600mm high but I still hanker for a bigger printer than my "GinaRep Titan" with around 300mm cube build volume. I guess my desire for a bigger 3D printer aligns with the "Dob Mob" desire for bigger and bigger telescopes Also, I'd quite like to make use of the experience of building my Titan printer. So how big is actually practical? Of course it depends on how much space is available and ATM for me it is not much! But I'm making progress on clearing up and will soon have my "workshop" room cleared. One totally MAD idea I had was to clear out the smallest bedroom and build a 3D printer into it. Accessibility would be a question of walking or crawling right inside the printer Size of prints would be limited by what would go through the doorway Apart from available space there is virtually no limit to the frame size depending on materials used. V-Slot aluminium extrusion is readily available up to 1.5m long. If you want transparent acrylic sides, 2ft square or up to 2ft x 4ft are readily obtainable and I think larger sizes can be obtained as secondary double glazing. In researching all this it's the print bed size that seems to be the most difficult, principally due to wanting it heated. 400mm square bed heater pads are available and borosilicate glass plate 400mm square used to be available but only 3mm thick which I think is too thin for 400mm square though it has been fine in my 300mm square Titan. I gather that aluminium is suitable for a print bed and then it's mainly a matter of getting a piece that's sufficiently flat. I have already ordered and received a 400mm square silicone heater pad with a self-adhesive side to attach to the bed plate. Its mains voltage and 1200W - that should heat up a decent lump of aluminium pretty quickly

Firstly, a change of plan - this printer will have the print bed fixed and move the extruder to provide the Z axis and include moving the whole XY frame. The Y rails will move up and down the corner uprights on V-slot wheels. More of this later, first the construction details.

Haven't ordered any acrylic sheet as yet so I'll just have to make them a bit bigger than I thought...