Gina

M6 tapped hole completed successfully Took it slowly, a couple of turns cutting at a time so lots of goes at it. Swarf cleaned off and re-lubricated each time. Hole drilled with 3mm then 4mm then 5mm Bosch titanium drill bits, lubricated. Tap only lightly tightened in drill chuck to limit torque. All operations using drill stand with mains drill with limit set to a low speed. Those spiral fluted taps are really sharp! Went through the aluminium like a knife through butter What a difference using the right, high quality tools makes

The power tapping taps and drills have arrived this morning so I shall be having another go at tapping the M6 hole through the aluminium heatsink block. They look very good, as usual from Axminster Tools & Machinery. Everything I've bought from them has been first class.

Now I know the amount of XY movement, I can calculate the amount of wrap wanted on each of the CoreXY drums. Starting off with 20mm diameter drums and a print area of 460mm square, the maximum movement of either A or B cord is twice 460mm = 920mm (eg. from X=0, Y=0 to X=460, Y =460mm, for the X+Y drum). The circumference of a 20mm drum is 20 x Pi = 62.83mm which gives 920/62.83 revolutions = 14.64. Cord is 0.4mm in diameter so 14.64 turns would occupy 14.64x0.4 = 5.9mm. That's fine. NOTE - Above edited due to silly mistake.

Designed and printed new Y carriages with three wheels - two on top and one underneath. Plus the LHS Y carriage has been designed to take the X endstop.

Having looked into how to arrange a moving bed I've found it's not as simple as I thought and would involve quite a lot of extra work so I've decided to stick with a moving XY frame and leave the bed stationary on the floor.

Having a moving XY carriage is so awkward that I decided to compare the weight of this and the print bed. Frame complete with X carriage and rail = 2.9Kg. Print bed aluminium panel with heater = 4Kg so over a Kg heavier. However, breaking strain of cord = 80lb = 36.3Kg so four of them could carry 145Kg. So a 4Kg print bed plus a bit extra for the wheels and brackets is hardly heavy in comparison. Even adding a couple of Kg for a huge print it would still not be significant. Another point - the most accuracy wanted in Z is when the printing level is low. Using a moving print bed the amount of cord carrying the weight is at a minimum at the beginning of a print - cord is unwound off the horizontal bar to lower the bed. OTOH with the XY frame moving the cord is fully unwound when the printing starts. OK the bed levelling corrects for height errors but why make things more difficult than needed? A moving print bed would mean that all motors are on the fixed frame.

X carriage mounted on X rail. The limit on printing size due to range in X and Y directions plus probe offset seems to be 460mm x 460mm on the 500mm square aluminium bed. With the heater pad being 400mm square, this seems adequate. Printing area of 18" square in Imperial measure.

Moved the air duct.

More photos.

That was very instructive The air duct for part cooling needs to be 12mm lower and 8mm further forward than I first though. I find that however well you try to model things in CAD, there's nothing like real 3D parts

I watched the launch and was relieved that all went well.

The heater block is being produced by another member for me so as an interim I shall print this plus the heatsink (which I haven't made yet) as a model in plastic to check how everything fits round it.

Screenshot of model for first test print of X carriage.

Designing the X Carriage around the hotend. A bar across the front screwed onto the X carriage main part will hold the hotend system in place and the heatsink against the water block. The round part to the left of the hotend will be glued to the air duct for part cooling.

Been trying to make the heatsink block only to break an M6 tap I'll try it another day...

With medical problems resolved and now feeling much better I'm looking into what I might do towards widefield astro imaging for the next dark-side main season (not much of this one left) and the micro dome housing this little fork mount is what I'm thinking of. Putting a light-weight widefield imaging rig on the mighty EQ8 mount looks daft, even if I had the EQ8 working which I haven't at present. So it's the secondary pier (SW Pillar Mount) plus DIY fork mount and micro dome. Dome and mount will use stepper motors and the electronics replaced when upgrading 3D printers.

All these people buying eyepieces... I wonder if they know something I don't - I mean are they special see-through-the-clouds-and-rain devices or something???

The parts for the frame and Z carriage have arrived so now it's a matter of connecting it all together. The corner joining pieces came a few days ago.

Postman :- Some pieces of brass to make things. Courier :- All sorts of professional artists materials for my watercolour painting

Well done As I recall I was successful with a 450D but later models were "better protected and vandal-proof" Then there was the problem that these sensors didn't respond well to cooling with no improvement in noise below -5C and only a little below zero.

I tried debayering - I gave up after spending something like a grand on non-working cameras from ebay and finishing them off completely!! And I don't give up easily as many on here will know.

To be the same size :- Corner uprights will be 600mm. 4 off. Bottom and top horizontal rails will be 500mm. 8 off 6 available. The Z carriage will consist of 2 500mm rails with threaded holes and 2 460mm rails. Y rails are 500mm. From original. X rail is a little shorter than 500mm. From original. For the order :- Corner uprights will be 600mm. 4 required. Bottom and top horizontal rails will be 500mm. 8 of 6 available. 2 required. The Z carriage will consist of 2 500mm rails with threaded holes and 2 460mm rails. All required.

That is the problem!!

A clip will hold the heatsink against the water block with thermal grease between to aid conduction. The clip will attach to the X carriage. To change hotends only the clip will need undoing. Then the heatsink, heatbreak, heat block and nozzle assembly is simply swapped for the alternative assembly.

Now with heatblock and nozzle added. Bowden coupler, heater cartridges and clamping screws plus water cooling tubing omitted for simplicity.