Scratch build large format - extruder cooling question, and Bowden

I've been designing and building a cubic 400x400x500 printer for weeks - mainly reinventing the wheel because I thought I could do it better, then repeatedly discovering that I couldn't.

It's running on a RAMPS1.4 with Arduino Mega, Marlin 2.0, and Octoprint. X- and Y-axes are on the top face, and the print bed is on the Z axis (cantilevered, with one lead screw) - vaguely like an Ultimaker 3.

Anyway, the mechanics are all working now, but before I finish it up and go for a first print I have a couple of questions for the experienced people here:

1) I'm using an E3D v6 clone. The fan it's supplied with is terrible, and I've got space to put up two 50mm fans in to cool the fins, plus a 40mm ducted fan to cool the print - is there any such thing as too much cooling on the heat break in an E3D?

2) Thinking about the length vs bend radius trade-off of a Bowden tube - in my printer, the print head only moves in X-Y so I don't have to worry about enough bowden tube to do the full height to the furthest X-Y. I was initially thinking to mount the extruder on one side of the printer (X=0) and halfway along the Y-axis (Y=200) - but when printing at that point I think the bend radius will be very tight - is it better to mount the extruder higher up on the printer at, say 30 degree angle, and accept a longer bowden tube, to get a larger bend radius?

3) Regarding the firmware - as stock, I think Marlin assumes that the build plate is the Y-Axis, X is X, and Z is the height of the print head. For mine, X is X, Y is Y, and height of the print head from the printed piece is the Z axis moving down. Do I need to do anything special in the firmware configuration, or will it 'just work'?

Thanks for any advice!

The 30mm fan that comes on an E3D v6 is plenty enough to cool the hot-end. I wouldn't use a 50 mm fan and certainly not two of them. Why move around all that extra weight/bulk on the extruder carriage?
Sunon makes quality 30 mm fans with mag-lev bearings that run quietly and almost forever. They cost a few $ but you'll never have to take apart the hot-end to unclog it because the fan died.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

The 30mm fan that comes on an E3D v6 is plenty enough to cool the hot-end.

Edited 2 time(s). Last edit at 08/12/2021 03:01PM by VDX.