Looking for large 3D printer

[curious aardvark]

Here's the thing in situ:

filament holder (Small).jpg

works well - currently printing a 185mm back plate.

I have noticed a small potential issue.
If you had a really full spool, like the BQ filament I like - which is wound right to the edge of the spool. On a long travel back towards the spool there is a risk that the filament can come off the reel and get caught around the shaft that holds the spool.
This is something the replicator clones are notorious for. And one of the main issues I had when I first started printing.

As the spool is on an angled holder so that it can't come off, I can make an extension to the main shaft that should prevent the filament escaping the reel.

Currently printing a 185mm back plate, this goes down the shaft and prevent spools with holes or sutouts from catching on the top of the main shaft.

I'll take some pics without filament when the plate has finished.

But looks like this will do the job without my having to build something huge :-)

A side observation on the corexy system.
when the print head goes left - both belts go right. when it goes right, both belts go left. When it travels in a doagonal only one belt moves. When it goed forwards or backwards both belts move in opposite directions.

It's fascinating to watch - almost as hypnotiic as watching a delta print at speed.

How on earth did someone work this out ?
I'm now going to have to find out who invented the system.

Around 2013, a new motion system was developed by an MIT engineer. It became known as the CoreXY.

so now you know :-)