Yes, I changed the kinematics of the X/Y motion setup.
It now has only two motors (X+Y and X-Y) at the back using a single very long belt.
It eliminated the X motor from the carriage entirely.
Then with the DotBit extruder (thanks once again for your excellent suggestion of it!) I am able to run a pancake motor on the direct drive extruder setup.
Between these two things alone it made a major reduction in the moving mass.
All of the bracket parts on the carriage are printed now except for the original two mounting plates between the X-direction 2020 stock and the slide blocks (they were still OK).
I even re-designed and printed the duct for the E3Dv6 fan to tilt the fan with a 15 degree angle so as to be a bit kinder to its bearings.
Here are some CAD renderings of my setup as it is now (please pardon the crude DotBit extruder model though)-
I would be happy to take and post actual photos of the installation if you would like.
However the CAD renderings are easier to understand because they don't have all the clutter.
And I would be more than happy to share the CAD files with you if you wish.
I already posted the E3Dv6 fan duct design on Thingiverse, and was considering posting the H-Bot conversion parts as well, but they would take a fair amount of work to clean up for general posting.
Plus, I used metal spacers and a metal mounting plate on the carriage that possibly not everyone could fabricate.
Here is a photo of the double Z plate bearing setup and a glimpse of the thick heater plate I am running-
The double bearings made a world of difference.
And I added some thin aluminum angle ribs below the drive plate to eliminate any sagging problems (it is still the original melamine).
I am, as a reminder, running a single Z motor with a 1360mm belt.
That would be quite a good feature, I think.
I bought mine at Ace Hardware.
Our local store has an excellent selection.
I don't recall the part number but they are conical in shape and are definitely stout.