Workable dual extruder or light weight single extruder

The pictures below show a plastic piece that replaces the upper plastic and stepper. It mounts with 4 m3x50 socket head screws. The PCB mounts with m2.6 sheet metal screws. There is a removable plastic plate that has one or two, tube to thread adapters mounted with an m3 screw to a m3 threaded insert. The Robo has a plate in the back that may be removed for a stepper to be mounted on the inside, connected to an extruder on the outside.

The caps are threaded so the STLs are large here is the link:
https://drive.google.com/file/d/1q5_cX2En9bX0PfSKLI4YkhN6cpE5yOTR/view?usp=sharing, https://drive.google.com/file/d/1zlPmSBPspbqLqINj6j-D0Ot0Z7rdqYGU/view?usp=sharing

The print head is now half as heavy as it was before and the system moves from direct to Bowden extrusion.

As all of the parts come in I will keep updating this until the project is complete.

So it is working now. This is a movie of me printing something that has always been hard for me as it is only 0.75 mm wide. https://drive.google.com/file/d/1NqxBHl6f7cioEfqsezVLr1PnSzS3BOUu/view?usp=sharing. I am able to print at 1 1/2 times the speed I could previously while maintaining the same quality of finish.

The https://www.amazon.com/gp/product/B07VFHJPVY/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1 extruder is the best that I have tried. It is dual gear and left handed if you wish to mount it in the rear of the box in the place provided. This extruder is amazing, tremendous grab and no distortion of the filament. A word of warning: I just lost a stepper driver, not a problem with a Partsbuilt board. The extruder drive gear extends into the arm of the driven gear. It ground into the arm and I guess it grabbed because the stepper driver died. I had to grind down the arm until it was below the teeth of the gear. Now is printing again, fingers crossed.

In my opinion it would be best to mount both extruders to the top of the box. This allows the the extruder to be mounted through a metal plate. The pressures are such that I feel mounting through plastic will eventually cause problems due to the heat of the stepper. It is also easier to load what you can see, and can be mounted allowing the use of the filament out sensor.

I have no use for dual extruder but if anyone wants to go there, they can just let me know what boards, bed, hotend they are using and I will send them the correct hex code.