I saw a brush mount elsewhere on thingiverse. but i wanted a different location and height.
my starting script to preform the wipe
G28 ; home all axes
G92 E0 ; reset extrusion distance
G0 Z3 F5000 ; prep for prime and clean
G1 E19 F600 ; prime nozzle
G0 X60 F6000 ; wipe nozzle
G0 Y30 F6000 ; clear of obstruction start print

this design uses a cheap nylon brush that can be found at most hardware stores.
just remove the handle and sand down the back so that its square and fits into the mount.
you may also add a drop of hot glue for peace of mind that the brush doesn't push out.
here is a link for reference on what to look for
https://www.amazon.ca/dp/B06Y3XX3LD/ref=as_at?slotNum=0&ie=UTF8&sr=8-14&linkCode=g12&imprToken=8-mG4Ducm-tQ11cYuyd1OA&creativeASIN=B06Y3XX3LD&tag=thingiverseca-20
and
http://www.canadiantire.ca/en/pdp/wire-brush-set-3-pc-0490511p.html#srp

Since my hotend cannot move off the heatbed I need to have the nozzle brush above the bed when cleanng but off the side when idle.
small video:https://youtu.be/kWGmyQm7iAg
Be aware that the length and angle of the arm holding the servo is specific for my printer, so you may need to modify the attached fusion 360 file.
The mount of the arm is for a 2020 extrusion using 2 2020 t nuts and 4mm screws.
The brush used:https://www.ebay.com/itm/1x-Stainless-Steel-Wire-Brush-Tooth-Brushes-Plastic-Cleaning-Rust-Detailing-New/132545087951?ssPageName=STRK%3AMEBIDX%3AIT&var=431896604988&_trksid=p2057872.m2749.l2649
The servo used:https://www.ebay.com/itm/4pcs-Rc-Servo-9g-Mini-Micro-for-Trex-Align-450-Rc-6ch-Helicopter-Airplane-Car-E/382585778668?hash=item5913e3b1ec:g:sdsAAOSwLmVXEFea:rk:1:pf:0
Just cut of the the handle of the brush to size. And the arm that folows with the serve is glued onder the brush holder and screwed to the servo
For the Duet WIFI  I connected it:
servo                 Duet
GND(brown)     pin 30 GND…

Ender 3 Pro MeanWell PSU fits perfectly under Y axis extrusion in the back.
You can print 1 or 2 front parts (to be put into cenral 4040 extrusion), I decided that one is enough for me.
To fix left and right part you will need 4pcs M5 screws (I used ISO7380 M5x10) and 2pcs M4x6 (I used ISO7380 M4x6)
There are 2 versions of the left parts with different power plug fixing screw holes diameter.