Adjustable gantry mounted nozzle park and brush

This is an adjustable gantry mounted nozzle parking spot and brush for Vorons (2.4 & Trident) using bambu lab's silicone wiper using high temperature silicone RTV to further improve nozzle heat handling (can withstand sustained 287C)

Why?

When putting together my ERCF I was annoyed by the slight oozing that happens when changing filaments. No matter how much you retract the filament during a swap, there will be some oozing simply because of the time it takes to perform the change. This ooze then transfers over to the purge tower causing a small bump which when printing can cause slight layer shifts and bend your nozzle if its too severe.

In addition if you have a runout or using the endless spool functionality, that stray filament will transfer over to your print, causing a bump either on the infill or the external surfaces.

This mod aims to address this by introducing a location to park the nozzle while filament is being swapped and a mechanism to wipe your nozzle before resuming your print.

Benefits

It is gantry mounted, which means you don't need to lower the Z height (on a Voron 2.4) to wipe against a brush fixed on the bed. If you lower your toolhead to the rear of bed to wipe, your head may end up colliding with printed parts surrounding that area. A gantry mounted brush solves this issue as you dont need to change Z height to wipe.

In addition, I have selected to use the bambu lab silicone wiper (https://uk.store.bambulab.com/products/heatbed-nozzle-wiper-a1 / https://us.store.bambulab.com/products/heatbed-nozzle-wiper-a1) instead of a brush bristle brush. I find it is gentler on the nozzle, it is non conductive which helps if you have a beacon or cartographer probe on the toolhead and leaves no metallic residue on the nozzle. It is also cheap and reasonably readily available.

Also you can use the this version from Aliexpress  - https://www.aliexpress.com/item/1005007402118137.html 

It also has an integrated, spring loaded nozzle parking spot, to reduce any ooze happening during a tool change. This reduces the amount of stray material in the chamber by preventing the nozzle from oozing when it is parked.

Finally the mount is flexible so it should not bend your nozzle or place too much strain on the stepper motors causing them to skip steps.

After close to a year of using the brush mount I have refined the design and produced a single option. The new design has the following benefits:

1. Uses high temperature silicone RTV to fill the nozzle stop area. This has several benefits, namely higher temperature resistance (up to 287C sustained depending on the silicone you use), improved nozzle sealing and higher wear resistance compared to the foil options.
2. Modular design:
   1. The brush mount is  its own component facilitating easier replacement. 
   2. The design  has three options for the extrusion mount to cater for longer toolhead.
   3. A brush holder extender has been provided to allow for use with tool heads that have the nozzle further forward from the gantry. The provided extender is 5mm deep. If moving the brush further to the front is necessary, resize it accordingly in the slicer.

Video in use:

BOM:

Materials:

1. Silicone brush
2. Silicone High Temp RTV: https://www.amazon.co.uk/Weld-31314-Temperature-Silicone-Sealant/dp/B00ID8IUJY
3. HVAC aluminium self adhesive tape (optional): https://www.amazon.co.uk/dp/B07KQDQHC9 

Hardware:

To mount the assembly to the extrusion:

1. 2x M3x10 BHCS screws
2. 2x M3 Ball Spring T-Nuts

To put the assembly together:

1. 6x M3x8 SHCS screws (M3x10 will also work) to mount the joint to the extrusion mount and brush mount.
2. 2x M3x10 SHCS screws to mount the brush base to the brush mount. If using the extender longer screws will be needed (M3x16) 
3. 8x M3 3x5x4 heat set inserts

Print using ABS/ASA for flexibility and heat resistance using the standard Voron parts print settings. 

To assemble:

1. Install the heat set inserts in the parts.
2. Using 2x M3x8 screws put together the brush mount to the joint
3. Using 4x M3x8 screws put together the vertical mount to the joint
4. Assemble the screws loosely so you can move the parts up/down/front/back
5. Fill the nozzle stop area all the way to the top and some more,  with high temperature silicone. Using a piece of cardboard that has been soaked with water, smooth it over the top surface and following the curve of the model. Let it cure overnight. The water on the cardboard helps avoid the silicone sticking to it and allows for easier levelling. Use a piece of paper towel to clean up any excess as much as possible.
6. Once cured, clean up the excess silicone that may be stuck to the brush mount and cut optionally cut and install a small piece of self adhesive alunimum tape to the leading edge of the nozzle stop.
7. Install the silicone nozzle brush using the double sided sticky tape on the brush itself.
8. Fit the brush assembly to the brush mount using 2x m3x10 screws (or longer if using the spacer)
9. Install the M3 Ball spring t-nuts to the rear extrusion
10. Install the assembly using 2x M3x10 screws
11. Move your toolhead over the brush area and adjust the screws so the nozzle is just over the middle of the brush and touching it about 1mm deep. You want it to touch the brush but not hit the bottom of the wiper.
12. Lower your gantry to Z 5.0mm. Check that there is adequate clearance between the brush and the bed. Be careful as you lower your z height if you've moved the nozzle brush too much forward it may collide with the bed. If that is the case, move the wiper arm slightly back till it clears the bed.

Design by ioannis on MakerWorld (license: BY).