new model files:

mainbody 31a: enlarged support surface of filter

fanbody: enlarged support surface of filter

fanmountplate v7: changed hole position to match fanbody

Heavily inspired by this K2 Plus Addon: https://www.crealitycloud.com/de/model-detail/677ae50d06c912fef1ef3082 I was about to print that and while doing that, I came across different things I wanted to change.

I ended up redesigning the whole thing with the following goals:

- integrate into bottom plate to retain stability in K2 Plus

- also to not have dead space which has to be heated up

- easier cleaning

- less filament for the model

I then designed the filter box and the fan-box from scratch.

Since I had already printed out the fan assembly plate I reused that from the original model and reworked it but now I also redesigned that.

Please don't mind if the pictures look a bit different then the current model, during the hole build process I came across some things which I then changed in CAD model but did not print it again.

So for the parts you will need:

- filter: https://a.co/d/70GO9mC (use the "Toxic" variant). In general filter size should be L X B X H 32cm x 29cm x 3,5cm. Don't make it smaller in L x B, else it will "drop" into the filter housing.

- 3 x 80x80x25mm 24V Fans (your choice what you take, I used these: https://de.aliexpress.com/item/1005001288581957.html

- 6 x Thread inserts: M3 x 4 x 5 mm (L = 4, OD = 5)

- Optional: Sealing for the fan box for highest performance

- 6 x Screws + Nut + Washer: M6x18, I used https://de.aliexpress.com/item/4001072025844.html which I suggest for the big flat head

- 12 x Screws + Nuts: M3 with cone head, length 8-12mm

- 6x Screws: M3 with cone head, length 8-10mm

- optional: 6pcs 4x2 mm round magnets for the coarse filter plate

- coarse filter I used this: https://amzn.eu/d/eYhJIRL

- Tools to drill and flex the bottom plate (I used Dremel 3000 with Dremel SpeedClic SC456B)

Print Instructions:

Print with temperature resistant material, I used PETG.

Use support for Tree (Auto) Slim with 30° angle, don't check "on build plate only" and "support critical regions only".

Assembly:

- Start with printing out fan housing and fan assembly plate

- make sure the holes in the assembly plate fit to the holes in the fan housing, if not rework them

- install the fans using the M3 screws and Nuts

- insert the thread inserts to the fan housing

- assemble the assembly plate to the housing using the M3x8mm cone heads, optionally what I did is using Silkaflex 522 to seal the surface

- lead the cables in direction of the power supply bore and merge them with some connectors of your choice at the outside of most right vent windows. Check function of the fans.

- print the filter housing

- Use the snap fit to bring the parts together and use 2 of the M6 screws, Nut and Washer to screw the parts together. Use tape to strengthen the connection and make them sealed.

- lead the power supply cable to the outside, ideally give it a plug at the outside to easily remove the assembly

- remove the bottom plate of the printer, (don't forget the 3 screws at the front which are hidden behind the door sealing)

- arrange the filterbox assembly on the plate, make sure it is centered in the x-axis and aligned at the front. Then sketch the bores for the connection between filterbox assembly and bottom plate

- screw those holes and connect the assembly and bottom plate once using the M6 screws, nut and washer to make sure it fits. In this state sketch the outlines. Remove assembly again and then sketch the inlines. I made a big window for the filter and a smaller windows for the 3 fans.

- make the cutouts at the bottom plate, make sure to smooth the edges to not hurt yourself.

- assemble the filter assembly and the bottom plate using the M6 screws, nuts and washer

- lead out the power supply cable through the according bore and seal the bore with sealing (I used Silkaflex 522)

- your choice for power supply if external or internal or using a switch or regulator - I used this: https://amzn.eu/d/dH7b3Op which leads to a nice and clean inner. Make sure whatever you use that it won't be in the way of the print plate or other moving parts or lasers next to the z-screw

- test your setup once more before you reinstall the bottom plate

- install bottom plate

- as a cover to prevent dirt to fall in I rebuilt the original and made it bigger to also cover the fans cutout and same time use less material. If you want you can insert magnets 6pcs 4x2mm.

Print it, glue it together, use some mesh of your choice (heat resistant) and glue it to the frame

Any suggestions / improvements / questions welcome.

Seamless in bottom integrated Filterbox for K2 Plus

0.2mm layer, 2 walls, 15% infill

0.2mm layer, 2 walls, 15% infill