SV08MAX Cabinet Heater Ducts

Sovol's stupid design draws room air into the heater, forcing the heated air to escape through the exhaust fan back into the room. What were they thinking???

This project requires making new holes in the rear cabinet panel. Otherwise it's plug-and-play. Combined intake area equals the fan's intake area and curves are gentle to preclude restriction. I printed it in eSun ASA+ with a 0.8mm nozzle for speed -- it doesn't need to be real pretty. About 19 hours to print the duct pieces if all on one plate (or print separately if you are cautious). Compare to Orca's 47 hour estimate to print the same filament with a 0.4mm nozzle. 

Theoretically, this could be printed in PLA or PETG. The cabinet temperature should not exceed 50°C (the maximum ambient temperature rating of the gantry A and B motors). But I used ASA just in case!

I had a steep learning curve fine-tuning the printer for ASA with a 0.8mm nozzle (PLA is far more forgiving). USING DEMON'S DKEU MACRO PACK with Sovol's version of Klipper. Anyone printing this will have a MAX so I am including my .3mf file with my settings -- they should be close IF you are using DKEU -- I'm not sure about a bone-stock machine or mainline Klipper. I won't claim they are perfect but they worked. I oversized the sockets by 0.5mm but still had to dress them with some light sanding to clean up imperfections. If anyone has suggestions for improvement, I'm listening! 

Supports are required. Sorry. Use Organic ("Tree") supports and print in the orientations shown to minimize. You may need some long needle-nose pliers to remove the supports inside the left and right ducts. I've tried to make them as easy to remove as possible. 

I am also including two versions of the template. Use the Drilling template if you have access to a hole saw (2-7/8" +/- 1/8"). It will properly locate a 1/4" hole for the hole saw pilot bit. Otherwise you can use the Large Hole template to scribe the hole circumference and cut it out with a Dremel or similar. Choose one or the other, you don't need to print both. 

The mounting flange holes should be drilled with a 5/32" bit to accommodate M4 x 12 socket cap machine screws (8 required, with nuts). The flange hole spacing is sized to fit a standard 80mm case fan grill (optional but recommended -- 2 required). 

To install: unplug the fan and heater wires. Remove the rear panel and take it to your workbench. Remove the wire guide cover, cabinet heater and lower intake fan (upper exhaust fan can remain in place if desired, but I removed it for simplicity). Discard the intake fan grill and filter. 

Use two of the mounting screws in the lower pair of original fan mounting holes to position the template chosen above. There is a bridge in the template to cross over the wire guide so no need to remove that. Use clamps or double-sided tape to ensure the bottom can't shift while drilling. Drill the 8 flange mounting holes with a 5/32" drill bit. The raised sides of the template will help you keep the drill vertical, but remember: they are only plastic. 

Drilling template: drill the centre pilot holes with a 1/4" drill bit. Remove the template and finish with a 2-7/8" (72mm) hole saw. 

OR

Large hole template: scribe or mark the circumference of the holes. Remove the template and cut with Dremel tool or similar around your marks. 

The MAX heater has a gap between heater and cabinet. Apply the TPU printed gasket to the heater body and re-install the heater, ensuring the gasket remains in place. Place the fan over the heater (MAKING SURE IT BLOWS IN!) with the cord to the left (as viewed from behind). 

Insert the Heater Connector inlets into the Left and Right duct sections. Make sure they are fully inserted. Rotate each as required so that all 3 flanges are roughly parallel. Insert the original 2 lower screws into the top (large) flange that mounts to the heater. The ductwork overhangs these so they need to be inserted now. 

Place the assembly over the heater inlet and start all 4 original screws. Those holes are tapered to fit and they are long enough because the intake grill is no longer required. They won't be long enough if you forgot to remove the grill! 

Fine tune the intake flange spacing by rotating on the Heater Connector inlets as required to align the mounting holes. Secure with the M4 x 12 machine screws, installing the 80mm fan grills (if desired) on the inside. Tighten the heater intake fan screws (a ball-type Allen key is very handy here!) Reinstall the exhaust fan if removed earlier. 

Feed the wires in the guides as before. Re-install the rear panel. Reconnect the wires (I'm embarrassed to say I forgot that last step).

Enjoy! My cabinet now reaches 42°C from a room temp of 20°C in two minutes with the bed heater off. And uses less power to maintain the temperature because it's not trying to heat the whole room anymore. 

In respect of Sovol's commitment to fully open source this printer, this project is released under the CC "Share-alike" license. Please respect it.