Sovol SH02 Modifications

The Sovol SH02 is a vast improvement over the original SH01. It has better internal airflow, a one-handed latch, higher internal temperature, lower external temperature, longer duration, desiccant trays and an internal power supply.  But it has 3 critical flaws. 

1. The filament guides are the wrong angle and bind vertically or horizontally, especially with a full roll. This has already been addressed by others here and here. 
2. The desiccant trays are in dead air, lying on the bottom out of the airflow so they have minimal effect. 
3. There is a nice vent hole on top to allow warm, moist air to escape – but it doesn't work very well because there's no way for air to enter the system with the lid closed. The lid is sealed to the chamber and the flow path within the base is also sealed. Great for a storage system, not so much for a dryer. I want a dryer, I'll use vacuum bags for storage. 

The mod is simple. Remove the bottom cover by removing the 6 screws. Drill a 3/32" hole in the bottom of each desiccant tray, outside the inner sealed area. Add two additional holes at the rear to allow air into the unsealed area. 

When the lid air vent is open, escaping moist air will draw in fresh air over the desiccant packs by convection. The result is notably lower humidity – and in less time too. Coupled with the filament guides mentioned above, I'm printing nylon at 10%-15% indicated where previously I typically saw 25%-30% – and that took the full 12 hours. 

Interestingly, it seems to maintain that level for at least a day after shutting down. I suspect the convection flow stops as the air cools down and the desiccant packs take care of the rest. But that may change in summer months when the ambient humidity is higher. 

(Note: Printables won't let me publish this without a design file, so I tacked on my SV07 runout sensor repair guide. It really doesn't have anything to do with this other than being filament related. That project is published separately here.)