PTC Heater Mount for the RatRig VC4

Hello!

Here is a mount enabling the attachment of a 60 mm PTC Heater (like this one) in the RatRig VCore 4.

Tested in a 300 size, according to the CAD models, it should fit in the other sizes.

BOM:

• PTC Heater (https://www.aliexpress.com/item/1005003140673176.html?spm=a2g0o.order_list.order_list_main.64.9c8c1802sJTuv8)
• 1 x M3x35 screw and an M3 nut for the pivot;
• 2 x M3 heat set inserts;
• 2 x M3x10 screws to be able to attach the PTC Heater to the mount;
• the M6 bolts that hold the bottom panel corner in place are used without the washer.
• enough AC rated wire and 24 volt rated wire so the connections reach the electronic enclosure.

Since this is a AC powered heater, you will need a second SSR to control it. There are options to mount a second one in the backpack or the route I took, was to replace the standart SSR with a dual SSR with the same form factor (like this one). 

For controlling it with the macro already implemented in RatOS, you will also need 2 extra thermistors, one inserted in the fins of the PTC Heater to be able to PID tune it and one mounted at the level of the toolhead to measure the chamber temperature.

The 24 volt fan that comes with the PTC heater can be connected directly to the main board.

Also dd the config to your printer.cfg as instructed here (https://github.com/HelgeKeck/RatOS/blob/documentation_v2.1/site/docs/configuration/chamber_heater.md).