Hot Glue Extruder (7mm HMA)

Few words: I've seen a couple of videos on youtube from people trying to use hot glue guns as hotends. They were all relatively janky and were made out of plywood and random gears laying around. While that is a liable choice for a repstrap printer, I've been thinking of creating a "proper" design for such an extruder in case anyone who is adventurous enough to give this a shot. This is desgined for 7MM glue sticks with some room for error and has to be paired with a stripped down dollar store hot glue gun in order to have a complete hotend. I chose to modify mine by removing the 220V heater and replacing it with a 5Ohm 5W wire wound resistor and 100K thermistor for better temperature control and safety. Alternatively you can use a 30W hotend heating cartridge which was my original intention however I did not have a way to correctly mount it to my glue gun without it being exposed to open air potentially causing damage to it in the long run. The easiest way to go about this would be to use the original 220V heater, however this is NOT RECOMMENDED as it would be HIGHLY DANGEROUS especially for people that do not have experience around high voltages.

BOM: 
1x 608 Ball bearing 
1x 11mm Brass fine tooth gear (Feel free to use any Drive gear you have for this as long as it's close enough) 
1x Nema 17 motor  
3x 3mm Screws (For connecting the motor to the extruder) 
1x 4mm 35/50mm Screw + nut (Use 50mm for spring tension) 
1x 4mm 15-20mm Screw (For connecting the idler to the main body, 15mm to screw into the body, 20mm to use with a nut) 
1x 5mm Screw+nut (For attaching the 608 bearing)