Hi I am in the process of designing/building a small extruding device it will take plastic pellets and melt them and extrude them into a filament and I have a few mechanical design questions I am hoping you can help me with. I am new to this forum so please bear with me. Description: In my system I have a tube going from point A to point B in this tube is an auger that for the most part completely fills the ID of this tube. At point A is the nozzle, the nozzle had a small concave section to begin channeling the molten plastic into the nozzle. just in front of the nozzle is the heating element that melts the plastic pellets prior to extrusion. The auger is cut flat at the tip end and rest right up to the nozzle at point A and extends past point B and point C on to Point D where it attaches to the motor. From point B to point C it is not surrounded by any type of tube it is the entry point for the plastic pellets. Distances tube ID = 3/4" auger OD = ~ 3/4" :it just fits inside of tube very small gap surrounding it maybe 1/32"-1/16" Point A to Point B = ~ 5" Point B to Point C = ~ 6" Point C to Point D = ~ 2" Conditions: Mechanics are put into place to prevent auger from moving away from nozzle tip yet allowing for free rotation inside of tube. Goals to achieve fast extrusion of material that is uniform in nature. To achieve these goals I have a few questions 1. Does it matter if the auger extends completely to the Point A or can it be shortened to say point A1 and leave an open area between the end of the auger and the nozzle that would be simply enclosed by the tube? My thoughts: Having the auger go completely to Point A maintains as much as possible the flow of material into the nozzle eliminating much of the outward force directed toward the inside of the tube between point A and point A1. Here, the forces will spread equally toward the nozzle opening AND the inside of the tube. Is this difference negligible? 2. Would increasing the distance between point A and point B by 3" and decreasing the distance between point B and point C by the same amount add any benefit to the flow of material? My thoughts: Between points A and B it is a more of closed system where direction is primarily driven by the auger with a minimal chance to move in other directions. If this area is increased, is this a benefit to increasing extrusion speed and uniformity? Beyond point B pellet material can move in and out of the auger area freely, reducing the driving force into the nozzle area. 3. Would simply reducing the overall length of the system by shortening the distance between points A and B and points B and C as well as the auger length be of any benefit other than a shorter overall length or would it have an effect on the the uniformity and speed at which we could extrude material? I mention uniformity because coloring can be added to material to change its overall color and it should all be the same color the coloring is controlled by the addition of a colored pellet at approximately 1 per 50 of the colorless pellets. My concern is that in a shorter system the color will not be mixed well enough to become uniform. Thank you for your assistance and please feel free to ask me any question I will do my best to answer them.