Thermoplast Extruder Version 2 Improvements
This is an idea that I came up with, reading in several blogs that some extruders got severely damaged when output is blocked, and feeder motor still keeps running.Pressure builds up, and at some point, something must snap. Maybe this is something, (with parts even printable I think), that can prevent this from happening. Imagine the device mounted between the feeding driver motor and the feeding pinch or feeding screw (you can mount it in any device where you want to protect excessive movement or tork). The driving axel, in the middle, carrys two 'wings'.They push against springs (eventually adjustable), who in turn will turn the pinch or feeding screw.When for some reason then pinch or feeding screw blocks, the springs will be pusched in, opening the contacts on the top, thereby interrupting the driver motor.As soon as pinch or feeding screw blockage is released, they will again start moving under pressure of the springs, and as soon as the contacts close, the driver motor again starts running.So, the pinch or feeding screw allways tries to 'follow' its closed contact, bus as soon it runs behind, the driver motor waits until it can level again. This is very basic drawing, but these kind of protections exist in some transmissions.If this idea is worth working out, let me know.
I also do miss some 'protection' mecanisms or protection steps in other parts of the extrusion process. For instance, it is very easy to protect the machine of working unnoticed without output (for whatever reason).Think of a small 'port' with led and lightdetector(like in a wheel mouse) where you let the system detect if your extruders produces output by letting it extrude a small string of plastic in this detection 'eye'.When there is output, carry on. When no output , stop working, sound alarm, whatever, but do not keep on running for a night without producing something ...
Another idea is this : collection of ball park figures. There are a lot of people experimenting with different materials under different settings etc. Although these data are not really direct implementable for every setup, if we could collect them in a central spreadsheet, the longer we collect and the more data is collected, the more accurate we can predict setups for new starting projects or experiments.
I read in some blogs as well about ideas to find a way to interrupt the output by reversing the feeder motor etc.Problem with this approach is that you have two 'soft buffers' between 'output on' and 'output off' : 1 : the time your complete mechanism needs to revers the pressure due to mechanical distance to bridge 2 : the buffer of 'molted plastic' between input of plastic and nozzle. Maybe a solution would be to close off the nozzle with a needle, thereby : - halting output immediatly - keeping pressure on molted material to reproduce output immediatly after reopening nozzle. Anyone interested in going this way ? I am looking around for a simple and existing solution for this.
Maybe I miss these things because I am fairly new to these blogs,and I did not already dig into it deep enough, nevertheless, let me know if there is any advise, interest,comment etc.