Why does the crowded of the pipe need heat?
Transfer from http://diy3dprint.blogspot.tw/2014/01/blog-post.html
From the j-head tube, the plastic that is glued to the inside of the Teflon tube after the backflow. This is the crowded out of the head stuck in the meta-killer.
Everyone is excited about the machine, and can quickly start printing. Almost all of them are eager to print before they have a hot fan of the pipe. Good luck can print a small square box what's the problem, the weather is bad is the crowded material completely crowded, and then abortion into the clear to the hell. Why does the crowded need to be heated? Don't melt the plastic, soft enough, can crowded out?? It is a pity that the matter is in violation of the petition. Crowded out of the structure of the pipe, must have a good heat, in order to guarantee the smooth crowded material.
This picture on the RepRap Spoolhead blog can clearly explain why the pipe needs heat.
Crowded the tip of the head is a hot tube that melts the plastic into a rubber state. The plastic on the back continues to push forward crowded, allowing the plastic to crowded out of the hole. This is the operating principle. But the diameter of the hole in the central channel of the pipe must be larger than the diameter of the plastic. Even the plastic itself has a bad path, and sometimes it's a little bit more subtle. So the pipe through hole and plastic between, there must be a gap. The plastic that melts at the front end is crowded, not only crowded out from the spray hole, but also back from the gap between the back end. It is not often seen that it can be exaggerated from the back end of the pipe, but if the distance of the backflow is slightly longer, the friction between the plastic and the Hou Taizhi becomes very large and cannot be reversed.
The solution is to let the hou tube heat up. Add heat to the other part of the heat. For example, the position of the Heat sink (loose heat), as far as possible to heat, so that the temperature is low enough to make the back of the plastic solidification, to prevent the flow of reflux. The solidified part also increases friction, but the range is small enough to control the increase in friction.
E3d disassembly photos of all metal e3d crowded out of the head, in the throat pipe section above the heat, arranged the structure of the loose heat environment. In the photo, the top of the list is the "loose heat", the pipe, the hot aluminum block, the yellow nozzle. The pipe is also particularly thin, the intention is to reduce the heat through the pipe and continue to pass upward. At the top of the heat cycle, doing so much of the bulk of the heat is to reduce the temperature, reducing the problem of backward. Although the heat is very large, but the pipe and the heat of the thread between the surface area is limited, the heat effect is not good enough, so that the temperature of the upper half of the pipe is still unable to effectively reduce. It is suggested that a half-section of the pipe should be smeared with a powder. (Paint a little bit, if there is overflow after the installation, wipe off.) It is possible to reduce the temperature of the pipe effectively by cooperating with the wind fan to blow off the heat. The pen's e3d, after the heat, has been stable work 三、四個 months have not stuck.
Graphics Source: J-head mk-iv hot End Clone Design Quick Review
1.75mm Plastic J-head, designed to be special, the pipe Center uses the Teflon tube to cover the plastic, all the way from the end of the consistent through the crowded hole. The Teflon tube itself is not very hot and the plastic will turn back the distance should be full. It is supposed to be very abrasive, but the characteristics of the Iron Dragon are very smooth, the surface friction is very small, so still can crowded out plastic. But good heat, still can help j-head crowded material few laps some. If not for j-head, though there is still an opportunity to crowded the material, but if the temperature of the black peek tube is gradually increasing, it is possible to heat up the j-head bracket that the PLA prints to a soft change. This j-head will skew, sway, and not good. The fan still can't be saved.
Atom's earlier version of the J-head dispersion structure
Atom's earlier version of the J-head, using a strong 蝸 fan, is paired with a top-down dome that allows the j-head black pipe to heat up as much as possible. Wind exports face down, and then blow the workpiece, really a number of Ah!
Prusa i3 Direct Drive Bowden extruder
Simon's design of the fan frame, can directly buckle j-head, the actual use. J-head blow the wind to guarantee a long time printing problem.
The design of the Cranerap is designed to design a J-head fan hood.
The design of the Cranerap is designed to design a J-head fan hood. The J-head clips, fan racks, and wind fans for concentrated wind power are combined. The expectation is that j-head can be crowded for long periods of time.
3D printing larger objects, the craftsmanship takes 10 hours. If the crowded out of 10 hours after the development of blocking, then the hard print 10 hours of work pieces will be destroyed once!! (not "overnight", "once".) Crowded will pick up the sun, but you don't wake up when the strikes work! Long time to print the most afraid of the machine is not stable, especially before the end of the printing, will be very worried about the situation of the machine. Crowded the heat of the throat is a critical environment that can reduce the rate of print failure. Tens have to be patient to get the pipe hot fan installed AH!!! Hope that no one else to ask me why crowded, j-head how will get stuck ~ ~
Update (2014/01/28)
Colleague's machine has been printed, the spit material is not smooth. After removing the heat resistant tape from the black peek, you can print it smoothly. Long ago said to be torn down, has been not superstitious, and today finally took off the heat resistant tape, and then can be printed.
Why does the crowded out of the pipe need heat?
