The problem of overheating is quite common but having an unequivocal symptom it is rather simple to solve it instantly.
Overheating literally means overheating! But this is probably not the right word to describe the phenomenon. When we think of overheating we think of an inadequately cooled electronics, a car engine with a broken radiator and a whole series of situations where something is heated that should be kept cold.
Overheating of the extruder, on the other hand, is simply giving more heat than necessary, so perhaps the best definition could be too much heat or ice cream syndrome.
The identification of the problem is just seeing the top of our prints take the same shape as the ice cream.
The plastic coming out of the extruder can, depending on the composition, be extruded from 190 to 240 degrees. The plastic is still warm, flexible and can easily be deformed. But when it cools down, it quickly becomes solid.
The job of the printer is to find a good compromise between the extrusion temperature (to emit a nice soft filament) but not too hot that then solidifies almost immediately.
The extruder’s too much heat occurs for 2 reasons, one of which is purely dependent on human error: a temperature that is too high is set. The typical case is to print PLA thinking that it is ABS then completely wrong settings.
Or sometimes we are led to raise the temperature because the filament seems too solid, but there is a remedy, we will return later.
The second cause is the reading error of the temperature sensor. The sensors are not infallible and should be replaced periodically. After intensive use, they may read less degrees than the effective or, more frequently, jump from one temperature to another with a gap of up to 50° in a few seconds. This pushes the electronics to heat more than necessary.
Once we have checked that we have no problems with the temperature sensors and the reoccurrence of this problem we are certainly using more heat than necessary, so it will be sufficient to decrease by 5/10 degrees, until the machine will extrude well into the filament, these changes can also be made in the race.
There is the possibility, which is also widely used, of equipping the printer with a fan that blows directly onto the newly extruded plastic, to ensure instantaneous cooling.
Most of the printers sold in Kit have the possibility to add a fan, and connect it to the appropriate socket: “fan” on the electronics, the firmware is already set to control a “flat” fan and all in all the installation will be quite simple.
The only thing to do is go to one of the virtual warehouses or marketplaces and take the support project that we like best or that seems to work best.
Normally every printer has many possibilities, for the use of classic or radial fans.
Always check 2 or 3 sites to see the proposed offers!
However, if we are printing a material that cannot be cooled by force, such as ABS, then the possibility of using the fan will be precluded.
In this case, the printing speed must be lowered to allow time for the layers to solidify well before depositing another one.
With some slicer it is possible to decrease the speed during printing. With others you can set the minimum time for printing a layer. If, for example, it is printed in less than 20 seconds, the nozzle will still wait for that time, giving the plastic a chance to cool down. Slic3r and Cura have the possibility to set min time every layer.
Overheating: Some Tips
There is also a very simple method to lengthen the printing time without decreasing the speed or stopping the nozzle for a while. . As already mentioned when dealing with other articles, downtime is the home of stringing. This method consists, if it is possible as a size to print two or three objects at the same time.
The movement and time taken to print the second and third object will be used to allow the last layer of the first object to cool down well.
If you follow this guide you will only see ice cream in the ice cream shop and no longer on the top of your prints!