It recently came to our attention that many MakerBot Operators are skipping the crucial ceramic tape insulation stage when building and using their Plastruder MK5s. We have a tendency to display the Plastruder MK5 in kits without the tape to show off the beautiful thermal core and nozzle, and have been less emphatic about this point in the past. But no longer.
My Elite Wrapping Techniques Are Unbeatable
Up until now, this was something of an veteran Operator trick, now we are suggesting that this slips into general practice. Applying ceramic tape reduces the radiated heat, insulates the thermistor or thermocouple, and makes the thermal core a bit safer from radically burning your fingers. As a result, you will require less juice to get your hot end up to temperature, less juice to keep the temperature steady (also isolating hot end temperature readings from environment factors), and no Aloe Vera juice on the fingers.
To accomplish this feat: Simply take the piece of ceramic tape and wrap it around the hot end. I tape a long strip of kapton to the ceramic before wrapping, and then secure it in place by taping kapton on one side onto the kapton on the other side. Additional loops of kapton around the ceramic wrap to hold the tape in place helps keep the insulation from dipping below the bottom of the thermal block where it might drag on the model. Make sure tape is firmly attached (kapton taped against kapton: the kapton tape will not stick to bare ceramic tape), as you don’t want it falling off during a build.
An elite trick Adam introduced to the Botcave: cut short rectangles of ceramic tape (1/2 in to 3/4 in) to slide between the teflon-coated wire (that connects across the power resistors) and the thermal block, and tape these in place. This approach is particularly recommended for the front of the thermal block to insulate the thermistor or thermocouple from being exposed to ambient temperature fluctuations. Not only do these rectangles help to insulate the hot end, but they offer additional protection for the teflon-coated wires whose casing, under extreme heat, can bake off the cores, introducing the possibility of shorting against the metal thermal block.
What the PID?
If your wrapped Plastruder still has difficulty reaching and maintaining the target 220˚ temperature, you may need to make changes to your Extruder Controller’s PID settings. In the v2.x firmware release, Adam opened up the ability to control the heater’s control system Proportional, Integral and Derivative (PID) parameters within ReplicatorG in the Machine > Extruder Onboard Preferences… dialog box.
From the “MK5 PID tuning?” discussion, the following PID settings may be a good starting point:
- Set Proportional to 5.143
- Set Integral to 0.0612
- Set Differential to 108.0
Also working well for many Operators, are the “Bre” MK5 Settings:
- Set Proportional to 5.1367
- Set Integral to 0.055
- Set Differential to 108.0
For further discussion, see PID Controller Tuning for one approach to manually tuning the parameters beyond default values.
– Matt
