3D printing for many novice users is challenging due to low adhesion to cold surfaces and delamination due to temperature changes. In this article, we will try to talk about how to improve print quality using ABS.
ABS plastic is the most popular material for 3D printing, as it has the following obvious advantages:
AVAILABLE - due to relatively low cost.
SOLUTION - in acetone and ethyl acetate. They are used to smooth the effect of "steps" in printing, cracking and mechanical post-processing results. Ethyl acetate with the same efficiency, safer to use. It has a mild fruity odor and is safe even after extended indoor use.
EASY TO COLOR - both with safe acrylic paints and budget nitro enamels in cans.
SUITABLE FOR MECHANICAL POST-PROCESSING - cutting, grinding, painting.
MELTS IN A WIDE RANGE OF TEMPERATURES
………………………………………………..
But with all the obvious advantages of 3D printing using ABS plastic, for many novice users, there are difficulties associated with low adhesion to a cold surface and delamination due to temperature changes.
In this article, we will try to talk about how to improve print quality using ABS plastic.
Stages of preparation for successful 3D printing and printing itself:
1. Modernization and maintenance of the 3D printer.
2. Preparing the 3D printer platform.
3. G-code preparation or slicing with desired print options.
4. Control and management of printing.
Stage #1 Modernization and maintenance of the 3D printer:
1.1. Platform.
I recommend upgrading your printer platform once and forever forget about glues, adhesive tapes and other expensive consumables that improve the adhesion of ABS plastic to the platform.
a) The platform must be heated or made of thick plexiglass (acrylic). ABS plastic adheres well to cold acrylic coated with a light solution of ABS plastic and ethyl acetate (hereinafter referred to as "ABS solution"). Select the concentration of the solution empirically, based on the haze of your surface. But the disadvantage of acrylic (unlike ordinary glass) is that it has less rigidity and can be deformed as a result of heating from the ABS plastic. Therefore, the thickness of acrylic should be taken at least 6-7 mm (optimally 10 mm), or acrylic should be fixed to a rigid frame to prevent deformation. Please note that if you overdo it with the ABS solution, the model is difficult to remove from the acrylic platform.
b) A platform made of ordinary glass must be heated and frosted. Frosted glass is sold in any glass shop. The size of the glass lining (in length and width) is desirable to select such that it is no more than 5-10 mm of the heated platform. Thus, the glass can be pressed to the overlay with stationery clothespins.
For a small platform area (like the MakerBot Replicator), 4-5mm non-tempered glass can be used. For example, we use ordinary glass 260x150x4 mm for many months without problems. If you have the opportunity, use tempered frosted glass. In the event of a fall, it crumbles safely and is not so afraid of temperature changes. But this is not a mandatory requirement.
1.2. Contacts, thermocouple 3D printer.
For high-quality printing with any plastic, incl. and ABS, the printer must keep the set temperature on the extruder in the corridor at a maximum of 4-5°C. Large temperature drops lead to uneven shrinkage of the layers and, accordingly, to their different stiffness.
The reasons for large temperature fluctuations can be:
a) poor contacts between the extruder and platform. Oddly enough, but if the contact on the platform is lost, the controller can often incorrectly maintain the temperature on the extruder.
If temperature jumps / dips are detected, check all contacts, tighten them and lubricate (lightly) machine oil (preferably contact grease).
b) the thermocouple does not adhere well to the heating block or is located on the opposite side of the heating block from the heater itself. This results in pauses in the response of the thermocouple to the heater. If the thermocouple is not isolated from the air currents around the extruder, it will also measure the temperature with a large error. To do this, move the thermocouple as close as possible to the heater and fasten it with FUM tape to the heating block. Since the FUM tape is a fluoroplastic (Teflon), it has all the necessary, in our case, advantages - high heat resistance and low thermal conductivity. This procedure will also reduce the heat loss of the heating block and save on electricity.
1.3. Airflow and camera.
In my opinion, the need for blowing occurs when the print time of each layer is less than 20-30 seconds. I recommend using vertical spherical (around the nozzle) airflow (fig. above), rather than frontal. With such blowing, the layers are cooled more evenly, and the part does not warp due to uneven shrinkage on the sides of the model. The fan must
Write a comment