Comparison Sunlu SL-400 vs Sunlu SL-300

3D pens in most cases are designed to work with various types of plastic ( ABS plastic, PLA plastic, PCL plastic). But there are other materials as well.

— ABS plastic. Synthetic plastic with a melting point of about 230 °C (softening point is slightly lower). This material has a fairly high durability and rigidity, it is suitable even for "drawing" free-standing parts (vertical lines, spirals, etc.) right in the air; however, ABS parts can be bent to some extent. The stickiness of this type of plastic is low: it is suitable for drawing on paper, but does not stick to glass, ceramics and other similar materials. The surface of parts made of ABS is glossy, the plastic itself is usually opaque. The univocal disadvantages of ABS are – firstly, the need to heat up to fairly high temperatures, which increases the risk of burns; secondly, the unpleasant smell of burnt plastic that occurs during operation. Thus, this option is considered to be best suited for experienced 3D artists who often operate with objects in the air.

— PLA plastic. Plastic of organic origin, produced from vegetable raw materials and related to biodegradable materials. Actually, one of the advantages of PLA over ABS is considered to be environmental friendliness. However, in addition to this, this material has quite practical advantages. First, it melts at a lower temperature, which som...ewhat reduces the risk of burns. Secondly, the smell of heated PLA is very weak and not as unpleasant as from ABS (similar to the smell of corn or caramel). Thirdly, this type of plastic readily sticks to various surfaces, it is suitable for drawing not only on paper, but also on metal, glass, ceramics, etc. In addition, PLA can be not only coloured, but also translucent and even luminescent. The main drawback of this material is softness: it solidifies rather slowly and is poorly suited for drawing “in the air”. In addition, objects made of it are quite fragile and short-lived. PLA is considered a good material for beginner artists, including children.

— ABS + PLA plastic. Pens capable of using both ABS and PLA plastic. The features of these materials are described in detail above. Also note here that, usually, a temperature controller is provided in pens of this type to adjust to a specific type of plastic. Such models are the most versatile, however, they are more expensive than analogues for a single type of material.

— PCL plastic. Another type of biodegradable plastic, along with the PLA described above. It has an even lower melting point — it reaches a plastic state at 45 – 50 °C, due to this PCL is the safest one among the materials used pens with hot printing (see "Product Type"). In addition, such plastic is positioned as reusable: for reuse, it is enough to soften the finished product in hot water. Finished products made of PCL have a glossy surface, the hardened material is quite elastic and flexible.

— WOOD plastic. A plastic-based composite material (usually PLA — see above) to which powdered sawdust has been added. Due to this, finished products made of such material look and even feel very close to wood. Wood-plastic usually has a specific wood colour, but the shade of this colour can be different — depending on the specific composition of the sawdust added during manufacture. In terms of most performance specs, this material is similar to the same PLA — except that the interlayer adhesion in the “wooden” variety is somewhat weaker.

— Photopolymer resins. A type of material used exclusively in pens with a cold printing method (see "Product Type"). Under normal conditions, this resin has a liquid consistency, and it solidifies under the ultraviolet light from the LEDs built into the pen. Photopolymer resins do not require heating while operate, making them as safe as possible in terms of burns; in addition, they are odorless. On the other hand, such materials are much more expensive than plastics for "hot" drawing.

— Glue sticks. Traditional glue sticks – like those used in glue guns. 3D pens usually differ from such devices with a smaller nozzle diameter and a more uniform supply of adhesive. This contributes to accuracy while operate and provides opportunities that are not available for regular glue guns – for example, the creation of fairly complex three-dimensional structures. At the same time, the pen can also be used in the classical way – for applying glue to fix various parts. And the glue sticks are cheaper than specialized 3D plastics and are widely sold in stationery stores; at the same time, among such compositions one can find quite specific options – coloured, glitter glue, etc. On the other hand, this material is generally inferior to most 3D plastics in terms of durability and reliability, and therefore such pens are not spread so far.

— Food paste. Pens made for such filament are intended primarily for confectioners and amateur cooks who want to give their products an unusual appearance. Food paste allows you to add original decor to cakes, pastries and other products, as well as to "sculpt" completely independent products – for example, sweets or candies. Such material may have a different colour, taste and composition, but manufacturers usually try to make it as safe as possible for health – for example, many food pastes contain specially selected substitutes of sugar. However, it would not hurt to clarify the specific set of ingredients of the paste separately – especially if one of the potential consumers suffers from allergies or intolerance to certain products.

The diameter of the nozzle provided in the pen.

The larger the nozzle, the thicker the lines produced by the pen will be (ceteris paribus; the actual thickness of the lines will also depend on the type of plastic and the adjusted temperature). In the thinnest models, the nozzle diameter is less than 0.5 mm, in the thickest models it is about 0.9 mm. Most modern 3D pens have nozzles in the range of 0.6 – 0.7 mm — this value is considered the most versatile and convenient for practical use.

Possibility to adjust the heating temperature of the pen with a "hot" type of operation (see "Product Type").

Most devices with this feature capable of working with different types of plastic — both ABS and PLA (see "Filament Material"). These types of plastics have different softening temperatures, and temperature adjustment is used in order to adjust the pen to a specific material. However, this function can also be found in models designed for one type of plastic. In such cases, adjusting the temperature allows you to prepare the device for threads of different thicknesses (the thicker the thread, the more intense the heating should be), as well as change the fluidity of the material (the higher the temperature, the more liquid the plastic coming out of the nozzle).

The number of fixed speed settings provided in the pen. This spec is specified only if there is more than one such setting.

The speed control allows you to adjust the mode of operation to the circumstances: for example, a low speed will be convenient for fine work, and a high speed is so for large elements. And the more speed settings there are in the pen, the wider the choice for the user to configure the device more accurately. In the most advanced models, the number of speeds can reach eight.

Note that the speed adjust can be not only stepwise, but also smooth (see above).

Automatic power off of the pen for being idle for a while. Usually, auto-off triggers after a few minutes.

This feature is found mainly in models with a "hot" type of operation (see "Product Type"). It saves energy and reduces the risk of getting burned by accidentally touching the pen that is left on. However, there are also "cold" models with auto-off.

The availability of a built-in display. Usually, these are the simplest single-colour screens that display the basic operating parameters — speed and/or temperature. However, even such a display makes the pen more convenient and allows you to get important information about its operation.