Do-it-yourself BondTech BMG extruder: save on top products

We are all looking for something new, better. In the same way, it is always interesting to install something new on a 3D printer. Make him an update, along the way improving a number of parameters. This is the upgrade. A topic with a selection of non-obvious and useful things for a 3D printer from Aliexpress: to help a 3D printer is already on the site. And in this article we will talk about a unique BMG extruder from BondTech, a well-known company in narrow circles.

The extruder is quite thoughtful in design, it belongs to direct dual drive extruders — two gears are installed inside, tightly compressing the bar and pushing it into the hot end. This design is optimal for soft plastics: nylon and TPU/TPE/Flex. Another feature is that it is lightweight. Only 75 gr. Suitable for all types of printers. The engine is recommended to be installed thin («pancake»).

Compatible with popular E3D. Can be installed for Bowden without any problems.

An original BondTech BMG extruder costs about $80.

The cost is very high, especially for printers with two extruders (it turns out $160 + shipping, close to the cost of the entire 3D printer).

The principle of operation is similar to classic extruders with a slight difference — instead of a pressing bearing, a second feed gear is installed. An additional gear is installed on the axis and with a needle bearing, opposite the drive gear, which is mounted on the stepper motor shaft. The gears engage with each other and work in sync as a pair to push the plastic further. The shape of the inlet and outlet openings is optimized for soft plastics — now the filament will not jam in the mechanism.

External view of the extruder. For that. to «charge» the plastic, it is enough to press the lever and push it into the receiving hole.

Drive gear and channels for plastic close-up. The quality of the gears is high.

Actually, it is said that a copy of BondTech BMG can be made independently without any problems. The plastic case is printed on a 3D printer, a set of gears can be purchased. The cost is reduced by almost 10 times.