March 29, 2021
This week, we’re focusing on an upgrade that can help with expanding Quinly’s filament options: a direct drive extruder. So what is a direct drive extruder? Well the Ender 3 comes stock with a bowden style extruder, which is where the filament extruder pushes the filament through a long tube into the printer’s hotend where it flows out of the nozzle. This has some benefits, like reducing the weight of the moving hotend assembly for faster print speeds, and easier maintenance because the parts are separated. It’s for these reasons we run our own Quinly kits with bowden extruders. But there are downsides that might lead to you wanting to move to direct drive. For many who print flexible filament, for example, a direct drive extruder leaves less room for the filament to compress or bend, meaning that extrusions become more consistent and can be pushed faster without issues. That is not to say that flexibles cannot be printed on bowden setups, but often the results are less clean and take longer. So for users who wish to regularly take advantage of the VAAPR bed’s ability to print TPU, TPE or PP, a direct drive upgrade could be very useful.
An employee's printer featuring many upgrades, including a direct drive extruder.
Another reason many make the switch is if they are having problems with retraction and stringing on their prints. With a long bowden tube, there is typically play in the connectors, as well as inside the tube, and so filament can move back and forth during filament retractions. This means that in your slicer you often need to have long retractions at slow speeds on bowden setups like the stock Ender 3. On a direct drive setup, the distance the filament travels from the extruder gears to the nozzle is much smaller, so retractions are more precise, usually being only a millimetre or smaller, compared to up to 7mm on a bowden setup. These shorter retractions can lead to less stringing, less clogs, and even faster print speeds if the part requires many retractions.
A Klein bottle printed in polypropylene, a material that benefits from direct drive.
So what are the options for those wanting to switch? Well you can go from simply printing an adapter plate that moves the stock extruder to the hotend carriage, all the way to options like the E3D Hemera that combine the hotend and extruder into one piece, giving many benefits, but costing much more. Which option you choose is up to you, however the stock Ender 3 extruder is not very suitable for flexible filaments, so if you are upgrading primarily to print flexibles easier, you’re probably better off with a system that also replaces your extruder. Online, there are many different options of DIY printed mounts for various extruders, so look around and decide for yourself which is best for your use and budget.
have you upgraded you Quinly to direct drive? Tried it on Ender 3s in the past? Send us pictures of your setups or prints @3dquesystems!