The two most popular geared extruders are the Bondtech BMG and the E3D Titan, each of which has several clones:
BMG
The BMG has two basic styles of clones. The DotBit clone has a heavy rid running down the center of the handle. Its bearings don't sit tight in the extruder body which will allow them to turn in the body and cause issues later. Unfortunately, there's no real way to fix it. The CHPower is one of these.
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| DotBit style |
The other type of clone is simply labeled Dual Drive Extruder, and in those the bearings actually fit correctly into the body (a light press fit), but they use very cheap bearings which become notchy as soon as they're pressed into place. The Triangle Lab is one of these clones. If you want a BMG clone, your best bet is the Triangle Lab clone and replacing the bearings for higher quality ones if necessary.
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| Dual Drive style |
Titan
The Titan has three basic styles of clones, of which I've tried two. The first looked almost identical to the genuine Titan, but the quality on these is bad and they have chronic issues with the guide tube not lining up correctly. If you get one when everything does line up, it should work well. The Winsinn is this style of clone.
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| Winsinn style |
The second style has been redesigned somewhat and while it operates the same and is the same width and length, it's actually taller than the genuine Titan. The redesign includes a bearing in the tension arm for the motor shaft to turn in, and a resigned body that eliminates the bolt running through the center of the drive gear. I think this is design is actually better than the original Titan design, and if it fits your application I recommend it. The Redrex is this style.
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| Redrex style |
The third style has also be redesigned with the tension arm no longer pivoting on the motor shaft and an extra screw between the drive gear and the filament exit. I haven't had any hands on experience with these. The HE3D is this style.
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| HE3D style |
