I’m looking for a direct drive filament gear, and I’m interested to know what the community thinks are the best choices. I’m interested in the Arcol.hu mini hyena v2 or the QU-BD raptor, but I can’t find much in the way of useful real-world usage reviews on either. Is the hyena worth the higher price and pricier shipping? Does the raptor work for 1.75mm filament or is it really better suited for 3mm filament like the reprap wiki says? Is there some third, better, choice that I’m not considering? So many questions!
Gonna piggyback this post… How does http://arcol.hu ordering work? I submitted my order, they emailed me an email to paypal payment to. I do that and now what? Will it just show up in the mail in a bit, or will I get a confirmation email or…?
Basically, yes. Once you get the invoice with payment instructions you pay and within about four days (although I think the site says four to eight now, must be getting busy) you’ll get a shipping notification.
I remember my order coming quite quickly, but I don’t remember how many days it took. They’re also quite good about responding to emails. I say “they,” but I think (although I’m not sure) that Arcol.hu is the work of a single guy (Laszlo is his name).
I frequently recommend the QU-BD hot end, but their drive gear is terrible. I haven’t used the hyena V2, but it should be good. The one thing I would worry about is longevity, because it has thin, sharp teeth and is made of brass instead of steel.
Others to consider:
http://store.makerstoolworks.com/hardware/machined-hobb/
http://trinitylabs.com/products/hobbed-pulley
I live in Orlando, FL area, and my http://arcol.hu drive gears took 3 1/2 weeks to get here. They are definitely amazing, they have great grip, but I’ve found they have a tendency to actually eat out the filament easier than my other drive gear. The teeth cut into the filament so sharply in my experience that it seems like I get failure to drive quite often. If this is just to do with fine-tuning the pressure on them, I haven’t found out yet.
I have some experience with the MK7 drive gears, and I find using them to be extremely frustrating. Either I get too little grip, or I strip the filament, and the amount of fussing it takes to get to a steadily usable state drives me nuts.
Is that the sort of thing you see with the hyena @ThantiK ?
In abstract theory, thin brass gripping surfaces seems like a bad idea because they’ll bend or degrade easily, but how much is that an observable reality? The filament should be quite soft compared to brass, and I don’t think we’re applying enough force to deform the gripping surfaces… or are we? This is all based on gut feeling, though, I have no way to back it up.
IIRC, I’ve already seen this discussion about the Hyena when it first came out. The end consensus was that yes the teeth get deformed a ton but they’re still crazy sharp, and apparently the exact angles of the teeth don’t matter much as long as they’re pointy.
TL:DR yeah it bends, but doesn’t change behavior noticeably.
The Trinity Labs hobbed pulley looks extremely similar to the Mk7 drive gear. Going by the listed specs the valley on the Trinity Labs option is .5mm less deep, implying it might get better bite, but that’s assuming everyone lists exact measurements.
Can anyone confirm or deny the similarities between the two in terms of function? Is the resemblance just skin deep?
Based on visual inspection of the picture, the teeth are deeper than the (pitifully shallow) teeth of MBI’s gears, they just aren’t set as deep into the pulley. The diameter at the valleys of the teeth is greater, but so is the diameter at their peaks. As for the shape of the teeth, the trinity one is far superior to MBI’s. I’ve only inspected the picture, but I’ve ordered one for review, so I’ll have more definitive information in a few days.
There’s no picture on makerstoolworks, but knowing where they get it, I’m confident that it’s very similar to trinity’s.
They’re also cheap enough that I can just order one to check out too. Although I look forward to your more detailed review of it, too.
I personally prefer Trinity>MK 7>Hyena. Although I think I beat my hyena up quite quickly when my filament stripped. My true direct drive never worked well. I had issues with either too much tension and the stepper skipping or too little tension and stripping. I am going to try Airtrippers bowden extruder some time soon which allows for a bearing on the end of the Nema 17 shaft in order to reduce the radial loads from the idler, which should reduce the skipping issues. My solution for now has been to use a 5:1 planetary reducer on the stepper and it is extremely reliable with the MK 7 and trinity labs hob.