Looking at Bontech and Printerbot Gearhead extruder for CoreXY build. Which one would be the better choice?
Bontech - support the little guy. Printrbot is making enough money right now. 
Ha!! It’s not about the money! It’s about the cost to users and whether or not the gear head competes well. Don’t you wonder which is a better value? Ive wondered if it’s overkill.
I’ve never seen a head to head on the two. I just posted I’ll give 4 away to the first 4 with a bond tech willingbtobtest and publish results. I’ve considered putting a geared stepper on the gear head but haven’t needed it yet… “Geared gear head??”
Competition is good. I really like his design. Funny that we were both working on similar solutions at the same time. I open sourced mine (printed version first) and he posted his announcement a day or two later. I wish him luck. Glad the option is out there
Brook
There is a theory that breakthroughs in development happen around the same time (thus why the patent system is pointless). That is because the breakthrough is the next logical step from the previously developed technologies. It happens because it is inevitable like evolution.
Anyways, the bondtech seems to be the favorite of bowden users. Don’t know about direct drive. The gearing doesn’t just help with torque, it allows for a lighter motor, and higher resolution.
I just recently put a Bondtech on my kossel XL and it’s the most constant and precise extrusion I have ever seen. You won’t regret it
If bontech can come down closer to $100 I’d be all over it.
I’m running a beta set of the Printrbot Gearhead gears on one printer (direct drive, 48mm motor), and a beta set of the bondtech v2 gears on the other (short bowden, geared motor). They’re both very reliable once they’re dialed in. No problems with filament slipping or grinding with dozens of different kinds of filament on either of them (except for esun cleaning filament which gets too skinny in spots for both, they’re both set up as fixed width extruders, and some filled filaments with the smaller nozzle sizes). They’ve been maintenance free except for one bearing on the gearhead that broke (the bondtech uses needle bearings which seem more robust, but don’t look replaceable). I’m using my own housings for both so I’m just referring to the drive gears and not the stock extruder designs.
There’s a big difference in the pitch of the teeth between the two, but I can’t say that I’ve seen it makes any difference other than the filament wobbles a bit when entering the gearhead, and the larger teeth seem unlikely to wear over time. At one point I started to do some test prints for a comparison between the gearhead, bondtech and fostruder (a dual motor extruder) but they all looked the same so I didn’t bother. Sorry I don’t actually have an answer to your question, I like them both. The bondtech direct drive gears look nice too.
Thank you everyone for your posts! Both options look really good. Very hard decision. May end up going with the Bondtech direct drive.
Thanks for that report of the comparison between the two!
Best of luck
@Brook_Drumm You definitely need to try a geared stepper… A good single-hob design will stall a NEMA 17 before stripping, so there’s minimal value added with the second hob unless the motor also pushes harder.
Even a 3:1 or 5:1 would be perfect. Many people don’t retract at super high rates, still plenty speedy.
@ThantiK Agreed, I love my 5.2:1 planetary stepper extruders. A short-stack NEMA 17 with gearbox weighs about the same as an ungeared standard length NEMA 17… but you’re running in a much better region of the power curve and get a lot more torque even with pretty aggressive retraction.
Gearbox wear is a potential issue though.
On the talk of geared extruder setups I need serious help…here is the deal…long story short I CANNOT change the steps per min feedrate so please don’t ask or recommend that…I have a Wade Bowen extruder and my Feed when sending 50mm comes out to 151mm. HOW can I figure the size to Reprint the Gear to have this offset handled by the gears and not software? If someone could make it that would be insane awesome…please help. And once again I can’t change in the software (M3D)
This seems to be the right gears for my setup…just don’t know how to remake to reduce the 150mm to 50mm…