Hey, Do you know which gears they started outsourcing the production of? I'd like to try replacing the gears I have with the newer ones to see if I can quiet it down a little.RTIII wrote:If they all used the gear design like in my unit, they would all be silent running.Triketech wrote:I've been watching this topic a long time.
Last spring I ordered one from the factory, and made it clear I would be publishing an article about it.
(BTW, it was supposed to have 1M cables but came with short std cables, and built 3 days after the order.)
Summarizing what I've learned:
Tongsheng probably released the product a bit prematurely. Over time changes for cost & reliability while increasing power levels probably introduced a few new parts and software updates.
Early motors tended to make little gear noise, but louder motor noise typical of a Trapezoidal controller. Later motors tend to make loud gear noise, and less motor noise - although that may be masked by the gear noise. I haven't looked at the earlier versions, but on the one that was build for me last April (factory order) the secondary gear set (steel spur gears) have a Pressure Angle (PA) of about 12°, which is way, way wrong for this application; 20-22°. Low PA makes a stout tooth, and a lot of banging and sliding through the contact. Grease is the WRONG lube for this gear angle, needs to be a medium weight gear oil 75W. Teeth were formed on a shaper, and looking at the teeth at about 20X, an experienced eye can see burrs from a dull tool running too deep a cut on each chop.
If they all used this gear design, they would all sound like mine does.
It's virtually certain that they'd use a gear vendor for volume production. A far more likely scenario is that they started with gears made in house or small workshop in low volume and when the volume of production increased, they farmed it out to a vendor who makes the gears much more professionally in larger numbers, which is why the younger units are widely reported as being quiet while that can't be said for earlier units. ... A reasonable estimate based on a few known data points is that they sorted all this out in May of this year. In my view, you clearly got an older unit, before the change, and now think that applies to all their units, even current production.Triketech wrote:Its unlikely Tongsheng makes their own gears. And when production ramps faster than Vendor A can produce components you add Vendor B. And sometimes that's a scramble for Procurement so they compromise quality for Vendor B. All hypothetical, yet the everyday life in the world of manufacturing.
My motor is from june 2016. I've already replaced that big one-way-bearing-gear after the old one failed. The old one had ball bearings, while the new one had roller bearings. There's no difference in noise levels except it's a lot noisier when I'm peddling with the motor off.