tompoland Does anyone know if the Zerno, Sculptor, or other variable speed RPM are free of stalling issues?
If it “goes with the territory” then it’s not so much a design flaw as a design decision.
That said, it would be helpful if manufacturers clearly explained their decisions on their product pages. Virtually none of them do.
Webber Key and a few others. It basically seems a trait of certain brushless direct drive motor control systems that seem to be fairly ubiquitous in the Chinese made grinders.
One that uses a brushless motor and good control system (and a gearbox) that doesn’t stall is the Monolith Flat Max, that can go pretty slow…but there it’s from 1 - 400 rpm and I really only use it on 400, there is really no need to go slower and grind times really start to increase. Of course Monolith Flat Max owners don’t tell you this for some reason?
It’s over generous to call it a “design decision” rather than a design flaw…in fact as a reviewer of grinders I would have expected you to see it as a design flaw. If I designed a plane that couldn’t fly above 200ft, a car that had 5 gears but you could only use 3, a grinder that stalls on light roasts……..you get my point I hope.
They don’t say anything because that’s the nature of the Chinese…the real question is why the retailers don’t say anything, and of course the influencers, to clearly explain this “decision”. To me the decision doesn’t make sense. Why have speeds on a grinder you can’t use, why is hot starting/stalling suddenly OK?
The same thing goes for hot starting when grinding…is the decision, “we made it so cheaply/badly, that you have better run it before you put beans in”. This was never a feature of good grinders…I don’t remember any hopper fed grinder that needed to be hot started? Along came the single dosers and suddenly stuff comes out of China that needs hot starting. The job of people who influence, would be far better placed influencing the industry. you don’t see a Niche Duo ever stalling, or need to be hot started…because that wouldn’t be an acceptable situation.
I have been testing a grinder out of China for some months now. It’s variable speed 64mm, uses a brushed motor, which is just as quiet as the brushless. It will grind light beans from a standing start at it’s lowest rpm, no problem and has never stalled, or even come close to stalling. I tested out some beans @LMSC gave me (thanks Sundar) and I am drinking a coffee made with them now. I ground at 7 marks away from 0 (which is the touching point) and got a 58s shot from the Evo2 lever, so I have set it to 9. Does it slow down a tad when grinding at it’s lowest speed of 800 rpm, yes, probably around 10%, but it never struggles, or sounds as if it struggles. You would only know it has slowed down because of the slight speedup when it’s finished (there is no noticiable “ramp up” to speed as in some brushless. But of course this small slowdown under load is absolutely normal for a brushed motor (or brushless for that matter).
It’s turning out to be a great little grinder, especially for the predicted price…if, Bella Barista decide to stock it. Does it have whizzy grind cups that flick into place magnetically, hopper lids that click on magnetically and other oooh features the influencers like. No, but it’s a nicely designed thing that works as a grinder should. Although there are a few manufacturer changes being made that I asked for and one other change I am really hoping they make to put the cherry on the cake in terms of functionality as I see it.
