So today, I decided to try going hopperless on my Robur-E. It was easy to bypass the safety feature and so I removed the hopper. I cleaned out all the old grinds and put in 18.5gm of whole beans into the throat and ground. I was able to retrieve almost 18gm of grinds with sweeping the chute and pulsing the grinder. When I tried to pull a shot, I was met with an extreme gusher! Since I wanted to be sure it wasn't caused by some freak old beans left behind (very doubtful), I repeated the experiment, this time with a tamper over the throat (which doesn't really work since the beans are below the burr retaining bolt). Same result.

I thought the Robur-E has a device to guide the beans into the burrs so I was sure this would work but as soon as I put the hopper back on and half filled it with beans, all was back to normal. I don't think changing the grind is the correct answer. Perhaps some sort of tube like Andy's would work but then, I might as well use the hopper.

I guess my question is, did I miss something? I don't really mind using the hopper but I wanted to keep as much of my beans frozen as possible to keep them fresh.

While the Robur's auger may prevent popcorning, and may even provide a more constant level of pressure on the beans entering the burrs, it's still possilble that the pressure is somewhat greater when there's a load of beans in the hopper. Your results certainly appear to suggest that.

You should try grinding finer before dismissing the idea. If you get the same flow characteristics and flavor profile when you grind finer, then I think you'll have the answer.

The reason I didn't want to grind finer is that while it would improve the flow, I would think the particle distribution would be greater. I don't know if that would affect the taste but it should affect consistency which is what I seek.

Thanks Jim, I read through the threads you linked and am still confused. Hopefully, this latest experiment you are performing will shed some light on to this subject.

Between you and Dick, I have been convinced to revisit my hopperless experiment. At first blush, I was turned off because I was sure it would affect my shot consistency but after reading all the threads you linked, it seems likely that it will work and not adversely affect my shot's outcome.

I wish I had more beans for your experiment as I would have sent in hopperless samples too.

A shifting grind as the hopper empties is normal. Some grinders are more pronounced than others. You really only have two options. Set the grind finer to compensate or put a couple shots worth of beans in a stubby hopper and put a little weight (tamper) on top to provide positive pressure. The grinders were designed to run with a hopper full of beans. There is only one grinder that I know of that is designed for a grind per shot setup.

Isn't the Rober E among the worst grinders possible for single dosing?

Bob_McBob wrote:Isn't the Rober E among the worst grinders possible for single dosing?

I don't really know enough about other grinders to compare but I was able to lose less than a half a gram single dosing and I have to believe that the E versions have less waste because I can put a tool all the way into the chute and scrape out almost everything. There's no doser cleaning necessary. Just some tapping on the funnel and the grounds drop down.

I forgot to mention that since I live in a high humidity environment I've been able to completely remove the static screen so my results are not usual.