I have the Robur E and can't make single dosing work. If the hopper isn't in place, and at least an inch full, I get so much variation in grind quality that pulling shots is nearly impossible. I know the Robur has an auger but that doesn't seem to help very much. Does anyone have a solution that is consistent?

If you feed in only a single dose, i.e the 12 to 24 grams you want plus a gram or two margin, it will work consistently, i.e
-- the same setting for the same dose gets the same flow for almost all coffees,
-- and a linear increase in coarse settings required for increased doses.
However, the whole scale is offset from the full hopper settings, about 2 grams finer if I remember my time with it correctly, i.e. to grind a 16 gram single dose, use the 14 gram full hopper setting.

For this, you only need a lid to prevent the coffee jumping out, not any sort of mini-hopper

The picture shows something else, a mini-hopper executed in elegant blue file folder stock that was kept full at all times. This recreated the full hopper grind settings. I never use a mini-hopper for myself; instead I was abjectly bowing to the superstitious howls of unbelievers in my repeated inability to taste differences in single and hopper dosed shots

another_jim wrote:I never use a mini-hopper for myself; instead I was abjectly bowing to the superstitious howls of unbelievers in my repeated inability to taste differences in single and hopper dosed shots

Well, count me as another howling superstitious unbeliever. The Robur grind changes more dramatically for single dosing than any other factor, including beans, roast level, roast age, etc. Testing for taste differences is always tough; without paired Roburs, there is no way I could do it. So I'm relying on indirect evidence; to wit, gross changes in the grind. That is enough to convince me that single dosing, no matter how convenient, is not what these grinders are designed for.

I (arrogantly?) believe my method of single dosing with the hopper in place would suit you.
Post a video of your espresso making technique

Also, it would make you the second person in the world to my knowledge using that dosing method

Of course you can single dose and get a decent pour, regardless of whether you use a doser or doserless grinder. But the grind changes so dramatically below a certain level, that I prefer to keep a small column of beans in the hopper.

This subject (single dosing) has been discussed ad nauseum, and I'm not going to spend any more time posting on it. I was mainly responding to Jim's, um, flowery language above ("abjectly bowing to the superstitious howls of unbelievers").

I thought when reading this, to try to grind few beans at a time [throw them in to running motor], so all have consistent weight on them. It was a gusher. I expected it to flow a little faster, but not a 3 sec shot, since grind was already dialed for a single dose. Can test w/ finer setting, but isn't practical to grind so slowly.

It did make obvious that at least the last bit of beans in single dose have a much coarser grind than start of dose.

I noticed Jim said:

another_jim wrote: i.e the 12 to 24 grams you want plus a gram or two margin

What's the extra grams for? do u leave it in grinder? or does it just get lost?

I'm asking, since it made me think to try to grind a bit more, and not use the last [coarsest] grounds -- usually, I add .2g to intended dose and scrape everything out... in last shot, I ground 2.2g more... by luck, just grinding until chamber empty resulted in intended dose in basket with no cleaning of chute. Shot was much much better than in last couple days playing with this batch.... with a note of strawberry popping out... a note! [it's been a while ] -- will see... maybe just luck.

michaelbenis wrote:Considering the OP Mitch has a Robur E, a good first step to improving single dosing could be to remove the wire grid over the chute mouth, although I have no personal experience of this.

That screen's been gone for a long time!!

After visiting with Jim and seeing his ability to change beans so easily prompted me to change my current method of hoppered grinding. Since I've already modified my grinder to allow the hopper to be removed and still grind, I figured it would be a breeze to single dose but my shots were so inconsistent that I went back to hoppers. Using the column approach won't help me because I would still waste a good amount of beans when switching.

For now, I am stuck using the hopper and sticking with infrequent bean switching until someone comes up with a method for consistent bean fed single dosing Roburs!

Taking the big hopper off I have a great system for feeding 2-3 shots through at a time with 20 or so grams of waste per session. Keeping the black collar in place and using the weight of a tamper to keep pressure on the beans I get really good results.
If your goal is to try to turn this production beast into a single doser my suggestion is to buy a more appropriate grinder for the required task such as a Versalab or better yet a hand grinder such as an old Dienes.