Not sure if these are still used as much around here and if people are getting them these days, but this is what worked for me.

I stumbled upon some old SJs and got two for a very good price.

Converted one to single dosing with the Daniel Wong system, which is pretty awesome.

SSP V2 cast burrs were put in and I used the portakeeper anti popcorn device for the DF64 as my anti popcorn device. Had to dremmel it down a bunch so it would fit lower inside the throat of the grinder.
It works really well!

Got the DF64 bellows as well and they work perfect too.

I'm getting zero retention this way. 20g weighed before and get 20 out, pretty much 98% of the time.

I might get an occasional 19.7-19.8 but it's rare these days.

I'll try to keep this thread updated with other things that are working for me.

My last problem that I'm trying to work out is the are where the burr screws mount. That seems to be a point where I get some old stuff to hang out as you can see in the pictures.

Rohan has "The FrankenJolly" and did a good write-up on his approaches at https://pocketsciencecoffee.com/2022/03 ... nkenjolly/

Something there might help you reliably get that last half-gram or so of exchange even more under control.

Haven't seen that yet Jeff! Thanks for the link.

What is that sweeper in the second picture? Is it a printed part?

It's this part, dremmeld down to fit further down in the throat of the Mazzer.

https://www.espressooutlet.net/anti-pop ... -grinders/

I'm using a Macap M4 stepless as a single doser. Brushes are my friend. With the top open I brush clinging grounds down into the grinding chamber, put the bellows back on and pump out grinds with the grinder running. Brushing out anywhere grinds cling ends up with low retention.

Thanks! I was using brushes, but with the anti popcorn piece, it became a pain because I d have to remove it in order to brush.

Prior to the anti popcorn piece, I'd use the tamper on top of the grinder and then the brushes, but that workflow, even though less than a minute longer than bellows, got annoying.

I liked the bellows a lot more and was moving well through the work flow, so wanted to keep it that way. Appreciate the help and suggestions.

For the people using these commercial grinders for single dosing, do you guys have a preference in adding beans while it's running, or starting it with beans loaded to go?

I'm liking the process of adding beans with grinder running.

I've always added beans first with a hopperless set up but only because some would popcorn out before I could cap them. Don't think it affects the grinder or grind that much. Never tried slow feeding a running grinder. There was a concern sometime back about effects on grind uniformity that favoured bean weight to prevent popcorning as a way of getting a better grind. That discourages using a hopper machine for single dosing but closing the hopper flap kept beans from bouncing around too much. The advantages of single dosing outweigh any effects IMHO.