It's been a little over a year since I discovered HB, with it's great reviews, How-To articles, and informative posts. Hopefully this, my first post, will be something useful.
Last night I read a thread about modifying the La Cimbali Jr grinder to avoid beans hanging out on that ledge most of us have heard about. Yes, I single-dose. I didn't know this was an issue, let alone a contentious one, until I read a thread last night. Wow. Without going into the reasons why, I'm not going to change to loading the hopper; it's just not practical for me.
For most of the time I've owned this grinder my routine for preparing a shot has been to measure a quantity of beans by weight, pour into the hopper, activate the grinder and after most of the beans have been ground go in there and with a wooden stir-stick and carefully move whole/partially ground beans off the ledge into the whirling burrs. Using the black separator thingy helps to keep beans from popping up the throat and into the hopper and hanging out up there. This has worked ok but I've been getting tired of doing this and wish the hopper was more conical like on other grinders so all beans would naturally fall into the burrs.
Back to the mod article. I love idea of using the upper part of a plastic bottle as a hopper-in-a-hopper. It's brilliant! However, I don't have anything like that on hand right now. (I'll be keeping an eye out in case a suitable candidate shows up.) Instead I thought about using part of a paper towel roll but it was too wide. Ditto for a toilet paper roll. (I had several on hand because I give them to my gerbils to chew/play with.) So instead I cut part of a cardboard box to create an extension of the hopper throat directly down to the burrs.
Here are some pictures, first of the cardboard fitting, then how it looks with the hopper back in the grinder, and lastly how it looks with 16.8 grams of Ambrosia in there.
The results were so good I'm embarrassed I didn't try to do this long ago. I ground two doses and each time once the grinder was "finished" by force of habit I opened the black plastic thingy to go in and scoop the beans off the ledge... except there are none to scoop! All beans were gone and there was no evidence of grounds sprayed anywhere. With this mod in place I can confidently turn the grinder off when I hear it's stopped grinding and avoid playing tag with the burrs trying to get those last few beans ground. Sadly, I cannot retire the stir-stick just yet; the exit chute seems to hold about 0.4 grams of grounds and I've recently taken to getting them out. Oh well.
However, I now need to make adjustments to my dose and grinder settings. I noticed right away that the amount of grounds in the portafilter seemed different than usual and when I pulled the shot the machine choked. For the 2nd pull I altered the grinder setting from my usual 3.0 for this coffee to 3.5 but still it took over 30 seconds to get about an ounce, as opposed to about 20 seconds for @3oz before I did this mod. (Both shots tasted very good though!)
Based on my limited experience this morning, it certainly does seem like the "popcorn effect" affects the quality of the grind with the Junior.
Grinders are one of the keys to exceptional espresso. Discuss them here.