Good morning/Happy Holidays everyone!

I'm sure most of you are still on your holiday vacation so hopefully someone out there with a Compak K10, can chime in...

Background: I've had my Compak K10 (Pro) for about 2 months, bought it new from ChrisCoffee. I obviously did a ton of research when buying and found that most people can easily single dose this unit, which is good for me. My beans are fresh, anywhere from 3-10 days out of roast, occasionally frozen, but I would say once a month I'm using frozen beans, if that.

Issue: I weigh out 18g, plop it in the throat, put an empty Spice Island jar above it, and pull the trigger. About once a week it'll clog, burrs won't budge, I can hear the motor running, but no grinding. I have the unit on a darkroom timer (gralab 450, with a foot pedal). I thought maybe the start capacitor was weak, but I'm not much of an electrician, to figure that out. If I empty the throat, and coarsen the grind, it will spin free. This takes about 5 minutes, and quite frankly at 5:30am... not something I look forward too.

Another thing that I "can't" rule out is that with the foot pedal, the slightest amount of pressure flips the switch, and I've actually gone to press it, and actually turned it On then Off again in like a 10th of second, and wonder if maybe that tiny amount of time was enough time to lodge a bean which was enough to stop the burrs.

Has anyone else had this issue? Any thoughts? Any other good work arounds for the single dose? I personally hate the "On/Off" switch the unit comes with, and I enjoy having a timer, so I can hit it and walk away.

Thanks for your help as always!
-Justin

My morning routine is very similar to yours, with the exception of no dark room timer, and I've never had a problem with the burrs getting stuck. My first check would be to pull out the timer, and just run the grinder normally (or normal for single dosing), to see if that's where the problem is?

I'll usually weigh the dose going in to the grinder, and add an extra gram from what I need so I don't have to scrape every last grind out of the chamber/doser. Then weigh the dose coming out if I want to be precise, but it's usually within a couple 1/10ths of what I'm targeting. Does the darkroom timer make things easier for single dosing?

Considering the amount of bumping required to brush out the K10's chute, how is the timer all that useful in the first place?

The time really only facilitates the foot pedal, it also allows me to turn it on, and walk away from the grinder to do other tasks, knowing it will be done grinding when I return, and not still spinning freely. It's more of a "convenience" than anything else. At this moment, unless I switch to a small hopper, and small amount of beans and time my grinds, it's essentially just a means to use a foot pedal...

I've never experienced anything like this. I've had my K10 for about 6 months now and I either single dose or fill the hole leading to the burrs all the way, top it with a 53mm tamper and grind away - gives me enough for 2 doubles. I'd suspect the timer if I were you.

Over the last few years, the K10 has stalled two or three times. The Mazzers I've tested have never stalled, except one time the Super Jolly with Duranium burrs. I wrote that off as a consequences of the more aggressive cut of the Duraniums. While I have no proof of it, I share your suspicion that the Compaks have smaller capacitors for motor startup and thus are more likely to stall than Mazzer grinders.

That said, since you single dose, the startup demand on the grinder should be less than if the grind chamber is full of grinds and the hopper loaded. It's possible that your switch setup is aggravating the Compak's stall potential; I recommend trying a few weeks without the timer/switch and see if it continues to stall.

TrlstanC wrote:My morning routine is very similar to yours, with the exception of no dark room timer, and I've never had a problem with the burrs getting stuck. My first check would be to pull out the timer, and just run the grinder normally (or normal for single dosing), to see if that's where the problem is?

I'll usually weigh the dose going in to the grinder, and add an extra gram from what I need so I don't have to scrape every last grind out of the chamber/doser. Then weigh the dose coming out if I want to be precise, but it's usually within a couple 1/10ths of what I'm targeting. Does the darkroom timer make things easier for single dosing?

The darkroom timer would only make a difference if you were using a small hopper with a constant 100g or more in the hopper. Then you can set the timer to the 10th of a second, and let it grind per time, to get a constant weight. In my case of Single Dosing, the timer as stated by Bob is useless, and he's correct, but with this particular timer, you can hook up a foot pedal.
I have the timer in the cabinet below, and the foot pedal comes out on the floor:

so I feed the beans
click the pedal
step aside and start my flush routine
move back to the grinder and grab my acid brush
clean out the chute
click pedal on then off
clean chute
click pedal on then off
clean chute, and distribute.

This makes it more "hands free" than anything else, it adds no use other than convenience the way I'm using it.

HB wrote:Over the last few years, the K10 has stalled two or three times. The Mazzers I've tested have never stalled, except one time the Super Jolly with Duranium burrs. I wrote that off as a consequences of the more aggressive cut of the Duraniums. While I have no proof of it, I share your suspicion that the Compaks have smaller capacitors for motor startup and thus are more likely to stall than Mazzer grinders.

That said, since you single dose, the startup demand on the grinder should be less than if the grind chamber is full of grinds and the hopper loaded. It's possible that your switch setup is aggravating the Compak's stall potential; I recommend trying a few weeks without the timer/switch and see if it continues to stall.

I'll give this a shot and report back if there are any issues. Then I'll go Jon's route and call up Compak to see if I can get a replacement capacitor if the issue persists.

Thanks for everyone's help!