The pump dimmer mod - can I dim the entire espresso machine? - Page 2

#11: Post by **Nunas** » October 15th, 2021, 11:43 am

I don't recommend this for the reasons cited by others, but it would be a trivial exercise to temporarily remove either of the wires going to the vibe pump and send it and the vibe pump terminal out to a dimmer module. As others have mentioned, the results may not be what you're looking for, but at the cost of re-soldering one wire you could find out if your proposed mod is worthwhile.

#12: Post by **cafeIKE** » October 15th, 2021, 2:35 pm

Triac dimmers go from full on to full off. Fine control is next to impossible. They change with temperature and voltage.

Vibe pumps are quite sensitive, dropping ¼ to ½ bar for less than 5 volts RMS drop. Line voltage can vary that much in some areas. Few homes have properly wired screw terminal outlets instead using daisy chained quick connects. Achieving any kind of repeatable control with a vibe pump is likely an exercise in frustration.

See Pressure Perfect with Vibe Pump for an example of pump pulsing. This is on a 122V 20A dedicated circuit.

Were I to get serious about pressure profiling, it definitely would not be with a vibe pump machine.

#13: Post by **Chert** » October 15th, 2021, 2:56 pm

You have ruled out dimming the entire espresso machine.

I have my vibe pump on Olympia Maximatic wired to a dimmer.

The machine wasn't broke, no need to fix it; but I like to tinker.

I like being able to slow the preinfusion phase, ramp up a little, and slow the flow late in the shot with this means.

You can buy a Decent (two vibe pumps in that one with myriad controls of one kind or another), or a lever machine or or or or. But the little dimmer mod is the least expense and not much trouble in comparison.

#14: Post by **JohnB.** » October 15th, 2021, 3:44 pm

cafeIKE wrote:Triac dimmers go from full on to full off. Fine control is next to impossible. They change with temperature and voltage.

Vibe pumps are quite sensitive, dropping ¼ to ½ bar for less than 5 volts RMS drop. Line voltage can vary that much in some areas. Few homes have properly wired screw terminal outlets instead using daisy chained quick connects. Achieving any kind of repeatable control with a vibe pump is likely an exercise in frustration.

I used a standard 600W dimmer to control the vibe pump in my Strega for several years with no issues. It gave me a pressure range of 2bar to 11 bar. Tied into the feed line behind the group & added a gauge so I could see what I was getting into the group.

October 15th, 2021, 3:48 pm

The most useful dimmer might be a Variac, as a Variac does not alter the waveform - but it would have to be able to handle the full current of the machine unless it was directly wired into the pump that would be a smarter, better idea.

That said, I would not go down the dimmer/Variac route at all.