MattINLA Senior Member Joined: 2 Oct 2009 Posts: 72 Location: Glendale Expertise: Professional
Posted Mon Dec 2, 2013, 1:02pm Subject: Ulka Pump Control
Hi, I am interested in proven methods of controlling ulka pump pressure such as electronic. IMHO, the inability of ulka pump pressure to be controlled other than primitive OPV valves is a significant detriment to better espresso making. This really is a big problem and it is WAY more significant that retrofitted PID controllers which I consider to be a complete waste. These pumps just suck huge without any effective means of controlling output pressure. I am surprised that none of the home espresso machine mfg offer more sophisticated pump control. Does anybody out there have a pre-built ulka control I can buy? What is out there.
SStones Senior Member Joined: 24 Nov 2012 Posts: 440 Location: Canada Expertise: Professional
Espresso: Giga 5, ECM Giotto, Rocket... Grinder: Anfim Milano-Best Vac Pot: No :( Drip: Some $30 thing from Walmart Roaster: I buy pre-roasted.
Posted Mon Dec 2, 2013, 9:04pm Subject: Re: Ulka Pump Control
Assuming you already know that the brew pressure is controlled by the grist more than anything else, and limited by the relief valve, I suspect that your intent is to have a low-pressure pre-infusion flow for a set time before ramping up to a 9.5-10 bar brew. This might be more easily done (And certainly more accurately) by using a second relief valve set to the 3.5-4.0 Bar false-line pressure and a solenoid valve to close when the higher brew pressure is desired.
billc Senior Member Joined: 15 Jan 2009 Posts: 108 Location: Seattle, Washington Expertise: Professional
Espresso: CC1 - GS - GS3 - GB5 Grinder: Baratza - Mazzer-Marzocco Drip: My own Creation
Posted Mon Dec 9, 2013, 8:21am Subject: Re: Ulka Pump Control
Depends if you would like to manually control or have a pressure profile stored in the machine. Light dimmers have proven very effective. You must however get the "Phase Controlled" version of the dimmer. Link to explanation below. These are usually the more expensive ones (more than $18).
This has become more mainstream now and 50% of the super auto manufacturers now use this in their machines. There are a few traditional machines that use this also.
The reason you don't see this more is cost. If a machine does not already have an electronics board for some control then it is cost prohibitive to add a complete board for just this control. If there is an existing board already (not just a temperature controller), then it is a bit more cost to add this functionality. Usually however, just adding the electronic control is such an increase in cost and the manufacturer is at their cost limit already.
I have just finished a new prototype that has a manually controlled pump. I have experimented a bunch with pressure profiles but it is difficult without a pressure sensor. And of course the pressure sensor adds cost (bla bla bla).
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