gyro wrote:Is there any room in the chasis for insulating the steam boiler? If so, what thickness do you think? Hard to see from photos...

With the exposed group to radiate some heat, do you think that insulating the brew boiler also would still allow the PID enough room to move?

Hi Chris:

I think there's some room, not a lot. Actually I believe Kees is experimenting with boiler insulation for the Speedster, but as you can see from the pictures, mine isn't insulated.

I don't know how insulating the brew boiler would affect thermal accuracy, but it would be simple enough to test.

AndyS wrote:I think you're right. People seem to get excited about manually controlling brew pressure, but to me that's a PITA. I'd much rather program a profiling pump and let the electronics repeat the profile without my input. Or just go with a decent preinfusion setup and a standard pump.

It's amazing how much trouble people will go to . . . . . to try to get a rotary pump to mimic a $30 vibe pump.

ken

AndyS wrote:So it bypasses HOT water? Back to where? The drain?

Down the drain. It will divert pump pressurized water away from the coffee down the 3 way, the more you move the paddle to brew the less down the 3 way and more onto the coffee.

Ken Fox wrote:It's amazing how much trouble people will go to . . . . . to try to get a rotary pump to mimic a $30 vibe pump.

Now now Ken

Ken Fox wrote:It's amazing how much trouble people will go to . . . . . to try to get a rotary pump to mimic a $30 vibe pump.

Although vibe pump do come up to pressure more slowly than rotaries, many people (even Ken Fox, IIRC), report that some sort of pump-delay preinfusion is still necessary for best results.

Once you start modifying your machine with aftermarket pump delay relays, you no longer are dealing with a "$30 vibe pump." Profiling pumps can do what your delay relay does and more.

Not to mention the fact that if I had to listen to a stupid vibe pump rattling the glasses in my kitchen cabinets every morning, I'd probably give up espresso and stick with drip.

Paul_Pratt wrote:Down the drain. It will divert pump pressurized water away from the coffee down the 3 way, the more you move the paddle to brew the less down the 3 way and more onto the coffee.

Makes sense, although obviously it wastes hot water (not a "green" machine).

AndyS wrote:Although vibe pump do come up to pressure more slowly than rotaries, many people (even Ken Fox, IIRC), report that some sort of pump-delay preinfusion is still necessary for best results.

Where did I say that? I do believe that pump-delay preinfusion is helpful in rotary machines that would otherwise go directly to 9 bar without any sort of pressure ramp up, especially if one updoses. I never advocated any sort of pump delay on vibe machines. It was when I bought a new rotary machine that I noticed that it was not forgiving of updosed baskets (I had been updosing for years without even realizing it) whereas the vibe pump machine never gave me any problems with that, presumably due to its "built in preinfusion."

AndyS wrote: Once you start modifying your machine with aftermarket pump delay relays, you no longer are dealing with a "$30 vibe pump."

why would anyone do THAT?

AndyS wrote: Profiling pumps can do what your delay relay does and more.

the only thing missing is any sort of proof that this sort of modification produces "better" shots than does an unmodified vibe pump.

AndyS wrote: Not to mention the fact that if I had to listen to a stupid vibe pump rattling the glasses in my kitchen cabinets every morning, I'd probably give up espresso and stick with drip.

If I am not incorrect, the rotary pump in the Speedster is "outboarded." Dan has previously illustrated, in another thread, that "outboarding" a vibe pump eliminates most or all of the noise that comes from this sort of pump.

ken

Ken Fox wrote:I never advocated any sort of pump delay on vibe machines.

Oops, I could have sworn I read that in a recent thread.

Ken Fox wrote:the only thing missing is any sort of proof that this sort of modification produces "better" shots than does an unmodified vibe pump.

True, but espresso is an aesthetic experience, and the vibe pump ruins my mood.

Ken Fox wrote: Dan has previously illustrated, in another thread, that "outboarding" a vibe pump eliminates most or all of the noise that comes from this sort of pump.

Hey Dan, you still using that outboard motor?

AndyS wrote:Hey Dan, you still using that outboard motor?

Yes, I still used the outboard vibe pump, but not as often these days. The Elektra Semiautomatica is my everyday espresso machine, La Valentina is relegated to test duty (especially since we moved and I lost my workstation area in the kitchen). She recently went on a rode trip to Ian's:


From the Buyer's Guide to the La Spaziale Vivaldi II

You can see the funky pump setup hiding behind the grinder and knockbox in the photo above. Upon La Valentina's return, I temporarily camped out in the kitchen for some testing, running it from a one gallon jug. When the vibe pump is isolated from the casing, it's almost as quiet as a rotary pump.

The noise of a vibe pump doesn't bother me much; its noise is nothing compared to the normal background from our kids, TVs, etc.

Ken Fox wrote:It's amazing how much trouble people will go to . . . . . to try to get a rotary pump to mimic a $30 vibe pump.

ken

Maybe it would be more accurate to say it is amazing how much trouble people will go through to try to get a rotary pump to mimic your arm and a lever. Might be why I just can't cut the cord on having a manual lever machine around for occasional use.

Lever machines don't get anywhere close to 9 bars of extraction pressure . . . .vibe pumps came after levers, but they preceded the widespread use of rotary pumps by decades. Vibe pumps by design have a slow pressure ramp up, and when unregulated can go up considerably above 9 bar (which we address with OPVs).

So, I think actually that my statement was more reflective of what has been attempted with rotary pumps, in order to get "preinfusion," otherwise known as a slow pressure ramp up at the first part of the extraction. The thought could perhaps be clarified by changing it to reflect the pressure curve of a vibe pump operating with an adjusted OPV.

ken