shadowfax wrote:You can indeed use chokes inline or bypass chokes to control pressure, as Stuggi mentioned (failed to cite that it's BTDT for H-B). I am just skeptical that you'll save much money if you do this right. $200 for just the choke is... not an impressive saving over what I have so far, and it doesn't sound like the price for a properly spec'ed choke for this application.

Got my quote back, 100€ for the valve, 560€ for the controllers.

Right. In Melbourne, so off tomorrow to have some espresso from the Slayer at St Alis to see how it compares to the TMFR setup. Hopefully they won't be too busy (although unlikely from past experience). I'd quite like to have a look at their Renegade Roaster as well...

Hi Chris,

cool, let us know how it goes.

I've just noticed today that sometimes my pump drifts a bit around the max. pressure setting, ie. doesn't stay at say 8bar but goes up down between 7.9-8.1bar and you can hear the pump speed changing periodically, running a bit faster for a moment every few seconds. Dunno what it is yet (I have to check if it's due to changing voltage from the pot or not), but I was curious if anyone notices anything like this on their rig?

Regards,
dsc.

Also check that the inlet pressure is stable as that could present the same way.

-C

Just heading out the door shortly. I do see some small pressure fluctuations, maybe in the order of 0.2bar. I have no check valves or anything in the system but my line pressure is set with a pressure regulator and seems stable. In my case I suspect I need to drill the bypass a little larger, as at 9bar I am running the pump (best guess) at just under half speed with 2bar line pressure. I can also hear the occasional change of sound/speed?

Another point I have been meaning to mention, the gurgling Nicholas found when removing the gicluer. I get it on my machine sometimes if I just engage line pressure pre-infusion. I suspect that the pump does not allow the free flow of line pressure through the vanes (with the pump off) as well as some other pumps. I don't notice this all the time, but perhaps 50% of the time, so it could possibly be dependent on where the rotation of the vanes has stopped?? Engage the pump, gurgling stops quickly.

OK, so I made it for some espresso from the Slayer. Its a nice looking machine, more so than in the pictures. First up a double ristretto, very nice, probably the best that I've had. I'm a heathen at descriptions, but I would say initial citrus with a surprisingly pleasant acidity, medium body/mouthfeel and smooth finish without bitterness. It was very good. Had a 'magic', read double ristretto based 5oz latte, also very good.

They were very busy, but I couldn't help but ask to have a look (I had come 4000 miles or so, and half an hour walk). Had a chat to the barista, they were using the house espresso blend. They weren't 100% up to speed on what was in it, but I gathered a PNG base, some sumatran and others I guess.

Heres the interesting part though... 4 bar preinfusion until it starts to drip, then immediate jump to 9 bar brew, cut the shot from 9 bar (no ramp down at all). Aiming for a 40 sec ristretto (they said), circa 1.25-1.5 oz would be my eyeball guess from a triple basket, but with a low looking triple dose. I asked the dose, but didn't know the weight - just showed me the basket with coffee in it. Brewed at 199F from the PID under the driptray.

Keeping in mind this is a top notch outfit, I am sure they would ramp down the pressure on the Slayer towards the end if they felt benefit in it. But there was no misunderstanding, prebrew at 4bar (although it said 2 on the gauge), straight to 9 (9 on the gauge) and then cut.

They were using a Robur-E. The grounds come out differently than on mine, shooting to the side as mine does if I have cleared the burr chamber and chute when I first grind some coffee before it 'backs up' the chute. I wonder if they have removed the static grid on it? I wasn't going to start lifting the lid on their kit though, but it was certainly different.

Excellent shot reflector on the drip tray, I have a spare drip tray for the Speedster and I think I am going to have to hack into it after seeing it on the Slayer. I didn't see my shot being made, but I saw others. Obvious donut extractions (during the low pressure brew), but if it was also like that on mine, didn't make a difference in the cup.

Got a chance to talk to the roaster who was working the 5kg Renegade. Also have a 15kg Renegade, and a 4 barrel Probat sample roaster. Hario syphons and cold filters as well. Awesome setup.

Anyway, back to the pressure profiling part of it. Well, it didn't really seem as if there was any other than (effectively/equivalent to) line pressure to pump pressure. This is nothing a stock Speedster, Cyncra/Hydra or plumbed GS/3 paddle can't do (as far as I understand it), and nothing most other line pressure machines can't be relatively easily modified to do.

So while I did get some exceptional coffee from the machine, I suspect it was as much to do with the skill of the staff, quality of the grinder (I counted 5 Roburs) and the coffee being put into it as much as the machine itself. I've bought a pound of the coffee I enjoyed there, so I will be having a play with it when I get back to HK.

Please bear in mind, I only had a couple of coffees though on one visit, so I could be missing something here. But they were good .

Cheers, Chris

Chris,

I may be confused, but where was it you were playing with the Slayer?

-C

CRCasey wrote:I may be confused, but where was it you were playing with the Slayer?

At St Ali's in Melbourne, great outfit, cool vibe. Unfortunately I didn't get the chance to pull any shots myself. They have Slayer no 0001.

Hi,
working every day with a two group Slayer, I have to say, that the results are always exceptional. The taste and especially the mouthfeel of the Espresso is so different to other brew methods.
I have many customers which visit us, to have a test ride on the Slayer. They bringing there own Coffee Beans and Grinders (sometimes low quality) with them, some didn't tamp properly but still the Espresso is really good, what I mean is, the Machine is very forgiving. But it is right what Gyro did say, in the hands of a skilled master and in combination with high quality beans, the result is pure MAGIC.

Greetings
Ralf