Optimizing the Isomac Venus

Need help with equipment usage or want to share your latest discovery?
tegtmejer
Posts: 5
Joined: Mon Sep 10, 2007 6:48 am
Real Name: janus elgaard tegtmejer
Equipment: Isomac Venus, Rancilio Rocky (doserless)
Location: Copenhagen, Denmark

Postby tegtmejer » Mon Sep 10, 2007 7:23 am

Hi,
I have had the Venus for more than a year now, and I am quite ready for better brew pressure and temp control - and if it is possible :( a bit more juice from the steam wand.

I have seen the PID controllers with temp control and steam control, and my only complaint is that I can't seem to find anything for sale within Europe.
It would simply get too expensive to import it from the States.
So.. Anyone with suggestions or even experience with the Venus?
(Would be so much easier to have a Silvia :wink: )

Thanks,
Janus

good beans = good times
User avatar
erics
Posts: 4651
Joined: Tue Aug 09, 2005 2:32 am
Real Name: Eric Svendson
Location: Silver Spring, MD

Postby erics » Mon Sep 10, 2007 3:48 pm

Do you mean it is expensive because of shipping?

Shipping outside of the US via some traceable/tracking means that requires a delivery signature is probably $35 for a complete PID kit and that is via USPS Express Mail International, including packaging materials.

Good PID kits can be obtained here: http://www.pidkits.com/

Do you mean it is expensive because of duties imposed? Nutin we can do about that.

Skol,

Eric
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at erols dot com

tegtmejer
Posts: 5
Joined: Mon Sep 10, 2007 6:48 am
Real Name: janus elgaard tegtmejer
Equipment: Isomac Venus, Rancilio Rocky (doserless)
Location: Copenhagen, Denmark

Postby tegtmejer » Tue Sep 11, 2007 2:31 am

Hi Eric,
Thanks for the link - I'll check it out :?

Well.. Duties, tax and the fee for charging me these extra expenses.
Let's just say it would be cheaper for me to wait with this step until my next vacation in the US. Hopefully some time next year...

But until then I could really do with some advice regarding adjustment of the brew pressure (should go down from 14 to 9.5 bars, right?)

And somewhere someone wrote something about getting "a bit more oompf" from the steam wand. How is this done? Can I adjust the thermostat to generate steam earlier in the drop?

User avatar
erics
Posts: 4651
Joined: Tue Aug 09, 2005 2:32 am
Real Name: Eric Svendson
Location: Silver Spring, MD

Postby erics » Tue Sep 11, 2007 8:05 am

There is a ton of information on this site as regards the Isomac Venus - just key in "Venus" as the search term and sit back :)

As far as getting more power from the steam wand, a very helpful "trick" is to initiate steaming just prior to the light going out - very easy with a temperature controller and a temperature sensor (thermocouple, RTD, etc.) but a bit more difficult without. Here you would need to get some reasonable idea of the MINIMUM time required for the light to extinguish - say that it's 90 seconds, just for discussion purposes. Then, start steaming at the 85 second point and you will maximize the ompf available.

As far as brew pressure is concerned, are you reading 14 bar during a "normal" shot? i.e. 60 ml in 25 seconds. I am not familar enough with the Venus to know the exact method of adjusting brew pressure but assume that it would be similar to the Silvia. Again, not to sound like a smart-ass here but there is even more info on that subject which can be found using this site's excellent search function. A great tip on reducing brew pressure (towards the end of a shot) was posted by Tim Eggers as he described cracking open the steam valve as the shot poured in the latter stages of the shot.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at erols dot com

User avatar
Stuggi
Posts: 441
Joined: Mon Aug 06, 2007 5:50 am
Real Name: Sebastian Storholm
Equipment: La Pavoni Europiccola, Macap M7
Location: Jakobstad, Finland

Postby Stuggi » Tue Sep 11, 2007 12:49 pm

Wouldn't it be possible to bypass the thermostat with a jumperswitch, so one could pull the shot, and then flick a switch to engage the heater for more steampower...?
Sebastian "Stuggi" Storholm
LMWDP #136

tegtmejer
Posts: 5
Joined: Mon Sep 10, 2007 6:48 am
Real Name: janus elgaard tegtmejer
Equipment: Isomac Venus, Rancilio Rocky (doserless)
Location: Copenhagen, Denmark

Postby tegtmejer » Wed Sep 12, 2007 2:14 pm

Hmm... Okay, maybe I haven't searched enough :shock:
Well 12-14 bars during a normal shot. At 14 it spits.
I will try and engage the steam while pulling the shot.
...
Sometimes perfection is a lot of work :wink:

Thanks for the inputs, guys!

User avatar
iZappa
Posts: 44
Joined: Fri Sep 16, 2005 5:28 pm
Real Name: Nanook
Equipment: Isomac Millenium, Macap M5, Anfim Haus
Location: Norway

Postby iZappa » Thu Sep 13, 2007 1:10 pm

Stuggi wrote:Wouldn't it be possible to bypass the thermostat with a jumperswitch, so one could pull the shot, and then flick a switch to engage the heater for more steampower...?


:shock: Now that's a great idea.

Regarding the brew pressure on the Venus you can lower it by adjusting the opv valve. That is the valve where the return tube going back into the tank is connected. But you need to take it out first and cut off a small part of the spring inside it. If you choose not to cut down the spring you'll most likely get leaking. My personal experience with the Venus is that I never lower it more than 12 bar. That is because it is low in temperature. If one reduces it to 9,5 bar too much hot water will go from the boiler and into the reservoir resulting in brew temps under 90c.

tegtmejer
Posts: 5
Joined: Mon Sep 10, 2007 6:48 am
Real Name: janus elgaard tegtmejer
Equipment: Isomac Venus, Rancilio Rocky (doserless)
Location: Copenhagen, Denmark

Postby tegtmejer » Fri Sep 14, 2007 2:05 pm

Cutting the spring seems like a quite simple procedure.

Bypassing the thermostat with a switch sounds like it would work.
Adjusting the thermostat so it engages the heater after a much lower
temp drop was more what I had in mind... Is this possible without PID control?

User avatar
erics
Posts: 4651
Joined: Tue Aug 09, 2005 2:32 am
Real Name: Eric Svendson
Location: Silver Spring, MD

Postby erics » Fri Sep 14, 2007 2:45 pm

Cheerfully, I would not cut or grind/file away any part of the OPV spring until I had a new replacement spring in my hands.

I would also NOT install a "switch" to bypass the steam thermostat because THERE WILL BE that one time you neglect to "unbypass" it and the results may not be pleasant.

Steaming power can be "maximized" simply by initiating the steaming process just prior to the light going out (I'm assuming the extinguishing of the light is the indicator that it is ready to steam). Doing it this way will ensure that the steaming light remains on during the steaming process as you are removing loads of heat from the boiler.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at erols dot com

User avatar
jesawdy
Posts: 1557
Joined: Fri May 12, 2006 3:41 pm
Real Name: Jeff Sawdy
Equipment: Rancilio, Cimbali, SanRemo, Gaggia/LaPavoni, Mazzer and a few more...
Location: Black Mtn, NC

Postby jesawdy » Mon Sep 17, 2007 12:32 pm

erics wrote:I would also NOT install a "switch" to bypass the steam thermostat because THERE WILL BE that one time you neglect to "unbypass" it and the results may not be pleasant.

Steaming power can be "maximized" simply by initiating the steaming process just prior to the light going out (I'm assuming the extinguishing of the light is the indicator that it is ready to steam). Doing it this way will ensure that the steaming light remains on during the steaming process as you are removing loads of heat from the boiler.

We're entering the realm of a bit more complicated, but.... for increased steaming power, another option (beyond a dual setpoint PID or a dedicated heater switch) is to add a microswitch that is actuated by turning the steam knob. When the microswitch is depressed the heater remains on. When you close the knob, the switch is opened and the heater is controlled by the thermostat, so nothing to forget. This little trick is well implemented on at least some Saeco machines and the Solis SL-70/90 machines. I recall seeing a writeup on someone adding this to a Silvia. (I'll look for the link, any help appreciated.)
Jeff Sawdy