Optimizing the Isomac Venus

[tegtmejer]

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 )

Thanks,
Janus

[erics]

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

[tegtmejer]

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?

[erics]

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.

[Stuggi]

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...?

[tegtmejer]

Hmm... Okay, maybe I haven't searched enough
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

Thanks for the inputs, guys!

[iZappa]

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...?

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]

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?

[erics]

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 assumming 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.

[jesawdy]

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 assumming 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.)

[Kuban111]

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.

Hola,

My same thoughts when I was confronted with this.

What I did to overcome this was just simply place the spring in a vice and tighten it to make it smaller.( No cutting involve), this worked for me.
I placed it back in the OPV and was able to dial it down. I have it set at 9.5 for my taste but some times I change it to 10 or 11.

Luckily I never had a low temp problem on my Venus. But I do get the "earthquake shake", my cups shake when the pump start.

I did some research on the unit before I bought it and I notice that they did have problems on older units with steam power but that has been fix according to the Isomac rep by my area.

I would recommend getting in touch with Jim @ 1st-line.
they are very helpful and a great place to buy from.

http://www.1st-line.com/machines/...d/isomac/venus.htm
"Now in stock and IMPROVED with a higher temperature steaming thermostat which will provide greater steaming power."


Hope this helps
Enjoy
Michael

[iZappa]

Cutting the spring is very easy. Just remove one or two turns of the spring. No problem. The opv valve is an inexpensive part anyway

[habichuelas]

hello, newbie here with a new isomac venus and a new mazzer mini e type b. I've tried to read through all posts regarding the venus on this site and others. thank you all by the way for the countless, informative and dizzying posts! I'm still stuck, trying to decide whether to do any mods or not to the venus? opv valve, snip or compress spring, add pid kit etc.
I've had it for a week now and I'm certain my technique needs more modifications than the venus itself. I'm figuring I'll tough it out for a bit longer. my question for all isomac venus users is ... have you all modified the spring and lowered the pressure by adjusting the opv valve? mine seems to be consistently hitting in the 11 to 12 bar range. jim at 1st line said it would and others above mention not lowering the pressure beyond this point with concerns about low temp.
I don't want to go taking this thing apart until I'm sure it's not just me that's grinding, dosing, tamping etc. improperly. but then again I don't want to struggle in vain forever.

so, at what point and with what means can one determine whether or not a modification is necessary?

has anyone here actually put a pid kit on their venus?

I've tried to measure water temp with an "instant" read thermometer as it leaves the group and I'm getting 181 F tops ... can't imagine this is really the right way to know how hot the water temp is as it hits the coffee or is it?

any specific info on the venus is greatly appreciated! in the meantime I will keep searching the hb forums for relevant info and keep practicing my technique.

thanks!
vincent

[jesawdy]

I've tried to measure water temp with an "instant" read thermometer as it leaves the group and I'm getting 181 F tops ... can't imagine this is really the right way to know how hot the water temp is as it hits the coffee or is it?

One way to attempt to measure the brew water temp on the cheap is to cut down a styrofoam cup so that you can fit it into the grouphead (where the portafilter would normally go), and poke your thermometer through the cup so that it can read the temp at the bottom of the cup. You might also poke another hole up a bit on the side for the water to run out when you've hit a certain volume. It isn't perfect, but it'll be close. (You could also check the thermometer in boiling water and adjust for elevation, barometric pressure to see how (in)accurate the thermometer may be, link).

[cannonfodder]

It takes time to get the hang of a new machine. Don't be too quick to modify it. You say you are new here, but are you new to espresso making at home? Most new users take a good month just to start getting the basics down. Figure one month to get decent shots on a regular basis, six month to get consistently good shots. Espresso is not hard, but it does take a little time to get it down pat.

[Kuban111]

Word!
Those are some great advise, maybe not something one might want to hear.
But an honest advise at that.

The venus is capable of rewarding you with some great espresso.
I had many great shots from her.
Look here. http://www.flickr.com/photos/kuba...72157601326635101/

"so, at what point and with what means can one determine whether or not a modification is necessary?"

A great question.....this helped me out ...hope it will do the same.

http://coffeegeek.com./forums/esp...machinemods/139192

HB, Sorry for breaking any rules by taking this from CG but I think Jim Schulman can explain it a thousand times better than I can.


Michael.
Enjoy

[jesawdy]

HB, Sorry for breaking any rules by taking this from CG but I think Jim Schulman can explain it a thousand times better than I can.

Michael-

No rules broken... referring someone to a thread on CG or another forum is not a problem, in fact it is to be encouraged, especially if it can add to the discussion on the other forum, or help someone find resources at other sites they may not be aware of.

Cross-posting is discouraged, except in a few cases. This is when someone asks the same question in 2 or more forums, hoping for a shotgun approach to getting answers. Some of the forum regulars will recognize the cross post and ignore all instances of it.

[Kuban111]

jesawdy

Thanks for setting the record straight for me.





Michael.