Post By artman
Help to fine tune a Wega Mininova
Hi guys. I need some help to fine tuning my Mininova.
After purchasing a second hand Mininova that had been in an office environment for a few years then in long term storage t required a little TLC. After some investigationing, advise from this forum, a few parts and some effort, the machine is making good coffee. The problem is that I seemed to be able to make a better coffee with my sunbeam em6910. I think that if I tweak this right I should be fine.
This is a rotary pump unit that was set for mains pressure but at the moment i have it drawing from a container. I will get it plumbed in once I can convince the wife this much bigger machine actually has earned its position in place of the smaller EM6910
The sunbeam is able to run a finer grind of coffee without choking and froth milk much better.ImageUploadedByTapatalk1461462439.327579.jpg
I have fitted a pressure gauge out of an old em6910 to the t-fitting off the outlet of the pump and have increased the pump pressure slightly.
It now produces coffee through a finer grind then when I first got it running (not as fine as the em6910) Now it seems that the 2nd opv leaks quite a bit. I have tightened the opv completely but still leaks a lot under pressure. (Can you get new internal components for these opv's or do i just need to buy a new one?)
With regards to steam. I have tried a method explained on a forum about using full steam pressure for a few seconds then reducing until it heats up. I find this tip spits too much milk all over the place and makes too many large bubbles. I see that some people have replaced the 5 hole steam wand with a 2 hole tip. Any other tips.
Sorry for the long post but I thought I should offer all the info upfront to reduce too much backwards and forwards thanks guys
Re the brew pressure, you really need to hook up a pressure gauge to a PF to check/adjust it, otherwise you are flying somewhat blind.
Adjust so the OPV starts releasing at 12bar, and adjust brew pressure (via pump by pass ) back to 9 bar.
Take the OPV apart, they are simple device. Might just be a bit of crud in it preventing the rubber sealing?
Have a read of the steaming guide by Koffeekosmo , it's very good.
Don't forget it's not only the number of holes but also their combined area that will affect the way it steams the milk.
Well I have finally got my pressure gauge sorted. Coffee machine has been running at 12 bar. I'll get around to adjusting it down over the next few days and see how we go. Also the milk frothing is getting there. Thanks for the advise.
With regards to brew pressure,l via bypass to 9 bar, do I need to do this with an empty basket, or should I be dosing it with my normal amount of coffee. If I do the adjustment am not quite sure. Obviously with empty basket there is no pressure. Thanks