Hello!

I think the most fun for me is to play with the machines... Finally I've got the additional spring to the MCAL. In fact, I've done 2 different sizes, so I could make 13 of each one at a good price:



- Version 1, length 65mm, wire 3mm, external diameter 26mm, 9 coils.
- Version 2, length 73mm, wire 2.5mm, external diameter 21mm, 11 coils.

Both are made of 302 stainless steel. I remember the version 1 is something from 2 bar to 0,6 bar extra, and the second is less than 2 bar (but half of that pressure at the end, maybe 1,8 bar to 0,9 bar). The calculations are worthless without a real measure of the pressure... The lever is heavier but taking care and pulling down (not forward) there is no problem.

This is the first version installed:



And here is a video of one shot. Well, I think the shots have more body and crema, but far from the pump machines, and I think it keeps the "clarity" of MCAL. Each owner has to try to give his own veredicty.



Sorry about the light at the end...

Márcio.

Very interesting. Thanks for sharing.

Is it difficult or dangerous to replace the spring? The lack of crema is the only thing that's bothering me (a bit) about my MCaL. I wonder also if the naked portafilter has anything to do with the relative abundance of crema in your cup, well at least compared to what I'm getting.

Not so much difficult. I use two pieces (18cm each) of a M5 threaded bar with a lock nut at the top and a wood base with two holes. So I can compress the spring using this bars through the group top holes, and wing nuts at the base side of the bars. Damn, I can't explain that in good English, my bad. I'll take a picture as soon as I can.

I've tried the naked PF before the additional spring and I have the impression the crema is a little better now. But different coffee, day, grind setting and so on... I would have to make some tests and videos at the same day, without and with the spring, but no time for that...

Márcio.

This should bring a mcal into a more normal spring lever shot. I would think you'll sacrifice some clarity.
I use my mcal as a "specialist" for top SO Ethiopians. The lack of crema I find a plus with these coffees. Everything else I use the Cremina.

Yes, I need others to test, specially those who enjoy specially this clarity.

For me, is hard to test any SO other than Brazilians... I have some special dry processed coffee from some farms here that could be nice to make comparisons, but nothing like Ethiopians, Kenya etc.

Márcio.

The added spring should certainly make your Brazilians more enjoyable.

Another idea, one could always hold the lever a little bit to get less powerful shot, not consistent as the original machine, of course. Something like Jim suggests on his review of the Strega.

I'm looking at mailing options here, to ship a document envelope is cheap, around 2 USD (with 2 springs). But, I don't know if there could be problem considering the springs are metal and not a document. To ship it as goods is expensive, so I should send more springs in one package.

Márcio.

Count me in for a couple springs if You decide to ship them. I will be more than willing to pay a bit extra to cover your time etc...

I'm in for 2 springs por favori...

Me too! I just tried this with an old Mcal group from an old Sama club machine... The spring I found was quite weak though- yours look better.

Is you Mcal group the older type with the short spring (7cm?)- Mine is.

Happy to pay for springs+postage+time via paypal- shipping is to Australia