No, the spring of my machine is around 84mm. When installed it fits 65mm. Indeed, a 70mm spring would be not so strong at the end, but depending on the specs it could be very strong then compressed.

As far as I remember, the original is something from 6 to 3 bar, and I think someone measure some time ago. If yours is 70mm and very similar in other aspects (wire, outer diameter, coils) of the original, you would get something like from 4 to 1 bar...

I'll organize things here to ship US, EU and AU!

Márcio.

Just two more videos of shots with on a glass cup:

Carneiro has been kind enough to offer me three pair plus one small one of his booster springs for the MCAL. I will offer them at my cost, which includes shipping from Brazil plus shipping to you within the U.S. Please do not PM via H-B because my mailbox quickly fills. Instead use the website icon in my profile and e-mail me through the link on my site. When all are spoken for I'll post that here and if there is enough interest perhaps Carneiro can have more of these fabricated.

I am certainly very interested in a pair as well!!!

I may have only one small spring left to reserve. Please e-mail me as noted above if you want to reserve it.

Thank you Gary.
Since I really want to try both spring, I have sent a message to Marcio in the hope that there be more.

For those interested in the extra springs, I've ordered a new lot, but I've changed the smaller a little bit, as more than one person are willing to use both extra springs to boost MCAL pressure.

Regarding the stress on the parts, my main concern is the 2 M5 screws that hold the top cap on the group. But I even think about adding 2 more screws to avoid stress.

On the calculations I've done, I estimate the maximum force done by the original spring is 80kg. Maybe with the 2 extra springs the hole thing goes to 130 kg. This would be 65-70 kg per screw... I think the lever pins can handle this with no problem, as this is not a commercial machine and usually we don't use it all day long, barely 2 times a day. The 4 screws that hold the group on the boiler as long as the 3 screws that fix the boiler to the base can be safe if the user holds the porta-filter to counter balance the lever.

Again, I don't recommend the use of both extra springs, use them at your own risk!

Márcio.

This morning I did single and double pulls using my original spring. The shot first pulled as crema but the crema quickly disappeared. I was left with wonderful tasting espresso each time. It was not high concentration but it was very good. For me adding springs will be an attempt to see if this changes the quality in the cup. If I like the result more, it is worth using an extra spring or two. If it threatens to stress the machine too much, then maybe the solution is to keep the machine as it was designed and enjoy what it produces. If I want thicker shots, I have other machines that are designed to do that. The Amica on the left makes thick crema every time but does not have the flavor clarity of the MCAL. I like both machines (and the Lady Duchessa in the background too).





Just a quick fact check, Marcio. You saw that I measured 80 psi, which is 80 lb not 80 kg. My machine has not had much use so my standard spring is probably close to factory spec. But a kg is more than 2 lbs. Is that what you meant?

I mean 80 kg is the maximum load of the spring when the lever is fully down. I think around 70 kg (the lever a little bit up) the seal close the water inlet and the piston pushes the water. As the area of the chamber is close to 12.5cm², 70 / 12.5 = (aprox) 5.6 bar. And 5.6 bar is approximately 80 psi.

That's why I'm curious about the pressure measure with only one extra spring and both extra springs. The springs should add at least 20 kg to the maximum pressure measure so it would add more than 20 psi each.

Márcio.

I will be receiving a few of the newer springs from Marcio.
If anyone wants one, a pair or more, please contact me.