I just repaired my vintage Sama Club lever using seals for the MCAL machine (CO Orphanespresso). My group head looks identical to the MCAL- and the seals were a perfect fit. But my group is a thermosyphon group-

my question: Is the MCAL a thermosyphon group?

here is mine:

No it isn't.....

Sounds like you have a gem there.

I think it's like the PV group which is availiable as bolted to the boiler or as a thermosyphon.

No thermosyphon on the Elektra...

hmmm...

the machine this came off of was a Sama Club- (see my Sama club restoration thread) virtually identical to the modern Ponte Vecchio- BUT it is a 49mm group, with removable top plate- and identical seals to the Elektra. Also visually it looks identical to the elektra group- with the 'flange' at the top



On this group the dispersion plate is flush with the group seal- so you pack the basket virtually right to the top- is this the same on the MCAL group?

I am wondering if anyone has seen this 'Elektralike' group with thermosyphon on any other machines?

My question isn't purely academic- I actually want to trace down the source of this design for a Top Secret lever project...

So far using the machine- it seems to me that this is a fantastic group design- the piston can be removed in under a minute with an allen key for seal changes, cleaning, etc. To me this seems like a huge advantage over the pavoni, ponte vecchio, olympia, etc designs. No need for special tools, huge clamps or nerves of steel. Any home user could easily replace the seals in a few minutes. In addition 49mm seems like a very good size for a lever machine- not too big- not too small- and Pavoni baskets and PF's can be used.

I would really appreciate it if anyone could tell me more about this group.

sorrentinacoffee wrote:No need for special tools, huge clamps or nerves of steel. "

I thought the spring needed to be compressed in order to fit into the chamber? Is that easy enough to do by hand?

The group head certainly looks just like and Elektra apart from the two pipes for the TS. The spring on the Elektra stays fitted in the piston unit, which simply unplugs from the group head as a unit, allowing you to just change and grease the seals and pop it back in. It's just one way in which the Elektra is more than just a pretty face

Yeah, mine is the same- then entire spring/piston assembly slides as a single unit. No need to un-tension the spring- which is way too strong to compress by hand.

If these groups were still available in thermosyphon type- they would fit right onto a PV machine I think...

Kindof hard to say about that group.....the MCAL seals will fit a number of groups, even a Zacconi that takes a two seal setup, the Elektra sourced W seal is about the only two way seal that is available and thankfully it fits a lot of pistons. But then again, it could be that the Elektra cylinder and piston was made as a common product from some jobber....there is so much that we do not know for sure and have to guess on the chicken and egg question.....much like the Rossi group being in common on a lot of machines and the interchange between the old Zacconi machines and Sama and Ponte Vecchio, not to mention La Pavoni groups being on a lot of Spanish and Italian machines. The 4 bolt pattern is not that uncommon but the pipe setup is.....bolt a Sama Export (PV) on a Cremina, it works you know (if the bolts match up you can do anything), but somehow seems beyond Frankenstein.

somehow seems beyond Frankenstein

Nothing is beyond Dr Frankenstein! Not even modesty

Hello there Doug,

in your opinion what would be the best choice of group head for a modern lever machine? An existing item would be the first choice.

sorrentinacoffee wrote:Yeah, mine is the same- then entire spring/piston assembly slides as a single unit. No need to un-tension the spring- which is way too strong to compress by hand.

If these groups were still available in thermosyphon type- they would fit right onto a PV machine I think...

If yours is like this one I do not get how the spring and piston assembly would "slide" as a "single unit" out of the cylinder when you remove the cap from the top of the group. What keeps it a single unit? What keeps the spring from decompressing?

that's my group alright- originally the top plate was stuck- so I had to remove the pin and roller on the lever- which releases the spring. Having cleaned the piston and replaced the seals- now I just undo the two hex head screws on the top- and the entire spring/piston/top plate and lever all slides out as a single unit. I don't think I will ever need to release the spring again.

But didn't you write in the earlier thread from late May

To remove the piston I had to release the spring again- using a clamp to stop the spring ejecting violently.

Ah, so you're keeping the pin in? And it's the spring/piston/lever assembly as a unit. I must need more coffee

yes- when I wrote that the assembly was sticking. I tried to remove it but it jammed very tight. This was seemingly due to the old seals, the need of a clean, and a too perfect a match on the top plate and group body. I cleaned everything, replaced the seals, and took a small amount of material off the top plate- now the whole unit slides out smoothly. When my new seals arrived from OE- I was able to install them in under 5 minutes with my allen key and nothing more.


Having seen this design- I can not understand why other manufacturers have not adopted it.

Almost every commercial lever group works like that.
Also, i can change my piston seal too without clamps.

sorrentinacoffee wrote:I am wondering if anyone has seen this 'Elektralike' group with thermosyphon on any other machines?

Here is the group from a 70's-era Bezzera:



Like yours it has a thermosyphon, and it is 49-mm, and it has two screws at the top. Not exactly the same, but close.

sorrentinacoffee wrote: Having seen this design- I can not understand why other manufacturers have not adopted it.

Yeah I love it on the Elektra and wish it was the same on the Cremina I've bought to keep it company.

A very interesting and practical design. Can you describe the thermosyphon and water feed galleries within the grouphead.

Thanks
Geoffrey

Wow- That Bezzera is almost identical to my Sama- same steam and water valves, same cabinet, etc.

But those frothing and water arms- that's what I need. On the sama they point down like the PV (but already come out lower, below the steam/water taps)- and you can only fit tiny jugs underneath- which is not so great given the steam power involved. Also the frothing tube sits right behind the group handle making it even tighter in there. The way Bezzera solved that with those twisting out-and up tubes is brilliant. I need me some of them.

Also the Bezzera group looks impressive- with the heavier top and roller mechanism. Is Bezzera still around? Does that group turn up on any modern machine?

As for describing the thermosyhon on the Sama group- I am not sure what you need to know? I am not sure what a 'water feed gallery' is? The two pipes go in the back of the group- but in the piston cylinder there is only one water inlet. It looks as if water can circulate between the seals on the piston, until the piston is raised filling the chamber. Pretty simple. There is a screw at the base of the bridge part- I have not removed it. So far the results have been excellent- seems very hard to pull a bad shot with this machine. I leave it on for hours and just walk and pull a shot. Never had a burnt tasting one yet.

I have another question about that Bezzera group:

Can you 'help' the lever return? On the PV- and on my Sama- it is not possible to push the lever upwards and add extra force to the returning spring. I had a Mini Gaggia lever and on that machine you could 'help' the spring in this way and thereby increase the pressure and get more manual control of the shot.

seems like all such groups should be like that? All you need is something to lock the lever to the piston on the return stroke- so it is like a fulcrum both ways.

i think.... please forgive my ignorance of the terminology here.