Faema Mercurio 3rd Series Tall Group - Page 5

A haven dedicated to manual espresso machine aficionados.
User avatar
IamOiman

#41: Post by IamOiman »

My metal guy was really quick and I picked up my stuff today after 24 hours. The boiler had three welds added with silver solder, and the cam extender for the water inlet valve was fixed up as well.



I did some more descaling of some little bits. The valves are now all apart and I am ready to place my parts order after seeing everything I need. One thing I am concerned about is the cam for the inlet/hot water valve is very stuck on the large fitting and cracked on the tip. It appears at some point the rod became stuck with this fitting and the cracks are from someone exerting force on it in an attempt to move it. I bet that is what also caused the cracks on the now fixed rod extender. I hope I get all the scale out and coax out the rod to see if I can salvage it or if I can manage it in its current state.







This is the entire preinfusion mechanism apart. I'll explain how it works once I get it assembled again. The group I noted easily accepts an IMS shower with an E61 gasket. I will need an 8mm height for proper locking of the portafilter.



The group piston is still stuck so I have that soaking still in penetrating oil after heating it.
-Ryan
Using a spice grinder violates the Geneva Convention
LMWDP #612

User avatar
IamOiman

#42: Post by IamOiman »

My parts order is sent out. The only odd gaskets of the bunch was the boiler gasket and the small 7x4x4mm gasket in the preinfusion mechanism. Brooks espresso/Thijs was able to custom order that gasket for pretty cheap and he sells the former by default. All other gaskets like the valves, sight glass, and group gaskets are still commonly available today which is incredibly convenient. There is no group gasket and instead the group is bolted directly against the frame. My Gaggia lever group gasket would fit however the thermosyphon fittings prevent this without modification. I can cut the gasket to adapt the fittings but my current decision is to keep it original and have no gasket. I have the old gaskets chipped out mostly, using a small pick and hammer to lightly tap the chunks out.




I've been polishing and cleaning pipes, fittings, and panels up. Of all the body panels I only used Autosol on the backsplash, group cap, bottom front panel, and the lower rear panels just to get rid of the last of the nicotine. Everything else will essentially remain original, even on the inside. The only notable difference I saw in the polishing was the rear of the backsplash. You can note on the photo of the rear backsplash the little holes on the right side where the rivets would go for the old style labels for the massimo and minimo pieces.





Last thing on my mind is the fact there is only one inlet hole in this group unlike the two seen on the Zodiac group. The little screw I noted on the back of the group is the plugged hole that was made during the boring of that inlet. There is an ongoing discussion about this and I kept thinking about it. How do thermosyphon lever machines work?
-Ryan
Using a spice grinder violates the Geneva Convention
LMWDP #612

User avatar
IamOiman

#43: Post by IamOiman »

I doubt this is a question many people have an answer for, but is the rod threaded CCW for the piston? It has been painful to get it unscrewed with a leftie-loosie mantra. I spray penetrating oil almost every day, whack the piston with a mallet to shock the threads a little, and heat the thread area with a propane torch, the whole shebang. I do not want to be doing all this effort only to find out the thread is opposite to what I am trying to get loose and am actually tightening it...

Trying to loosen it as if it was CW did not reveal anything since it did not budge.
-Ryan
Using a spice grinder violates the Geneva Convention
LMWDP #612

User avatar
IamOiman

#44: Post by IamOiman »

Well until I figure out what thread direction the piston is (pretty certain it's right handed/loose ccw but I like to check) I'll try going at it from above and make a jig. I am looking at the clips for the lever fork and they are different from the ones seen on the Zodiac. They are much thicker and are very sturdy. My ring pliers are not having a good time getting them off but that may be due to gunk build up. If there is a different tool that I should use I'd love to know.


I did my best for what I had but I just could not get the piston off today. I had a small chisel that I struck the notch where the c-spanner went and tried pulling after with no success. I had the lever nearly cocked fully and had zip ties added and tightened to the point the spring was exerting almost no force against the piston thread and I could very slightly jiggle the fork.


-Ryan
Using a spice grinder violates the Geneva Convention
LMWDP #612

User avatar
IamOiman

#45: Post by IamOiman »

These are my notes for the jig I plan to make. I need the jig to hold the group by the two ledges on the sides of the group head one 'level' below where the bearings rest. I took out the bearing guides so I had more ledge to hang off of. The jig top may need to be cut into from a side as the bearings stick out 4mm further than the ledge wall. I'll have some wiggle room with it though if I just cut a rectangular hole in the middle. This is a beefy group so I will be using four threaded rods and 1-1.5" plywood (real plywood not that compressed wood shavings stuff) for compressing the group.

The wood will be pretty thick and I will use fender washers to distribute the force more evenly. Double nuts will be used on the bottom so I do not unscrew anything while tightening from the top. I need start from a mininum of 10" of height since the 7.5" measured contains a somewhat compressed spring already and I also need to include the wood height for the top board. To be safe I will do 12" for a reasonable maximum height allowed by the threads. I am thing of 1' square boards but I believe I can shrink it to 8". The rods will be 3/8" and if needed I can go bigger to be overkill.

I need the center of the bearings to be at least 2" above the top board as my bearing separater needs to fit properly to take the bearings off to access the rod smuggling pin. Once that is knocked out I got a disassembled group. Besides getting the materials those thick c-clips are the thing stopping me from proceeding. I am doing it this way as I am rubbish at welding and I have the capability of processing wood.

-Ryan
Using a spice grinder violates the Geneva Convention
LMWDP #612

User avatar
Paul_Pratt

#46: Post by Paul_Pratt »

IamOiman wrote:I doubt this is a question many people have an answer for, but is the rod threaded CCW for the piston? It has been painful to get it unscrewed with a leftie-loosie mantra. I spray penetrating oil almost every day, whack the piston with a mallet to shock the threads a little, and heat the thread area with a propane torch, the whole shebang. I do not want to be doing all this effort only to find out the thread is opposite to what I am trying to get loose and am actually tightening it...

Trying to loosen it as if it was CW did not reveal anything since it did not budge.
image

Yes anti-clockwise to undo it. If it really does not budge it would be prudent to try and disassemble from the top end as the aluminium top half of the groups are known weak points and do break quite easily.

User avatar
Bluecold
Supporter ♡

#47: Post by Bluecold »

I've recently stuck a few scouring pads to a wood screw, mounted that in a drill, and really nicely cleaned up the inside of my cylinder. Like a very gentle hone.

As for your snap rings, do you have fancy (knipex or similar) snapring pliers? Fancy ones do work better for tough rings such as those.
LMWDP #232
"Though I Fly Through the Valley of Death I Shall Fear No Evil For I am at 80,000 Feet and Climbing."

User avatar
IamOiman

#48: Post by IamOiman »

Bluecold wrote:I've recently stuck a few scouring pads to a wood screw, mounted that in a drill, and really nicely cleaned up the inside of my cylinder. Like a very gentle hone.

As for your snap rings, do you have fancy (knipex or similar) snapring pliers? Fancy ones do work better for tough rings such as those.
I know what you mean for the scouring pads. I did something similar for my Faemina boiler to clean it up and could do that as well

The pliers I have are my grandfather's but they seem to be for smaller or weaker snap rings. I'll need to get or borrow a stronger pair like you note.
Paul_Pratt wrote:The aluminium top half of the groups are known weak points and do break quite easily.
I was afraid of that as well. This housing seems different from the Zodiac groups in that the upper housing is not hollow where the fork and bearings rest, but rather solid aluminum that appears machined. Nonetheless the jig plan proceeds today when I head out to do some other errands for materials procurement.
-Ryan
Using a spice grinder violates the Geneva Convention
LMWDP #612

User avatar
IamOiman

#49: Post by IamOiman »

Today was a good day.

First thing this morning I went off to Home Depot to get my materials. The jig costed about $27 in materials. I used the following:

12 x 1/2" Fender Washer
25 x 1/2" Nut (it was cheaper for the bag than 18 individual nuts)
One 3/4" x 2' x 2' BC sanded Plywood where I cut out two 9" x 9" pieces.
4 x 1' 1/2" threaded rod

I marked out the cuts on one of the 9"x9" pieces with a right edge. Threaded holes were two inches away from the edges and I made a rectangular hole with a jigsaw to snugly fit the group housing. The holes were drilled out with the little drill press I have with both pieces clamped together and marked on one side so I would always keep the holes together. Two nuts and a fender washer are on the bottom of each threaded rod with one nut and fender washer on top. The top piece also had one nut and one fender washer per threaded rod.




The security/c-rings were so buggered they came off in pieces. I have no idea what happened to them but I used a dremel to get the remaining chunks cut off. These can be replaced so it's not the biggest upset. I compressed the group such that I could fit my bearing separator onto the bearings. One of the bearings could be taken off by hand and the other one did not show much resistance against the separator. The pin was finally unearthed and tapped out easily. It is likely not original as the original had a knurled end on a side. In fact my new pins look exactly like the old one. The group is now apart and literally the only thing still together is the water inlet rod and its fitting. Something wild happened with it and it's still stuck fast.





I used just enough threaded rod for this jig!

-Ryan
Using a spice grinder violates the Geneva Convention
LMWDP #612

Marcelnl
Supporter ♡

#50: Post by Marcelnl »

nice work! Seeing that jig helps me as I may need to compress the spring in my Urania at some point!
LMWDP #483