The C'lever Project: Building an espresso machine from Cremina parts - Page 3

[TUS172]

Go Bob Go! Go Bob Go-- is there nothing you can't do?!

Ya there is plenty I can't do... But this is all stuff I played with before...

You know me Greg... I love these machines but with the availability of parts being so restricted... As if they are gold or something... I just got sick of it... So when I decided to build this thing I decided to make it as easy as possible to get replacement parts without having to pay an arm and a leg or worse yet not be able to get the parts at all... La Pavoni piston seals can be gotten for $6.00 each... So when is the last time you saw that for the Cremina? Any O-ring, any part I can fabricate and/or anything I can replace with a high quality readily available substitute will be done.

Thanks to those here (including yourself) who have given suggestions and done their own DD to keep these fine machines up and running.

[TUS172]

Below is a pic of two options on the piston solution for the Cremina seals. Both shown have the La Pavoni seals installed. The piston I made has a nice fit... The Cremina piston now has a nice fit with the addition of a food grade Buna gasket I made out of FDA approved sheet gasket material...

Also I had a chance to finish the ends on the steam tap shafts. One is in the shown steam tap and the others I fit to the knobs I had from the original taps. I was able to sharpen up the threading for the steam tap shaft in this steam tap body that is shown and I will be using it in the 'C Lever' when all else is complete.

Edit: 6:15PM... It has been suggested by one of our resident pros that I could have used a more appropriate material as a spacer. He is probably right... I could have went with silicone or FDA Viton. But this is just another expeiment... First, I wanted to see if .0625" material would be appropriate and it is. Second, this material will never see any real service other than to act as a spacer. It will not act as a seal and it will not really be in contact with anything other than the back of the La Pavoni seals. Third, it is pliable and easily formed and above all it was inexpensive. Fourth, It won't be put into service until one of the other Creminas I own needs a piston seal replacement. My newly turned piston will go into the 'C Lever' machine.

[TUS172]

Well one more accomplishment... I got the time to turn the shaft for the piston and got it securely mounted.
The pic is not that good but you get the idea... its done.

I ended up threading the top with 3/8 X24... As you can see it is a finer thread.

[mogogear]

Now we know that the"C"after Bob - standsfor Cremina!! Great job !

[TUS172]

Now we know that the"C"after Bob - standsfor Cremina!! Great job !

Doesn't sound too bad... For a couple of minutes I actually put that as my last name but figured I was getting too big of a head...
As I mentioned on another thread, I have not gotten too much further on my 'C' Lever... But I did go to the Parts Guru and worked out a deal for 4 complete sets of pistion seals... With the 2 I already have on hand I should be set for life! I now have two pistons, shafts with set and stop nuts done.
I have yet to send out the Grouphead, or anything else for chrome or powder coating since the body has not yet been formed and since I changed the dimensions of the original frame I will need it around to get the body, face plate, drip tray and grate, and cap fitted properly. Also I have a bit more welding to do on the frame itself to mount... well lets say some custom additions.
I am procrastinating on any of the sheet metal work until I have the assistance of one of the mechanics to assist me with the final measurements, scribing and layout before sheering, cut outs and bending. I am pretty nervous about that because you can't take back a mistake and with the costs of those metals...

[chopinhauer]

So how do the La Pavoni gaskets work? Have you tried pulling a shot with them? Is the shot the same as with proper cremina gaskets? Is the pull the same, or different?

I'm keen to know these things because here in Sydney pavoni gaskets are easily available and if they work then there is a solution to one parts problem.

[TUS172]

Excerpt:

So how do the La Pavoni gaskets work? Have you tried pulling a shot with them? Is the shot the same as with proper cremina gaskets? Is the pull the same, or different?

Well I have yet to get them in a machine for use. I have been told by others on this site that La Pavoni piston seals have been used as replacements on Cremina pistons (without the cutout that I placed under each in the Cremina piston shown previously) and have worked fine and with no noticeable difference in the operation of the machine. I have put the pistons with the Pavoni seals in the grouphead that I am about to send out for chroming (once the body work is done ) and I could feel no difference in the way the piston traveled in the cylinder. But of course that is not any where near actual use. Also in the 'C Lever' I will be using one of the pistons that I turned and not the Cremina piston.
Additionally I know that the piston shaft seal and metal retainer ring and C clip for the Pavoni work in the Cremina... I did try that replacement on my '86 Cremina...

[chopinhauer]

Additionally I know that the piston shaft seal and metal retainer ring and C clip for the Pavoni work in the Cremina.

that's good to know because the c clip is not available from Olympia even if you manage to get a piston seal replacement set. The c clip they send out is improvised and having put it in my machine doesn't work all that well. I think I'll get a pavoni clip and maybe some piston gaskets when my cremina ones begin to falter.

[TUS172]

I had some time in the shop last night. Again these pieces have not been polished and need a bit of fine tuning but you get the idea. I took 2 disks of .5" X 3.0" stainless and turned them to be the rings that are now surrounding the steam tap and boiler cap knobs.

There is a .0625" space between the knob and the surrounding ring that creates reflective/insulating attribute. I believe that brass has an heat conductivity rating of around 70 as where stainless is 8. With the .0625" air space and the .1875" thickness of the stainless I should have a great window of time to use the knobs with comfort.

[starry]

I like your specs down to the ten-thousanth of an inch! Very nice job!

[espressme]

Hi Bob,

I should have a great window of time to use the knobs with comfort.

Yes, that is a valid method of slowing heat transfer. Nice idea and execution!!
Cheers
Richard

[TUS172]

Richard,
Thanks... I think when the whole project is finished it will add to the unique look of a custom designed machine... I have yet to see any machine that has custom turned knobs trimmed out with polished 304 stainless steel. The handles may remain black phenolic at this point but I may contract your expertise at some point in the future if you are willing... perhaps with a wood like Greg went with. The costs of this custom work are reaching genuinely astronomic hieghts. The cost of materials (stainless and brass sheet goods, rods, angles, couplers, fittings, bushings and tubing) not to mention the electrical and safety features has been an eye opener... but something that was expected. To this point it is well over... well perhaps in a PM Richard... But I will say that I have over 120 hours in research and shop time in this... The 'C' Lever Project... I am still having a BLAST!
Besides I realized that I probably could not do as good a job as you do with exotic woods since I have no real experience at turning wood. The pics you sent of "Cleo" put an exclamation point on your ability with exotic woods... My hat is off to you and a salute!

[espressme]

Hi Bob,
Thanks for the ego boo! I had no wood turning skills when I started. A friend wanted to trade a machine for a few tampers. Trial and error and a metal turning lathe made the deal. Anyone with a bit of hand eye co-ordination can do this work. Some towns have evening Vo-Tech or Community classes that give machine access.
I am really enjoying the trials and tribulations of the C'lever work you do.
I well know the feeling of starting and sticking with a project. Surprises are expensive!! And, the time needed to recover is a pain!
Here is a good place to buy metals cut to length at the cheapest rate I have found. And..they ship to your door at the quoted price.click here
And, for the handles perhaps a black Delrin would be appropriate. You can turn that on any lathe. A pm will return some simple tooling for onesies/twosies. Howsomever, I would love to see a stainless steel spline as a core and a polished 304 or brass tube outer wrap. Or even, carry out the similar setscrew motif that you have going over a 304 core. A Pm could get you a couple finished stainless 9/16ths round x3.5" cores.
Many happy hours to you!
Richard/ espressme

[TUS172]

Howsomever, I would love to see a stainless steel spline as a core and a polished 304 or brass tube outer wrap. Or even, carry out the similar setscrew motif that you have going over a 304 core. A Pm could get you a couple finished stainless 9/16ths round x3.5" cores.
Many happy hours to you!
Richard/ espressme

You know Richard I have given this some thought and my initial reaction was to doubt that if I offset a brass handle from a stainless shaft with with the set screw configuration that it may not hold up over time. But on a 3.5" - 4.0" axis with set points at both the top and bottom perhaps it is a viable option. I could thread on a stainless shaft both to the fork of the grouphead and the threaded end of your finely crafted portafilter handle and then do a brass offset in perhaps 3/4" brass.
Any other thoughts?
Perhaps what I would do on both the group and portafilter handles is to turn a stainless core and bond a brass grip over it... that would make a solid handle and the stainless should give enough insulating quality to ensure the 2 or 3 doubles I do in a row each morning. If that doesn't work I can always turn an offset brass grip at some future time.

[TUS172]

Excerpt:

Hi Bob,
Here is a good place to buy metals cut to length at the cheapest rate I have found. And..they ship to your door at the quoted price.click hereMany happy hours to you!
Richard/ espressme

You were right Richard this site does have prices that beat others that I have dealt with. There is a local machine shop that does work for most of Central VT. I can get stainless and aluminum pieces from him fairly cheap but when it comes to stuff like 1' brass rounds it is out of their ballpark. I will definitely keep this site on "My Favorites". Thanks

[mogogear]

Glad to see you are still progressing.....looks great

[TUS172]

Thanks Greg,
Hey I have aquestion for you. When you sent your groupheads out for chroming was it necessary for you to find the various plugs to protect the inside of them? Or was it a cost savings to do it for the people who did the chroming? And where did you send them to for chroming? I know you probably mentioned it in your thrread but hey... I am lazy today...

[mogogear]

Nope- they ( the platers) only strip , buff and plate. I was instructed what I needed to do- just not how to accomplish that.

So I took my group-head and walked through several hardware stores... A rubber expandable plumbing plug worked for the big end, a rubber "cork" was driven in from the top of the piston rod opening and a brass fitting was screwed into the water feed hole.

Good luck

[TUS172]

General question for everyone... Has anyone used a plater that they could recommend? I live in the north east quadrant of the US but in this day and age I guess that doesn't really matter. I have found a couple online but would like to see if I could get a recommendation from someone. Thanks...

[Fullsack]

High Lustre in Hayward, CA mostly does chrome work for Harleys, but did a beautiful job on the Creminas both in nickel

rebuilding-oly-twins-saga-t2504-60.html

and chrome.