The C'lever Project: Building an espresso machine from Cremina parts - Page 4

[TUS172]

Another Question...
I have been considering the way the grouphead on these machines draw heat form the boiler. I know at one point some have considered placing a sheet type gasket in between them instead of the o-ring that is used. I have used .125" PTFE sheet gasket material for the boiler to heating element gasket. It has excellent heat resistant qualities, is totally inert and is hard enough to withstand significant pressures... I was wondering if anyone has tried the same type material (perhaps thinner .03125 or .0625") for the grouphead to boiler connection?

[TUS172]

Another Question...
I have been considering the way the grouphead on these machines draw heat form the boiler. I know at one point some have considered placing a sheet type gasket in between them instead of the o-ring that is used. I have used .125" PTFE sheet gasket material for the boiler to heating element gasket. It has excellent heat resistant qualities, is totally inert and is hard enough to withstand significant pressures... I was wondering if anyone has tried the same type material (perhaps thinner .03125 or .0625") for the grouphead to boiler connection?

The quote above is a question I still have if anyone knows or has given it a try I would appreciate the answer.

Other than that I have been busy with life and work... But should have some time in the next week or so to attempt the daring deed of 'body work'... I have also located a company in the Northeast that does precision water jet metal cutting on a CNC type machine and I am using it's services to do the cuts for for both sizing the panels and all the openings in the face plate, cap, drip tray and bend points for the break work. The decision to go this route actually got my design away from pencil and paper and transformed it to credible CAD prints. That was one of my major quandaries and I am relieved to know that it is in capable hands at this time.
I have yet to send out the grouphead and other parts for chroming but am going to do so once I have all the body work completed. Perhaps in a month or two (after final assembly, polishing and primping) I may be completing this little (but extravagant) project and have my own 'C Lever' to enjoy for years to come.

[orphanespresso]

That's what is in the Riviera that we have (don't remember the exact thickness right off, I think it's 1/16" & we're at the SCAA so I can't check to be sure), but we've also used the standard black high temp automotive gasket material - not as good as the teflon, but it has worked.

Touring around the SCAA we've noticed a number of different machines using PTFE group to boiler seals (few levers though...)

[TUS172]

That's what is in the Riviera that we have (don't remember the exact thickness right off, I think it's 1/16" & we're at the SCAA so I can't check to be sure), but we've also used the standard black high temp automotive gasket material - not as good as the teflon, but it has worked.

Well then using PTFE is certainly worth the effort... Besides its an easy fix if it does not work. Thanks for the response.

[GB]

The Ponte Vecchio Export has a Teflon Group Head (GH) gasket which if I remember correctly is about 2 mm thick - it could be more. The PVE's GH takes a long time to heat after start up and when left on idle. This I attribute to the teflon gasket, the small area of the GH that is exposed to boiler water (the inside diameter of the gasket is about 1/2"), and the small cross section of the GH brass feed tube. This is all theory and there are other factors like the large size of the PVE's GH compared to other direct lever machines.

To further improve direct boiler heat conduction I mused over changing the GH feed tube to stainless steel - which has a considerably lower thermal conductivity than brass - and making the inside diameter of the teflon gasket a tight fit over the GH feed tube. The latter to reduce the varying effect of direct boiler water contact with the GH and no contact when the boiler is 1/2 full.

For me changing the GH feed tube is a lot of work but the next time I remove the GH I will make a new teflon gasket that is a tight fit over the GH feed tube.

I hope this helps
Geoffrey

[TUS172]

Excerpt:

To further improve direct boiler heat conduction I mused over changing the GH feed tube to stainless steel - which has a considerably lower thermal conductivity than brass - and making the inside diameter of the teflon gasket a tight fit over the GH feed tube. The latter to reduce the varying effect of direct boiler water contact with the GH and no contact when the boiler is 1/2 full. For me changing the GH feed tube is a lot of work but the next time I remove the GH I will make a new teflon gasket that is a tight fit over the GH feed tube.

I hope this helps
Geoffrey

Yes indeed it has helpled. I will put in a PTFE gasket and I will do the Stainless feed tube. An excellent !

[TUS172]

Good news... The body, face plate, cap and tray will be done tonight! Perhaps tomorrow I will get some pictures of the set. I am currently trying to get bids on the chrome work but that is going a bit more slowly than I had anticipated.

[TUS172]

Well here are the photos of the work thus far. The panels have gotten a polishing on the showing surfaces but not on the inside surfaces where brazing was done. With the thicknesses of the metals that we worked with I had to keep the intricacies of the bends as simple as possible. I think it looks rather elegant... but of course I am very biased.



As you can see the frame and internal parts are missing but probably the next time I include photos everything should be polished up and the chroming done.
Finally things have moved forward... The bids are beginning to come in from various businesses that do chrome work and soon I will be making the decision to get it done... but most of these businesses say 6 - 8 weeks to get the pieces back.

[espressme]

Hello Bob,
Nice work!
Richard / espressme

[mogogear]

Bob - thats is so great looking!!-



I am glad to see you are completing this journey!! She will be some one of a kind machine!! Congratulations!

[Fullsack]

Bob,
What a beauty! Congratulations on an incredible job.

[GB]

Wow!

Geoffrey

[TUS172]

Thanks guys it is appreciated. I have been getting what I consider high end bids for the chroming but perhaps I am wrong. Below is a picture of the parts that I want chromed. The bids are coming in so far around $400.00... Mogo... Fullsack... Espressme and others what do you think. The frame is already sand blasted and has a bit of surface rust but I have told these businesses that I can do it again before shipping.

[espressme]

I pulled this from the "Oly Twins" thread:

I forgot, the original quote was to nickel plate the pieces for 2 machines. For the entire brite work for the one machine, it was $332.
Doug Jamieson
Full Sack Jack Coffee Roasters
LMWDP #017

So, you have a bit more area with the frame and so I guess the extra $75? And, they have to strip the older plating off the Group. Sticker Shock yeah!
RP
PS, Mogogear had a neat way to prep the group for plating with rubber plumbing stoppers. You must fill all holes in the parts with plugs or the plating will build up in them. Photos are near the middle of the page:
rebuilding-oly-twins-saga-t2504.html#p26715
PPS It is not a good idea to chrome Stainless steel. It polishes well.

[TUS172]

Thanks Richard... Yeah you are right about sticker shock but since I am so close to the end of the body and brite-work... everything is going out the 1st part of next week.

[mogogear]

The chroming process is less about adding the plating as it is about buffing and prepping the surface so the plate lies smoothly.

You are paying for a lot of buffing... Bob- I know it is what you want- it is your baby...With bolts and screws clamping down on it--I would just opt for some of the really chrome-esque powder coating available out there..durable and will not show defects----- instead of high lighting them.

It is your baby.. but I think the buffing on all the inside corners of the frame will never work out to such a degree as needed and the chrome will look like silver spray paint over many parts of the frame.

I humbly apologize for this dire assessment Bob. You have done superlative design and work!!

[TUS172]

Yep I just got that assessment. But I am a stubborn old fart and I think I will attempt to get these up to the point where the company that does the work will not have to be overly concerned about taking off too much material. I still expect to pay around $400 though.

[farmroast]

Stubborn Yankee craftsmanship! Taking arguably the best home appliance ever made in the world and making it the best it can be. I want a signed picture of it to frame when it's done!
Ed

[TUS172]

Farmroast Wrote: "Stubborn Yankee craftsmanship!" Yup
Anyway I have spent 10 hours or so... after an additional sand blasting with fine grit white sand, with dremel in hand and with 400-800 grit sand paper ripping and tearing until I began sputterin' and spittin'. It is being sent out today via Staples through UPS... I am to the point of thinking, "Hey this is it whether it looks good or not... It is good as I am going to get it!" I ended up getting 5 estimates and two real appraisals of what it would take to get the frame up toward a good looking chrome job. The guy I am sending the work to said that they would do the final estimate only after assessing how the frame would look if chromed since they also do powder coating. So as of 0900 this morning it will be out of my hands... I am sure it will be a couple of months before I see the parts that are out for chroming again. In the meantime I will be buffing the brass and stainless parts for the assembly work when it gets back... But not this weekend.

[caeffe]

Bob-
Quite impressive feat you've under taken here.
We are all anxiously waiting your 1st espresso pull with you C'lever 'spresso

I have to say though - as a kibitzer, mind you. I would have been doubly, triply, impressed if you'd built a C'lever Speedster Mk TUS172: sneak-peek-at-all-new-speedster-mk-ii-by-kees-van-der-westen-t7154.html

Again, this is easy for me to say as one who is viewing from the stands. I hope you don't take this comment as slap in the face for your outstanding efforts.