First ever lever pull pressure mod - Page 9

A haven dedicated to manual espresso machine aficionados.
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arriflex

Postby arriflex » Aug 21, 2007, 11:50 am

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What I was thinking was that instead of having to deal with a sleeve that goes all the way through the shaft and needs to be sealed against 200psi while transferring the lever forces to the shaft... one could have 'ears' that protruded from the shaft. Pins probably would have been a better description. In hindsight, both require talented welding, something I'm not capable of!

The closest pipe I could find to being workable was 1/4" schedule 80 Stainless.

Actual Pipe Dimensions
Nominal 0.25"
OD 0.54"
ID 0.302"
Wall 0.119"

I never really bothered to check the actual shaft dimensions to see if it would work.

arri

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ogatasan

Postby ogatasan » Aug 22, 2007, 11:35 am

What a great thread- I enjoyed reading it last night and want to make a deep bow for all the pro's here.
Greg summed up the discoveries and implications in one sentence on the previous page, and i was very happy that it pretty much mirrored my own experience and observations over some brutally empirical and unscientific years.

I always feared i might push the lever too hard as a result of the fine illy grain (sorry still without grinder but not for long) but how to find out if i was pulling around the 9 bar or an equivalent of 18 to 20 kg on my Europiccola, as calculated somewhere else in this forum.

So for my curiosity and your entertainment i came up with the following daringly adventurous setup :D - may i note that i am terribly underequipped as i hardly stayed in a country longer than a year in the last decade


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-------20cm----X--------------80cm-----------------
18kg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,5 kg

By pushing the model handle at 18kg i should be able to hold the the waterbottles off the ground.
to my surprise it took more force than i actually thought but was quite comparable to the force of my pushes on the Pavoni.

This means:
1) i didnt push way too hard over the years at which time i knew nothing about a targeted pressure.
2) the lever seems to be on the weak side, as you can see from my first image it is loose for some time now - just like it happened to my brothers machine. this is easy to be fixed but i wonder if anybody else made a similar experience?

am i very weird? my girlfriend just said so..
Chris H
LMWDP #148

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espressme

Postby espressme » Aug 22, 2007, 12:09 pm

ogatasan wrote:What a great thread- I enjoyed reading it last night and want to make a deep bow for all the pro's here.
Greg summed up the discoveries and implications in one sentence on the previous page, and i was very happy that it pretty much mirrored my own experience and observations over some brutally empirical and unscientific years.
snip
2) the lever seems to be on the weak side, as you can see from my first image it is loose for some time now - just like it happened to my brothers machine. this is easy to be fixed but i wonder if anybody else made a similar experience?
am i very weird? my girlfriend just said so..



Hello Chris,
Great solution to the question!
The loose lever is a common problem. It may be solved by "peening" the lever as you would "set" a rivet, using a small blunt ended punch and a hammer. You must support the handle end ( handle removed, and the end of the threads protected by hard wood ) of the lever against a very tough, sturdy surface. Or go to an art college and ask a senior metals student to help you! Or a local sheet metal ( ductwork)shop.
sincerely
richard
richard penney LMWDP #090,