Positioning lever on spline - help please.

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LeverFever

Postby LeverFever » Jul 24, 2018, 4:58 am

Hi guys, long time lurker of this great forum.

I've got myself a Gaggia Compacta. All is working ok, but it appears the final position of the piston is fractionally too low, therefor not exposing the filling hole enough (when lever has clicked in the horizontal position)

If i push and hold the lever another inch at the bottom of the stroke, the cylinder will fill.

My question is - whats the best way to address this?

Can i just re position the lever one spline further back, therefore giving a slight higher final piston position without messing with anything else.
(currently no leaks or anything)

Many thanks

Will post some pictures soon!

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Paul_Pratt

Postby Paul_Pratt » Jul 24, 2018, 5:48 am

I try and set-up it up so that the bottom of the piston is just level with the bottom of the sleeve of the group.

You can then experiment with the spline set ups. With regards the top 2 nuts (one hex and one acorn style) make sure you have enough threads of the rack exposed so that the hex nut is screwed down and you have some threads exposed for the acorn nut. IIRC you should be able to have at least 2-3 threads for the acorn nut to thread onto.

After that just play with the set-up of the main lever arm and the locking mechanism. It is complicated but great when it is all working
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LeverFever

Postby LeverFever » Jul 24, 2018, 6:12 am

Brilliant thanks.

I was concerned that moving the lever might just be covering up a problem.

kitt

Postby kitt » Jul 24, 2018, 7:24 am

I think the Compacta is the Spanish Gaggia group , also known as the Gaggia GX group . It is also used on a few other Spanish machine lever groups (Italcrem , Visacrem ....)

Pauls comments are spot on though , just line it up so the piston is just below the lip of the bore . On my Italcrem , with the piston fully screwed on , it sits a little below the lip . In that position using Faema piston seals, the piston was not going high enough to clear the inlet hole either . But the factory Gaggia seals have a higher lip by the look of it, and may work at that piston position . I got around it by using a spacer to move the whole upper group assembly higher by 1-2mm , and using Faema piston seals, it now clears the inlet hole . Later on , i may get some Gaggia piston seals , and try them (they are not easy to find here , but Ascaso stock them)

Let me know if you need pics of the locking mechanism positioning - it's a bit of a fiddle to get right
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LeverFever

Postby LeverFever » Jul 24, 2018, 4:37 pm

So the re positioning of the lever on the spline doesn't work - as the outer spring steel release fouls on the locking mechanism.

I had the piston out but couldn't budge the piston on the shaft. (Maybe need a bigger C spanner)
However the bottom of the piston seems perfectly aligned with bottom of cylinder when assembled.

One would assume that is screwed home fully and tight, so i don't see what adjustment can be found there.

On the very top of the group i have an acorn nut - no spacers or anything underneath.

Short of different seals, wheat should i try next?

Should i be using a c spanner on piston and spanner on top nut to undo assembly?

Kitt you suggested spacing the upper assembly - i assume you managed to get a shim the whole circumference of the group head? As i don't see any satisfactory way of raising it.

Spot on regarding the type of group - it is the same as this....
Visacrem lever rebuild

thanks guys

kitt

Postby kitt » Jul 24, 2018, 5:17 pm

If the piston lines up with the bottom of the bore , it should lift above the inlet hole if the right seals are on the piston, can you post a pic of the piston and seals?

Yes, a C spanner should be used, but they can be tough to start un-doing

I used two stainless washers between the upper group section and the spacer ring. It worked temporarily to test my piston height, but after that oi made a more permanent spacer . I think if i had the right seals, no spacer would be needed .

Here's a pic of the lever orientation , to get it on, i had to hold the locking mechanism in place with one hand and slide the lever on, it's very tight , but works perfectly;

Image

LeverFever

Postby LeverFever » Jul 24, 2018, 5:54 pm

Image

Sorry, only one i have to hand.

LeverFever

Postby LeverFever » Jul 24, 2018, 6:16 pm

So if i wanted to raise the piston a few mm - i should be able to turn him with the C spanner?

Is it likely to have spare thread that will allow him to go further up the shaft?

thanks

kitt

Postby kitt » Jul 25, 2018, 3:32 am

If the bottom of the piston is flush with the bottom of the bore , i don't think you should be raising the piston - the height is not the issue, it's more likely to be;

- the seals are not factory (note how the ones in the linked thread have a higher outer lip , if your piston has other seals fitted it may not work like mine did )

- Your not getting full travel on the piston due to the lever or catch mechanism not mounted correctly

LeverFever

Postby LeverFever » Jul 25, 2018, 5:04 am

You mean this image? (Thanks to whoever i borrowed this from)

You're right, i don't think my seals are as thick. They have the V lip, but not the rest of the body that fills the space on the piston. I wonder if mine have a few mm to move around their slot on the poiston..

So i will be need actually Gaggia seals from somewhere...

Thanks again Kitt.




Image