Question about the 67' Olympia Cremina steam wand - Page 2

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Eastsideloco
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#11: Post by Eastsideloco »

samuellaw178 wrote:The microfoam on the new Cremina wand is a lot better, but none comes close to the ease of blocking the other 3 holes.
Good to know. If I'm looking for better results, I'll block some holes. I've been hesitant to do that with the old wand because the tip isn't removable. At least with the new one you can open it up later if need be.

wintoid
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#12: Post by wintoid »

Eastsideloco wrote:Round tip w/ 3-holes. Rather than pointing directly to the bottom of the pitcher like the late-model wands, the holes angle slightly outward toward the side of the pitcher.
On my 2002 wand, the holes look like they point straight down, but the steam actually comes spewing out of each hole at an angle. Does the steam from the latest wand (with slot for screwdriver) come out straight down?
Simon
LMWDP #486

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Eastsideloco
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#13: Post by Eastsideloco »

I see. The bottom of the new wand is flat, but the steam probably still comes out at some angle.

Here's what the '74 tip looks like:



Since the tip of the new wand is removable, I suspect there must be a way to replace it with a single-hole tip. That might be the best of all worlds.

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rpavlis
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#14: Post by rpavlis »

It is extremely easy to make one hole steam tips with a lathe. This reference gives the basic idea: La Pavoni steam tip - How I made one:

More information about diameter, etc. can be found here: Optimal steam tips

I am not sure, but I think that the thread on Creminas that are not soldered on are M7x1.0. This is the standard 7mm thread.

As the references imply the diameter of the oriface is fairly critical. For boilers around 1000 watts optimal for a single hole tip is about 1.4 mm.

I am of the opinion that the best design for one hole tips is to have them shaped like bullets. There is a slight learning curve making these things on a lathe. Brass is certainly the easiest material to use. To summarise the process:

1. Cut a piece of round brass stock about 10mm in diameter to about 18 to 20mm length.
2. Put in lathe chuck and face the end. Use a very small centre drill to make a slight indentation in the centre.
3. Take a 1.4 mm drill bit (#54) and drill into the brass about 6 or 7 millimetres.
4. Turn over the brass piece and face and drill the other side with a larger centre drill.
5. Drill into the brass with the correct tap drill size for the required thread. For M7x1.0 it would be 6mm. For M6x1.0 it would be 5mm, for M6x0.75 it would be 5.25mm. Try to drill as close to half way through the piece as possible. Be careful not to drill too far!!!!
6. Tap the bore with the appropriate tap.
7. Use a 3mm drill to drill into the now threaded end of the brass until you meet the 1.4mm hole coming from the other end. Be careful not to drill too far! (You might want to round the end of the piece with a file at this point so it is smooth to avoid turbulence, and to make easier to clean.)
8. Turn around the brass piece and carefully machine a tapered shape down so that at the end of the taper it is just a bit larger than the 1.4 mm hole. The taper should be shaped like a bullet. You can easily ruin the piece by having drilled too far with the 3mm bit or tapering too strongly. (Remember if the i.d. of a bore is larger than the o.d. the hole is on the outside!!!)

I am of the humble opinion that cappuccinos and certain other types of foam are best made with high velocity steam such as comes from one hole tips. There is a slight learning curve to learning to use this type of tip.

wintoid
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#15: Post by wintoid »

Thanks for this super-informative post. I have a friend who is handy with a lathe, and persuaded him to follow your instructions and make me a tip for my Cremina.

We went brass, and bullet-shaped, but went for 1.3mm in the first instance, figuring we can expand the hole if it's too small. I seem to be able to produce decent microfoam (I'm aiming for flat whites, not cappas), but I have to tip my milk jug at quite an angle to achieve this. Is that what you meant by the learning curve?

Anyway, so far so good. Much better looking than the franken-machine I had with the Rancilio steam wand, and *almost* as good at making microfoam.... perhaps with some practice it might even be as good.

The brass also looks quite blingy!
Simon
LMWDP #486

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Eastsideloco
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#16: Post by Eastsideloco »

While I haven't customized anything, I did install a late-model Olympia steam wand (from Cerini Coffee) on my vintage machine:



While I have yet to make truly silky microfoam with it, it is a clear upgrade over the original 1974 steam wand. The performance difference probably has less to do with the geometry of the holes/tip and more to do with the interior diameter of the wand.

The interior diameter of the tubing that Olympia now uses for the Cremina steam wand is larger than what was used on my vintage machine. Just looking at the two wands side by side, the increase in cross-sectional area is significant-perhaps 50% larger. That explains why the old wand just seemed hopelessly underpowered, like it was always partially clogged.

I'll need some time with the new wand to find the pitcher approach angle that results in the best microfoam. However, I'm confident that I can get decent and repeatable results with the late-model Olympia wand.

Nevertheless, I'm going to keep tabs on this project:

http://hg-one.com/cremina-sproline-adapter/

Now that I have a Cremina wand with a removable tip, the Sproline tip is in play as an option in the event that HG One releases its adapter. (Kind of a pricey option. But less expensive than tooling up my own machine shop. ;-))

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