It is controlled by the pressure and can let steam out, it has a weght in the bottom so that it stays down when the pressure is lower. Perhaps it helps the the steam pipe to increase in pressure?
perhaps that locking screw is only there to keep the brass rod aligned vertically?
Does the little red ball turn like a knob or lift up and down? When you froth the milk do you do anything with that little red ball?
Also Petter I sent you a PM- I am not sure if you realise it but coffeesnobs has an email service. If you click on your profile you should be able to see any messages you have received.
It is controlled by the pressure and can let steam out, it has a weght in the bottom so that it stays down when the pressure is lower. Perhaps it helps the the steam pipe to increase in pressure?
that narrows it down. I could just be an additional safety pressure release valve- like on a pressure cooker. Or it could also act to increase the pressure of the water as it goes through the coffee. This would also have the affect of increasing the pressure for steaming...
All in all a wonderful variant of the Atomic design.
thanks for posting these images it is much appreciated.
I have the last few times experienced some difficulties getting enough pressure in the atomic. The coffee extracts alright but when I am about to heat the milk the pressure is to low. Perhaps the seals are to old and I should wait until the new ones arrive?!
I also tried with very very fine milled coffee and packed it a bit harder. The machine didn´t even seem to be able to handle it. How much water is recommended and how fine should the coffee be??
I did get really nice pressure the first times I used it, now the steam is coming out of the brewing head as well. Must be the seals.
I think I need some brewing advice since it doesn´t seem to work as a regular espresso machine. :-?
Hello there Petter,
the machine will not work like a regular espresso machine. It is designed to operate at around 1.3 Bar of pressure and no more. So when packing and grinding you should never grind so fine (powdery) that the coffee cannot flow out, or only dribbles out very slowly, whilst steam escapes from the release valve (usually found) in the black knob.
Grind like fine white sugar- and only tamp moderately- or just smooth over the top of the coffee.
The next issue is the filter baskets: original Italian baskets have large holes in them. For these baskets you need to get the grind and tamp just right: the coffee should flow out smoothly in a steady stream. It shouldnt rush out- or dribble out. You are looking for the middle road which I suspect applies to all coffee machines :-) After oyu have made the coffee on aa normal atomic the coffee itself acts as a plug allowing pressure to build for frothing the milk. If the coffee is too coarse you wont get much pressure for frothing. If it is too fine it will dribble out and be burnt tasting. Get it just right and it can be close to a true espresso- with some crema. Get it half right and it will be like a good Moka pot.
Also good tip is to start with less water in the machine: use only half an (atomic) jug of water as a measure. This will make a smaller more espresso like coffee- around two or three serves.
Alternatively: You can use a new stainless baskets with smaller holes- and this makes it easier to get good pressure for milk steaming and more crema in the espresso. You must take care with these baskets not to use powdery coffee at all.
On your machine it seems that the steam ball/weight is essentially a secondary pressure release valve. This may complicate matters if it is stopping the machine getting to full pressure.
By looking into the machine at the back can you see if the device on the neck attaches to the inner water tube that runs up inside the Atomic body? If it does (as a valve) there could be more to the device than simply a safety release valve. It could act as a pressure sensitive valve- only letting the water into the head of the machine when it reaches a specified pressure... This would make it a brew pressure increasing device.
When you make coffee does it release steam during the process? Does the ball suddenly move when the coffee starts to come out?
New seals and so on should help your machine and stop any leaks. What is the condition of the black knob part? Is it worn? Are there any leaks from the Milk steam arm part of the machine? Is the machine clean looking on the inside?
It´s like a little bit of steam is released through the black knob when brewing, and lately the machine has had a hard time building the pressure for the steaming. It doesn´t leak through the steam pipe. The coffee that comes out is really good. I must admit that i have tried with really fine milled coffee but that didn´t work out.
I will try some more with less water i think. The inside seems fresh but perhaps the knob is a little worn. It´s hard to tell.
Sometimes while brewing the knob on top releases steam, but thats perhaps only if you have packed it to hard.
looks like someone has just drilled a hole and put a spanner socket in then used one of the group steam stem blockers. but yeah..the red knob is smaller...mmm
hi guys, i can across an iteresting variation in a standard brevetti robbiati. The sandcast either didnt turn out ok or it was an earlier mold. in any case it is an original atomic.
The head filter plate "screw retaining poles" are usually long and cast as the original mould.I guess they are then drilled and tapped.
In the case of this atomic the "screw retaining poles" are much shorter. definitely not altered from the original sand casting! They then have screw tapped brass pipes..very unusual...
I have actually seen these before-though as you say they are highly uncommon. I think I can only remember one and I must have restored 50+ Atomics over the years.
what do you think? Is it a sandcasting error? or just trying another method...? Im pretty sure its a save from a bad casting...froma collectors point of view,as you say very rare as this mod (fix) was done in the robbiati factory...
Its strange to me why they just didnt remelt it and just cast again though...the most labour intensive part is the tap,polish and finish i would imagine...
Also near the steam insert you can see a hairline fracture...It does in no way seem to effect the functioning of the device...have you come across this before? Im wondering in the case of significant cracks if "aluminium welding " is an option...there is a product called alumiweld that would do the job..just like soldering actually...
I noticed that crack in you picture. I dont remember ever seeing one like that before. That part of the head is very thick- and at a guess I would say the crack developed when the machine cooled after casting. If it doesnt leak through the top at all I would say it probably doesnt matter...
I have no experience welding alloy- I have heard it is difficult. Is that product a type of two-pack metal glue? With your machine I wouldnt bother doing anything unless it leaks.
Hi guys, I have a question i bet cant be answered but i hope someone can!
I need to know the thread type for the steam wand arm. I know its half inch (1/2) diameter but I think there are other things to consider. I went to bunnings and used there thread size checker in the bolts department...There is fine and regular thread (classified by blue or red) but it doent seem to really perfectly fit either....
well..this is the challenge...dave
I actually have one with an extra steam valve/safety valve as well - however, mine is not directly into the body of the machine, but more on the side, as the steam arm is. Have you gathered much information about the models with that extra valve?
I am trying to post pictures but somehow I am not allowed to, it seems..
-Christian, Copenhagen, Denmark-
I managed to upload the pics!
Please note the extra arm opposite the steam arm. Like Petters, it occasionally sprouts small drops of water when brewing.
My black knob leaks a bit of water when brewing as well, small dribbles down the handle of the machine. I reckon a new seal would help a lot.
Hi, I've just joined the forum - picked up an Atomic that was in pretty bad shape and am currently restoring it - It's a red painted Bon trading unit, but i'm probably going to strip whats left of the paint and spend a thousand hours sanding and polishing it... Or, if I get sick sanding it, I might hit it with a coat of VHT wrinkle paint in Black (or maybe red wrinkle - like Ferrari cam covers).
I'm going to need to PM Sorrentina about some spares for it.... as per expected I broke the steam valve housing trying to undo it, the Bakelite filler knob has seen better days, and the cup is missing...
Is the bung with the square socket really removeable?
I got my new (old) atomic in the post today. Picked it up for $200, but needs alot of love.
Am waiting on sorrentina to reply to my pm to see if he can hook me up.
Plan is to strip it down and polish the heck out of it so it has a mirror like finish, and that way I can admire my good looks while I brew some black gold.
Broken bits : The actual steam valve pin is snapped, so I need new of those. I can salvage the steam ball handle atleast!
I have my work cutout for me..Funnily enough, the red ones i've seen have a rough finish, this one is smooth....
This actually looks decent.
You're going to be better off emailing laSorrentina - I emailed him after he didn't respond to my pm, and got a quick response. He's in the middle of moving premesis and his online shop is offline - I'm waiting for it to come back so i can order some parts too!
Ah cheers thanks for the advice!
Yeah I been watching then for many weeks but all been selling for much more than I want to pay for a project.
The paint on this is definatley NOT original, i gathered that much.
I'm hoping under the pain there is an Atomic badge, but I highly doubt it. And if so, I dont know if i'll be able to save it.
One thing I cant find is the steam pin....I'll email him now and see what he comes up with .
LaSorrentina has all the steam valve parts - although I suspect his pin might need you to use his valve body - which isn't a bad thing because he re-engineered the seals to get rid of the problematic paper/fibre gaskets and replaced them with a good silicone o-ring.
Been reading through the threads and hope somebody can help me with my problem.
I recently in a stroke of genius (or madness if you speak to my better half) bought not 1 but 2 used Atomics.
As with a lot of things I get myself into I act first and learn quickly afterwards, such as that the units are available new for the same price I paid
But if I had have donethat I wouldn't have had the pleasure of learning, disassembling and breaking a machine all within a week.
Cut a long story both machines had already been restored and worked fine, but one worked really well the other not so.
Therefore a decided to start fiddling and now I have broken the steam arm assembly and have what is remaining stuck in the body of the Atomic. Please help, how can I get this out and not destroy the thread in the Atomic in the process ?
Yep. Been there done that! Use a screw remover set. Go to Bunnjngs and they will show u. They are a tapered looking drill that has a reverse thread on it. As u tighten it it losens what it grabs with the teeth tbst grab and loosen the stuck device. Very easy and u will use it again!
I had a fair amount of force on the spanner on the flats to try and loosen this, not sure an easy out will work. I guess I should soak a little olive oil in there to act as a penetrant??? not keen on using WD40 or any other petroleum based penetrators.
Second question I had, is there a replacement part available?
Edit, just found LaSorrentia site, Do I need to get the whole steam valve assembly, or can I just use the fitting, so I can keep some of the patina???
Any help muchly appreciated. Yes MUCHLY is a word, I just used it!
New to the coffee forums!
Just picked up my second atomic.
going to give it a tidy up and new seal kit from bon trading.
mostly apart except for the steam knob and the screws from the head (need to find my smaller screw driver for this), iv taken the screw out but no dice getting the ball/handle off (bottom of first picture)
is it just a case of pulling?
Here is a picture of both of them, has anyone full polished theirs? if not, is there any reason not to do so?
my original one came in much better condition, both groups, and minimal scale and scum inside. no real leaks or air escaping that I can see .
Will the filter plate from from a 3 cup moka machine work on the Atomic? This way there is no need for the pop rivets.
BTW Fantastic thread
Hello - new to this group. I own a classic, brown Atomic Milano bought in Montreal in the mid-1990s. Is anyone aware of where I can buy parts for it in Canada or the USA? I see a supplier in Australia but the postal rates will kill me. Thank you in advance for any info.
I was just given a model B Atomic with steam capability, manufactured by Robbiati in Milan. When I first tried it, no water came through, only steam around the periphery of the group. I did a thorough descale using 50/50 water/white vinegar, because citric acid can harden into its own deposits. After removing the shower screen I found lots of white crystals. So after several runs of descaling and cleansing water, I've been able to brew and steam with it quite nicely. I've wanted to remove the boiler plug to make sure the pipe is thoroughly clean, but was unable to do that. It appears to be fastened into an aluminum lock washer. If that's not the issue, I'm not sure what is. See the two concentric rings around it. The machine is functioning well otherwise, so there may be no need to do anything more. However the manual for the Sassoon Atomic recommends removing the plug periodically to clean out the inner pipe.
Robbiati Atomic Plug.jpg
As a comparison, here is the plug on my Sassoon model B Atomic, a machine which has barely been used.
Sassoon Atomic Plug.jpg
Guidday all. Just discovered this site. Looks like hours of fun reading.
I have picked up an Atomic, in need of some love and fettling for about $300 on Trade Me in NZ.
The Black water tap is stuck (The plywood gentle wrench idea sounds fun), and filter/head bit is missing(sounds easy to replace as no broken screws stuck in there). The steam valve seems ok, but I haven't pulled anything apart yet.
I can't wait to post some photos, order parts, and fix it up.
Thankfully I have an Otto, so will be able to make great coffee during the journey. Ive been up since 330am, reading through posts here for 2 hours now. Sky is starting to lighten up and the birds are singing. Time to go n make a coffee. Have a great weekend everyone!
Hi all - new here.
I'm cleaning up an Atomic from the in-laws. I've got the gasket set from Bon.
Could someone please help me? How does the steam arm brass shaft come out of the steam arm body? There are three plastic washers and one brass washer that should be fitted to the shaft. But gotta get it out first.
Is it just a straight pull and I need to have a firmer grip and pull with a little more force?
Many thanks in advance,
Recently, I scored a Bon Trading Atomic in NZ for $300 on Trade Me. Sadly it had a stuck filler knob, and missing gaskets etc. I went online to find the best way to unstick the knob, and discovered here, as well as various you tube videos. All the methods I found looked complicated or damaging. So... I went and had a natter to my old man who is good with innovative ideas for fixing things. We found a really easy and cheap way to unstick filler knobs with no damage. I hope this idea will be of use to all of you if you have not figured this out for yourselves. All we did was buy a hose clamp for about $5. we then got a piece of bike tyre inner tube, wrapped it round the knob, attached the hose clamp and tightened it up, then gave it a couple of taps (on the screw head in the direction to loosen the knob) And that was that. It didn't even need a vice. The clamp meant that even pressure was applied around the knob with no damage to the bakelite. Now I am awaiting a new head gasket and seals with anticipation. I hope that this very simple and effective method will be useful for anyone with a stuck filler knob.
Somewhere on one of the Atomic threads I wrote about my method of removing a filler knob that had been locked in place for years, but it seems the restorers thread might be a good place to mention it too.
Grab a webbing strap type Oil Filter tool, a half inch ratchet drive (socket handle) and if you need it, a bit of pipe to extend the handle leverage.
Then, heat the Atomic - knob and all- with very hot water for a while. I held mine under the hot water tap until it was too hot to hold. The knob originally binds in place because of the aluminium cooling and clamping onto the bakelite. Then corrosion over the years finishes the job. Heating the aluminium gives it a chance to expand just a tiny bit and release its hold.
After heating it, handle the body with leather gloves of towelling because it should be extremely hot.
Wrap the webbing strap around the bakelite knob just as if it was a really small oil filter. Take up the slack, with the ratchet and apply pressure. If it doesn;t move, try lengthening the handle (use the pipe).
The webbing applies nice even pressure all around the knob and there's a good chance that, like mine, it won't break. Applying pressure with most other things, except the hose clamp idea mentioned above, puts opposing stress on the bakelite. Either method, the hose clamp and the oil filter strap, can grip all the way around.
I'm new here, have just aquired an Atomic from my local "Tip shop" all that seems to be wrong is that the black knob is broken under the head and before the seal. Have ordered a new head and seal set. I have tried to remove the steam valve and arm assembly but the thread seems to be stuck, got about half a turn movement but it then stuck, it took a disconcertingly considerable amount of force to move it that far, does anyone have any suggestions as to how I may proceed from here? I am going to try a few drops of ATF/Kerro mix and see if that helps. But would appreciate any other suggestions.
Got the screws out of the "filter head" if that is what its called, kept putting drops of ATF/Kerro mixture on them and then tried with a ratchet stubby screwdriver and to my surprise (after reading of the problems encountered by others), they cme out with little difficulty. However I am still trying to get the steam wand/valve assembly off. Sofar have only managed to unscrew and remove the red knod screw plus after a bit of heaving the red knob abd the knurled ring off. The valve, valve body and steam wand are still refusing my advances, can get less than the half turn I previously mentioned. I am still adding the ATF/Kerro mixture in the hope it may do some good. I wouls still appreciate any suggestions that may be offered.
Does the valve stem just unscrew from the body once the knurled ring is removed? If so mine appears to be stuck at that point as I unscrew it.
It seems brute force prevails! The valve stem does indeed just unscrew from the body once the knurled ring is removed, all it needed was a pull to release the seals from the body. I have also finally removed the valve body, again brute fore won the day, I had to use a mallet to strike the adjustable spanner I had locked across the flats on the body. Had to use an adjustable as none of my metric, AF or whitworth spanners fitted snugly enough although a metric one came closest. I think before I reassemble I will clean out the threads with suitable taps. From a post on UTube I understand the water inlet hole has a 1/2" BSP thread, does anyone know the size of the thread where the valve body screws into the machine, 1/4" BSP maybe? I now have only the main body plug to remove, unless anyone has a spare key they would be willing to sell me (cheaply) I will have to make one.
It seems that this post answers IGW's question posted unanswered some 5 months ago. Is this thread so infrequently visited by others?
Another couple of questions hopefully someone will answer.
I gave up waiting for a reply on the thread sizes, I know the filler thread is 1/2" BSPP, wheras the thread where the valve body is held in the main body appears to be 1/4" BSPP, or at least the thread external diameter measures up at the same size as !/4" BSPP and as close as I can tell the pitch is that expected from a 1/4" BSPP. So I have gone ahead and ordered the relavant taps.
Can anyone explain why some of the "Atomic Experts" on other sites recommend never removing the boiler plug when in the old user/owner manuals the removal of the boiler plug was a recommended proceedure during maintenance.
I would also ask what is the thread for the small screws that hold the shower filter in place, again I would like to clean then out and possibly look for replacements that will not corrode.
Seems that nobody who knows about the thread sizes on the Atomic checks or responds on this thread, its been over a month now and nobody has replied to my questions!
The thread taps arrived as well as a new valve stem, bought because I was unhappy with the damage I caused to the chrome finishwhen getting it off the body and an examination of the thread on the that goes into the body showe that it was damaged. (no wonder it was hard to remove from the body).
For those interested I can confirm that the thread for the water filler cap is definately 1/2 inch BSPP and the thread for the part of the valve stem that is screwed into the main body of the machine is definately 1/4 inch BSPP.
I am still waiting for someone to inform me as to the thread size for the screws than hold the "shower filter" in place.
I have an issue with my black filler knob not tightening. On examination, it looks unfortunately like the thread in the body is worn, rather than the knob, which would have been an easy fix.
Does anyone have any experience repairing or replacing the filler knob thread? I assume it is an insert but I don't imagine it is easy to replace.
Hoping this isn't terminal.
Thanks in advance.
Hi all, off topic but I’m new at starting a thread and I can not find how to do it. I’m trying to list an old Atomic I have had for years for sale, however can’t find a link to new post?
Toys! I must have new toys!!!
dear coffee lovers,
i've bought a atomic espresso machine for 80 euro's
there are some missing and broken parts that i already ordered.
butt i have a question. the thread in the base of the machine where the steamer goes is quite bashed. almost no thread left.
is there a way to fix this?, i know i can fix the steamer with a lot of tape or Locktite glue, that will work i hope. but are there other ways to repair this?
Sorry KristenG, I have not looked at this thread for ages. I also do not know if you still monitor the thread if you do then:
If just running the correct size of tap down the thread does not clear it up so that it can be used then as suggested above you can always have a helicoil inserted, or indeed do the helicoil insert yourself. You would need to buy the correct helicoil kit comprising the special tap, helicoils and insertion tool and possibly the correct sized drill. See this https://www.youtube.com/watch?v=9rtiFBC0wms for how you do it.
Hi, i have just bought an old atomic machine who’s knob is clearly stuck in... the previous owner clearly tried hard to remove it and slightly damaged the plastic knob, but it remains stuck... any advice on loosening it would be appreciated... considering spraying it with wd40 but will hold off to hear from you.
Hello Triky as an Engineer I tipicaly use hot and cold to free parts on ally gearboxs etc, trick is to get the housing hot and try moving the stuck part before the heat also expands it. If possible to gain good access to the part, try spraying freeze spray on it after housing has been warmed, this shrinks it and increases the clearance between the two parts and helps break the the oxidisation holding it all together. Repeat as many times as needed, also try tightening the part slightly before loosening to help break the oxidisation. Brute force should not be required just persistance, also use some penetrating fluid and allow a day or so for this to do its thing before trying the heat. Good luck.
You could also try the suggestion in #134 further up this page.
The webbing strap oil filter tool is cheap and you might even have one in your garage if you do your own oil changes.
The method uses the suggestion the previous reply that you should heat the body of the Atomic, particularly around the filler area, then using the webbing strap is fairly foolproof and a number of people have apparently used the idea successfully since I suggested it.