Peppina Marries MiniGaggia - Page 3

[timo888]

If for some reason you were required to work with an existing piston, like the Peppina's, with a single o-ring at the end of it, and yet you wanted to implement this dual o-ring design, you could place an o-ring in a channel running around the inside wall of the piston housing, as the Caravel does. This seal prevents water from entering the piston housing above the ingress ports. It is under significantly less pressure than the o-ring at the business end of the piston head.
Regards
Timo


P.S. I'm superimposing several 'views' in this quick-and-dirty drawing. You're seeing a cross-section at the upper o-ring and a frontal view on the bottom o-ring. The bottom o-ring is made of a new see-through material Remember, the port-holes are in the wall of the piston-housing.

[hbuchtel]

Tim-o,

I think Jim Schulman mentioned that an issue with the Peppina (related to the one-way washer?) was that there was a long wait between shots because the pressure had to bleed off by itself.

Have you run into this? Is it because there is pressure trapped between the one-way washer and the coffee puck?

Henry

[timo888]

Peppina has a canal connecting piston cylinder to group. A pliable one-way washer on the group prevents backflow from the puck into the canal. If the puck is too dense (too fine a grind/too heavy a tamp) the piston will be unable to push the water through the puck and the water will be under pressure. Just as blocking a running faucet with your thumb gets your shirt wet, if the Peppina is choked in this manner the PF will spew or sneeze if unlocked before the pressure dissipates. It's easier, of course, to choke a machine with an oily dark roast than with a lighter northern-Italian-style roast. There is no wait between shots when the grind and tamp are in the groove, and you can remove the PF immediately from the Peppina without a 'sneeze'.

ADDENDUM:
But this 'sneeze' (when it happens) is in the nature of things when pressure backs up. It all comes down to the force of the water versus the degree of impermeability of the puck-in-basket. The flow-rate through the puck-in-basket is the place to look, and the basket itself is implicated: water flows through some baskets more quickly than through others. If you have two baskets with the same diameter at the top and one of them tapers conically, water will flow through the conical more slowly than through the cylindrical basket because there are fewer egress holes in the base of the conical basket. A plugged cylindrical basket could present with similar symptoms. Then you'd need an espresso acupuncturist.

The sneeze does not affect the Peppina alone. Again, however, if you're not pushing the puck to extremes of density/dose, it shouldn't happen very often with the Peppina. Of the three machines I am using now, the one that is hardest to stall (i.e. the least likely to stall) is the Peppina. The Arrarex Caravel is the easiest to stall. The Cremina occupies the middle ground.

ADDENDUM2:
I've heard of people pumping the Peppina's lever up and down repeatedly as though it were attached to a car jack or air mattress. On a properly functioning Peppina, you don't have to pump with multiple shallow motions, although you could do so as alternative way to get the preinfusion going. But doing so you run the risk of turning the Peppina into a sneeze machine. If you pull the lever all the way down in one smooth motion, you should get a full draught of water from the kettle. Allow the lever to rise and water should be pushed to the group. For preinfusion, you simply guide the lever half-way or two-thirds of the way on its first ascent, count off the duration, and then allow it to continue under its own power. A double takes two pulls. The Peppina's cylindrical basket is a double. The single basket is conical.

...
Regards
Timo

[espressme]

Is there a functional reason behind chrome-plating brass? Or is that purely aesthetic? If the latter, I'd like the group to be naked brass please.
Regards
Timo

Hello Tim,
That is a darn good question. Brass and copper by nature are ok for use in food processing. "However" if they become dirty or are left unused and damp they corrode, the chemical reaction forms salts of the copper and those may be toxic. ( Copper salts are used to make timber rot and bug proof ) Silver or gold are nice, gold does not tarnish. Chrome works and is highly wear resistant but is expensive. Nickle is a toxic substance and is no longer used for food service items since 1923 or so. Tin is the common copper plating for food service. It is applied modernly by electroplating but historically by hot painting or swabbing at its melting temperature; like soldering the whole piece. It is suggested that the "tinning" extend outward about a ¼" from the food contact area. Tin is also impervious to almost all chemicals used in the cleaning of food service items. It does wear over time but has been in use for centuries.
So, in answer to your question, yes you may have a lovely shiny all brass group if you keep it spotless{ or tin plate the inside and top}. Many of the brass groups were "tinned" on the inside surfaces. ( See: http://www.home-barista.com/espresso-machines/cutaway-of-la-marzocco-saturated-grouphead-t700.html the cutaway of the Marzocco . That shows internal tin plating. )
Regards
Espressme

[espressme]

Mathias,

In the design I have in mind, the one-way valve assembly (I call it the 'group cap') is a threaded cylinder with a plate which contains the array of egress ports and the valve(s). The group cap connects the bottom of the piston cylinder to the top of the group cylinder, which protrudes into the boiler. The group-cap is a fairly extensible design and it could accommodate other kinds of one-way valves. It's not clear to me where the one-way valve fits in your diagram and I'm not familiar with the All-Clad one-way valve. Could you describe it?

I am certainly a proponent of simplicity. The group should be very simple. It needs a cylinder that projects up into the boiler, and collar to bolt it to the underside of the boiler, and a cylinder on the bottom into which the PF locks. The water will be at the correct temperature and so we don't need anything fancy in the group. No thermosyphons etc etc. I would like to be able to make use of readily available OEM portafilters.

Regards
Timo

Hello Tim,
Here is a high tech/ low tech home-made "one-way" washer/valve used by modelers to cover valve ports in pulse jet engines. It has the advantage of "washer"simplicity and may be configured to valve multiple ports. It could be etched, or laser or water-jet cut in multiples for a very low cost. Please be sure to read the "Etch your own valves" link! Don't forget to think outside the box. Could there be: flappers inside an outer ring?, inner and outer ring with radial flappers like a wind mill? Two rings with flappers; inside and outside?
http://www.aardvark.co.nz/pjet/valvelife.shtml
Have fun!
Regards
Espressme

[espressme]

Timo, do you know how to design the o-ring seating (diameter and tolerances)? I never found information on that.

Hello Mathias,
Here is a company's info I've used for years:
http://www.precisionassoc.com/contribute/tcom.htm#
go to O-Ring Design Dimensions and click the links there. You will get printable Adode Reader documents that explain the factors needed for design of the grooves &c, also you will find on the link page info for deciding which "O" ring compounds. Go to their home page and find which compounds for food and medical use.
Have fun
regards
espressme

[timo888]

For the material of the piston o-rings, I would use EPDM NSF61-compliant for drinking water. The same material could be used for the one-way washer. It's good to 300 degrees F.

If NSF61-compliant washers would be acceptable nowadays to the various regulatory agencies that monitor food service equipment for food-safety compliancy, then they present the least expensive and simplest alternative. There are also bushing type valves like the one pictured below which comply with the European Pressure Equipment Directive of 2002 (not sure if that directive applies to domestic/commercial food/beverage equipment and appliances):



Are there advantages to the finned valves used for rockets other than inexpensive manufacture? Can they be made of stainless steel to minimize the galvanic corrosion issue? Would they be better and/or cheaper than NSF61-compliant EPDM (assuming it would pass regulatory muster)?

Could the group be made of stainless steel? What are the heat properties of stainless steel? What manufacturing processes would be required to make a simple cylindrical group, with a flange so it can be bolted to the bottom of the boiler, and with the requisite collar and grooves to lock a portafilter in? The group could be sophisticated in its utter simplicity rather than in its ingenious complexity. Nothing like an E61.

Regards
Timo

[mogogear]

Nice find in that valve!! Keep it MR. Tim

[timo888]

On a different subject yet related to the choice of metals, we want to make sure the heating elements for the two boilers and their electrical connections cannot corrode or 'erode':

10 June 2006
http://www.conformity.com/current_newsbreaks.html

... Eugster/Frismag of Switzerland has recalled about 28,000 automatic espresso coffee makers. The company says that the electrical connectors in the espresso machine can erode and pose a fire hazard. Eugster/Frismag has received four reports of fires started inside the coffee maker, but no reports of injuries or property damage. The espresso machines were sold through department stores and independent specialty stores nationwide from July 1999 through October 2005 for about $800.

http://www.cpsc.gov/cpscpub/prerel/prhtml06/06106.html

[espressme]

Are there advantages to the finned valves used for rockets other than inexpensive manufacture? Can they be made of stainless steel to minimize the galvanic corrosion issue? Would they be better and/or cheaper than NSF61-compliant EPDM (assuming it would pass regulatory muster)?

Hi Tim,
All the usual disclaimers and IMHO
Yes, the valves could be made of shim ( spring temper) .010 ( .2mm ) 18-10 ( 304 in the USA.) Using water jet or etching could leave them absolutely flat. 18-8 and 18-10 are ok'd for food service. Don't lose that bushing valve tho!

If NSF61-compliant washers would be acceptable nowadays to the various regulatory agencies that monitor food service equipment for food-safety compliance, then they present the least expensive and simplest alternative. There are also bushing type valves like the one pictured below which comply with the European Pressure Equipment Directive of 2002 (not sure if that directive applies to domestic/commercial food/beverage equipment and appliances):

And, yes the washers could also be readily made from an acceptable silicone material that would take the heat. Many newer stove top gaskets are made from these materials and it is easy to cast into a simple one sided mold or a two part one. Also there is a injection moldable material available. They could even be stiffened by the stainless steel shim cast into them or, the elastomer ( rubbery material ) valve seals could be cast into the SS shim plates.

Could the group be made of stainless steel? What are the heat properties of stainless steel?

Hi Tim,
For the simplistic answer, conductivity of Stainless steel is about .17, and that of Aluminum is about .344, that of brass/copper is about 1.041 and that of silver is about 1.1. That means the metal will conduct/lose heat at that speed/rate. So, a metal is chosen for its ability to hold or lose heat for each application. For food service Stainless steel is very good for holding heat and real poor for a quick start-up to a stable temperature.

Enough for this post, All the usual disclaimers and IMHO
regards
Espressme

[espressme]

...merged with related thread at Espressme's request by moderator...

Could the group be made of stainless steel? What are the heat properties of stainless steel?

Hi Tim,
IMHO with all the usual disclaimers!
For the simplistic answer, conductivity of Stainless steel is about .17, and that of Aluminum is about .344, that of brass/copper is about 1.041 and that of silver is about 1.1. That means the metal will conduct/lose heat at those proportionate speeds/rates. So, a metal is chosen for its ability to hold or lose heat for each application. For food service Stainless steel is very good for holding heat and real poor for a quick start-up to a stable temperature. The mass/amount of a material gives stability of temperature but the mass takes time to heat. Brass has been the favorite compromise.

What manufacturing processes would be required to make a simple cylindrical group, with a flange so it can bolted to the bottom of the boiler, and with the requisite collar and grooves to lock a portafilter in? The group could be sophisticated in its utter simplicity rather than in its ingenious complexity. Nothing like an E61.

Well Tim,. Were I given my druthers, for these kit machines, the group parts could be cast by the "cier perdue," "lost wax" method. What that means is that a master model is made in a chosen material eg: wax,plastic,clay,metal, or whatever which is easily worked and holds its shape. Then the model is cast over with 2 part, somewhat flexible, silicone rubber. Remember the answer to the All-Clad Presso? { an aside- al-clad is a common practice of coating the casting or sheet with 99.9% pure Aluminum.} After pouring the parts of the mold, the model is removed and wax may be injected to fill the void. Then the wax could be taken to an investment casting shop capable of using shaw or shell molding and burning out the wax before pouring in the hot metal. One shop I used years ago would take the finished waxes and give smooth cast parts in two weeks. They require only final machining and polish. Prices have gone up but for a perfect machine $2-300 would be a ball park for 4 to eight pieces or more { That depends on the enthusiasm of the owner of the facility and whether the parts could be attached to a tree ie. many parts on a column to be cast at a metal pouring as one item, then separated.

Brass may be able to be founded at a local art college if their centrifugal casting machine is big enough. The effect would be very close to the early professional machines. They often used lost wax casting for the groups as sand casting would not hold detail.

Brass has been the material of choice due to its ability to transfer heat and easily machined. Stainless Steel is a real bug-bear to machine with home shop equipment and has its troubles in a manufacturing environment also. CNC comes to mind an may be cheap in a well equipped shop. Castings could make it reasonable for a kit purpose. The holding of the parts ( fixturing ) for machining would have to be carefully looked at to save time and money. Inexpensive modern espresso machines are most often of die cast of aluminum or plated pot metal ( Zinc. ) Some boilers are made of Stainless steel stampings, formed by machine like the filter baskets/screens.

On a different subject yet related to the choice of metals, we want to make sure the heating elements for the two boilers and their electrical connections cannot corrode or 'erode':

The early submerged coils were tinned copper tubing over a plaster/ceramic powder packed onto a coiled Nichrome wire or rod running centrally/axially through the whole tube with a connection outside the wet zone spot welded to the nichrome. After a while they would lose their coating and be a health risk. Also the coating would melt at about 470F and thin or evaporate. Older machines yet had a coil of nichrome wire that was inserted into a long spiral slot in a ceramic block. They really heated up fast though. Modern heaters are usually a Cal-Rod unit similar to the old copper tube ( eg. electric stove element.) Some are bent, like Hot water heater replacements inserted into a screw in fitting, found at your local building supply house ( good choice as they are made for potable ( drinking) water. Others are cartridge heaters. A very hot plug is in the wet zone. Many small machines use a calrod unit "staked" ( held in place by pressing metal over the tube) Your idea of a band heater outside of the wet area is a great one.
Erosion/corrosion may be caused by water vapor in the area. It could well be caused by arcing ( electricity jumping to parts of another polarity or potential, even the connector to the heater is not safe if at all loose or of too small contact area.) perhaps caused by a coil releasing energy ( like the spark coil on a car when shut off.) There are fixes for these problems.

Enough for one night!
Regards and may your minds brew even fresher ideas!
Espressme.
Probably too long as the quotes don't look right in the preview..

[timo888]

...Your idea of a band heater outside of the wet area is a great one. ...Erosion/corrosion may be caused by water vapor in the area. It could well be caused by arcing ( electricity jumping to parts of another polarity or potential, even the connector to the heater is not safe if at all loose or of too small contact area.) perhaps caused by a coil releasing energy ( like the spark coil on a car when shut off.) There are fixes for these problems.

To give credit where credit is due, Mathias proposed the banded heater that runs around the outer wall of a cylindrical boiler. I am familiar with the Calrod style from Peppina (and mogogear and I have each found a few sources for this immersible variety) and am also familiar with the under-boiler style used by the Caravel. I am favoring the under-boiler element used by the Caravel, for reasons I will elaborate inside the Peppina Marries MiniGaggia posting.

Regards
Timo

[timo888]

There are three basic types of heating element under consideration:

° dry radiant coil

° immersible calrod

° banded collar

The immersible calrod makes direct contact with water and is subject to galvanic corrosion. Also, bend-radius constraints place some limits on the shape. Element and the kettle should be made out of stainless steel.

The banded collar requires a cylindrical kettle which is not the most efficient use of space inside the machine; the band continues to heat the kettle above the water-level as the water in the kettle diminishes; in order to attain 500ml of brew-temperature water (one of the design goals of the machine I propose), the band must have quite a large diameter which reduces its efficiency: the narrower the column of water the more efficient it becomes.

The dry radiant coil makes no direct contact with the water and is therefore nearly impervious to galvanic corrosion; it can have narrow-radius bends (see photo below) which permits optimization of the element's shape; it does not place any limitations on the shape of the kettle; it sits beneath the kettle and does not lose efficiency as the water-level in the boiler becomes lower. It could be seated in a groove in the base of the kettle, and a plate could be bolted onto the base, effectively sealing the element inside and directing its heat upwards.

Regards
Timo

Arrarex Caravel's dry radiant coil heating element is situated below the kettle (on the right):

[timo888]

Were I given my druthers, for these kit machines, the group parts could be cast by the "cier perdue," "lost wax" method.
{...}
Brass has been the material of choice due to its ability to transfer heat and easily machined. Stainless Steel is a real bug-bear to machine with home shop equipment and has its troubles in a manufacturing environment also. CNC comes to mind an may be cheap in a well equipped shop. Castings could make it reasonable for a kit purpose. The holding of the parts ( fixturing ) for machining would have to be carefully looked at to save time and money. Inexpensive modern espresso machines are most often of die cast of aluminum or plated pot metal ( Zinc. ) Some boilers are made of Stainless steel stampings, formed by machine like the filter baskets/screens.

Let's eschew aluminum and plated pot metal. I don't like the thought of the plating flaking off years hence. And that's one less step in the process. I do like stamped stainless steel for the brew-water boiler -- what I've been calling the "kettle" to emphasize the fact that it is not a closed boiler under pressure. The second closed boiler for steam could also be stainless.

The lost wax method with a brass group seems fine to me, as long as the tolerances are good enough.
Metric 1.5mm parallel male thread has to be machined at the top of the group so the female-threaded 'group cap' can screw down flush onto it. The group cap houses the plate containing the one-way valve assembly, whatever that turns out to be, a simple EPDM NSF61-compliant washer screwed into a center tap so that it blocks a circular array of ports, or a more sophisticated array of male-threaded bushings containing one of the typical backflow prevention valves: spring, umbrella, duckbill, cone, etc.

Would the tinning on the inside of the brass group (to make it food-safe) present corrosion issues inasmuch as the group would be connected to a stainless steel boiler? Is the tinning significantly less noble than stainless or are they roughly the same?

I have no experience with fixturing-- is there anything about the group-with-flange in my drawing that leaps out at you as problematic in this regard? I would hope that the flange makes it fixturing-friendly?

Regards
Timo

[timo888]

I need to bone up on conductivity of metals and the physics of heat transference with water and metal. In the meantime, one lazy question, please.

Let's say we have equal surface areas of two metals, stainless steel and brass. Let's pretend the metals have been shaped into funnels. And let's say (loading the dice) that both funnels have been heated to 80 degrees C.

Now, let's pour a 20ml slug of water at 95 degrees C. into each funnel. All things being equal, which funnel robs the water of more heat?

Regards
Timo

P.S. I have noted the relative difficulty of machining stainless steel versus brass. There is a cost associated with that difficulty. But is that cost greater than the cost of sending the brass groups out to be tin-plated?

[mogogear]

I need to bone up on conductivity of metals and the physics of heat transference with water and metal. In the meantime, one lazy question, please.

Let's say we have equal surface areas of two metals, stainless steel and brass. Let's pretend the metals have been shaped into funnels. And let's say (loading the dice) that both funnels have been heated to 80 degrees C.

Now, let's pour a 20ml slug of water at 95 degrees C. into each funnel. All things being equal, which funnel robs the water of more heat?

Regards
Timo

P.S. I have noted the relative difficulty of machining stainless steel versus brass. There is a cost associated with that difficulty. But is that cost greater than the cost of sending the brass groups out to be tin-plated?

Lino is your man- 'course you know that. Just for the record- lost wax method- which Mitchel employs in Canada, is really a low volume production oriented production model.
S/S pipe could be your piston cylinder. Cut to order, flange (already produced with thread etc) can be welded on , your stamped s/s kettle will have a hole in the bottom to accept the cylinder. Possibly with a close tolerance flange) the pipe could press fit through so the threaded "business end could protrude through to the group area. Cating seems soooooo expensive and a hard process to really get designed IMHO. Using materials already in the form you need( saving the stamping of kettles) really seems a realistic aspect to having a production process. Stamping metal is relatively easy in comparison. And a durable metal. No flaking and I think the pipe could be sourced in a heavy enough gauge that by adding a brass or what ever group head -you would have the "umphf " you are looking for.

[timo888]

Let's say our goal with the group is to leave the water temperature as unchanged as possible, because the water leaves the kettle at the right temperature. All other things being equal (which might not be the case) would we choose brass for our group over stainless?
Regards
Timo

[lino]

Hey Guys,

meant to respond sooner, but I've been so freakin' busy....

Anyway, Timo, here's my attempt at an answer to your question

Brass (a typical naval brass) has a thermal conductivity of 116 W/m-K
it has a specific heat of .38 J/g-C

Stainless Steel Type 304 (the cheapest, but one of the more dificult ss to machine) has a thermal conductivity of 16.2 W/m-K
and a specific heat of .5 J/g-C

We're more concerned with thermal conductivity here for two reasons. First we're dealing with a short (time) event, second because the values of specific heat for brass and stainless are fairly similar and so for comparison purposes, can be ignored.

So, if we take your funnel question the answer is pretty clearly the brass will conduct more heat out of the water. Roughly 7 times more heat.

Hope that helps...

ciao

lino

[espressme]

Let's say our goal with the group is to leave the water temperature as unchanged as possible, because the water leaves the kettle at the right temperature. All other things being equal (which might not be the case) would we choose brass for our group over stainless?
Regards
Timo

Hello All,

I would tend to believe that the stainless steel group would be less apt to lose heat to the water, or atmosphere. That being said, when it does lose heat to the water, it would take more heat energy to come back to temperature. So in the case of the Lil' Monster as proposed, it should be a better choice than brass. The reasoning being that it has the mass of the boiler and water in it at the correct temperature plus its own mass which would be less apt to be reduced by the greatly smaller mass of the shot. That is the reason the Peppina is so accurate at temperature holding.
On the other hand ( can you imagine a one handed politician? ) The Brass would be constantly transferring heat from the boiler to all parts of the group at a greater rate and so would really be homogeneous within the group and have no cool spots.

To give credit where credit is due, Mathias proposed the banded heater that runs around the outer wall of a cylindrical boiler. I am familiar with the Calrod style from Peppina (and mogogear and I have each found a few sources for this immersible variety) and am also familiar with the under-boiler style used by the Caravel. I am favoring the under-boiler element used by the Caravel, for reasons I will elaborate inside the Peppina Marries MiniGaggia posting.

I have used a company called Minco that makes 600°rubber covered heaters in any shape and watt density( calories given off per unit of area.)http://www.minco.com

The lost wax method with a brass group seems fine to me, as long as the tolerances are good enough.
Metric 1.5mm parallel male thread has to be machined at the top of the group so the female-threaded 'group cap' can screw down flush onto it. The group cap houses the plate containing the one-way valve assembly, whatever that turns out to be, a simple EPDM NSF61-compliant washer screwed into a center tap so that it blocks a circular array of ports, or a more sophisticated array of male-threaded bushings containing one of the typical backflow prevention valves: spring, umbrella, duckbill, cone, etc.

Would the tinning on the inside of the brass group (to make it food-safe) present corrosion issues inasmuch as the group would be connected to a stainless steel boiler? Is the tinning significantly less noble than stainless or are they roughly the same?[/quote]
I would suggest that the group material would be of a non- tinned variety due to wear as shown in Marzocco. The Tin in brass could serve as a lubricant but would wear in the grooves, but not in the food contact area.

[/quote]I have no experience with fixturing-- is there anything about the group-with-flange in my drawing that leaps out at you as problematic in this regard? I would hope that the flange makes it fixturing-friendly?[/quote]

I don't believe that the flanged part in question would be a great problem to fixture.

I have noted the relative difficulty of machining stainless steel versus brass. There is a cost associated with that difficulty. But is that cost greater than the cost of sending the brass groups out to be tin-plated?

The probability is no.

S/S pipe could be your piston cylinder. Cut to order, flange (already produced with thread etc) can be welded on , your stamped s/s kettle will have a hole in the bottom to accept the cylinder. Possibly with a close tolerance flange) the pipe could press fit through so the threaded "business end could protrude through to the group area.

I agree with 'mo' That flange would be a solid mounting for the group. I might disagree about the portafilter clamping around the short projection. Altho, the clamp ears could be welded to the flange and be cleaned up and machined to accept a portafilter. My old Salton/Vessuviana/Atomic steamers had the portafilter around the long strainer projection and they are a bleep to get apart and/or clean. They are very messy.

I am answering the questions as a means to brain-storm and not as a final answer. Been too long a modelmaker and would like to view possibilities before cutting material.

Regards
Espressme

[timo888]

I have moved things back into the Peppina Marries MiniGaggia thread.

.... So, if we take your funnel question the answer is pretty clearly the brass will conduct more heat out of the water. Roughly 7 times more heat.

Thanks Lino. That's what I thought the numbers were saying.

So, brass is good for making heat-sinks to COOL the water down. But if the water is already at or near brew temperature as it leaves the boiler, and our goal is to keep the water at temperature, does it not follow that we would want to use a relatively non-conductive metal for the group, other costs permitting?

Time to start looking for heavy-gauge food-grade stainless steel pipe with a diameter capable of accommodating a ~51mm basket? The housing for Peppina's 51mm piston is ~58.5mm outer diameter, 52mm inner diameter with a wall thickness of ~3mm.

The idea of cutting the slot for the PF ears into the flange rather than into the group cylinder is a good one. I will think more about that. The collar on the flange, into which the ear-groove would be machined, that collar could be created as part of the stamping process, no?

The Cremina's PF is 51mm inner diameter; 56mm outer diameter not including the ears; and 62.5mm including the ears.

Regards
Timo