La Pavoni top cap thread size

[BramJ]

For a little project I want to replace the top cap of my La Pavoni Professional but I can't seem to find fittings that screw right in, does anyone know the size of the thread of the top cap?

I want to add a temperature sensor (attached to the top cap, but so that the sensor itself is positioned in the middle of the boiler and a way to add a air pump to pressurize the boiler at temperatures below boiling point

[coelcanth]

it's a metric thread,
the cap is 31mm in diameter

so i guess it'd be called
M31 x 2.0mm

i don't think you'll have much luck finding an off the shelf part to fit

[benhogan]

that sounds like quite the project. I'd love to see it. Please post as you put together.

[BramJ]

hmm, M31x2
doesn't look like a standard size indeed...

This project is kinda a first step for a bigger project where I want to make a machine based on 2 pavoni's, one for the espresso's and one for steaming/hot water

[RayJohns]

I think it's probably M32 x 2.00, which is a standard size. There's a slight taper also, but I don't know if it is pipe threads or not. It's definitely 2.00 mm pitch.

Ray

[coelcanth]

well mine measures 31mm with no taper..

anyway, it looks like the only thing 32x2 is commonly used for is plugs in motorcycle gearboxes.
i see lots of links for 'brass vent plugs' but only in minimum orders of 1000 or so.
but here is a link to one as used on a bmw S1000RR:

http://www.bmwmcchattanooga.com/showAss...bly=478747

no mention of material, though, and i think it will be too tight a fit..
but it's only four dollars...

if you are going to undertake your own machine project, it might be worth making connection with a local machinist that can easily turn simple parts like these when you need them. can you find people like that in Europe ? they are a dying breed in the US. here you are best off learning to do these things yourself...

[BramJ]

I was hoping I could just simply buy a piece, but that seems not so easy...
My brother has a lathe and we also have one at work, so those are the next options

Mine seems more like 31 too, as far as I can measure here
I really need to get a caliper to do some accurate measurements

[RayJohns]

I measured mine using digital calipers. As I recall, it was ~ 31.8 mm near the top (by the sealing O-ring) and more around 31.5 at the start of the threads. That let's out any sort of 31 mm threads in my book.

I have a jewelers lathe here, but it's not setup for cutting threads. For cutting threads, I find it's easier to use taps and dies most of the time. For M32x2, however (especially given the depth of the thread on that top), I think it would probably require a larger lathe or fixture than what I have here.

Ray

[rpavlis]

I just received an M32x2 die in the mail. Its thread matches the Europiccola boiler cap perfectly. I found it at an eBay store from China. It is my intension to try to machine one of the chunks of polyetherimide that I have to make a base for a boiler cap to which to attach a wood one. Die stocks for large dies like this are expensive, but because polymers are not as hard as steel, I think I will be able to turn it with a pliers. The hard part is getting it started absolutely straight. I think I have a large aluminium block somewhere, perhaps I could make a die stock from it, but I do not think that will be necessary.

Assuming that I can succeed in cutting threads in the pieces of polymer I have, I also need to figure out how to attach the wood top to the polymer.

[TomC]

^ This would be awesome. I was just telling Ray how much I'd like a temp probe sitting right in the middle of the boiler. I imagine one could be made that could sit in the center, yet not need to actually be wrenched on, itself to take the top off.