The BDB has very uneven flow from the shower head. After removing the shower screen it shows the plastic inner screen is broken.


I also wanted to give the IMs shower screen a try and found this on Amazon, which has both the inner and outer screen I needed. But the inner one is made of brass.



Anyone tried it before?

Several of us have the shower screen and it's nice. There are two versions, with one of them having a non-stick coating.

I think one person was going to try the thicker second piece, but I don't recall the result. Hopefully they will chime in. I believe plastic was chosen as a thermally insulating material so that water flowing through is not affected. With this in mind, the brass might work against you until it had enough time to warm up. After it's sufficiently warmed up, it would probably help maintain thermal stability during your shot extractions.

There are a handful of people who have switched, but I would actually argue most still have the stock shower screen, and those who have switched haven't really seen any noticable improvement.

The use of plastic is actually intentional, I believe in the 900 they were made of metal (not sure which) but then the plastic allows for not heat loss. The plastic ones are also quite durable as long as you don't overtighten the screw, and they are cheap to replace.
Also, see post 44, Peter is at least one individual who has the brass insert and has actually chosen to continue to use the stock one due to potential corrosion issues.
Using IMS Competition Shower Screen on Breville Dual Boiler 920XL

Thanks! Glad that I asked. Ordered the stock replacement from Breville. Less than $10 with shipping and tax.

Thought I'd chime in here, but not much to say. You guys have it (and me) down pretty much right.

To the OP... in your photo of the cracked plastic dispersion disc... the part around the center screw hole looks like it has seen considerable trauma. Makes me go hmmm...

OT moment: Also to the OP... Since you are using the Forte, you must read this: The Alicorn: Achieving Precision Alignment with the Baratza Forté/Vario and Baratza Vario owner experience

I've had the original metal disc from the -900 family and the plastic ones that came out later. Never had a problem with either. I do mostly use the IMS competition shower screen, but I'm not sure it makes a big difference. I mostly use it because it seems cool. Like what the other cool kids are using.

A word about dispersion... I hang with some people with some big dog machines... GS/3's, Slayers. They use a dispersion scheme in which the water comes through the same center hole as the screw. The screw is fat and hollow and has holes in the sides that spray the water out like spokes, which in turn gets filtered through the screen. The BDB relies on the dispersion disc to make sure the water gets out evenly. It is possible that this is an area where the big dogs have an edge over the BDB. Possible. But I'm not sure. Mine seems to do really well here though, and I don't think it has anything to do with my plumbing or rotary pump.

Here, where I profile by speeding up the flow about halfway through, then slow it down before I cut off the pump: And here again where I am practicing speeding up and slowing down the flow and showing the pressure gauge, for the flow profiling community: If I am suffering a water distribution problem I can't tell from the videos. These are both with the stock plastic disc and the IMS shower screen.

-Peter

Thanks Peter! Thought about aligning the Forté but haven't got time to give it a try. I am waiting for a Monolith Flat in the next batch expected in February. Hopefully that marks the end of my grinder upgrade.

I have never unscrewed the shower screen on the BDB actually. When I unscrewed it yesterday, it was so tight that I had to try pretty hard with the Allen wrench. I think the over tightening might have been the cause.

Monolith Flat? What a coinky dink? I have one of those too. Several of us BDB'ers have them. It is one formidable combo. About as good as it gets. I sprung for the SSP burrs. And aside from being slow and stall-prone at very fine grind settings, it is great.

BUT since the Forte (or a Vario updated to Forte spec), can be aligned to Monolith level planarity in just a few minutes with no special tools, I decided that that characteristic made it too valuable to just let go for a song.

-Peter

Good to know that the Monolith and BDB work well together. I also got the SSP burrs. I will try to give the Forté alignment a try tomorrow.

have you done the "Slayer mod"? It's HUGE if you like light roasts

-Peter