Lelit Bianca User Experience - Page 6

Need help with equipment usage or want to share your latest discovery?
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another_jim
Team HB

Postby another_jim » Oct 30, 2018, 10:35 pm

A Scace takes about 7 to 10 seconds to stabilize and read correctly. On an E61, the group acts as a heat sink, cooling the water and itself heating up. So the actual temperature over this time also tends to rise slowly. That means by the time the Scace stabilizes, it will read a degree or two higher than the initial temperature. But from an extraction viewpoint, the temperature of the water first soaking the puck is the biggest factor.

This makes little difference when making your own coffees for yourself, since you adjust the temperature by taste, not by absolute numbers. But it would be nice to have an easy way to get all the machines on the same page if you're sharing recipes. Looking at this thread and the flash boiling one; we're still a ways off.
Jim Schulman

Graham J

Postby Graham J » Oct 31, 2018, 6:45 pm

Here are some photos of the Bianca E61 control valve assembly. I was interested to check the design detail and its condition after 557 cycles on the shot counter.
I left descaling until after this exercise. Lelit recommend descale at monthly intervals and it looks that this will be the correct thing to do. This is two months from first use. You'll see that there's some moderate loose scale on the valve gland seal and the mushroom. I live in a moderate water hardness area, nominally, but Yorkshire Water Authority network their water around the county, so hardness and mineral content can vary. I've maintained the refill counter and used a new Lelit filter as required.
Checking torque with a traceable calibrated wrench, before disassembly, I found the torque settings used to be low, at 6-8 Nm for the metering valve chamber sleeve nut and 8-10 Nm for the Mushroom sleeve nut. These values make sense for the moulded polymer washers used, which are of high quality. stepped as required. I rebuilt the assembly to these torque values with a smear of HT silicone grease. The assembly photos are after reassembly and with the machine at operating temperature. No evidence of leaks.
If rebuilding your own Bianca, I'd recommend use of 12 point sockets (22mm and 36mm sockets needed) and an accurate torque wrench. This will avoid damage to the surface chrome or distortion of sealing washers or the valve seating and alignment. The paddle clamp screw is a 2mm hex socket.

Fit and finish of parts are good to high standard, with good machining attention paid to bore and thread form to control the centring of the metering valve and jet - users will notice the smooth operation of the paddle and its metering is very repeatable when measured. An exception is the mushroom which is already showing signs of surface corrosion degradation.
The metering needle is 4.8 mm in operational length and tapers from 1.45mm at the shoulder to 1.28mm diameter at the tip. Measured at 5 points, this is a constant taper grind. The jet measures around 1.4mm diameter, but my measurement technique of the jet bore with a plug gauge, is not very accurate.This is a finely made assembly and delivers accurate repeatable control. Scaling or contamination here will degrade metering performance so maintaining group cleanliness and monthly backflushing are going to be required for keen users.
I'd advise measuring outlet water flow at operating temperature, before removing the paddle and opening the valve assembly. I had a graph of flow from the group at 6 points of paddle position, posted elsewhere on H-B,but four measurement points will be enough. You'll need this data to return your paddle to its previous flow set points. One spline change can make a 5-10% difference in flow rate.
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User avatar
another_jim
Team HB

Postby another_jim » Oct 31, 2018, 6:58 pm

Thanks for posting these pics; I'll link to them in the bench review.

If I'm not mistaken, I can see why they didn't patent their paddle group, it looks a lot like the prototype E61 with needle valve.

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Jim Schulman

Graham J

Postby Graham J » Oct 31, 2018, 7:11 pm


To be correct, its not descaling, but backflushing that Lelit recommend monthly for the Bianca. Thats the process I should be naming here, using a proprietary compound such as Cafiza or Puly Cafe etc. It has a descaling effect also, for the localised E61 group area. Next strip down in maybe 3 months , will reveal if this is effective in maintaining the metering valve in good condition.

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Jake_G

Postby Jake_G » Oct 31, 2018, 8:55 pm

Thanks Graham,

Were you able to get a read on the thread pitch?

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sweaner

Postby sweaner » Oct 31, 2018, 9:00 pm

wesleynance wrote:Any ideas about a shot mirror for this machine? I probably will never run the regular portafilter, since I'm always wanting to watch the extraction. So I'm constantly bending under to check the shot.!


I use something like this: https://smile.amazon.com/uxcell-a140210 ... dpSrc=srch

Just sit it on the drip tray and adjust as needed.
Scott
LMWDP #248

www.coffeefreek.com

Mesmer

Postby Mesmer » Nov 01, 2018, 7:30 am

So i take it that mushroom valve is the same as a regular E61? Is it only the top part (with the paddle) that's different?

iggles_and_espresso

Postby iggles_and_espresso » Nov 01, 2018, 9:37 am

another_jim wrote:If I'm not mistaken, I can see why they didn't patent their paddle group, it looks a lot like the prototype E61 with needle valve.


Has Lelit said that it isn't trying to patent the paddle group?

ndl

Postby ndl » Nov 01, 2018, 10:29 am

I recently received my Bianca and I love that there's so much useful information on this forum already! I hadn't seen a lot of reviews on other espresso based communities that I follow, so it's really helpful to have everyone's expertise involved here, so thanks everyone.

I was very impressed with the packaging and shipment from 1st line. I am a bit disappointed in some of the finish details (a couple scratches -- one hairline and one deeper, two small pits/slight dent on the drip tray corner, black pinhole and dent on the portafilter handle, etc), but I'm actually really enjoying the machine itself. I haven't had a chance to play with the paddle too much yet, but I expect to have a lot of fun with that soon. Super excited to get moving on that front!

Stanic

Postby Stanic » Nov 01, 2018, 1:38 pm

Anybody knows, is the Bianca's user manual available?