Cafelat Robot User Experience - Page 465

#4641: Post by **imp96** » December 9th, 2022, 4:58 pm

I time my pre infusion of slow ramp up to 2 bars with first drops, which I see at around 15-20s into the shot. At that point I do a quick ramp up to 7-8bars. From here on I maintain the same pressure with my hands which yields an ever-declining pressure profile as the puck erodes. I am unusually done at 45-50s into the shot at like 4bars. I use very fine grind from flat ultra-low fine burrs. If you go coarser or use different burrs your times/ratios will vary from mine.

I think the most important thing is not to grind to fine. Fine grind results in channeling which produces espresso that tastes very strange and hard to understand what is wrong with it. When in doubt go coarser/longer ratios. You should get a tasty shot, but it will not be as concentrated as it could be, which is also not a bad thing.

As an extreme example, I have done shots where I used very coarse grind and very low pressure (~1-2bars) for close to a minute shot. This was me making a pseudo aeropress/pourover type drink which came out quite good. Espresso isn't as black and white like it is often portrayed. There isn't one magic recipe that will get you the perfect shot. You have a lot of liberty to play around and get the result that suits you.

December 11th, 2022, 3:05 am

I just wanted to thank all of you who talked me into getting the Robot as my first espresso machine. 2 months in and I'm now pullilng consistently better shots than even my local third wave roaster. I'm one of the few people who loves to tinker nad be a master at something, so the Robot with it's ability to adjust pre infusion, bar pressure and timing on the fly really felt like the perfect mix. My J-max grinder and light roasts have made some AMAZING shots, to the point where I'm now actually enjoying sipping espresso straight instead of making milk drinks or Americanos. I'm pulling 2-4 double shots (14 -16 gram input) a day and not finding it laborious or painful at all. In fact, I think it's easier than waiting for a double boiler to heat up and get ready. It takes 3 minutes to clean up and I'm usually done pulling 2 doppios in under 15 minutes.

right now I'm using S&W roastings "Tropical blend" which is a medium roast (by Nick's standards, which are lighter than most Happy Mug medium lights) and it's basically pure cocoa powder to the taste buds. I've gone through half a pound since monday afternoon when it arrived. I'm having an absolute BALL and haven't drunk more than 3 cups of filter brew in the last 2 months lol....this was a dangerous rabbit hole (thinking of adding a Niche zero to supplant my J-max just because it's so damn convenient)

#4643: Post by **ojaw** » December 11th, 2022, 12:48 pm

Good stuff, there may be some Niche alternatives around by now like the DF64 or Eureka Oro et cetera.

#4644: Post by **ojaw** » December 11th, 2022, 1:11 pm

December 15th, 2022, 2:13 pm

Lance Hedrick's Robot uses Gabor Laczko's naked cyberpunk faced pressure gauge. TBH, I would love this . I was early adopter for Gabor's pressure gauge via piston rod for Olympia Express Cremina. But much less discretionary income and too many other hobbies and child' college to pay for

So I have paper scale taped to OEM pressure gauge. I found this gauge paper on this thread ~page 430-ish IIRC.

#4646: Post by **ldubz** » December 18th, 2022, 5:39 pm

Not sure if this has already been proposed but has anyone tried a 24v 30w heating pad like this: https://www.amazon.com/Flexible-Polyimi ... r=8-2&th=1

It's rated for a max temp of 170°C.

I stumbled across this youtube video and he seems to have installed something similar to the piston of his robot: http://www.youtube.com/watch?v=dLXpnaEcfHo

jpender wrote:I did some experiments where I had embedded some flexible heaters inside the piston. This kind:

image

At 12V I think they were rated for about 28W and were supposed to self-limit to 97°C.

They heated up the piston, eventually. It just took a long time.

image

These particular heaters self-destructed, with the fabric portion melting.

image

I bought some alternative heating elements, PTC heaters, aiming for more wattage. But it's a cramped space inside the piston. You want the element to be in direct contact with the inside face, not the sides of the piston. And it's hard to get enough of something in there.

When I discovered that I could accomplish the same thing using an FDA silicone covered non-metal piston I decided that was a much better way to go. No electricity, no cup of hot water, no waiting time. Here is a prototype in PVC, with the face covered with silicone and the sides with a film of FDA silicone adhesive:

image

Simple, passive. I just need to make a final version that is safer to use. I've had the materials sitting here for many months. I'm just easily distracted. And also, I've gotten on a darker coffee kick where I not only don't preheat the piston, I actually stop the kettle before it boils since I've found that water in the 92-97°C range often seems to work a little better.

It would be nice if someone made and sold a replacement piston but it doesn't seem that one is coming soon.

#4647: Post by **ojaw** » December 18th, 2022, 6:15 pm

Jpender has possibly the most posts on this thread : )
You can ask him yourself

December 30th, 2022, 7:32 pm

rv03 wrote:Hi,

I searched in the whole thread but didn't find this subject. Perhaps I will raise the hair of Paul on his head if he reads that (sorry in advance) : does anyone tried to cut the bottom of the pressurized basket ? It seems not tapered as the unpressurized, to brew low doses.

Check your PMs

January 1st, 2023, 12:38 pm

Since i've had my DE1 for a few months now, i've mainly been using the Cremina lever profile, getting amazing results with that. I was thinking it would be fun to go back to the Robot now and try to emulate this profile and see how close I can get the shots to taste, now that I have a great reference point.

January 10th, 2023, 10:04 pm

Any opinions on what the best color robot is - only colours that are currently available now.

Ty!