Fascinating. People like me are completely indebted to guys like you and Stephen who take the time to do this sort of stuff. We just read, wonder and admire. Can't wait to read more!
I like doing challenging things and the clear pf was right up there! Much easier building 40mm projectiles and cartridges for that cannon, which by the way was very accurate! Shooting silhouettes at 500 meters was pretty easy.
The clear pf was a challenge in as much as the material incompatibility with adhesives, heat and pressure. I was surprised it lasted as long as it did!
To enjoy the view through the glass sides, the machine had been (on the long braided hose) on a trolley for a few months, in the middle of the room and there I could turn up the P-stat to have a max at 1.4 bar and enough room temp air was flowing on all 4 sides to prevent the group from getting too hot.
For this video project I moved the machine to a corner in the kitchen where it was suddenly snug, a wall to the left, wall in the back (warm air from the fridge cooler behind it), the big heavy espresso centrifuge to the right. There, the group temp was easily 90ºC and it showed at the start of pre-infusion as the water came in bubbling.
I could have seen it if I had taken the time before filming, checking the group temp probe and checking the water coming out during a short flush.
I lowered the P-stat considerably but I haven't read the dials yet.
Anyway, it will be different for everyone else in different climates, different central heating thermostat setting / room temp and depending on the amount of free space & air flow around the machine.
David Kidd post=3308 wrote: Any plans on making these available Stephen? I found something similar on Youtube some time ago.
what i love about the 'correct' extraction is the cone is off centre by about exactly the same amount as the 'wrong' extraction video
i think it highlights how we have to be very careful when making extrapolations from a good theory
i.e. the 'correct' extraction might be tamped nice & level, but it is defective for some other reason, presumably channelling, the result of poor distribution before tamping, or sometimes just plain unlucky
Reiss Gunson post=3310 wrote: [quote=David Kidd post=3308]Any plans on making these available Stephen? I found something similar on Youtube some time ago.
what i love about the 'correct' extraction is the cone is off centre by about exactly the same amount as the 'wrong' extraction video
i think it highlights how we have to be very careful when making extrapolations from a good theory
i.e. the 'correct' extraction might be tamped nice & level, but it is defective for some other reason, presumably channelling, the result of poor distribution before tamping, or sometimes just plain unlucky The LaSpaziale videos you are showing were shown to show what they were attempting to emphasize. Frans and I were working on what happens inside the Lever Group.
Reiss Gunson post=3310 wrote: i think it highlights how we have to be very careful when making extrapolations from a good theory
i.e. the 'correct' extraction might be tamped nice & level, but it is defective for some other reason, presumably channelling, the result of poor distribution before tamping, or sometimes just plain unlucky
I agree. I am learning some things about tamping now, for instance.
With the flat "button" tamper I have more trouble getting an even extraction than with the convex tamper, so I assumed a convex tamper bottom has a better effect than flat.
Then in the above video testing, I found that a flat tamper with a little more space around it did better than a flat one that just barely fit into the "basket".
So I got the idea that a tamper that is very very tight could introduce the flow along the outside of the puck I sometimes observe.
The "puck slam" in the test video should confirm this, but: even a puck which has lifted briefly during pre-infusion does not necessarily deliver a chaotic extraction. You see the puch lift, dunk down, and what follows is a fairly normal pre-infusion, no early droplets and then a nice flow. The one or two tiny 'spits' are mainly visible because of the high speed filming of sop many details.
Now I got a friend make me a flat tamper of the exact same bottom size as the "button" tamper, but this time for the MACAP tamping device that I have:
(the tamping disc in the above picture is another one)
So if the tight fit would cause the early appearance of coffee droplets along the holes on the outside ring of the bottom of the filter, they would also appear when tamped with the MACAP device.
Over three test shots, these droplets did not appear.
So it seems more likely that my hand is less steady when using the button tamper, and the button tamper simply needs more careful handling than I usually provide.
Also, when I checked the bottom of the VST filter basket that I'm using, it looked quite clean, but after I used the steam wand to blow some powerful L1 steam through the bottom holes, the extraction was more even still with cofee appearing through all holes about the same time, within a second.
So although it may be tempting to draw quick conclusions on what you find, it's always wise to think again, and double check the facts you think were obvious hard facts...
please don't think i am being critical, but just to point out that the increased depth of the transparent PFs (necessary to facilitate observation) is greatly exaggerating the amount of 'puck jump' that can occur relative to a 'real' PF as the distance between the top of the puck and the shower screen is significantly less in a 'real' PF
There would be nothing to see if it was as short as the 16g OEM basket. It is about as deep as the 22gVST basket as it was videoed.
The puck jump is directly related to the firmness of the tamp, the speed of the pull on cocking the Lever and the oiliness of the beans. If they are oily they compact a bit tighter and tend to stick together.
Making another one of those thing??!!?? When I stop laughing I'll let you know :-)
If someone has access to a 3-D Duplicator to get the 3-D Coordinates then possible a CNC multi-axis mill could make a PF out of a block of Cast Acrylic or Lexan. The you would still have to make a provision for holding a Basket bottom onto which you could tamp the grounds.
In June, if I get a moment of boredom, I will be working on a small, ie 7g basket, model but it will still have a larger volume of water above it so the video can take place.
joe jeczen post=3400 wrote: This is awesome!! Too bad it self destructs eventually- it could be a useful tool to dial in shots.
We rented the super cam again this weekend, but the TPF gave up after 1.5 shot ;-) Roemer continuted to shoot other stuff so we may come out with some footage but not necessarily much about coffee ha!
We used the TPF on the Rocket and it was nice to see the slow trickle of water onto the puck instead of the whooosh of water over the puck in the lever machine. It demonstrates, I think how one does not need to temporarily stop the pump to get "pre-infusion" because the slow buildup of water and pressure allows for this already.
Great producing and editing in the video!! I thought I had a lot of equipment to get the perfect shot, but it looks like a nuclear scientist was making that shot!!
I know it was all for show and not for coffee, but a nice touch to make a very entertaining video!!
One last go with the TPF. It was restored, the acrylic re-polished and the metal bolts driven deeper into the top to get a stronger connection between metal and acrylic, but even then the heat & pressure combined is too much. Nevertheless, we did manage to test if the puck still "jumps" when the puck is tamped with a tamper that isn't such a tight fit. This time on pulling the lever the puck isn't pulled loose from the basket. Lowering the lever / raising the piston does not make the puck 'jump' now.
Comments
People like me are completely indebted to guys like you and Stephen who take the time to do this sort of stuff. We just read, wonder and admire.
Can't wait to read more!
Nice job(s) Stephen!
The clear pf was a challenge in as much as the material incompatibility with adhesives, heat and pressure. I was surprised it lasted as long as it did!
We all knew how important tamping was and this just confirms it!
[video width=425 height=344 type=youtube]0zgC1M1iQLA
Steve
A kayak is almost always fun but you are correct, the bridge is waaaaay faster!
S.
For this video project I moved the machine to a corner in the kitchen where it was suddenly snug, a wall to the left, wall in the back (warm air from the fridge cooler behind it), the big heavy espresso centrifuge to the right. There, the group temp was easily 90ºC and it showed at the start of pre-infusion as the water came in bubbling.
I could have seen it if I had taken the time before filming, checking the group temp probe and checking the water coming out during a short flush.
I lowered the P-stat considerably but I haven't read the dials yet.
Anyway, it will be different for everyone else in different climates, different central heating thermostat setting / room temp and depending on the amount of free space & air flow around the machine.
http://kostverlorenvaart.blogspot.nl/2014/03/stephen-sweenys-tpf-transparent.html
what i love about the 'correct' extraction is the cone is off centre by about exactly the same amount as the 'wrong' extraction video
i think it highlights how we have to be very careful when making extrapolations from a good theory
i.e. the 'correct' extraction might be tamped nice & level, but it is defective for some other reason, presumably channelling, the result of poor distribution before tamping, or sometimes just plain unlucky
what i love about the 'correct' extraction is the cone is off centre by about exactly the same amount as the 'wrong' extraction video
i think it highlights how we have to be very careful when making extrapolations from a good theory
i.e. the 'correct' extraction might be tamped nice & level, but it is defective for some other reason, presumably channelling, the result of poor distribution before tamping, or sometimes just plain unlucky
The LaSpaziale videos you are showing were shown to show what they were attempting to emphasize. Frans and I were working on what happens inside the Lever Group.
No plans on making them again; major PITA.
I agree. I am learning some things about tamping now, for instance.
With the flat "button" tamper I have more trouble getting an even extraction than with the convex tamper, so I assumed a convex tamper bottom has a better effect than flat.
Then in the above video testing, I found that a flat tamper with a little more space around it did better than a flat one that just barely fit into the "basket".
So I got the idea that a tamper that is very very tight could introduce the flow along the outside of the puck I sometimes observe.
The "puck slam" in the test video should confirm this, but: even a puck which has lifted briefly during pre-infusion does not necessarily deliver a chaotic extraction. You see the puch lift, dunk down, and what follows is a fairly normal pre-infusion, no early droplets and then a nice flow. The one or two tiny 'spits' are mainly visible because of the high speed filming of sop many details.
Now I got a friend make me a flat tamper of the exact same bottom size as the "button" tamper, but this time for the MACAP tamping device that I have:
(the tamping disc in the above picture is another one)
So if the tight fit would cause the early appearance of coffee droplets along the holes on the outside ring of the bottom of the filter, they would also appear when tamped with the MACAP device.
Over three test shots, these droplets did not appear.
So it seems more likely that my hand is less steady when using the button tamper, and the button tamper simply needs more careful handling than I usually provide.
Also, when I checked the bottom of the VST filter basket that I'm using, it looked quite clean, but after I used the steam wand to blow some powerful L1 steam through the bottom holes, the extraction was more even still with cofee appearing through all holes about the same time, within a second.
So although it may be tempting to draw quick conclusions on what you find, it's always wise to think again, and double check the facts you think were obvious hard facts...
Also thank you for the detailed review Frans! the pictures are great as usual ...
I also think that the depth of PF increase the moment of the coffee pack, is it possible to make it shorter like the original L1 PF ?
Kfir.
The puck jump is directly related to the firmness of the tamp, the speed of the pull on cocking the Lever and the oiliness of the beans. If they are oily they compact a bit tighter and tend to stick together.
Making another one of those thing??!!?? When I stop laughing I'll let you know :-)
If someone has access to a 3-D Duplicator to get the 3-D Coordinates then possible a CNC multi-axis mill could make a PF out of a block of Cast Acrylic or Lexan. The you would still have to make a provision for holding a Basket bottom onto which you could tamp the grounds.
In June, if I get a moment of boredom, I will be working on a small, ie 7g basket, model but it will still have a larger volume of water above it so the video can take place.
We rented the super cam again this weekend, but the TPF gave up after 1.5 shot ;-) Roemer continuted to shoot other stuff so we may come out with some footage but not necessarily much about coffee ha!
We used the TPF on the Rocket and it was nice to see the slow trickle of water onto the puck instead of the whooosh of water over the puck in the lever machine. It demonstrates, I think how one does not need to temporarily stop the pump to get "pre-infusion" because the slow buildup of water and pressure allows for this already.
We will see what can happen with version 3 of a clear PF this summer. Maybe the cat will not be so indifferent to it...
I know it was all for show and not for coffee, but a nice touch to make a very entertaining video!!
[video width=425 height=344 type=vimeo]96310486
S.