3-D printed WDT tool (Umikot) - Page 7

Want to talk espresso but not sure which forum? If so, this is the right one.
Capuchin Monk

#61: Post by Capuchin Monk »

selfiegram wrote:It didn't channel a lot today for some reason,
:lol: I think that's a quantum physics level phenomena, so called "observer effect".
but you can still see some minor channeling.
I did notice what appears to be a spritzer that got on the mirror at 12 sec mark. What I'm getting at from your description is that the grind size may also need to be changed depending on fully manual WDT or Spirograph type WDT.

luvmy40

#62: Post by luvmy40 »

selfiegram wrote:I am curious, for the standard double shot breville BDB basket, what size base did you print? I am using the 24mm base with the 55mm and 65mm cut pins.
OK, I measured the depth of the Breville double basket at 23mm. I printed the 23mm lug/magnet base. The first coup[le needed to be sanded a bit so as to not stick on the filter basket and pull it out when removing the tool. I then printed a couple sliced at 101% scale. The so not stick to the filter basket but are just a tiny bit too loose. The magnets hold them down fine but there is just the slightest slip laterally when spinning. I am printing one sliced at 100.5% right now.

luvmy40

#63: Post by luvmy40 »

Sorry for the clumsy, one handed camera work. It does show how smoothly the Umikot operates. The video of the output isn't as clear as I would have liked to see, but you can see there is no channeling and the shot pulls nicely.

selfiegram

#64: Post by selfiegram »

luvmy40 wrote:OK, I measured the depth of the Breville double basket at 23mm. I printed the 23mm lug/magnet base. The first coup[le needed to be sanded a bit so as to not stick on the filter basket and pull it out when removing the tool. I then printed a couple sliced at 101% scale. The so not stick to the filter basket but are just a tiny bit too loose. The magnets hold them down fine but there is just the slightest slip laterally when spinning. I am printing one sliced at 100.5% right now.
Thanks, this gave me some pointers on what was going wrong. I inspected the puck to verify, and it seemed like the bottom of the puck was not getting distributed well because my 65mm needles with the 24mm base were not going all the way to the basket bottom. I cut 5 needles 1mm longer (66mm instead of 65mm) and now things seem a lot more consistent and less channeling. Ideally I should've just printed the 23mm base, but this gets me to the same place without having to reprint the base.

I still feel that the newly added dedicated pin that sweeps the side of the basket with V2 is being counter productive. I'm going to try a few shots with and without that to check.

luvmy40

#65: Post by luvmy40 »

I see quite a few comments on the Weber Moonraker about the grounds forming a ridge around the perimeter of the basket. I have never seen my Umikot(no stationary needle) do this. I have only printed one with the stationary needle for another member, but I haven't seen any posts about it's performance.

selfiegram

#66: Post by selfiegram replying to luvmy40 »

I do see a small ridge even with the v2 dedicated needle. Vertical tap seems to fix that easily, but I generally feel that side needle is not needed.

jedovaty

#67: Post by jedovaty »

Apparently I'm supposed to have v2 but mine doesn't have a needle fixed on the edge so must've been the incremental version before that.

Occasionally I do get a small ridge of grounds up the side on one part of the grounds, but it is inconsistent and I haven't found a correlation whether bean, speed, etc related. It occasionally happens even with slow turning the beans. I have my other wdt tool which I then rake quickly if the grounds pile up on one side. This is with the cafelat robot basket.

selfiegram

#68: Post by selfiegram »

selfiegram wrote:Thanks, this gave me some pointers on what was going wrong. I inspected the puck to verify, and it seemed like the bottom of the puck was not getting distributed well because my 65mm needles with the 24mm base were not going all the way to the basket bottom. I cut 5 needles 1mm longer (66mm instead of 65mm) and now things seem a lot more consistent and less channeling. Ideally I should've just printed the 23mm base, but this gets me to the same place without having to reprint the base.

I still feel that the newly added dedicated pin that sweeps the side of the basket with V2 is being counter productive. I'm going to try a few shots with and without that to check.
I've been using the Umikot v2 for over 2 weeks now, and I can confirm that this needle length increase by 1mm (since I was using the longer 24mm base instead of 23mm base) has fixed all my issues.

For the side needle I tried several things. Removing it does create a bigger ridge on the side, so the needle seems to be doing something right. But instead of 55mm (or56mm in my case with the 24mm base), I cut about 1.5mm shorter (i.e. to 53.5mm if you have the correct size base) so it "just" touches the top of my puck. This seems to work very well to the point that after a vertical tap things settle almost perfectly in place for me.

Finally, I have found in my case that 12 rotations give me the best balance between channeling and time spend. Going for more rounds probably is better (I went up to 20) but the difference start to become less noticeable for me after 12 rotations.

I thankfully got a lot of extra needles to play around and experiment, but I'm super happy with his it's configured now. So no more needle wastage for me !