Now 39% larger!

I've posted a second version of the exit chute on GrabCAD:
https://grabcad.com/library/df64-exit-c ... ownspout-1

Look for the phrase "larger aperture" in the file names to find the proper .step and .stl format files.

This was intended to address choking/clogging issues reported by a couple people on this thread. I was never able to duplicate the issue myself, so I can't confirm if this will help or not. Just my opinion, but if you're not experiencing clogging issues with the earlier version, then it might not be worth the trouble to replace it. If your grind is already freely flowing through your chute, this version may actually allow more retention/carryover (just my theory).

The primary change is to the area of the opening facing into the grind chamber, now 39% more total area. The area of the opening at the bottom of the chute is unchanged, so there's less taper in the cross-section along the length of the passage - but there is still a uniform taper, which I think is important. The two holes for the mounting screws are also just an eensy bit bigger, 4.2 versus 4.0 mm diameter.

The new model is drop-in compatible with the previous version, so if you printed the downspout it will fit just as before. Here's a side-by-side comparison of the two versions:

Nice! After that blockage that happened to me and before you uploaded the update i edited the original files, not as nice as you did, but i also combined the expansion chamber with the spout so there won't be any step inside

Wow thanks for this. I'm somewhat amused at the design of the expansion chamber heh.

Looking to use JLCPCB to do some of the printing, got a some questions since I'm 100% new to 3D printing terminology.

1) Would SLA work for the downsprout and expansion chamber? In an earlier post you mentioned you designed it for FDM. SLA for those components is very cheap while the FDM option 3x or 4x the price in the JLCPCB site.

2) What's the difference between the 25/35 degree downsprout

3) I dose directly into the portafilter as I read this reduces channeling and inconsistency substantially from some of the DF64 users. Can the current design work that way?
(I'm thinking flipping dosing cup with fines at the top into the portafilter means that fines are now right below - that's the theory anyway - so I grind direct since day 1.)

Additional question not related to the chute. I'm thinking of getting JLCPCB to print the antipopcorn funnel and the SLA option costs $8 while the FDM option costs $33. I wouldn't have any problems with the SLA option..would I? Safe? Haha

Hey j_bravo14, did you have to adjust the dimensions before JLCPCB could print?

I just submitted my request to JLCPCB to print but the customer service tech told me to "adjust the dimensions of the wall thickness marked red which has a high risk of crack, loss and deformation. Best to adjust it to 0.8mm or 1.5mm"

Additional details: SLA(Resin) // Material: LEDO 6060 Resin

Does anyone have advice?

j_bravo14 wrote:Received the resin prints from JLCPCB! Now just waiting for the grinder from espresso outlet

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CrazyBlue wrote:1) Would SLA work for the downsprout and expansion chamber? In an earlier post you mentioned you designed it for FDM. SLA for those components is very cheap while the FDM option 3x or 4x the price in the JLCPCB site.

FDM more expensive than SLA?? I never thought I'd ever hear that, wow. I have both, and the resin I use is 5x more expensive than my filament...

Anyhow, yes, the expansion chamber can be printed with SLA - However:

It was designed to fit very snugly into the downspout. Depending on the dimensional control of the SLA print, the expansion chamber may have to be sanded down to fit into the downspout. The models for the downspout and the expansion chamber can be combined into a single print - might even be cheaper than two separate prints.

It was designed for FDM because I wanted to inexpensively experiment with different shapes for the expansion chamber, only $0.20 per print. My long term goal was to come up with an expansion chamber that will evenly distribute the grind. The current design isn't even close, so I still have a lot of work to do, but it's sufficient for the time being.

CrazyBlue wrote: 2) What's the difference between the 25/35 degree downsprout

3) I dose directly into the portafilter as I read this reduces channeling and inconsistency substantially from some of the DF64 users. Can the current design work that way?
(I'm thinking flipping dosing cup with fines at the top into the portafilter means that fines are now right below - that's the theory anyway - so I grind direct since day 1.)

The 25-degree downspout is for people that have a 10-degree base tilt under their grinder.

The expansion chamber was designed to fit into a portafilter, but the grind will pile up way too tall. Some sort of dosing funnel seems essential to contain the grind.

I haven't looked to see if there's some study of the distribution of fines as the grind proceeds, but someone did study the optimum distribution of grind size in the puck: https://medium.com/overthinking-life/st ... 0b68144f94

CrazyBlue wrote:Additional question not related to the chute. I'm thinking of getting JLCPCB to print the antipopcorn funnel and the SLA option costs $8 while the FDM option costs $33. I wouldn't have any problems with the SLA option..would I? Safe? Haha

Heads-up that I'm working on an alternate bean flow restrictor that may look considerably different than the current one I'm using, so you may want to wait on that one. Plus, JLPCB is charging over 100x what I spend to FDM print one myself ($0.20). I'm also not certain if a more uniform grind is actually better than having some fines included (for espresso).

The current design is definitely not 'antipopcorn' - the beans will still jump around in the dosing funnel. It's only purpose is to cut the flow of beans into the burrs.

haematit3 wrote:Hey j_bravo14, did you have to adjust the dimensions before JLCPCB could print?

I just submitted my request to JLCPCB to print but the customer service tech told me to "adjust the dimensions of the wall thickness marked red which has a high risk of crack, loss and deformation. Best to adjust it to 0.8mm or 1.5mm"

Additional details: SLA(Resin) // Material: LEDO 6060 Resin

Does anyone have advice?

0.8mm seems really conservative for SLA printing. I'm accustomed to closer to 0.4mm. The thin-wall sections identified are very short and bracketed with much thicker material to keep it well supported. There is a risk of cracking when stuffing in magnets however, so I cleaned out the holes with a drill bit so the magnets would slide in with minimal force.

Appreciate the response and insight Gary.

No adjustments, told them I will take the risk and print it as is