Hacking the DF64 exit chute - Page 17

Grinders are one of the keys to exceptional espresso. Discuss them here.
GDM528 (original poster)

#161: Post by GDM528 (original poster) »

victor_rf wrote:Hi guys!

I'm planning to print a modified exit chute for my DF64 to replace my current declumper.

I have a doubt that may sound ridiculous, but I never work with these type of products: how do you trate the inner part of the exit chute with epoxy resine and make the coatting smooth and regular?

Thank you very much!

Depends on how the part is printed:

Resin (SLA printed):
Surface should already be smooth, so a relatively thin layer or two of epoxy should be enough to create a smooth surface. See post #158 in this thread.

Filament (FFF, FDM printed):
Surface will be rougher, so it may take considerably more of the coating material to smooth the surface. I personally don't have any practical experience with surface-treating filament-printed parts, so perhaps someone else here can comment.

In either case, I would put a high priority on the coating integrity: it should bond aggressively, and not disintegrate over time. I wouldn't want the coating material to end up in my grind.


#162: Post by victor_rf »

Thank you very much for the info GDM528

So. Do you think coating the inner part with a Foam-tipped swab is the best way to apply the epoxy?

Planning to print the piece in resin as recommended.


GDM528 (original poster)

#163: Post by GDM528 (original poster) »

victor_rf wrote: Do you think coating the inner part with a Foam-tipped swab is the best way to apply the epoxy?
A foam-tipped swab worked well for me: lint-free and firm enough to be able to spread the thick epoxy smoothly.


#164: Post by victor_rf »

Thanks a lot!

Would you please share the shape and size of the swab you use?

GDM528 (original poster)

#165: Post by GDM528 (original poster) »

victor_rf wrote:Would you please share the shape and size of the swab you use?
You can find them online by searching for "foam applicator swab"


#166: Post by victor_rf »

Thank you!


#167: Post by dis236 »

Hey, thanks for creating this mod and all the work you've done here!

I got the large aperture exit chute printed and installed, but then found out that without the downsprout and expansion champer it's a static mess.

The original reason I did'nt want to use the downsprout was that I didn't want to bother with sourcing small magnets for it so my question is: can you attach the downsprout to the xit chute without magnets? Would a friction mount work here? Would it need any kind of modification to the model?


GDM528 (original poster)

#168: Post by GDM528 (original poster) »

I've found the static effects are highly dependent on the coffee. Origin and roast level can make the difference between a clean grind and a static mess. I tried increasing the amount of water misted on the beans prior to grinding (RDT). While it did solve the static issues, that also led to the burrs getting clogged from the fines mixed with the moisture. Fortunately, I've found origins and roast levels that are both well-behaved and taste good.

I get the hassle of sourcing the particular magnets used to attach the down spout:

1) If you permanently attach the down spout you'll lose line-of-sight in the chute up to the burrs. That may not be that big a deal, but I found it useful to visually check for accumulation. And it's much easier to run a toothpick up the chute to clean out any obstructions. You can still clear the chute from the other direction, via the burr chamber. With regular maintenance (weekly firm smacks on the bellows with the grinder running) this should be a rare circumstance.

2) I did consider friction/snap fits, but those aren't stable over time and increase the risk of permanent damage if (when?) something smacks into the down spout.

3) Food safe silicone glue could be used to make a semi-permanent bond that you can tear loose non-destructively if the need arises.

4) The down spout is flared such that it can be easily taped into place. If done carefully it can look good, and also be removable as needed.


#169: Post by moonshine-sg »

I just ordered this from a local shop in SLS-PA12
Let's hope it comes out smooth.

Any idea where I can order magnets? or at least the size? I probably missed it , but can't seams to find the info about the magnets...


#170: Post by dis236 »

Thanks for the detailed response and sorry for the late reply from me.

I've considered what you've written and ended up just scouring the net for a local shop that sold similar magnets and ended up getting some that were fractionally smaller and a bit weaker as well, but they're strong enough to hold the sprout and the expansion chamber.

I just installed them and man am I glad that I went this route. Not only is it a breeze to just take off but it also allows for easier cup placement.

You were also correct in that different beans behave very differently and the first one I've tried was very prone to heavy static and hadn't encountered one with such issues since.
However I was still getting some spray especially when bellowing so I still wanted the downsprout and expansion chamber and can confirm that it keeps stuff really tidy.

Thanks again for this!