Improving my tamper

I’ve been very much enjoying the Flair, and have gotten very used to pulling shots with it. Since the making of the video I’ve streamlined my morning routine, and also started using a cork trivet as a tamping pad, which is easier on my countertops and the portafilter.

The big downside to the cheapest Flair model is it doesn’t really come with a tamper though, it just comes with a dosing cup that sort of doubles as one. But it’s not very good.

So I’ve been having a lot of fun designing my own tamper, printed primarily out of PETG. After digging out my long-disused calipers and doing some measurements and some test prints, I determined a perfectly-fitting tamper that, at least on my printer, fits the Flair portafilter perfectly. And it also fits very nicely in my hand. Initially I printed it in just PETG:


and at 100% infill it had a very nice feel to it, both in terms of surface texture and weight. It got even better when I sanded it down a bit.

But I thought, you know, one of the things I want to do with this printer is print things out of both PETG and TPU, with grippy/flexible bits. So, I tried out the Palette’s splice calibration thing and very quickly found values that work to fuse them:


So, I decided to try using Canvas to do a simple “paint job” to add a few horizontal bands of black TPU to make a grippy section.

painted design 1.pngIMG_1699.jpegIMG_1700.jpeg

Unfortunately, the print failed — but not because of a TPU-PETG adhesion issue, but because the Palette lost its connection to OctoPress for some reason. Weird.

Anyway, seeing it in progress like that made me think that the rigidity of the tamper would suffer since painting makes coloration go all the way through, so I spent a bunch of time playing with p2pp and Chroma, but lost patience with trying to figure out how to make all their parts fit together (although I’m iterating on getting PrusaSlicer set up correctly, I think). So instead of dealing with that I experimented with a few more colorations to see what Canvas would do:

painted design 2.pngpainted 2 slicing.png

The slicing wasn’t really ideal, and still meant that the tamper might be a bit wobbly since it was basically building the coloration out of pie wedges. But I printed it anyway:


So, visually it looked okay but not quite what I was going for. The white segments ended up looking dark with a small amount of clear coating on them, partially because the infill was partially mixed with TPU but mostly because, like, it’s transparent, right? Which is the whole point? So it was transmitting the color behind it. This does give me a bit more confidence in how I was planning to work color into my designs but it’s not actually what I was going for.

To make things worse, it turns out there’s a bug in Canvas that makes it not place seams correctly on curved objects. (This has apparently been fixed, and will be rolled out tomorrow. Huge props to Brandon at Mosaic for fixing this so quickly!) It was also affecting the way that seams work on painted surfaces. So, that makes multimaterial prints currently look kind of meh, although it’ll get better tomorrow apparently. I guess that’s one benefit to cloud apps (although arguably this also highlights one of its biggest problems — you can’t decide to stay on an older version if a bug appears or some functionality gets removed).

I decided that since this one didn’t look quite how I wanted it to I’d use it to experiment with heat-polishing PETG:


While it did make everything shiny, it also made it pretty ugly, didn’t help with the visible seam, and also made the TPU harden, so it became not particularly functional.

Anyway, because of the way that Canvas does its slicing based on surface colors, I was worried that it would also do the same thing for solid fills, but nope, it turns out that solid models keep using their existing extruder and just get their own perimeters and infill areas:

solid design.pngsolid parts cad.pngsolid parts.pngsolid slicing.png

Although I’m getting a bit head of myself here, as this is actually one of several iterations on this solid-modeled design. In particular, I had tried printing a previous version, which looked amazing, right up until I tried removing it from the print bed:


I’m not entirely sure what caused this structural failure. I think it’s a combination of things; while the PETG core went all the way through, some strings of TPU made it into part of it, and also in my attempt to anchor the fake gasket, that also weakened the core further. So instead of making it a literal O-ring, I decided to just give it the visual affordance of one, where it actually only barely goes down into the surface and the actual PETG is almost as wide as in the original setup. I also changed the slicer settings to lengthen the transitions from TPU into PETG to cut down on how much mixed filament ends up in the structural parts of the infill (although I still have it set to allow infill as a transition region, which is probably a mistake but it saves a lot of filament).

I think it would be really nice if Canvas had mesh modifiers like PrusaSlicer, so I could say “on these layers, don’t use infill for transition” or “on these layers, don’t worry about purging transitions from TPU to PET” or even things like “and here don’t do perimeters on the material interface” or whatever. It would be very helpful for saving filament and also providing better control over the slicing. So that’s still a bit of functionality that has me wanting to get this work with PrusaSlicer (which, incidentally, also lets you do things like using different materials for perimeter and infill, which is something I’d love Canvas to support as well).

Anyway, one neat thing I’m finding about how Canvas does its purge blocks: This is probably accidental but the low-infill parts of it tend to have the little threads break apart and end up acting like a perfect little wire brush, helping to clean off strings from the nozzle. If it’s purposeful, kudos to Mosaic, and it’s a happy accident, please don’t fix this!


Ennyhoo. I already have a perfectly wonderful tamper (the very first one I printed at 100% infill, go figure) but I’m having fun experimenting with this, and maybe if there’s enough demand for these sorts of things I could start selling them or something.

I mean, me being me I went ahead and released my files on Thingiverse so if you want to experiment with this yourself, feel free! I’d appreciate being tipped if you find it useful.

Also, I’ve been discussing 3D printing stuff over on my discord, if you’re into that sort of thing.


Before commenting, please read the comment policy.

Avatars provided via Libravatar