Well, I was going to order a 49mm naked portafilter for use on my little used La Pavoni (which I recently bought off Craigslist), but instead I decided I would just cut it myself and see how it came out.
Originally, I wasn't going to mess with the OEM portafilter. However, after some research on-line (and in speaking with Doug from OE on here), I came to the conclusion that the portafilter which came with my machine probably wasn't originally from La Pavoni anyway. As such, I decided "what the heck" and figured I would try my hand at the DIY naked portafilter route tonight. I'm happy I did, because the end result came out absolutely beautiful.
The entire job took approximately 90 minutes, but that's largely because I took my time and wanted to make sure it came out extra nice. Below are some of the better photos that I snapped along the way. I haven't pulled a shot using it yet, but when I do, I will be sure to follow up with some additional pictures here. I may also modify the handle a little bit, although for now I'm just using the standard handle that came on the portafilter.
Enjoy the photos and if anyone has any questions, please feel free to post them here. Thanks!
Here's the portafilter in the vice
As luck would have it, I just happened to have a 48mm bi-metal hole saw handy (1 7/8")
Here you can see the start of the cut. I just used a hand drill for this and it worked fine
Almost through the bottom after only about 5 minutes of chipping and cutting
Here you can see the progress. I stopped just short of going all the way through
Bye bye bottom!
Not too shabby for a hand drill and a hole saw!
I used to port cylinder heads using this bit, so I'm pretty sure it can handle a brass portafilter
After doing a little blending with the die grinder
Checking to make sure we have consistent width front to back and side to side
Time for some further blending & smoothing with the trusty sanding wheel
Post sanding. As you can see, things are starting to take shape pretty nicely!
Now time for some polishing
Doing some polishing inside the portafilter basket area
After the initial polishing
This is after using some 600 & 1500 grit sand paper in order to produce a more satin finish
Here you can see the radius on the bottom edge
All done! Just needs a little further cleaning
A quick self portrait with my little brass masterpiece
After washing in the sink with soap and water - looks pretty good no?
Here's a shot showing how it sits on the edge of the counter (complete with my 49mm SS tamper)
And here is the final result, locked into the La Pavoni & ready for extraction