The humble beginnings of the tumbler container: an empty drywall mud bucket with a hole drilled in the bottom.
A short section of PVC electrical conduit will do for a spacer. A completely sealed container would be nice - especially as it would permit running the tumbler media wet - but this way has the dual merits of convenience and simplicity. It may be possible to find some kind of epoxy that will stick to whatever plastic the bucket is made from as well as to the PVC.
I welded a piece of 1/2" threaded rod to the top plate of the platform. A recycled angle-iron frame to support the assembly...
...along with some scraps of 2x4 and plywood.
After a couple of tests, I added a plywood spacer to the compensate for the lip on the underside of the bucket and another steel plate with a rubber sheet laid over it to clamp the bucket to the shaker platform.
After changing the media to broken glass for a far more agressive cut, the machine will deburr and remove chrome in about eight hours. A little slow, but better than doing it by hand!
Now that the platform has been mounted to the motor, it is time to move on to the shaft parts. As this isn't strictly related to the main build I'm going quickly here and the documentation isn't incredibly detailed. The stock is 1 1/2" 6061 aluminum - aka bread and butter. I turn down a roughly 1 1/4" stub - nothing ultra precise here - the diameter is sized to fit comfortably inside a larger spring.
Cut off and face the other end.
On the mill, I drill an off-center hole that fits the key on the slotted drive shaft and then drill a centered hole for the shaft itself. I also cross-drill and tap for a 1/4-20 grub-screw that will clamp everything together.
A second transverse tapped hole is added for a socket head cap screw to hold the spring on the shaft and to transfer the torque. What kind of spring? A surplus Aurora piston spring!
The shaft at the top has a matching stub for the spring plus a smaller section at the top that fits the bore of the bearing. The shaft is cross-drilled...
... and power-tapped for a 3/8-16 bolt.
Lower shaft installed on the motor (you can just see the square key in its slot at the bottom right corner of the frame) and the spring in place.
Top of the shaft with the 3/8 bolt and a nut to lock it into place on the shaft.
A closer look with some extra hardware to increase the eccentric weight that is going to shake the whole platform.
Last time I was fortunate enough to be in Rome, I came across the Shakerato, which, ten commandments notwithstanding, I covet. So of course, I decided I had to make one! Sort of. Read on MacDuff to know more. Starting with a hockey-puck-sized piece of Acetal, I cut out an internal bore to fit a bearing.
(Of course, said bearing is a surplus part from a grinder restoration).
I add a triple of counter-bored holes to accommodate some machine screws.
It just so happens that I have a whole stack of roughly 10" square plates of 1/4" mild steel gathering rust on a shelf that fit the bill for the next parts. I clamp two of the plates together with a pair of teeny Kant clamps so that I can drill both plates at once and maintain their alignment when changing the setup. (Note the block of wood at the back of vise which crushes and grips the slightly different plate widths. The block is actually on the wrong vise jaw - it should be on the movable one at the bottom so that the plates are always positioned the same with respect to the fixed jaw datum - it was moved after the photo was taken.)
Power tapping the pair of holes at the corners with a 1/4-20 spiral tap (interestingly, (depending on you point of view of course) as aside to this aside, I have it on good authority that of all nuts and bolts, the 1" 1/4-20 socket head cap screw is the best selling).
Some larger clearing holes for some 1/2" bolts.
With the plate firmly clamped to the table of the drill press, I cut a hole in the middle one of the plates. The hole saw is really good at grabbing the work piece and spinning it around - this, we do not want - thus the clamps.
Then the plate goes into the four jaw chuck on the lathe to enlarge significantly, 'cause I changed my mind / didn't measure properly the first time. This is just about the largest thing I can work on with this machine - there is about 1/4" of clearance between the corners of the plate and the bed of the lathe.
Now the purpose of all those holes will become clear. Short 1/4-20 machine screws (torqued down with red (permanent) Loctite (mmmh - as I believe I've mentioned elsewhere - I don't know what they put in this stuff, but it sure smells like it is cherry flavored1)) in the exterior holes act as positioning studs for some sturdy flat-ground springs. The middle set of 1/4-20 holes have a split washer under a regular washer that just engages the last coil of its spring. And the set of four large un-tapped holes are for bolting the lower plate onto....
... a HUGE (ok, not huge, but it's still 1 horse power so I'm gonna call it laaaarge) motor.
The group cap has been a tail of (minor) woe for a while now.
I was all happy when I got the first batch out of the box what-seems-like-oh-so-long-along-now. Until that is, I put them on top of the group and discovered that the color of the chrome didn't match. That micro tragedy was joined by a second, rather more important problem: like, ya know, it don't fit! Seems like someone can't read their own writing: I made a transcription error when I was making the drawing for the part and the slot for the lever is 22mm wide instead of 32mm! The first problem is easy to remedy with some sandblasting and a trip to the chrome store. The second one requires some slightly stronger medicine. This cap was sandblasted down to at least the copper layer under the chrome. The 1/4" endmill is just long enough to reach the bottom of the curve at the perimeter of the cap - which is a bit of luck as otherwise this would be a bit more tricky to CNC.
The 1/4" bit leaves the appropriate radius in the corners of the slot.
The other half of the slot has to be machined with the chuck axis parallel to the table. This setup required a little bit of head scratching and some laaaaaarge clamps.
This isn't the stiffest of setups, so light cuts are in order.
All done - except for deburring (and sandblasting and re-chroming, (very small sigh)).
Tschörgen (Kaffee Netz) - Brugnetti Aurora 1G - Europe - Diagonal HX - Serial no.? - Date?
OrphanEspresso (OE / Home Barista) - Brugnetti Aurora / Termozona - U.S. - Horseshoe HX - #16777 - Date?
This is the one that I bought!
TurboYeast (koffiepraat) - Brugnetti Aurora 1G - Europe - Horseshoe HX - Serial no. 9231 - Date?
Paffee (koffiepraat) / Wouter (Home Barista) - Brugnetti Aurora 2G - Netherlands - HX? - Serial no.? - 1960? Note the steam and water joysticks and the old style group caps! Would love more information on this machine.
Hbrocks (Home Barista) - Aurora Europa 1G - U.S. - Diagonal HX - Serial no.? - Date?
JMC (Home Barista) - Brugnetti Aurora 1G - Australia - Pre HX dipper - Serial no.? - Date?
