Sunday, February 27, 2022

Thursday, February 10, 2022

Foot Mechanism Prototype

 Quick and dirty prototype of a passive foot pitch mechanism:



CAD cross section:


To make a return spring I flattened the end of a 1mm spring steel rod and drilled a 1mm hole through the end for a dowel pin axle:


A drilled out screw acts as a guide bushing for the spring:





Tuesday, January 25, 2022

Organization

I was inspired by my friend Ethan to finally start organizing my fasteners and other little bits of hardware:



Ethan designed these 3d-printable stacking sub-bins - I have a lot of small fasteners, so these were really helpful:



Beginning of the stack:


 

Friday, January 14, 2022

Spinning things!

It spins!  A good end to the most productive week I've had in quite a while (on personal projects, at least):

More spinning things: turning the 3mm cam followers:


Tiny cam follower shafts done.  Thumb for scale:


Assembled cam follower "spindles" with a bearings:


Real blog post with more explanation coming soon-ish.

Tuesday, January 11, 2022

Undercutting tool

I needed an undercutting tool for the part in the last post, so I made one from an old HSS end mill.

ER32 chuck loosely held in an ER40 collet, serving as a manual rotary/linear axis.  Grinding wheel in the mill spindle:



One of the features it cut:



Saturday, January 8, 2022

Screw mechanism progress

 Machining the rotor/cam nut for the screw mechanism:



Turned on a manual lathe to this point, then milled on the 5-axis:


Mid-finishing passes:


Saturday, November 13, 2021

Today's contraption

The astute reader can probably figure out what this is and what it's a test setup for:




Oh how I missed you, MITERS Hardinge




Thursday, August 12, 2021

Espresso machine software testing

 Testing a mostly-functional espresso machine gui.  Somewhat Decent inspired.  While I don't have an interface for creating espresso profiles from within the gui, I can write arbitrary espresso profiles/state machines in python which is pretty powerful.  Testing with the Puck Simulator.


The profile in the video does the following:
  • Cycle water through the tank at 2 mL/s until the water and the group head get up to temperature (I cheated this in the video and turned off heater power)
  • Flow water through the group head to the drip tray at 2 mL/s for 2 seconds to purge the air from the group.
  • Block off the drip tray, flow to the group at 2 mL/s until the pressure reaches 6 bars.
  • Run at a flat 6 bars until the shot weight (estimated from the pump speed/pressure/flow curve since I don't have a built-in scale yet) reaches 32 grams.
  • Open the valve between the drip tray and group head to rapidly purge pressure (so it doesn't keep dripping)
  • Reset to the beginning and wait for input.

Tuesday, August 3, 2021

Adjustable Puck Simulator

Needle valve + basket with the bottom cut out + aluminum "puck" with an o-ring = adjustable coffee puck simulator.