Reaction Wheel

Back to making shiny things

Mini Cheetah Clone First Test Drive

 One of the Chinese mini cheetah clone manufacturers was nice enough to send me one.  Stay tuned for a  detailed (non-destructive) teardown.

More Coiling

Once again Mike's tesla coil worked flawlessly - at least until someone tripped over the extension cord powering a fan cooling the primary capacitor bank.  We didn't notice until the capacitor bank burst into flames.

 

First outdoor tests of the screw mechanism!

 Gremlins eradicated - USB hubs are  bad, don't use them:

"Only" ~3.3 meters in this test - not maxing out the motor/mechanism yet, there's still some motor control tuning to do.  And probably another round of transmission ratio optimization once the actual robot mass and inertia get finalized.

Finished Test Fixture

A robot-weight steel puck:

Test setup outside, before being beset by electrical gremlins:

Hopper test fixture

Not done yet, but almost ready for some high-power testing.

 

More Screw Mechanism Testing

 Now controlled over CAN and USB, using a gui based on the espresso machine software

The the USB communication plus Python GUI gives me nice live-plots and logs.  Here's a plot of the fast position steps:

Screw moving under power

 

Guide Rollers

Putting the lathe to work:

CPW Coiling

 Austin and I turned on Mike's tesla coil in the parking lot outside MITERS, for MIT's Campus Preview Weekend.  One precharge switch and resistor got toasted, but otherwise it ran flawlessly for two nights in a row:

Chips

Lathe restoration has gone much more smoothly than anticipated:

Lathe Preview

Lathe backstory and move post to come, but here's a sneak-peak.  Lots to do still to get it up and running, but so far I've been amazed by how little wear there is under all the gunk.

Tool Holder Tightening Fixture

 

Needs a cam handle, but it works.  3 different brands of tool holders with 3 different torqueing features, so I made this fixture that clamps a cylindrical section of the tool holder, which is the same on all of them

Another weird part

Turning off the fixturing boss from milling:

Undercut boss machining:

Ioniq HSG

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: