Notes - Improve rotor heating system - Add screen / safety protection around the exposed motor shaft. Takes ~5minutes to ramp up from 0 to 30 Hz. Machine is fine and capable of rotation in both directions (requested by positive and negative velocity) 20 bit encoder Velocity is in encoder. 104.32 = 1 Hz roughly -- this number by 100 to get frequency. request for -8000 to 8000 while accelerating, after a request, it won't let you ask to change the velocity. (so can't request a different voltage.) "FAILURE" MODE TEST: - Entered "30 Hz" while at 10 Hz, and confirmed that it did not via display of beckhoff monitor of the velocity. 600 ct = 3 A current limit set to 200, then shuts off. 130-150 is maximum observed during "full speed accelerations 30-35. substantial fluctuation in velocity. drive currently set up as small impulses because rotor is stable and don't want to touch it if not needed. Can change several control laws to adjust this. will look at this later. 1st test -- spinning with no tungsten masses. 1 Hz/100 encoder counts 5 Hz/ 200 encoder units. ~11:45 p PDT 10 Hz / 1043. encoder units 40 units of current draw "15 Hz" = 14.38 / 1500 encoder units 56 - 63 current draw on motor while accelerating Power supply current draw 0.7 mA @ 15 Hz with everything enabled. Notable "clicking" in the motor at this speed. not loud 20 / 2046. encoder units noticing more current draw fluctuations that we've seen before. 11:55 "24" 23.93 / 2500 12:01 30 Hz / 3130 60-65 current draw beckhoff units. as expected have run at 30 Hz for 3 hours. FAILUREMODE TEST - have seen beckhoff lose its connection. want to test when computer gets disconnected. TURNOFF TEST - ramp up to maximum request, and request zero turn off. hit "STOP" on PLC controller. "slave access has lost its control enable signal" from 25 Hz. SET CONTROLLER BACK TO ZERO. Open question -- what happens when you restart the PLC? can run ~1 minute at each frequency. Can ramp, ramp time is an input parameter, at the moment set to "a few minutes" below 20 Hz, you could probably run it for days. That's the threshold above which one can start to feel vibrations. Beckhoff motor spits out many more variables than just current draw and velocity. There is a torque value, but it's zeros, and obviously not. TODO disconnect motor MUST CHANGE CONTROL PARAMETERS. Currently the control parameters are set to drive something with a huge moment of inertia. Disconnecting and running with those parameters will damage the motor. Temporary C# code (visostudio2017) code that serves as EPICs IOC. c:\\Downloads\piezo-sinedrive master Also now lives on desktop under ConsoleApp 12:56 back in optics lab. HEATING UP ROTOR. McMaster heater plugged in to a variAC. Disconnect encoder from pre-amp box. Disconnect motor 9/64 #8 wrench. on shaft collar. Loosen shaft collar Take 5/16 wrench. loosen and remove 3/8-16 bolts from "top surface" of cage. remove 3/16 bolts from motor securing shelf, remove motor mount entirely. Be mindful of shims. Keep shims matched to each angle brace. Unscrew 3/8-16 bolts from underneath the shell (they hold the frame to the platform). Left shell & frame from mount. Set shell / mount on its side. Remove 1/4-20 bolts from a NCAL cover rails (those point towards the motor shaft NOT those pointing down towards the rotor), 3 per rail, and 4 rails (above and below the rotor). Remove shell halves. Set shell halves on their side, vertically, use as stand for exposed rotor and frame (to allow for rotor / frames system to be restored to horizontal / normal orientation and get clearance of the optical encoder on the main shaft.). CAREFUL -- NOW THE ROTOR IS EXPOSED. Pinch points. DON'T STICK YOUR FINGER IN THE EMPTY HOLES WHILE THE ROTOR IS ROTATING. ALSO NOT ON THE SIDE FLATS IN THE DIRECTION OF SPIN. GOOD PRACTICE -- CLEAN ROTOR SLUG HOLES with alcohol wipes before attempting to install slugs. The masses of the five tungsten cylinders (in Kg) were from FDR: 1) 1.0559, 2) 1.0560, 3) 1.0559, 4) 1.0555, and 5) 1.0561. #3 & #4 use for quadrupole. 1 2 and 5 are the hexapole. #4 slips in in its appropriate hole when rotor is at room temperature. Clearance is tight with the quadrupole masses in terms of fitting in next to the rotor shaft. HEAT THE ROTOR TO INSERT SLUGS GOOD PRACTICE: - Check for resistance between positive and negative legs of the plug going in the variac - Check for electrical shorts between positive terminal and NCAL. SAFETY NECESSITY: WEAR HEAT PROTECTIVE GLOVES. ALSO -- BUY BETTER (LESS SHEDDING) HEAT PROTECTIVE GLOVES. CAREFUL: at ~70-75V = to heat rotor 75 deg C in 10-15 minutes. HEATER REACHES over 150 deg C. DO NOT TOUCH IT. IT WILL GET HOTTER IT LEFT ON FOR 30-40 MINUTES. Have a thermometer handy to check temperature. Clamp heater to outside edge of rotor with custom clamp. Plug heater in to variAC. 13:28 PDT Turn to 70-75V. Monitor temperature with with portable thermometer head. #5 is the heaviest mass. 1:59 ~43 C. 2:26 #4 installed! 2:58 all masses in. #1 required lots of cajoling (wiggle, twist, and tap with heater on an close to it [need about 65 deg]). WHILE WE WAIT: Trying motor max speed test. Set up motor dog clamped to table. TIGHTEN THE SHAFT COLLAR BOLT BEFORE STARTING. In DRIVE MANAGER TwinCAT "project3" Channel A Configuration Control overview Velocity controller Low pass time constant 15 sec lower to 5. The gain setting of the controller (Kp) from 0.030 to 0.010 Accel / Decelerations parameters still the same. 2:20 Start at 100 ct / 1 Hz. velocity control will be terrible. The low pass frequency is set high. Bump up to 1000 / 10 Hz. Bump up to 3000 / 30 Hz. 2:31 TEST DIGITAL REQUEST. 4000 doesn't work (internal software threshold in beckhoff). 3999 does. Need to understand this better. Krishna's installed limit was 4000 and he changed it for this test. Must be some internal software limit, or physical limit. Regardless, calibration of motor request is ct = 10000/2^20 Hz / ct 4000 = 38.14 Hz. cylinders matched to holes at 10 um. "close fit" to shops. Clearly much closer than we want. TO REMOVE MASSES Heat up rotor again (today we just left it hot.) unbolt 10/32 from the rotor base plate. First attempt to place frame on its side, and sliding masses out horizontally. Hexapole can use 10/32 allen driver to help guide push out. DESIGN FLAW -- No bolt/access holes for quadrupole. Must rely on gravity for this. Flip rotor back on the the shell halves as a stand, let heater and gravity do the work. 3:13 PDT some masses slip out Masses slip out. CAUTION MASSES WILL BE HOT. Get a good look at the optical encoder and its mount. Could be more robust, but want it to be flimsy. Mass #1 was a LOT more difficult than expected, going in and going out. Needed agressive hammering and dedicated heating to get it out. Remember -- the slugs were asked to be ~10 um but came back from the shop much closer. Maybe ask shops to have cylinders "lapped" down a few microns. Also need cleaning -- particulate is a risk. Maybe class B future assemblies. 4:08 REMOUNT NCAL ON BASE Again -- watch out for the encoder cable. FOR FUTURE DESIGN guide alignment pins to align frame to base. Holes for 3/8-16 bolts have lots of slop in this design. Also -- cannot remove half shells while mounted to base because of interference with base pegs. Reassembly of motor -- very important for the motor and shaft to be well aligned. Use shaft collar on motor to align on rotor. THEN bring in the angle braces, slowly and carefully so as to not move where the motor sits. Vertically -- inside the motor, there is some 10mm necked down to 9mm shelf. Do not fully engage the rotor shaft to that shelf. the rotor shaft must be past the shaft collar, but there's not need to go further. So use the shaft and motor alignment, and then bring in the angle process. Tape on the side of the frame has a purpose -- prevents aerodynamic drag. MU METAL SHIELD No securing of motor shield. Probably fine for testing below 20 Hz. Mu metal shield for motor has been annealed. shielding is a factor 100 the bigger housing has not been annealed. somewhere between 3 to 10 TIMING BELT MOTOR SETUP. Set up should be in the NCAL photos Need a keying part from Krishna Gear meant for the Shaft is a little tight, but don't force it. open question: Does the Mu Metal Box cover the NCAL when using the belt drive system? SET screws for the optical encoder: metric thread. pain in the butt. can find the size on manufacturer's spread sheet. Mems accelerometer. needs 3V has XYZ out Could be used for safety device. Fast spin down (as a result of stopping the PLC process, e.g.): does it do damage to the motor? "don't think so." Shouldn't do it as "the way" to spin down the NCAL, but should be fine to do occasionally. STILL TO DO -- Test what happens upon computer failure. (decouple the motor, set up as test described above, THEN kill the thing.)