CAT+MOUSE I built a turntable

Earlier this spring, I found a great deal on a Rega 303 arm, and decided to build a turntable as a fun summer project.

Behold the C.A.T. Custom Audiophile Turntable.

I sourced a subplatter from Tangospinner, and cut the plinth out of a nice teak 2'x3' project board from Lowes. I used the VPI Scout and Rega R8 tables as inspiration for my plinth design. It is quite solid and resonance free.

The motor is the Anaheim Automation BLWS231S-24V-2000. This motor was recommended in the previous thread from Pyramid on a 3-phase sinusoidal controller board build. Pulley is just an old sewing machine part for a 1/4" shaft sourced from Amazon.

I was originally inspired by Pyramids board, but I have wanted to try out an Arduino for some time, so I used this opportunity to order one for the motor control unit. At first I tried a new Arduino R4 Minima, but have now settled on a Nucleo FE446 for the controller processor (it was faster, and will eventually better support utilizing the Hall Sensors for more control). The SimpleFOCShield is a great low cost BLDC motor controller, and perfectly fits the requirements for driving this motor with a sinusoidal waveform. And it plugs right into the top of either the Arduino or Nucleo for a small form factor.

I have dubbed it the M.O.U.S.E. Massively Overcomplicated Unnecessary Stabilizing Energizer. I will eventually add an LCD and buttons to adjust the speed up/down if necessary.

I am currently driving the motor in Open Loop mode at 25rad/sec, which gives me a solid 33.3 rpm platter speed. I eventually intend to get Closed Loop mode working with both the hall sensor and inline current sensing.

The only minor issue I have is that the motor runs hot, around 120F. It is dead silent tho. No cogging at all.
 

Attachments

  • 20230725_161747.jpg
    20230725_161747.jpg
    324.9 KB · Views: 340
  • Screenshot_20230607_182415.jpg
    Screenshot_20230607_182415.jpg
    77.1 KB · Views: 267
  • bldc.txt.txt
    bldc.txt.txt
    2 KB · Views: 165
Last edited:
You might find some cooling options in your local outdoor store too. Heat exchanges are commonly used on cups/mugs used for heating water and food by the mountaineering crowd. They're basically heat sinks used in reverse.

Nice woodwork! Teak, eh? That's pretty hard on the tools I hear.

Tom
 
Thanks. I am hoping to better tune the motor controller parameters to increase motor efficiency, and thus reduce the heat produced.

If anyone else goes this route with the SimpleFOCShield and an Anaheim motor, please let me know. I would be happy to collaborate on tuning. I already noted one mistake in my code above. I incorrectly used the line-to-line resistance instead of the phase resistance (which is half of l-l) in the code, which increased my current draw. I will test to see if the change helps with the heat issue.

The teak was fairly easy to work with, actually. I used a bandsaw and jigsaw to make the cuts, and an orbital sander to clean it up.
 
Nice table. Interesting that the Anaheim only needs two pole pairs. Which model did you use? I am using iPower motors which do have cogging but cleaned up with some isolation. However tried a new 5208 24 with more magnets and have too much vibration. Running the same Arduino/SimpleFOC shield setup.

I had heat issues when specifying resistance as well. Using the über simple simple open loop setup was best. Tried sensored and did not like it. Members on the SimpleFOC community page confirmed that open loop should be the smoothest.

Results so far.
 
Do you find the ultralight base/plinth/arm an improvement over the previous heavier design?

I have an extra subplatter, and I am thinking of ordering an acrylic platter, and carving a base from structural polyurethane foam like the Rega 8/10.
 
It sounds phenomenal. I currently run an AT-VM95E cart, which is beautiful and airy. I love the thick glass platter. I am now experimenting with various mats (felt, rubber, cork) to see how they change the sound vs the glass platter alone. (Altho I cant adjust for the height change with the Rega arm).

I wanted to get table fully sorted before I upgrade the cartridge as well. Either a stylus change to an ML/SH, or perhaps I try an MC cart. I would need to add a couple of Lundhahl SUTs to my EAR864 clone if I picked up an MC cart.

I originally picked up the Rega 303 arm to replace the original arm that came on my Audio Technica LP-30 table (pic below). I did not like that the motor power supply and tonearm shared electrical componentry, and I would get a pop out of my speakers when I tuned on the turntable. With the dedicated interconnects on the Rega arm, I could easily eliminate that. Then the bug to build my own table got me...

Next step is to fashion/bend a polycarbonate cover for the table.
 

Attachments

  • 20230519_180609.jpg
    20230519_180609.jpg
    269.7 KB · Views: 89
I wanted to get table fully sorted before I upgrade the cartridge as well. Either a stylus change to an ML/SH, or perhaps I try an MC cart. I would need to add a couple of Lundhahl SUTs to my EAR864 clone if I picked up an MC cart.
If you like the AT sound, the internet loves the VM540ML, which should work well on your Rega arm. The Goldring 1042 (and Audio Note derivative) also would work very well. Lots of choices.

jeff