Hello Drew, welcome!
But now, of course, we would really like to see the pictures of the replacement plate immediately and urgently!
Best regards
Arndt
Thanks for the warm welcome, Arndt. I don’t seem able to do anything immediately or urgently in this project but I’ll do my best to satisfy your enthusiasm.
The ugly metal disc in the first picture is the base for the platter. It started life as the base for a swivelling computer monitor about 15 years ago. It’s a little over 3mm thick galvanised steel and most of the holes are of no use at all. It’s good and heavy and it’s flat. And the centre hole is in the centre, which is a plus.
The larger plate is the ultimate size of the platter and it’s made from 3mm of a weird 1950’s composite wall board similar to Formica that was made by The Bakelite Company. It’s stiff, easy to cut and I had a sheet of it handy. You can see the eight screws that’ll hold the two together. The idea is to cast a thin layer of silicone rubber between the two and use the screws to dial-out any departure from perpendicular.
I haven’t seen the original platter, other than a picture elsewhere on lencoheaven so it’s all a matter of guesswork. The “receiver” part of the bearing is intact and I’ve cobbled together a spindle from various parts, starting with an 8mm OD / 6mm ID tube and figuring out a way to set the remains of a HSS drill bit, ground down to a rounded point into the end of the tube. At the other end I’ve currently got a tubular spacer that fits the adjustable opening of the “receiver” and a thrust bearing. Right now I’m not certain that I need the thrust bearing AND the point bearing as I’m really making things up as I go along.
Under the steel plate there’ll be a ring cast from epoxy which is what the drive wheel rotates. Wish I knew the exact diameter of the original. I’ll need to grind it down to the right diameter. Thankfully there’s a speed tuning control.
Yup. That’s a stack of old DVDRoms that I glued together for the inner diameter. The outer was an HDPE microwave pot of approximately the right size.
The full visible part of the platter should end up around 25-30mm thick and I have some clear acrylic sheets around 10mm thick from the screens of the previously mentioned computer monitors. I might even place some LEDs to give the whole thing an eerie glow.
While I’m at it, the neon is burned out so I’ll probably replace that with an LED that’s set to 50Hz. Really not sure about setting the platter speed from a mains-driven neon anyway since surely that would be driven from the same source as the motor. Maybe I’ve missed something there.
Anyway, thanks for taking an interest. Right now I’m summoning up the courage to attack those acrylic screens with a jig saw and trying to unstick that PTFE washer which was intended to be the upper surface of the thrust bearing from a smaller epoxy casting in the centre of the base plate. Will post more when I manage to extricate it.
Cheers!
Drew
