![]() Stick one such disc to the base platter which we will attach to the motor using the coupler. For those in India, the earthing pin of a standard 6A plug is exactly 7mm in diameter, and of the correct height to comfortably seat a phonograph record. Next, in the centre of all but the base platter make the centre hole just large enough to accommodate a 7mm spindle of about 1 to 1.5 inch height. The nuts go under the coupler (the opposite side) and are fixed concentric to the mounting holes with super glue. When placed on the platter base and matched with the holes you will see that when the bolts are put, the bolt heads are nicely concealed and the top surface is completely flat. In the remaining discs mark out holes at exactly the same positions but drill them big enough to accommodate the bolt heads. Ensure that the holes are enough to allow the 1/2 inch bolt shanks to pass through but not the heads - this is the platter base. Take any one disc and using the coupler as a template mark out as precisely as possible all the mounting holes in it. Useful to have in order to correctly adjust the cartridge.įind the exact centre of all the MDF discs and drill a small pilot hole in all of them. There are PDFs available freely which can be printed and used. Rubber-based adhesive, super-glue (for sticking metal parts together) Softboard sheets (for the tone arm, and other miscellaneous use - see video)ġ/2 inch long Philips head bolts/nuts (to mount the platter to the coupler. Plywood (for the box and other items - see video) (for the platter)Ģ inch long bolt and nut 2.5 to 3 mm dia - 1 no. See video for the kind I used)ġ2-inch dia, 2.5 mm thick round MDF discs - 4 nos. 40-pin header strip (break out as per need).īall bearing 608-2RS (8x22x7 mm) - 1 no. (Optional) Red LED for power indication (not shown in the schematic)ġk/0.25W resistors - number depending on need.įlexible/thin wires for cartridge - coloured red, yellow, white, green (or blue) each of suitable length Suitable power supply - one that can supply 12VDC at 2A for the stepper motor/controller and dual +/-12VDC at 1A to power the preamp (if you intend to include it). Phono pre-amplifier (parts not included in this article). A motor with a smaller step angle is preferred as it makes it that much smoother while running.Īrduino UNO (or equivalent) microcontroller board. The one I used is specified for 1.8 deg/step. Stepper motor - NEMA 23, 10 kg-cm, 2-phase (4-wire). This is where the Arduino platform comes in. ![]() #Rohit pick the phone tones driver#Again a search revealed mostly discouraging posts about using stepper motors for phonograph turntables! But still, I marched on.Īll we need to get it to work is a suitable microcontroller and a stepper motor driver with some programming. Then I thought about using stepper motors as they can be made to turn as slow as we want via suitable digital means. To make it run at the slow turntable speeds would require very low frequency sine waves, that too amplified to 230VAC (and even so the torque would remain questionable at such slow speeds) or using gear mechanisms - something I did not want to undertake. ![]() Most available were rated for 230VAC/50Hz and offered RPM ranging from 800 to 1600 RPM. I determined that a synchronous motor can be used for this purpose.but finding a suitable unit was hard. I searched on the internet for design ideas and most of them were belt-driven designs. I wanted to build one because of a fascination with it in part, and because of the torque and speed precision that it offers - speed can be controlled by frequency rather than voltage. ![]() Please see the video above to get an idea of how things are mounted since describing it exactly in written form is a bit tedious and will get unnecessarily confusing. ![]() This page describes the construction of my direct-drive turntable which I built from commonly available items without any specialised machining. ![]()
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