#1 The Bastard
Posted: Wed Apr 19, 2017 12:10 pm
Take a nicely brought up young turntable from rural south Devon. Introduce her to a disco king from Japan and leave them to have an illicit liaison in a shed and what do you get? A Bastard!
I've been intrigued by some of these DJ turntables with their high torque DD motors, so when Adam Smith on AoS offered a damaged but working Vestax 2000 free to anyone who wanted it, I was first in the queue. It's a horrible turntable. The plinth is a big hollow plastic moulding, the platter is a thin steel pressing and the arm, which is straight and stubby with no offset angle, is flimsy and floppy. The motor however is a different story. It's a big nicely made self-contained unit with prodigious torque and a half decent bearing that could probably be improved to something quite good. The intention is to build the motor into a solid plinth built up from layers of 6mm MDF, possibly interlayered with bitumin pads or maybe lead sheet. It's not finalised yet. I'd like to have been able to use slate, but this is a low cost project, and I don't currently have the tools or the facilities. The platter is a spare Heybrook TT2 platter and sub-platter assembly that I've had knocking about in the shed since the early 80s. To give you some idea of the torque available I've had to drill and tap the platter and sub-platter and bolt them together to prevent the sub from spinning inside the main platter on start-up!
There's a surprising amount of electronics and a hefty mains tx to accommodate, so I may go down the route of a remote PSU box. It has the usual two quartz-locked speed settings, but can also operate unlocked with the speed variable by a slider pot between about twenty and eighty RPM. It also has a reverse button. I have no idea why.
The motor:
The bearing is a ball approx 4mm in diameter set into a recess in the bottom of the shaft, resting on a nylon thrust pad supported by a bracket (apologies for the crap picture of the pad):
You can also see the slotted disk and opto sensor for the motor speed sensor.
I'm hoping to replace the nylon thrust pad with a hardened steel shim, and I've inserted a washer between the bearing bracket and the bottom cover. Once the motor's fitted to the plinth, i'll fit a bolt underneath which will be tightened up against the cover to provide direct support under the bearing.
As you can see, the power transformer is pretty big and will nee to be housed remotely:
I haven't decided wheth to build the power supply and processor boards into the base or put them in with the trafo. They're quite big too:
Probably they'll go onto the bottom of the plinth.
I've put together a lash-up of push buttons, leds and vero board to bring all the switches into one place. This will probably go under a bit of black Perspex eventually:
This is starting from min speed, moving up to max,then reversing. Revere is achieved within half a rotation:
I've been intrigued by some of these DJ turntables with their high torque DD motors, so when Adam Smith on AoS offered a damaged but working Vestax 2000 free to anyone who wanted it, I was first in the queue. It's a horrible turntable. The plinth is a big hollow plastic moulding, the platter is a thin steel pressing and the arm, which is straight and stubby with no offset angle, is flimsy and floppy. The motor however is a different story. It's a big nicely made self-contained unit with prodigious torque and a half decent bearing that could probably be improved to something quite good. The intention is to build the motor into a solid plinth built up from layers of 6mm MDF, possibly interlayered with bitumin pads or maybe lead sheet. It's not finalised yet. I'd like to have been able to use slate, but this is a low cost project, and I don't currently have the tools or the facilities. The platter is a spare Heybrook TT2 platter and sub-platter assembly that I've had knocking about in the shed since the early 80s. To give you some idea of the torque available I've had to drill and tap the platter and sub-platter and bolt them together to prevent the sub from spinning inside the main platter on start-up!
There's a surprising amount of electronics and a hefty mains tx to accommodate, so I may go down the route of a remote PSU box. It has the usual two quartz-locked speed settings, but can also operate unlocked with the speed variable by a slider pot between about twenty and eighty RPM. It also has a reverse button. I have no idea why.
The motor:
The bearing is a ball approx 4mm in diameter set into a recess in the bottom of the shaft, resting on a nylon thrust pad supported by a bracket (apologies for the crap picture of the pad):
You can also see the slotted disk and opto sensor for the motor speed sensor.
I'm hoping to replace the nylon thrust pad with a hardened steel shim, and I've inserted a washer between the bearing bracket and the bottom cover. Once the motor's fitted to the plinth, i'll fit a bolt underneath which will be tightened up against the cover to provide direct support under the bearing.
As you can see, the power transformer is pretty big and will nee to be housed remotely:
I haven't decided wheth to build the power supply and processor boards into the base or put them in with the trafo. They're quite big too:
Probably they'll go onto the bottom of the plinth.
I've put together a lash-up of push buttons, leds and vero board to bring all the switches into one place. This will probably go under a bit of black Perspex eventually:
This is starting from min speed, moving up to max,then reversing. Revere is achieved within half a rotation: