Hello to all, I have a question to propose here : a direct drive turntable as for example an American Audio TTD 2400 from 1 kgf/cm of torque or more could be enough for cutting or no ?
Is there someone here that cut with a turntable with this torque ?
Thanks to all.
Cheers.
dd turntable 1 kgf/cm of torque
Moderators: piaptk, tragwag, Steve E., Aussie0zborn
Hi,
I don't know if this is enough torque, but for comparison, the old Presto 6N has a 1/25 HP Bodine synchronous motor. If you do the math, at 33 RPM this equates to about 87 Kg-cm of torque. There is probably a good deal of loss from the motor shaft to turntable platter and there is a large amount power needed to drive the overhead mechanism, but it gives you some idea of the requirements. In the case of a direct drive, you may be able to get away with much less since there is a servo in operation and if the head advance is done by an external drive motor, you may be ok. I susupect if you are just planning to cut laquers, you should be fine. If you want more torque in a cheap TT, the Newmark TT200 specs 1.7Kg-cm of torque.
Mark
I don't know if this is enough torque, but for comparison, the old Presto 6N has a 1/25 HP Bodine synchronous motor. If you do the math, at 33 RPM this equates to about 87 Kg-cm of torque. There is probably a good deal of loss from the motor shaft to turntable platter and there is a large amount power needed to drive the overhead mechanism, but it gives you some idea of the requirements. In the case of a direct drive, you may be able to get away with much less since there is a servo in operation and if the head advance is done by an external drive motor, you may be ok. I susupect if you are just planning to cut laquers, you should be fine. If you want more torque in a cheap TT, the Newmark TT200 specs 1.7Kg-cm of torque.
Mark
No laquers, I must start to do experiments possibly with polycarbonate, or other similar material with my Poltz Freres that I have restored in this last month.
I don't know if you know as has built a Poltz, but is similar a Rek o Kut M12S, only the mechanism has moved by a belt under the plate.
Yes, then I am thinking to insert another motor for move the head advance, but I am dubios about a question : is necessary that this second motor must be in sync with the direct drive motor, or no ?
Thanks.
I don't know if you know as has built a Poltz, but is similar a Rek o Kut M12S, only the mechanism has moved by a belt under the plate.
Yes, then I am thinking to insert another motor for move the head advance, but I am dubios about a question : is necessary that this second motor must be in sync with the direct drive motor, or no ?
Thanks.
Hi,
There is no need to have the motor(s) in sync. In fact, having the head advance separated from the platter motor is a plus. It allows you to easily change the groove pitch of your cuts. When using a Presto 6N and similar units, you have to change feedscrews to accomplish this. With a separate drive for the head, you just change the motor speed and you get variable pitch. You could implement a real-time variable pitch system in the future with a setup like this.
Mark
There is no need to have the motor(s) in sync. In fact, having the head advance separated from the platter motor is a plus. It allows you to easily change the groove pitch of your cuts. When using a Presto 6N and similar units, you have to change feedscrews to accomplish this. With a separate drive for the head, you just change the motor speed and you get variable pitch. You could implement a real-time variable pitch system in the future with a setup like this.
Mark
overhead feed accuracy
Mark,
is the speed accuracy of motor for overhead feed as critical as that of the turntable speed accuracy?
emidisc
is the speed accuracy of motor for overhead feed as critical as that of the turntable speed accuracy?
emidisc
Absolutely NO , the Autogroove , Ptich Boxes , Auto Distancers are the demostration , the advance speed didnt have any effect on the audio (unless a modulated groove reaches the groove before) , in that systems the advance speed it's changed continuously and no heard effect about. not sirs?
About that low torque , in the VR the carriage advance don't depend of the TT torque , coz of that can cut with 1,2 Kg/cm2 , the VC 200 seems works pretty good with the Technics , maybe some users here can give more details , recently I gift an M12 overhead to a friend that is starting in cutting , the Technics can move the carriage without strobe movings , but maybe when have a stylus the things change , if you have the TT , simply , TEST IT.
About that low torque , in the VR the carriage advance don't depend of the TT torque , coz of that can cut with 1,2 Kg/cm2 , the VC 200 seems works pretty good with the Technics , maybe some users here can give more details , recently I gift an M12 overhead to a friend that is starting in cutting , the Technics can move the carriage without strobe movings , but maybe when have a stylus the things change , if you have the TT , simply , TEST IT.
Very Busy days , some cutting works at least , soon online again
We must promote the use and abuse of vinyl records.
We must promote the use and abuse of vinyl records.