RCA MI-12701 78 Only Cutter - capstan dimensions?
Hey everyone,
I bought a 78 onoy RCA cutter, but the rubber capstan was terribly warped (it's almost square!), and was wondering if anyone had one of these machines with a good one that could get me measurements of the capstan diameter.
Thanks!
I bought a 78 onoy RCA cutter, but the rubber capstan was terribly warped (it's almost square!), and was wondering if anyone had one of these machines with a good one that could get me measurements of the capstan diameter.
Thanks!
I Buy/Sell/Restore Vintage Machines/Parts and Provide Phone/In Person Tech Support
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Re: RCA MI-12701 78 Only Cutter - capstan dimensions?
Terry of terry's rubber rollers "may" have the original dimensions.
I say may because that's probably not something he see's everyday. But it's worth a try
I say may because that's probably not something he see's everyday. But it's worth a try
My d.i.y. audio electronics channel:
https://www.youtube.com/user/samealalan
My d.i.y. audio electronics blog:
https://junkyardstudio.blogspot.com/?m=1
https://randomlyassoertedangels.bandcamp.com
https://www.youtube.com/user/samealalan
My d.i.y. audio electronics blog:
https://junkyardstudio.blogspot.com/?m=1
https://randomlyassoertedangels.bandcamp.com
Re: RCA MI-12701 78 Only Cutter - capstan dimensions?
You may calculate it if you know the RPM of the motor, which may be listed on the motor or via the motor data sheet.
PullyRatio = RPMRoller ÷ RPMPlatter = DiameterPlatter ÷ DiameterRoller
Punch in what you have [platter diameter, desired platter speed, and roller speed] and simplify to obtain the diameter of the roller.
PullyRatio = RPMRoller ÷ RPMPlatter = DiameterPlatter ÷ DiameterRoller
Punch in what you have [platter diameter, desired platter speed, and roller speed] and simplify to obtain the diameter of the roller.
Re: RCA MI-12701 78 Only Cutter - capstan dimensions?
In other words you can use the calculations found on the following link, just note that the only difference between a belt drive/pulley system and a direct contact roller system is that the direction of rotation is opposing for the two diameters in the latter.
http://www.cousesteel.com/AndysPlace/Pulleys.html
http://www.cousesteel.com/AndysPlace/Pulleys.html
Re: RCA MI-12701 78 Only Cutter - capstan dimensions?
Hi,
I don't know the RCA lathe, but if its done like the the Presto 6N, the roller in question is a idler and does not influence the platter speed. In that case, the diameter is not so critical as long as it allows the power to be transmitted to the platter from the motor.
Mark
I don't know the RCA lathe, but if its done like the the Presto 6N, the roller in question is a idler and does not influence the platter speed. In that case, the diameter is not so critical as long as it allows the power to be transmitted to the platter from the motor.
Mark
Re: RCA MI-12701 78 Only Cutter - capstan dimensions?
This is an actual rubber capstan that directly turns the rim, so it definitely affects the speed.
Bahndahn, thanks for the formula!
Bahndahn, thanks for the formula!
I Buy/Sell/Restore Vintage Machines/Parts and Provide Phone/In Person Tech Support
www.MichaelDixonVinylArt.com
www.LatheCutCamp.com
www.RecordLatheParts.com
www.MobileVinylRecorders.com
www.LatheCuts.com
www.MichaelDixonVinylArt.com
www.LatheCutCamp.com
www.RecordLatheParts.com
www.MobileVinylRecorders.com
www.LatheCuts.com