MadModder
Gallery, Projects and General => How do I?? => Topic started by: John Hill on March 05, 2009, 03:10:16 AM
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My lathe with a 2 HP motor trips the circuit breaker when starting under load. Of course one would never really start a lathe under load but when starting in the higher speeds the motor has to spin all to cogs in the thick oil which puts more load then starting in a lower speed and in my case is enough to trip the breaker.
Besides, if it trips the breaker the motor is drawing a fierce current and one must remember that it was made in China!
So, how to resolve this? Slow blow circuit breaker (that would do it but I dont want to compromise safety in the house wiring if I can avoid it), constant voltage transformer or other surge stabiliser, maybe but I wouldnt know where to find one. That leaves some sort of clutch so that the motor can get up to revs before starting to turn the lathe.
A clutch comprised of a longer belt with a jockey wheel tensioner attached to a handle would be a practical project but before I embark on that I am sure there must be a preferred solution in 'the trade'?
[The old farm milk seperator used to have a slip clutch for starting as there was no way the 1/4 HP motor could spin the centifuge up to 9000rpm before the start winding burned out.]
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Fit a 3 phase motor with VFD, these can be programmed for a soft start.
As regards high speed when cold you will just have to let it warm up. Our old Harrison with 2 speed motor and on 3 phase always slipped the clutch if you tried high speed from cold.
JS
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JS, a VFD would be nice but out of budget right now. I guess it will be the jockey wheel clutch or slow speed only. :(
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John,
Fill your gearboxes with a 32 grade hydraulic fluid (a standard grade), you will find the head turns a lot freer. Mine used to sometimes have difficulty spinning up from cold when a high speed ratio was pre selected, changing the oil cured it.
Bogs
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Good point John, it is about due for its first oil change.