Newb 7x10 operation and mod questions

ric686

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Operational question:
While I'm in the process of turning something I've been using the speed pot and it's switch to start and stop the lathe and leaving the F/O/R switch generally in the Forward position. Knowing that the quality of the pot is probably questionable, I figure that it's not going to last long using it for stop/start functions. I'd prefer to leave the pot set for the desired speed and use the F/O/R switch for stopping and starting, and stopping with it isn't a problem, but using it to start the motor causes a quick surge to a much higher speed, which I'm sure puts extra strain on the motor and gearing. To avoid that, I start with the pot turned to a lower speed and bring it the speed up to where I want it, but then I'm back to using the pot again. Is it better to use the pot or the F/O/R switch for stopping and starting? If using the switch, should I ignore the initial starting surge or is there a way to mod the controller for smoother start of the motor?

Mod question:
My 7x10 has the single half nut below the lead screw with a simple curved brace in place of the upper half nut. Would it be worthwhile to get the parts to convert it to dual half nuts?

Thanks!
 
Definitely yes. Stop by LittleMachineShop.com for some extra pots too.
 
Hi G
The recommended method is to reduce the speed first this stops spikes caused by braking the circuit at high speed and saves blowing the control board. Not that it saved mine but I suffer from intermittent supply and low voltage so that was possibly the reason for my three board failures. I now have a 1hp single phase motor, that works very well.
Brian

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Depending on the brand, the potentiometer may the mfg. preferred method of starting and stopping the lathe. The HF lathe manual call for turining on the F/O/R switch, then rotating the potentiometer from the off position to desired speed. shut down is the oppositie steps.

I know this specifically since my lathe came to me for CHEAP because the previous owner kept blowing fuses and figurd the lathe was bad. He sold me the lathe, some tooling and all for "scrap price" of $35. I downloaded the manual, read it, put in a new fuse and it's been good to go ever since.
 
mine won't start unless the pot is turned down.
 
At some point I'm going to look into controller alternatives because it shouldn't be that much of a problem for a circuit to ramp the speed up and down without having to do it manually with a pot. That way you could leave the speed pot set for the desired RPM and use the F/O/R switch to turn the motor on and off without undue surges. It should be possible to also get a three position switch with a safety latch for one position to keep from going into reverse accidentally when going from forward to off. In the mean time I'm going to look up some alternative high reliability pots rather than replace the cheap stock pot with another cheap pot. If I find any good substitutions for the switch and pot, I'll post them here.

As soon as LMS gets some more half nuts in I'll make that upgrade too.

thanks for the good advice!
 
Mine will stop or start with the F/O/R switch (though the startup makes that undesirable) unless the chuck cover is opened, triggering the safety interlock circuit. In that case the pot has to go to zero so the switch on it closes to reset the safety interlock circuit. I've got the FC250BJ/110v controller.
 
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