returning to turning

[Terry Miller]

Hi Brian if the box that houses the inverter is not much bigger than the inverter itself then you need holes to let the heat generated by the inverter to dissipate as the inverter can generate a fair bit of heat which in turn can damage the electronics. If the inverter is mounted on the lathe then a filter of some kind is preferable to stop any ingress of dust just like they use in dust extraction or in a filter above a hob on an oven. If the inverter is well away from the headstock then I wouldn't worry too much about filtration.
Secondly if you stop and start the motor on the potentiometer only then you are never switching off the electronics and potentially supplying power to the motor which can cause it to overheat and possible burnout. Remember a motor needs to run near its rated speed when used for a long time for the motor''s fan to keep it cool (see motor nameplate for rpm). If you control it purely on the potentiometer it is still getting a supply but the motor's fan is ineffective. Therefore it pays to switch off by the switch on the inverter for stopping and starting and by the switch on your socket when leaving the workshop.
I hope this helps.
Regards
Terry

[BrianH]

Ta for the advice,Mark, looks like I need to retrain my left hand to use the push and twist switch instead of the speedy wheel,what a pain
I will also give some thought to keeping the dust out of the inverterworks. You would think the nice man at Axminster might have mentioned the problem, he works with lathes all the time, after all.
Tarra
Brian

[Woodcrafts]

Hi Brian,
Your thread has raised several good points about inverters but, from your last comment:-

Ta for the advice,Mark, looks like I need to retrain my left hand to use the push and twist switch instead of the speedy wheel,what a pain

that sounds like you don't have an actual Run/Stop switch. A 'Twist to set/push to release' switch is normally used as an Emergency stop, as all you have to do is 'hit' it. Emergency stop should be wired to its own input on the inverter, and a separate Run switch wired to that input, to purely control the motor. If that is not the case with yours, may I suggest you ask your friend to add one.
By the way, I would concur with other posters that using the pot to start/stop the motor is not advisable for the reasons I gave in my earlier reply to you, namely the motor may still have power to it, even though it isn't turning.
Hope all this chat about inverters etc. isn't keeping you from your turning