Cone Pulley Question

[CRAFTY]

homemade timber lathe,i was going to put cone pulleys on the lathe with 3 speeds,but i have just realized i may not need to as i will be fitting a speed controller,so is there any point in fitting cone pulleys,if i still need to ,what sizes should they be,they look to be about 4"/3"/2" or maybe a little bigger,if i do not need them? how big should i make the wheel? 4"??? thanks

 

[Walney Col]

If you use a speed controller you'll lose full torque whenever you turn the speed down. If you use pulleys you'll acually increase the available torque on slower speeds.

 

[CRAFTY]

ok thanks for the input,i just don't like the thought of the motor running constantly at full power,even with the wheels,this motor is fairly powerful ya know,i think i will put a speed controller on it to be safe,so i will put 3 gears on also,i like that idea anyway,thanks

 

[CHJ]

What type of motor are you talking about?

To control the speed of a mains powered motor it normally needs to be one of two types.

1. A universal ac/dc (brushed) unit fed from a triac controller or in very crude conditions a variable resistor.
Or
2. A 3 phase induction unit supplied from an electronic invertor.

The alternate would be a modern DC permanent magnet unit driven through an appropriate electronic controller.

You can't control the speed of a single phase motor and get any meaningful power out of it, attempts to slow one down can cause it to rapidly overheat if it does not blow the supply fuse.

 

[CRAFTY]

hay thanks for the reply,i searched all the shops in my area,the last shop i checked had a few sizes,was worn out at that stage so i just brought home two 25mm,to see if my plan was going to work,and i am about to go find out,i have two motors,one universal with brushes,fairly powerfull which i intend to use for the lathe,and one without brushes,i think is from a dryer,nowhere near the power of the other, i have a place not to far to order what i need if this does not work out,be back later with hopefully a good result,cheers for now.

 

[mayo.mick]

hay thanks for the reply,i searched all the shops in my area,the last shop i checked had a few sizes,was worn out at that stage so i just brought home two 25mm,to see if my plan was going to work,and i am about to go find out,i have two motors,one universal with brushes,fairly powerfull which i intend to use for the lathe,and one without brushes,i think is from a dryer,nowhere near the power of the other, i have a place not to far to order what i need if this does not work out,be back later with hopefully a good result,cheers for now.

Any chance of a few photos of the wip?

 

[CRAFTY]

well how's it going,yes i will throw one or two up tomorrow as i can't find my phone for photo's only, it takes ages to upload a photo with the other phone for some reason,i only started it yesterday so not really ready for pics,although i could have all the timber work done tomorrow as i got the guts of the base done today,if i had a table saw i would be nearly done now ha
UP THE DUB'S (hammer)