Parvalux 1/4 hp motor

Hi All

I have an independent overhead drive which I use occasionally to power my potts spindle

It takes a short while to set up on the lathe bed but is usually worth the trouble if I have a lot to do.

Despite it's somewhat cumbersome look it does function well.

The 1/4 hp parvalux provides ample power for end mills up to about 1/4" but is under powered on start up. I have to tug down on the belt to get the spindle running.

Is it feasible to wire in a capacitor to provide a "kick start" and overcome the initial frictional resistance.

cheers geoff

Geoff, a Parvalux would normally have a run capacitor anyway, does yours not? The one I have on my Quorn came with it. Without a cap it will run but needs a kick to start it. How many wires go to the motor?

To use a capacitor it needs an extra winding, whether cap start or start and run.

Geoff,

You don't mention the model number, but here's the page to start looking for info.

**LINK**

http://www.parvalux.com/products/ac-motors-and-geared-motors/ac-induction-motor-single-phase

MichaelG.

Hi Gents,

Thanks for your replies.

I had a look at the link Michael, my motor is an sd38 and from the data sheet I can see that it already has capacitor start, which is what John indicated.

It starts fine with no load, problem is the Potts plain bearings are "heavy" and the motor has not quite enough "umph" on start up, but is fine when it gets going.

I may have a look at some sort of simple sliding clutch so I can introduce the power gradually.

Thanks again geoff

Geoff,

Please forgive my confusion:

In your opening post you mention 1/4 hp

... but the highest power that Parvalux skows for the Single Phase SD38 appears to be 60 watts, at 2800 rpm

... which is only about 0.08 hp

MichaelG.

.

Edit: Quick conversion here:

http://www.rapidtables.com/convert/power/watt-to-hp.htm

Edited By Michael Gilligan on 29/01/2017 11:56:34

Can you just ease the belt tension on starting, let it slip for a second or two. Crude but might work

The puzzling thing is that there is no sign of a capacitor in the pictures! According to that data sheet one of the options for this style of motor is shaded pole, and I wonder if this is such a motor. How may leads are there Geoff? If there are only 2 (plus earth) then it's probably shaded pole which would explain the low starting torque. The size of the motor relative to the pattress box is consistent with it being an SD38, but as Michael says this type is much lower than 1/4 hp (especially if shaded pole).

Hi Gents,

Thank you all again for your comments.

I will be setting it up later in the week as I have a few small jobs to do. I'll have a look at the wiring.

Yes Michael you are right the hp is much less than I thought. I bought it off ebay and it was listed by the seller as 1/4 hp I assumed that was correct, clearly it was not.

That was what attracted me to buying as it was compact and at 1/4 hp would probably have had ample power on start up.

I'm going to try it with a long bungee instead of the weights, as Duncan suggests lifting the arm and further tensioning the bungee will relieve the tension on the drive belt and give me a slow gradual start up, we'll see?

thanks geoff

Hi all, a little off subject.......

Geoff, just like what u have done although it awakens memories as a child going to the dentist, does anyone else remember the treadle drill....?......

Clogs.......

just like what u have done although it awakens memories as a child going to the dentist, does anyone else remember the treadle drill....?.....

Treadle drill, nah don't remember that, do remember the gas mask and then waking up and spitting in big enamel sink.....brrrr

geoff

Remember the treadle drill very well. Maybe that's why I look after me teeth. Held down by an assistant and a smelly bag over the mouth and nose. Come a long way since then. About that time the Myford was all the rage ?

Geoff

I believe what you have is a 3 lead induction motor, 2 white and 1 black leads from the motor. Although I can't see the type of switches you have I guess 1 is for on/ff and the other to reverse.

The 2 white leads are connected to L1 and L2 of the 2 way switch, the 2 leads from the capacitor are also connected to L1 and L2 (either way round ).

The live supply from the on/ff switch is connected to the 2 way switch common terminal.

The neutral supply from the DP on/off (switched fuse spur fused at 5A) has the black neutral connected in it.

The switch shown does not have any fuse so the plugtop needs to be fused down to 5A.

The size of the capacitor would be somewhere between 5 and 10 uf 400v working, if yours has a 5 fitted you may get better starting if you increase to 10uf 400v for 230v working.

Emgee