Thread: How do you check the speed of a lathe?

Hi Ghost, welcome to the forum.
I don't know the answer to your question, but I guess you have to start with the speed of the motor and then work out the lathe speed depending on the size of the pulleys.

cheers macca

Hi Ghost

Welcome also.

With the Jet Mini Lathe it has plate showing the RPM for the given pulley setting. Don't know about bigger Jets but possibly so if it is on one type I would think they would put it on all their models.

The fun way would be with a variable speed strobe, $15 from Jaycar if you want to make one, http://www.jaycar.com.au/productView...Max=&SUBCATID=

Probably the easiest way would be to refer to the manufacturers manual for the lathe,

Sebastiaan

this is how i do it ..... motor speed x diameter of motor pulley then divided by work pulley diameter doesnt matter what units you use ...eg inches cms... mm as long as they are the same.

eg motor speed 1440rpm
motor pulley diam 10cm( or 4 inches)
work pulley diam 5 cm( 2 inches)

1440x10/5 =2880

Originally Posted by tanii51

this is how i do it ..... motor speed x diameter of motor pulley then divided by work pulley diameter doesnt matter what units you use ...eg inches cms... mm as long as they are the same.

eg motor speed 1440rpm
motor pulley diam 10cm( or 4 inches)
work pulley diam 5 cm( 2 inches)

1440x10/5 =2880

That looks about right to me.

Thanks For All The Help
Have Got What I Needed Thanks Once Again

Hi regalghost
I've got a better suggestion, that I don't believe is known by most turners.

I already got the timber moister metter, which works a treat, and I got the RPM metter coming. I thing this is a must tool to have, insted of trying to work out the rpm from a graph. Anyway lathe RPM varies, depending on some circumbstances, with the size of the peace been turn a factor, and are other. You find that 90% of times the RPM showing on the lathe factory plate, are higher then what the simple turns.

This eBay seller, is ok and he sends the items very quickly, mine was a week from the US.

Have a look at his site for more info.
http://cgi.ebay.com.au/ws/eBayISAPI....X:NEWLIST#LIST
Cheers
GV

I just look at what the display says as I turn the knob.

I'd like to have a digital tach, but the formula is close enough for me.

Not tryin' to hijack the thread, but what is this 1440 rpm motor?
The usual motors that I see here in the upover are: 2 speed - 1140 & 1725. Single speed motors are normally 1725 or 3350.
Is 1440 a normal speed of motors manufactured in Oz? I noticed that the VS Vicmarc VL100 comes with a 1/3hp, 1440 rpm, 240 volt motor. Is 220-240 volt electricity the normal household voltage in Oz?
Just curious.

Originally Posted by OGYT

Is 220-240 volt electricity the normal household voltage in Oz?
Just curious.

Yes. Also 50Hz. That's one of the reasons very little power tools export from Oosa to Oz. Observe, too, that 1725 x 5/6 = 1438, or 1440 with rounding.

Joe

Joe, "what's the 1725 X 5/6 = 1438" mean? You tryin' to tell me that their 1440rpm motor turns the same rpm as our 1725rpm motor? I always thought rpms is rpms....
....Just dense, I guess.

Originally Posted by regalghost

Hi

Just wondering how you check the speed of a lathe?

Thanks

Looks like you have received sufficient formula to now check what your spindle speeds are.
My question is now that you have the speeds, what are you going to do with them.

Cheers
Woodfast Aust

Isn't the more critical factor the speed of the piece at the point you're taking shavings?

So you need rpm x circumference?

Other simple way is run it so fast it vibrates too much or you feel you need a continence pad to continue ... then back off

Added: btw, welcome regalhost.

Originally Posted by Skew ChiDAMN!!

Mount up a square blank, switch on the lathe and stick in your finger.

Count the OW!'s for one minute, then divide by four...

Skew was thinking that but wasn't willing to say it