Unknown Spindle Speed for Lathe (for eternity)?

[silver2row]

Okay,

So...I have an unknown spindle speed. I can adjust the spindle speed but only with a potentiometer. So, I can either go "Turtle" or "Rabbit."

Excuse my mowing expertise here...

So, in Intercon, I see an option for spindle speed while adjusting conversational programming and setting up builds.

I have smaller lathe here, i.e. obviously (Turtle to Rabbit was the clue)...

So, my questions are these:

1. Do I need to know the exact spindle speed?
2. If I do not know the exact spindle speed, is there a method to not "wing it?"
3. And finally, when adjusting the conversational programming, what should I put the spindle speed at during set up in Intercon?

Seth

P.S. Odd? Yes but this is what I get. So, for now, this is my shtick of building specific components.

[cnckeith]

buy a cheap tachometer and calibrate the pot knob so you know at least a general idea of what the spindle speed is.

https://amzn.to/3IoGF7u


yes you need to know what the spindle speed is to get the chip load right

[silver2row]

Okay...

Thank you for your reply. I will purchase the laser type in your link. I have one but it is of non-laser type. So, I cannot use the one I have currently.

Seth

P.S. So, I need to know the spindle speed not only for chip load but also for computation in the Intercon software to calculate the chip load. Okay. Dang. I was about to start my trillionth journey into the unknown. Back to basics!

[silver2row]

buy a cheap tachometer and calibrate the pot knob so you know at least a general idea of what the spindle speed is.

https://amzn.to/3IoGF7u


yes you need to know what the spindle speed is to get the chip load right

The item came in. I purchased the tachometer (laser type) and I need some non-error prone ideas from anyone that is familiar with Spindles on lathes and/or Spindles that have a different type of belt... I will be researching the offset of the spindle, belt, and headstock...

Code: Select all

Swing Over Bed                 3.50″ (90 mm)
Swing Over Carriage          1.75″ (45 mm)
Distance Between Centers	17.00″ (430 mm)
Hole Through Spindle         0.405″ (10 mm)
Spindle Nose Thread          3/4″-16 T.P.I.
Spindle Nose Taper            #1 Morse
Tailstock Spindle Taper      #0 Morse
Motor                               90 volt DC with electronic speed control that accepts any incoming current from 100VAC to 240 VAC, 50 Hz or 60 Hz.

Spindle Speed Range	       70-2800 RPM continuously variable by electronic speed control

So, even though the spindle, small lathe, has an RPM of 800, should I account for the actual moving part or the spindle speed or the headstock spinning rpm?

Seth

P.S. I have not plugged in anything yet as I am researching ideas. I want to be right the first time!

[silver2row]

Speed in rpm: 6100 rpm continuous

The above calc is the RPM of the Spindle motor and not with the ESC and belt. Just a heads up here...

I am working with a Sherline CNC ready lathe. The lathe is small and has a 90v Spindle motor attached via pulleys and belt.

Seth

P.S. If you need photos and/or other data from me, please ask away.

[tblough]

Spindle motor speed doesn't matter. You want the speed of the actual lathe spindle (the speed of the chuck). CNC12 does not regulate the spindle speed. It only measures the speed of the spindle via the encoder to synchronize the Z axis movement for threading and feed rate.

[silver2row]

Thank you for updating me on this build I am pursuing.

...

So, should I add piece of stock to the chuck to measure? @cnckeith let me know to purchase the inexpensive laser tachometer for testing RPM.

This inexpensive versioning of a tachometer states in the "manual", "Add reflective tape to the spindle to find the RPM."

It came with tape. I would rather put the tape on a 12mm piece of stock in the chuck than on the actual chuck. Does this make any sense?

I mean, would it make sense to use the stock instead of testing the actual chuck?

Seth