1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. ATTENTION FORUM MEMBERS!

    Guest, if you have not yet updated your forum bookmark to a secure log in connection, please delete your unsecure book and add the following secure bookmark: https://www.aawforum.org/community/index.php

    You can dismiss this notice by clicking the X in the upper right of the notice box.

    Dismiss Notice

Lathe's Minimum Speed - Too Fast

Discussion in 'Getting Started' started by Joe Sheble, Sep 20, 2019.

  1. Joe Sheble

    Joe Sheble

    Joined:
    Aug 14, 2019
    Messages:
    57
    Location (City & State):
    Apache Junction, AZ
    I have a Mophorn Variable Speed Wood Lathe, and the minimum speed on it is about 850 RPM... I see various tips and techniques using 500 RPM, and sometimes even less... I'm curious if there's anything I can do to decrease my minimum speed on the lathe, without having to rewire it (cuz I know absolutely nothing about wiring, and I don't really want to learn lectricity)
     
  2. hockenbery

    hockenbery AAW Advisor Staff Member

    Joined:
    Apr 27, 2004
    Messages:
    6,554
    Location (City & State):
    Lakeland, Florida
    Home Page:
    I have not seen a Mophorn, but most variable speed lathes have belts and step pulleys.
    Each step pulley pair changes the low to high speed on the dial.

    This is a typical diagram you find inside the door that protects the belts. 36571CA7-B7B2-4C98-ACC0-008A744E0680.jpeg

    If your lathe has a belt move it to the slow speed pair.

    The Mophorn I saw on Amazon said it had a low speed of 500.
    If this is the advertised low speed for your machine, contact the company for help.
     
  3. Bill Boehme

    Bill Boehme Administrator Staff Member

    Joined:
    Jan 27, 2005
    Messages:
    11,344
    Location (City & State):
    Dalworthington Gardens, TX
    Home Page:
    Which model do you have?
     
  4. Joe Sheble

    Joe Sheble

    Joined:
    Aug 14, 2019
    Messages:
    57
    Location (City & State):
    Apache Junction, AZ
    I know about the pulleys and the gears, it's set on the lowest one. The description and label on it say 500 RPM is the minimum, but the gear/pulley diagram shows 650 as the minimum, and when I turn it on, 800 is the minimum. So completely inconsistent marketing and product information.
     

    Attached Files:

  5. hockenbery

    hockenbery AAW Advisor Staff Member

    Joined:
    Apr 27, 2004
    Messages:
    6,554
    Location (City & State):
    Lakeland, Florida
    Home Page:
    Joe,
    You should call customer service.

    500 should be the lowest speed. That is lowest speed on the 5 speed mini lathes.

    It is possible the digital readout is reading high.

    The speeds shown on the belt door are troubling too.
     
  6. Bill Boehme

    Bill Boehme Administrator Staff Member

    Joined:
    Jan 27, 2005
    Messages:
    11,344
    Location (City & State):
    Dalworthington Gardens, TX
    Home Page:
    The speed of DC motors vary quite a bit with load. If you were measuring the speed under no-load conditions try measuring the speed under as heavy a load as you can apply without stalling the motor. This doesn't help answer your question, but there isn't an easy nor inexpensive way to make your lathe run slower. Lathes of that size are mainly for turning pens, bottle stoppers, peppermills, and other small diameter projects. While it is possible to turn bowls, the variable speed models are lacking on power at the low speed end. The fixed speed models are much better on power, but the minimum speed is usually too fast for bowl turning.
     
    hockenbery likes this.
  7. Perry Hilbert

    Perry Hilbert

    Joined:
    Sep 27, 2017
    Messages:
    301
    Location (City & State):
    Windsor, Pennsylvania
    Nearly 3 times per week, I pass a giant wood pile a few miles away. There is a maple log about 40 inches in diameter laying in 4 or 5 foot lengths. I envision what a whopper of a bowl might be made and then wonder hows slow a machine would have to spin to turn something that huge. And then what kind of machine could hold something that huge to spin it. Might have to jack up the tractor and mount the piece to the rear wheel. My HF lathe only goes down to 600, so I bought an old Delta that goes down to 300 and for a 17 inch piece the 300 rpms was too fast to rough turn the outside. The lathe started walking across the floor. So I mounted a router to the out board stand and slowly turned the piece by hand, until the router had rounded the piece substantially. At least enough to spin the 300 rpms. without major vibration.
     
  8. Emiliano Achaval

    Emiliano Achaval Administrator Staff Member

    Joined:
    Dec 14, 2015
    Messages:
    2,229
    Location (City & State):
    Maui, Hawaii
    Home Page:
    I feel your pain, 850 is super fast to start a lot of things, especially side grain turning, like a small bowl. I also understand that you are hesitant about doing any work on it, I'm the same way. I had to rely on people helping me, and even then the "expert" had no idea what he was doing. You have asked for help in the right place, here we have some very smart turners willing to help. Best of luck, and let us know how it goes.
     
  9. Mike Johnson

    Mike Johnson

    Joined:
    Jul 26, 2016
    Messages:
    1,884
    Location (City & State):
    Nebraska
    You need to diagnose the problem step by step and isolate the cause. You have (4) basic components used in the lathe drive, DC motor, DC Controller, Drive Belt and Pulleys. You might want to check the drive belt dimensions to see if the correct belt was installed on your lathe. A wider profile belt will ride higher on the pulleys generating a higher output speed on the spindle. Next you would want to check your motor and spindle step pulleys and verify they are the correct dimension for your machine. Next you want to check the specifications on the motor for your machine and verify the motor is correct for your machine. Last you want to check the DC motor controller and determine if it is producing the correct output voltage for your motor.
     
  10. hockenbery

    hockenbery AAW Advisor Staff Member

    Joined:
    Apr 27, 2004
    Messages:
    6,554
    Location (City & State):
    Lakeland, Florida
    Home Page:
    Also if the belt is inside out with the the wide part toward the pulley it will add to the drive pulleys diameter too.
     
  11. Bobby Smith

    Bobby Smith

    Joined:
    Oct 23, 2018
    Messages:
    240
    Location (City & State):
    Midland, TX
    Heck Bill, I bought my grizzly just so it would be enough for me should I get into larger turning. My lowest speed on my 16" x 46" is only 590. I would have thought it would at least go down to 300.
     
  12. William Rogers

    William Rogers

    Joined:
    Mar 19, 2016
    Messages:
    582
    Location (City & State):
    Haubstadt, Indiana
    I bought the PSI replacement VS for my Jet mini. My mini was a VS, however I could not use the motor pulley supplied with the replacement. Using my pulley the speed was way too high. PSI CS walked me through how to reset the pots in the controller. Yours looks similar, so I would call their CS to see how to adjust the speed. I was able to adjust the speed all the way down.
     

Share This Page