# Need some understanding



## mjmeldrum (Sep 16, 2017)

Hello Everybody.  I'm new to the forums and a greenhorn when it comes to lathes and turning in general.  I've only taken one turning class at my local Woodcraft store, but I've been bitten by the bug!

I need to ask you seasoned veterans and enthusiasts alike for some help in understanding the differences between a multi speed and variable speed lathe.  What I thought I understood was that with a multiple speed lathe you are limited to the 5 or 6 speeds with manual adjustments to those speeds.

I'm not sure what exactly happens with a variable speed lathe when it comes to speed changes.  I thought, and maybe mistakenly so, that the changes in speed were done much like an automatic car changes gears.  So I thought you just turned a dial and you could run through the slowest speed up to the highest speed without having to manually change where the belt is located.  I was reading some information on the lathes which interest me and it seems like I may have misunderstood how speed changes are accomplished on a variable speed lathe.  Could someone please set the record straight and help me to make a better and more informed choice on the lathes I'm considering?  Thanks in advance!


Sent from my iPhone using Penturners.org mobile app


----------



## magpens (Sep 16, 2017)

You're right about multi-speed. . And I think you know what variable speed is too.

With variable speed, you don't change pulley positions of a belt or the gear positions in the headstock, which allows you to have only 5 - 15 different speeds and nothing in between those discrete speeds . . With variable speed, you use a knob like the volume control knob on an older type of stereo to set the rotational speed of the lathe to any value of speed between the minimum possible (often as low as 100 RPM or less) and the maximum possible (often as high as 3500 RPM or more).  

So you can have an infinite number of speeds between the minimum and the maximum.

You can vary the speed up and down with complete freedom and you can do that even while the lathe is turning. . Getting a speed of 1427 RPM is entirely possible but you might not be able to determine that exact speed unless you used an electronic instrument called a tachometer which "observes" the rotation of the lathe.

With a variable speed lathe, the speed is changed and regulated by electronic circuitry which alters the characteristics of the electricity which powers the lathe motor. . This electronic circuitry is "instructed" by the setting of the "volume control knob" (ie. the speed control knob).

 Being able to turn different materials and different sizes of materials may require that you change the speed of your lathe. . A variable speed control on your lathe is extremely convenient for this purpose. . You may want a lower speed for the turning of acrylic (which does not like the heat generated by high speed turning), and you may want an intermediate speed for sanding wood blanks, and after you have created the shape you want on your material by turning and sanding, you may want a higher speed to buff tiny scratches away and polish the finish you have applied to the degree of gloss that you want.

The price of a variable speed lathe is typically about $75 - $100 more than a multi-speed lathe to pay for the electronic circuitry. . But if you can afford that price difference,  you are well advised to buy a variable speed lathe. . If you don't you will be forever wishing you had one.

Hope this helps.


----------



## randyrls (Sep 16, 2017)

Michael;  Take a look at this web page for the Jet 1015 lathe (page 7) which comes in both fixed speed and variable speed versions.  The majority of inexpensive lathes that have variable speed, retain several pulleys to set speed ranges.  So you can set the speed range higher for pens, and lower for Bowls and Platters.  Just as your car transmission is designed to match the engine speed to the speed of your car as it accelerates, Electric motors have a power curve and don't work well over large speed changes.

There are true electronic variable speed lathes, but they are much more expensive. Nova DVR lathes and others are in this group.  they do not have any pulleys.

The normal lathes like the one above you can normally set the speed range and then use the knob to vary it within the limits of its range

Ask Any questions you want, this group is very helpful and friendly!

Hope this missive helps dispel the fog...


----------



## WriteON (Sep 16, 2017)

Definitely get a VS. I picked the Jet 1015 VS as the higher puller range is 600-3000+. There is also a lower range pulley I doubt I'll ever change to. Do your homework...you will regret not getting VS. I also have a Jet 1221VS.
Push the button when you are ready...however CPO outlets currently has -10% on Jet and other lathes.....free shipping/no tax.


----------



## Jim15 (Sep 16, 2017)

Welcome Michael.


----------



## JimB (Sep 16, 2017)

You understand them correctly but you are missing one piece of information.

With the Variable Speed there are also pulley changes just like non-Variable speed. 

Non-VS: example is 5 pulley settings so you only have 5 speeds

VS : example 3 pulley settings and with each pulley setting you use the VS dial for infinite speeds with that pulley. Using the 3 pulley setting gives you a greater range when needed. I my Jet 1014vs I usually just leave it on the middle pulley because that gives me plenty of speed range with the VS.


----------



## chartle (Sep 16, 2017)

JimB said:


> You understand them correctly but you are missing one piece of information.
> 
> *With the Variable Speed there are also pulley changes just like non-Variable speed. *
> 
> ...



Confused by above. 

My mini HF lathe has VS and no pulley changes. I believe there are other much more sophisticated lathes that are the same. 

Also just to be complete are there not VS lathes that are 100% mechanical and use variable diameter pulleys versus electronics.


----------



## JimB (Sep 16, 2017)

chartle said:


> JimB said:
> 
> 
> > You understand them correctly but you are missing one piece of information.
> ...



Yes, there is a HF that is VS without any belt changes. I was keeping this simple for the purposes of the question asked by the OP. 

Yes also to your second question. Here are other options.

EVS - this is actually what I was referring to above when I wrote VS. EVS is Electronic Variable Speed.

DVR - this provides an all electronic Variable Speed without any pulleys. It tends to be more expensive. It is direct drive from motor to Spindle.

Reeves Drive - I have this on my Grizzly. It is not very common these days. It uses an expanding and contracting pulley system. You change speeds by moving a lever (not a dial) while the lathe is running. The lever has indents to lock in certain speeds. I believe my Grizzly has 10 speeds.

The problem with all this is that the manufacturers are not consistent with their terminology. They often refer to all of these (belt changer, VS, EVS, DVR and Reeves drive) as Variable Speed. You need to look at the specs/details to determine what the lathe really has and what system it uses to change speeds.

I hope this helps and doesn't confuse the issue further.


----------



## BeeAMaker (Sep 16, 2017)

chartle said:


> JimB said:
> 
> 
> > You understand them correctly but you are missing one piece of information.
> ...




They can be Muilt-speed only, Variable Speed only, or both. Mine is both with 2 pulley settings 500 - 1800 and 1000 - 3800. The VS give me anything between those two sets. Without the VS I would only have 2 speeds, 1800rpm and 3800 rpm.

Multi-speed (or "more than one speed") is a mechanical change and variable speed (or "gradual speed change") is an electronic change. 

For those interested, most motors are a DC variety so the variable speed is what is known as a "Pulse width Modulation" or PWM. The speed controller varies the ON and OFF time of the motor. so at 500rpm, the motor is OFF longer than it is ON. But it does it so rapidly, we don't notice it turning off. Most LED light dimmers work the same way. So at max speed the motor is full ON. As you adjust the speed from low to high, the controller lengthens the time the motor is ON and shortens the time the motor is OFF, thus increasing it's speed. As a result, there is some power loss with VS because the time the motor is OFF, there is no torque being applied within that fraction of a second.

An AC motor speed is controlled in a similar manner, but instead of PWM, we control the Frequency. Frequency is simply how many times your motor is getting usable power per second, similar to PWM. If you have ever been to Russia in the 70's or 80's (or seen pictures) you might notice the lighting is much dimmer there with your average light bulb. This is because they run 50Hz instead of 60Hz so our light bulbs are ON 10Hz longer per second. At lower frequency, the motor runs slower.


----------



## mjmeldrum (Sep 16, 2017)

JimB said:


> You understand them correctly but you are missing one piece of information.
> 
> With the Variable Speed there are also pulley changes just like non-Variable speed.
> 
> ...





This makes more sense to me now.  I was, believe it or not, checking out the manuals of several lathes and I was finding that there were pulley changes even with vs lathe.  So, if I understand correctly some lathes have two or three pulleys and they each have a speed range.  The speed is then variable from the bottom speed of the top of the range per pulley.

Thanks for clearing that up for me.  It was a bit of a conundrum.  Happy turning to you!


Sent from my iPad using Penturners.org mobile app


----------



## mjmeldrum (Sep 16, 2017)

magpens said:


> You're right about multi-speed. . And I think you know what variable speed is too.
> 
> With variable speed, you don't change pulley positions of a belt or the gear positions in the headstock, which allows you to have only 5 - 15 different speeds and nothing in between those discrete speeds . . With variable speed, you use a knob like the volume control knob on an older type of stereo to set the rotational speed of the lathe to any value of speed between the minimum possible (often as low as 100 RPM or less) and the maximum possible (often as high as 3500 RPM or more).
> 
> ...





Thanks Magpens.  What part of Canada are you from?  I was born in Saskatoon and spent a lot of my early years in southern Alberta.  Then out of nowhere my Dad got a new job in Virginia.  Just a wee bit of culture shock there.  Lol.


Sent from my iPad using Penturners.org mobile app


----------



## mjmeldrum (Sep 16, 2017)

randyrls said:


> Michael;  Take a look at this web page for the Jet 1015 lathe (page 7) which comes in both fixed speed and variable speed versions.  The majority of inexpensive lathes that have variable speed, retain several pulleys to set speed ranges.  So you can set the speed range higher for pens, and lower for Bowls and Platters.  Just as your car transmission is designed to match the engine speed to the speed of your car as it accelerates, Electric motors have a power curve and don't work well over large speed changes.
> 
> 
> 
> ...





Thanks for help Randyrls.  The Jet 1015 is one of the lathes that I'm looking at.  The others are Rikon 70-220; the Nova Comet II 46300; and the Turncrafter 12 vs.  I expect that you may be partial to the Jet from this list.  [emoji57]


Sent from my iPad using Penturners.org mobile app


----------



## mjmeldrum (Sep 16, 2017)

WriteON said:


> Definitely get a VS. I picked the Jet 1015 VS as the higher puller range is 600-3000+. There is also a lower range pulley I doubt I'll ever change to. Do your homework...you will regret not getting VS. I also have a Jet 1221VS.
> Push the button when you are ready...however CPO outlets currently has -10% on Jet and other lathes.....free shipping/no tax.





Thanks for the heads up on the sale.  Happy turning!


Sent from my iPad using Penturners.org mobile app


----------



## WriteON (Sep 16, 2017)

mjmeldrum said:


> WriteON said:
> 
> 
> > Definitely get a VS. I picked the Jet 1015 VS as the higher puller range is 600-3000+. There is also a lower range pulley I doubt I'll ever change to. Do your homework...you will regret not getting VS. I also have a Jet 1221VS.
> ...



CPO is first class. Will stand behind everything 100%. Wait until Black Fri and it's 15%off. I wanted a second 1015 so I paid retail.


----------



## Lucky2 (Sep 16, 2017)

mjmeldrum said:


> Hello Everybody.  I'm new to the forums and a greenhorn when it comes to lathes and turning in general.  I've only taken one turning class at my local Woodcraft store, but I've been bitten by the bug!
> 
> I need to ask you seasoned veterans and enthusiasts alike for some help in understanding the differences between a multi speed and variable speed lathe.  What I thought I understood was that with a multiple speed lathe you are limited to the 5 or 6 speeds with manual adjustments to those speeds.
> 
> ...




Micheal, you're right about the 5 or 6 speed lathe, that's how they operate. For the variable speed lathe, all you do is twist the knob. You twist it to the right to speed it up, and you twist it to the left to slow it down.


----------



## leehljp (Sep 16, 2017)

Several years ago I went through this process and suddenly Jet came out with one that they called "Continuous VS" and I liked it. I checked out the specs on it and I realized that they were just using words differently than other companies. 

Their "Continuous VS" was VS from 500 though 3500+, but in 3 stages, 500 - 1500 or so, 1000 - 2000 or so, and 1800 - 3500 or so. I forgot the actually figures as this was about 7 or 8 years ago.  Needless to say, I was disappointed in their usage of word to imply theirs would do different than others using the same setup. It had "Electronic Variable" but very limited within a belt range. 

HF was mentioned as having a variable drive and Grizzly has one with a similar drive but more power. These are mechanically variable without changing the belt.

I personally like Full DVR or VFD (Variable Frequency Drives) for 2HP and larger with 220V. These drives do not need belt changing for full speed ranges with torque all the way through. Low speed 0 - 300 are for turning 14" to 18" & larger bowls. Very Low speed but high torque are needed. some of the light weight Electronic VS has less torque at their lower speeds. DVR and VFD provide higher torque at lower speeds with no or no need for belt changing.

I will add in that for some people, changing belts for changing speed gets to be a pain after a while if you do much speed changes, such as is used in making pens.


----------



## mjmeldrum (Sep 17, 2017)

leehljp said:


> Several years ago I went through this process and suddenly Jet came out with one that they called "Continuous VS" and I liked it. I checked out the specs on it and I realized that they were just using words differently than other companies.
> 
> Their "Continuous VS" was VS from 500 though 3500+, but in 3 stages, 500 - 1500 or so, 1000 - 2000 or so, and 1800 - 3500 or so. I forgot the actually figures as this was about 7 or 8 years ago.  Needless to say, I was disappointed in their usage of word to imply theirs would do different than others using the same setup. It had "Electronic Variable" but very limited within a belt range.
> 
> ...





Thanks Lee.  That's was great information.  It sounds like the similar type of wordsmithing is still in use.  [emoji6]


Sent from my iPad using Penturners.org mobile app


----------



## magpens (Sep 17, 2017)

Hi Michael,

I was actually born in Regina and have lots of relatives in Saskatchewan.
Dad was in the army at the time, got transferred to BC where we settled after the war.  I have lived here ever since, except for 12 years in Australia during the 60's to 80's.

I have a son living in Bow Island in southern Alberta; another in Winnipeg.

Cheers,
Mal




mjmeldrum said:


> magpens said:
> 
> 
> > You're right about multi-speed. . And I think you know what variable speed is too.
> ...


----------



## KenV (Sep 17, 2017)

Variable speed motors have a down side.  As motor speed decreases, the torque from the motor decreases.  The type of motor and the paired controller makes a differencec in the amount of torque loss, and in general the lower the cost, the more loss of torque as speed drops.

As motor speed drops below about 50% the torque loss increases.  Using mechanical advantage of different sheeves is a design method to offset the torque drop as motor speeds decrease.   My large lathe with a 2 hp variable speed drive wll go very slow.  At 15 rpm, one revolution in 4 seconds I can stall the headstock with my hand on the handwheel.

If you want effective power (torque) at lower speeds, you need to use sheeves or money.  Sheeves give mechanical advantage and money gets you better motor/controller technology.

The PSI replacement variable speed motor and rectified power supply - controller needs sheeves below 50% motor speed (yes, I have one).   Permanent magnet motors a bit less so, and,so forth.

There are small lathes on the market now with VFD drives (Barry Gross at Az Sill is selling them).  The price is up around $1000.






.


----------



## mjmeldrum (Sep 17, 2017)

KenV said:


> Variable speed motors have a down side.  As motor speed decreases, the torque from the motor decreases.  The type of motor and the paired controller makes a differencec in the amount of torque loss, and in general the lower the cost, the more loss of torque as speed drops.
> 
> As motor speed drops below about 50% the torque loss increases.  Using mechanical advantage of different sheeves is a design method to offset the torque drop as motor speeds decrease.   My large lathe with a 2 hp variable speed drive wll go very slow.  At 15 rpm, one revolution in 4 seconds I can stall the headstock with my hand on the handwheel.
> 
> ...





Thanks for the explanation of torque loss.  You sound like one smart man!  Cheers.


Sent from my iPad using Penturners.org mobile app


----------



## nava1uni (Sep 23, 2017)

My first lathe was not an electronic variable speed but had two pulleys that gave me a combination" bowl with no bogging down of the motor.  I also have a Nova DVR XP with a complete range from 100 to 3200 rpm


----------

