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View Full Version : Jet Fixed versus Jet VS



Jon Shively
01-16-2007, 12:17 PM
I did not want to steal the thread below about lathe choices, but did notice Bill's comment, "The Jet mini (fixed speeds, NOT the VS -- please don't get the VS)". So my question is, is the fixed speed the one you manually change the belt on the pulley and the VS has the Variable Speed (thus the VS) option? If so, what is the rationale for the emphatic declaration? I am looking for a smaller second lathe to turn small items on and have for guests (my daughters, their boyfriends, my nephew and a few buddies that stop by and drool but live pay check to pay check poorly). I like the reeves drive option on my Craftsman so was thinking of spending the extra money on the VS until I read that. So, what gives?

Ken Fitzgerald
01-16-2007, 12:23 PM
Jon...I have the Jet VS......On both systems you have to change the belt. On the VS you change the belt to get to a different speed range....The VS uses a DC motor and at low part of each range it has reduced power...This means you can almost stop the thing by grabbing the handle with your bare hand. Myself....I like being able to change the speed using the VS knob....so I'd take a VS..but ...the non-VS will exhibit more hp at lower rpms as it uses an AC motor.

Some of the larger lathes, it is my understanding, use AC variable speed and don't lose horsepower at the lower rpms....

Gordon Seto
01-16-2007, 2:04 PM
I like the reeves drive option on my Craftsman so was thinking of spending the extra money on the VS until I read that.

Jon,

The Reeves drive is an antiquated speed change design. There has not been a new lathe (except clones) with Reeves drive for a long time. I would rather have a manual speed change than that.
The electronic variable speed is a very nice feature to have. It is a very desirable feature on a big lathe. The down side is that it lacks torque on low speed with small HP motor. You can't hog out as aggressively at low speed on VS small lathe. You may have to take lighter cuts.
If you intend to maximized the capacity of your mini lathe with unbalanced blanks that you have to rely on the slowest speed alot, then you may want to give up the VS.
But if you have a second bigger lathe for horsepower hungry work, then the VS is a big convenience feature. It allows you to do small off-balance multi-axis turnings, the convenience to sand at low speed. If I don't have VS, probably I would be too lazy to change speed during sanding even if it only take less than 30 seconds.
I have VS on my mini.
Gordon

Bart Leetch
01-16-2007, 3:48 PM
I have played with the Jet VS they are ok.

I was given a Jet with step pulleys & its quick & no problem to change the belt from 1 speed to the other.
I have turned on this style of lathe since childhood so I haven't gotten to spoiled to change the belt myself.:D

Bernie Weishapl
01-16-2007, 4:01 PM
I can't see spending the extra money when it only takes 30 seconds or so to change speeds.

Gordon Seto
01-16-2007, 4:17 PM
I can't see spending the extra money when it only takes 30 seconds or so to change speeds.

It is extremely useful if you are turning unbalanced blanks like in multi-axis turning. You can safely increase the speed slowly till the lathe shakes, then back of a tad.

Gordon

Ken Fitzgerald
01-16-2007, 4:50 PM
Bernie...I often use my when finishing on the lathe....I apply lacquer with a brush at slower speed.....Turn up the speed and let it spin for a minute or so....then friction at the faster speed........

Jim Underwood
01-16-2007, 5:08 PM
I have the FS Mini, and I love it. I don't find it's that big of a deal to change speeds.

I don't think the VS mini is worth the extra $. If you're paycheck to paycheck, save your money and get the FS, and spend the balance on a chuck or some turning tools.

If I was going to get a VS, I think I'd get a larger lathe too.

Bill Boehme
01-16-2007, 6:14 PM
Since I made the statement, I should explain what I meant. First of all, the Jet variable speed lathe is a very nice machine. However, its VS conveniece comes at a price in output torque at the low speed end. It is not a design deficiency -- it is merely the nature of the beast -- unlike an AC motor, the speed of a DC motor is determined by the voltage applied to the motor and the motors torque is determined by the amount of current that the motor draws -- sounds good so far, but there is a catch -- a variable speed controller on a DC motor is able to controll the voltage to give the desired speed, but it cannot do this while also keeping the current constant to maintain a constant torque. There are several factors that limit the current as voltage is decreased -- the most significant of which is motor winding resistance. Since the resistance is a constant, the current limit is a direct function of applied voltage.

For some uses like pens and other small diameter things, the convenience of the VS may outweigh its shortcomings. If you want to turn larger things like bowls, you may find that you are continually stalling the lathe until you develop a very light touch to compensate for the weak low speed torque.

Bill

Ken Fitzgerald
01-16-2007, 6:22 PM
Bill...........You and I agree! I don't want you to think otherwise!

Travis Stinson
01-16-2007, 7:25 PM
I feel like I need to defend the Jet VS mini. Of course you can't hog off wood and be heavy handed with it, but using sharp tools and a light touch (important no matter what size lathe you use IMO), it CAN do the job. All these were turned with my VS mini (which I love!;) ).

Gordon Seto
01-16-2007, 8:07 PM
All these were turned with my VS mini (which I love!;) ).

Stole from some guy's signature line:

Its not the arrow; its the Indian.
We have also seen cake pans out of Oneway 2436 or the likes; the only compliment was "nice wood".

Gordon

Bill Boehme
01-16-2007, 11:27 PM
Ken and Travis,

I didn't mean to "dis" the VS Jet mini (nor those that use them) -- why, heck, I even have friends with whom I am on speaking terms and who have and use VS mini lathes.

There are design tradeoffs in whatever lathe that you get and I was just attempting to give a technical explanation in my last post of what the design tradeoff is for having a VS DC drive. We all already know what the disadvantage is for a fixed speed drive. Cost also enters into the personal deliberation of which to get. And that is where my personal bias of spending a lot more $$$$ for something of questionable value to me led me to make the statement, ".... please not a VS".

One of my friends uses his VS Jet for demos just to avoid the interruption of stopping and changing the belt to a different pulley pair. He said that doing so always led to a side discussion of when to change speeds and what exactly the speed ought to be, yada, yada, yada. This is nicely sidestepped with a VS mini because he can say something like, "I don't have any idea what speed the lathe is running at".

And finally, I will certainly agree with Gordon that it is not the arrow, but the Indian. When I got my Jet mini, I discovered that I could use it to turn 90% of the stuff that I made on my larger lathe -- I just needed to do like Travis said and use more finesse and less muscle -- just because it is a fixed speed Jet mini doesn't negate the fact that the motor is still a wimpy half horsepower.

Bill

Ken Fitzgerald
01-16-2007, 11:58 PM
Bill............we do, in fact, agree. The dc vs has it's short comings...but it also has it uses too! I didn't have to make the decision as the idiots here gave me mine about this time last year. I do find it useful...the vs....and at the same time that is it's short coming.......As someone stated earlier..I'll start an out of balance bowl blank at the lowest speed...turn up the speed until I get some vibration and then back it off. If it's really out of balance ....I leave it at it's lowest speed. I do like it...but it does have it's short comings......dc variable speed that is........All in all.....it's a good little lathe....Would I pay extra bucks for it?...........I don't know....I didn't have to make that decision....:)

Gordon Seto
01-17-2007, 1:20 AM
If it's really out of balance ....I leave it at it's lowest speed.
Ken,

Pieces are out of balance because they are not round yet. You are cutting wood-air-wood.... In an interrupped cut, you lose bevel support when your gouge is cutting air. The more you turn, it became closer to balance. Therefore it is safe to bring the speed up. When the speed is faster, the duration of lossing bevel support is shorter. We can get a much cleaner cut.

With that said, the VS mini lathe is not an ideal lathe for out of balance work except off-center spindle. When you consider:
relative light weight
slowest speed of 500
anemic horse power at low speed

Gordon

Ken Fitzgerald
01-17-2007, 1:40 AM
Gordon......I realize what's causing the out of balance...wood ...air wood...but it's currently the only lathe I have. Given the alternative of turning on the lathe or not turning......I'll turn on the Jet VS Mini.....until I get a larger lathe to go with it........Then I'll still use it for smaller stuff.

Don Henthorn Smithville, TX
01-18-2007, 9:59 PM
is that the extra money doesn't buy you anything but convenience. The minimum speed is till the same as the non vs lathe. As someone has mentioned, you still have to change the belt for the different ranges and how often does one need to change the range? Not often for a lathe with that kind of minimum speed limitation.

Of course, with the help of Mark Kauder, I converted my lathe to true variable speed which gives a 0 to "whatever" speed range as well as the other ranges that the VS model gives. If I were going to buy a Jet mini today that is the route I would take.