1.5 hp vs 2 hp

[Gary Conklin]

So I am looking into the Jet 1642 and am curious, does a 1/2 hp really make that much difference? I am not currently wired at 220 v in the shop, but would like to down the line. Just curious if the extra 1/2 would make that much difference to justify 1. the cost of the machine 2. the cost to wire in 220?

[Reed Gray]

All of the woodworking books that I read when first starting out said that any motor 1 hp and below would work fine on 110 current. Any motor 1 hp and above would work better on 220. I did have 2 of my machines rewired for 220, a 1 hp PM jointer, and a Performax 1.5 hp drum sander. There was a definate difference in performance.

You can get buy with the 1.5 hp Jet. It will do a fine job, but you need a dedicated 20 amp circuit. The motor could probably be rewired for 220 as this seems to be standard on that size motor. As some one who did concrete work for 30 years, I prefer things to be overbuilt. I would go with the 2 hp.

robo hippy

[David Christopher]

Gary, my lathe is 1 1/2 HP and I have turned 18" pieces and have never bogged it down.......more HP is always nice but not always necessary

[Scott Hackler]

I have the Nova 1624 and its rated at 1.5 HP and its a 110v machine. I cant imagine why I would need the etra .5 HP. I just turned another monster bowl last night (14" dia x 8" tall) and it handled it like a champ. Now having said that, the 220v will draw less amps and I did run a conduit for "future" posibility of a bigger lathe. I just dont know why I would need a bigger lathe, at this point.

[Mike Lipke]

I had a 1.5 and never need more power. One thing: Not only should it have its own circuit, if possible, but it cannot be a Ground Fault protected circuit. Motor controller trips it out almost instantly.

[Don Orr]

I have the 1.5 HP Jet 1642 and like it very much. However, I can stop it when hogging off wood if I get real aggressive. I'll qualify this by saying I usually have the belt on the faster pulley set which results in lower torque. I almost never use the lower speed pulley set so I can't really say if I can stop my lathe on that setting. I have not tried the 2 HP version so cannot speak to that.

I bought my lathe before I had my current shop and did not have access to 220v power at the time. I would most likely go for the 2HP if money and power outlet were not an issue. Either way you are going to like this machine.

[Alex Shanku]

All of the woodworking books that I read when first starting out said that any motor 1 hp and below would work fine on 110 current. Any motor 1 hp and above would work better on 220.

Thats simply incorrect.

[Bernie Weishapl]

I don't have 220 V in my shop so running 1.5 hp 110 V and have not had a problem in 3 yrs of using it. Yes 220 V might be nice but didn't want to go thru the expense of rewiring the shop.

[Scott Hackler]

I believe the different makers are rating thier HP differently, because my Nova 1624 (1.5 HP, 110v) would likely snap your tool and your wirst off before stopping. Loads of power. I have even hogged out some big bowls, very aggresively, with a 1/2 HD scraper and it never shows signs of slowing down, let alone stopping.

FYI.

[Montgomery Scott]

I have the 1642-1.5 and the only time I have bogged it down it when doing very aggressive cutting with the Ci1 rougher (belt was on the larger, slower pulley) in a 12" dia wet cherry blank. That thing removes a lot of material in a very short amount of time. At the time the 1642-1.5 was $1299 including the bed extension and the 2hp was $400 more. At that point the decision would have been either the 1642-1.5 or the PM 3520. I sometimes wish I had the extra swing but 16" is pretty good.

[Bob Bergstrom]

We really could use someone with an electrical back round (not me). I was told once that 220 does not provide more power, but is just more economical. I have a 3520. The 2 hp. really comes in handy if turning over 16". It seems the stall factor becomes exponential.

[Rich Aldrich]

The real difference between 110V and 220V is that with 220V half the current (amps) is required to get the same horsepower out: Power=Voltage x Current Wired for 220V, you can use smaller wire size. The power is the same. You do not save on electricity bills either. If your service is close to max current, you might be better off to wire for 220V, but I would be surprized if this is an issue.

I am a gear head (mechanical engineer) - sparkies (electrical engineers and electricians) will have more qualified input.

[Jeff Nicol]

Just to add to Rich's post, as he is right on with his information. With the motor wired for 220 it can be worked a little harder and longer before it will heat up and that can be a positive if you are really hogging out a bunch of bowls. Horse power is the same but like Rich said the motor will be more efficient. I just bought a 220V small mig welder and it has more duty cycle and welding power at power level 2 than my 115V at high power so that may give you another comparison of sorts.

Jeff

[Brian Novotny]

Think about it el cheapos.....your going to spend $2000 on a lathe, but having 1 outlet rewired for 220v. is an issue????? Please tell me if I'm wrong here, but don't you save ALOT of electricity running on 220? I guess that's not much savings if this is a weekend thingy, but if it is, why do you need a $2000 lathe?

[Richard Madison]

Gary,
If the 2 hp motor on the PM3520 is adequate (most of the time), it seems reasonable to assume that the 1.5 hp on the 1642 is also adequate (most of the time). That said, I still bought the 2 hp just so I would never have to wonder if I shoulda bought the 2. So for me it was a "mind" thing and had nothing whatever to do with hp or electricity. If dollars are a significant issue and you will also have to pay an electrician to install a 220 circuit, you would probably be well satisfied with the 1.5.

Edit: For ref. I wired my own shop, so it has multiple 220 circuits including six outlets in the ceiling.

[William Payer]

Think about it el cheapos.....your going to spend $2000 on a lathe, but having 1 outlet rewired for 220v. is an issue????? Please tell me if I'm wrong here, but don't you save ALOT of electricity running on 220? I guess that's not much savings if this is a weekend thingy, but if it is, why do you need a $2000 lathe?


Pulling 15 amps at 110v consumes exactly the same amount of wattage as 7.5 amps at 220volts, so there is no savings whatsoever. The only advantage I have ever heard of for using 220 volts , other than the motor being specifically wond only for 220 , is that motors tend to run more efficiently (not necessarily less wattage, but slightly more hp produced).

[Wilbur Pan]

I believe the different makers are rating thier HP differently, because my Nova 1624 (1.5 HP, 110v) would likely snap your tool and your wirst off before stopping. Loads of power. I have even hogged out some big bowls, very aggresively, with a 1/2 HD scraper and it never shows signs of slowing down, let alone stopping.

One of the major differences between the Nova 1624 and a lot of modern lathes is that the 1624 gives you low RPMs using a belt/pulley system, while many other lathes with electronic speed controls give you low speed by slowing down the RPMs of the motor. This is very conveneint, but by slowing down the RPM of the motor, you lose torque. With a pulley system to drop the RPMs, you don't have the same loss of torque.

For example, suppose you have a 1.5 HP 1750 RPM motor on your lathe with a belt and pulley system to change speeds, and you have a pulley combination (1:8.7 ratio) that will rotate your workpiece at 200 RPM. The torque on your workpiece will be 39 ft-lbs.

On the other hand, take the same 1.5 HP 1750 RPM motor. The torque of that motor running at full speed is going to be 4.5 ft-lbs. Put a VFD on it, and slow down the motor RPM to 200 RPM. Most VFD keep the torque constant as they slow down the motor. So at 200 RPM, the motor is still giving you 4.5 ft-lbs of torque, much less than letting the motor run at 1750 RPM and using pulleys to drop the RPM at the lathe spindle. If you back calculate, you'll find that in the second case your 1.5 HP motor will actually have 0.17 HP at that low speed.

This is one big advantage of pulley systems for speed changes on a lathe -- you don't lose power at low speeds. This is also why lathes with electronic speed controls do benefit from higher HP motors -- if you start at a higher HP, you have more HP as you slow the lathe down.

[Jim Becker]

Wilbur, I've never noticed any perceived lack of torque at even "almost stopped" RPMs on my 2hp Stubby and I've put some pretty big things on it! The three-phase motors used on these machines with Variable Frequency Drives really work well, IMHO, and being able to adjust just a few RPM in either direction can often eliminate subtle vibrations for a finer finish cut.

[Wilbur Pan]

Jim, I didn't want to complicate the discussion too much, as three phase motors that are used with VFD systems do have more torque than their single phase counterparts, but the point remains that dropping the speed with pulleys acts as a torque multiplier, which leads to more or less the same HP as you lower the speed, while a VFD maintains a constant torque, resulting in a loss of HP at lower speeds.

I took a peek at the Stubby website to check out the specs. It looks like that the 2 HP Stubby has a 3700 RPM motor, and a pulley ratio of about 1:2.7 for the low speed spindle. So if you take your Stubby, hook up the belt to the low speed spindle, and drop the speed to 200 RPM, my back of the envelope calculations show that you might have about 0.3 HP at your workpiece. Now, that may be more than enough for roughing out a blank, but it's still not the full 2 HP that your motor can generate.

It may be that the usual advice of wanting lots of power at low speeds for a lathe is a bit overrated. My feeling is that increased power may just be a way to compensate for dull tools, less than perfect technique, or to be able to hog off a thicker shaving than you otherwise would be able to.

And I do agree that VFDs have great advantages for exactly the reasons you state. Converting the pulley speed change system on my Conover lathe to a VFD is definitely on my list of things to do, even though I know about the power loss with lower RPMs.

[Tom Steyer]

Two year owner of 1642-2hp. Very happy with it, and it was about $200 more that 1.5 at the time. You can never have too much power - mine is almost impossible to stall, even in "high" pulley range. If you are going to 220v anyway, all other things being equal (or close), buy the 2hp and get turning!

[Richard Madison]

Just for reference, torque (at whatever rpm) is what causes the spindle to rotate, not hp. Let's say that one ft.-lb. of torque at 100 rpm requires (or is equivalent to) "P" horsepower. The actual numbers do not matter in this example. That same one ft.-lb. of torque at 1000 rpm requires (or is equivalent to) 10P horsepower. But the ability of that one ft.-lb. of torque to rotate the spindle against the load (as applied by your bowl gouge cutting the wood) is exactly the same, even though the rpm and horsepower differ by a factor of ten. Now we just need a EE to show us the torque curves for modern single and three phase induction motors.

[Phillip Bogle]

I spent the better part of 20+ years running printing equipment and that may not translate to the right conclusions. I did notice that the presses and other machines that used 220 ran smoother, and cooler. I could tax the limits of a motor in 110 much faster than 220. The 110 motors would not last as long as either 220 or 3 phase motors. In any case, I was always taught that heat was to be avoided since heat destroyed motors. Any sort of excess strain or work load that a motor has to perform will cause heat increase and contribute to motor wear. That all said, most of us seldom use our equipment as much as we want to, much less using enough to cause breakdown. Just my thoughts on the subject.

[Skip Spaulding]

Gary, I have a Nova 1624 11/2hp, most of the time it is fine. I've decided to add a vfd so I ordered a 3ph 2hp 208/230v inverter duty motor to replace my 11/2hp 110v motor. I have found that a little more hp when using my McNaughton bowl coring system would help.

[Reed Gray]

Alex,
I am no electrical engineer, but that is what I read. Bigger motors need more voltage, and amperage to run better. It was a long time ago, but I read it in a couple of sources on selecting tools for the shop. Why do you disagree, or what do you know that I don't? You can run a 1.5 hp motor on 110, but it really does work better on 220. My understanding is that with 2 leads in, if you start to strain the motor, it can draw the extra needed amperage from 2 wires, not just one, and this is what makes it more efficient. A 15 amp motor will require maybe that much to start up, but with no load will draw much less amperage, maybe half. When you put a load on it, it draws more amps.

As to amount of torque, for me agressive turning is a 1 1/4 inch by 1/2 inch thick scraper fully engaged into the metal. No problem stalling the Nova, Robust, or PM. I was talking to Bill Grumbine and he said pretty much the samd thing, he even stalled a VB36. For highest torque, you need higher horse power, and lower pulley ranged speeds. Keeping the torque at higher speeds is much more difficult as the diameter of the bowl increases. Much easier to stall a lathe with an 18 inch bowl on than with an 8 inch bowl. Don't think I have ever stalled one while spindle turning though.

Do you need more horsepower? For most people, probably not. For production efficiency, yes, it comes in handy.

robo hippy

[Thom Sturgill]

Take this for what its worth, as I currently turn on a 1220. I find the 1220 (3/4hp VS) a little underpowered. I hear the same complaint about the 1236 (also 3/4hp, but not VS). The 1442 is 1hp and the complaints seem to center around the reeves drive NOT the power. And I have never read any 1642 owner complain about not having enough power. That leads me to think that 1 1/2hp is probably over the treshold unless you are turning really BIG stuff, in which case you probably need more than 16" swing.

At $450 difference (woodcraft prices) between the 1642 and the 1642-2, I would be hard pressed to justify the extra since there does not seem to be any other differences such as heavier bearings or castings. But then again, at 60 and a heart attack survivor, I don't expect to be lifting and turning any thing the 1642 can't handle.

[Philip Morris]

Keep in mind that the 1642-1.5 and the 1642-2 are both powered by 3-phase 220v motors (see page 8 of the owners manual). The difference lies in the VFD inverter. The 1.5hp inverter takes single phase 110v power and converts it to 3-phase 220v power. Whereas the 2hp model takes single phase 220v power and converts it to 3-phase 220v power.

What this means is that it will be very expensive to convert the 1.5hp model to run on 220v shop power. So besides asking if you "need" that extra 1/2hp, you should also ask if the flexibility of being able to plug the lathe into any wall outlet has value.

[Gary Conklin]

All very valued feedback. I still don't know which way I want to go, but it has given me more to think about. I do like the thought that the 1.5 is plug and play, but the 2 seems like it might be the better way to go. I am alos tryin to keep in mind the resale value for the future upgrade. I would think that most folks don't have 220 so in that thought the 1.5 sounds better. On the flip side if I get the 2 now the future upgrade may be delayed a little longer. Still thinking and waiting for a sale or a good used deal to make my mind up in the meantime.

[jason lambert]

I think you need to find someone with the situation you have that have tried both to really get a good answer.

Motors ratings and quality of motors can very so not every 1hp motor is the same and this measures max tork NOT tork at the RPM's we normally turn at. Variable speed lathe motors are a totally different animal than a jointer or bandsaw motor just keep that in mind.

It is possible that machines under a constant load run better on 220, just as they would run better and more efficent on 3 pahse this is because there is less pulsing of the motor. Now a jointer with a good heavy head taking off 1/32 I doubt you will notice it. A performax drum sander that is under load with a aluminum drum you may. But again machine and motor dependent. I wuld say there is a difference on the lathe but I am sure the 110 is fine if it where not people would not but the machine. On that note I did rewire to 220 and am glad I did because I have several machines that use it and I don't run on 110 so I would of had to do it at some point.

[Philip Morris]

Jason,
Keep in mind that both motors are 3-phase 220v. The main difference is the input voltage to the VFD inverter.

Gary,
I currently have the 1.5hp model Jet 1642 and find it very adequate for turning anything within the lathe's capacity.

I downsized from a Oneway 1640, 2hp, which ran off of 220v. The Oneway base motor is rated at 1.5hp, with the option of upgrading to 2hp. I ordered mine with 2hp since I was not sure what I would want to do with it. Oneway said that I would primarily appreciate the difference if I was coring or deep hollowing. The guy that bought my Oneway likes to hollow monster birdhouses with a 4" diameter Forstner bit. He also added the outboard extension to swing 24". He needs the 2hp motor.

[Rod Sheridan]

Electrical technologist here, the motor is actually a 120 volt motor, there just happen to be two 120 volt windings in the motor.

Assume that we have a 120/240v motor 15/7.5A

If you run it at 120 volts, the two windings are in parallel and each winding will draw 7.5 amperes, so 15 amperes total at 120 volts.

If you run it at 240 volts, the windings are in series, each has 120 volts, and the 7.5 A current flows through one winding, through the other and out of the motor.

This yields 7.5A at 240 volts.

In both cases, the motor windings had 120 volts applied, and 7.5 amperes of current.

The motor losses (heating) was identical in both cases.

Where a motor "runs better" on 240 volts, it's due to an inadequate branch circuit.

The motor has no change in performance running on the two voltages.

regards, Rod

[Richard Madison]

Thank you Rod. Now tell us about single phase vs. three phase motors. Am pretty sure I still have my EE101 text somewhere, but am not up to searching for it.

[Ryan Baker]

Realistically you will probably be happy with either. If you are planning on doing coring, definitely get the 2HP because you will want every bit you can get. Otherwise, get what you can afford. Of course, anything you upgrade to in the future will definitely be 220, so you will need the wiring eventually anyway...