Lathe Motor 3hp vs 2hp

[William Rogers]

I'm thinking about upgrading my lathe to a larger lathe. I have a Laguna 18-36 with a 2hp motor. Based on electrical calculations it is a true 2hp. The lathe has done everything I have asked, but looking for a little more capacity. Yes, I can stall the 2hp if I try, but not really an issue. I have heard others say they also stall 3hp lathes. I don't do coring and no plans to do so.

So is the 3hp just for bragging rights, or is there a real value to 3hp.

 

[Roger Chandler]

If you turn large heavy wood like I do a lot, the extra horsepower and torque generated will allow for the lathe to not bog down as easily at low rpm's. I had a 2 hp 18/47 lathe that I sold before I got my current 3 hp lathes, and can definitely tell the difference on heavy pieces. I could bog down my 2 hp motor a lot easier than now, with my 3 hp lathes. It has only happened once or maybe twice in 5 years with my G0766, and that was coring, which stresses the lathe more than most any other activity, and I have not as of yet bogged down my G0800.

 

[robo hippy]

For production work, the 3 hp has some advantages. Biggest thing for me is that I want speeds of over 1500 for turning the smaller bowls. Slow speed ranges don't go that high, and in the high speed range, they tend to bog down when coring...

robo hippy

 

[Dennis Weiner]

In general, an overspecified HP motor running at similar loads to a lower HP motor(all things being equal) should, in theory, run cooler under less stress and thus last longer. Resale may also be advantageous.
I was advised on 2hp ow 2436 in 2000. I never needed the additional HP but on occasion had to ramp down to the lower pulley to obtain more power.
I Don't know if it is cost justifiable but higher HP ownership feels better. <grunt grunt grunt>

 

[odie]

I Don't know if it is cost justifiable but higher HP ownership feels better. <grunt grunt grunt>

Yes, it does "feel better"......but, is it actually better?

One of the foundational principles of wood is.....it ain't steel!.....huh?

Wood compresses as it's being cut, and when you make those big humongous cuts, what you are actually doing is disrupting the fibers of the wood beneath the surface of where the cut is taking place. It is important to understand, or envision this, because it reduces the ability of the wood to take on that really nice final, and extremely fine sanded surface.

It is better to take smaller lighter cuts that aren't so traumatic to the wood itself.

-----odie-----

 

[Richard Coers]

Yes, it does "feel better"......but, is it actually better?

One of the foundational principles of wood is.....it ain't steel!.....huh?

Wood compresses as it's being cut, and when you make those big humongous cuts, what you are actually doing is disrupting the fibers of the wood beneath the surface of where the cut is taking place. It is important to understand, or envision this, because it reduces the ability of the wood to take on that really nice final, and extremely fine sanded surface.

It is better to take smaller lighter cuts that aren't so traumatic to the wood itself.

-----odie-----

You take light cuts while roughing? I'd think everyone agrees that you need to take light finishing cuts after hogging off the waste. On large 18-24" diameter work, most folks could stall 5hp. But that sure wouldn't be needed for those light form defining cuts.

 

[hockenbery]

Wood compresses as it's being cut, and when you make those big humongous cuts, what you are actually doing is disrupting the fibers of the wood beneath the surface of where the cut is taking place. It is important to understand, or envision this, because it reduces the ability of the wood to take on that really nice final, and extremely fine sanded surface.

I agree that taking the light cuts is essential for a smooth finished surface.
Your roughing method may compress the wood, mine does not.

I use a non bevel riding roughing cut - there is little if any compression - nothing presses on the wood.
What does happen is there is tear out some of it rather deep. 1/8” or so.

It is important to transition to the finish slicing cuts when a 1/4” - 1/2” of wood is left for removal.

I do it in a progression. 3/4” roughing cuts bevel not riding,
1/4 bevel riding slicing cut
1/8 bevel riding slicing cut
1/16 bevel riding slicing
1/32, 1/64, 1/128.... then shear scrape

When you work with large blanks you don’t want to rough with 1/4” cuts.
A 3/4” cut will slow down or stop a lot of lathes.
A 3 hp will let most people take a 1” cut.

 

[odie]

You take light cuts while roughing? I'd think everyone agrees that you need to take light finishing cuts after hogging off the waste. On large 18-24" diameter work, most folks could stall 5hp. But that sure wouldn't be needed for those light form defining cuts.

Shall we say roughing cuts are done "light-er" than most. Just because you can, doesn't mean you should......for the very reasons I mentioned.

-----odie-----

 

[Bill Boehme]

No pigging out here ... when it comes to roughing out the shape, I'm not a hog. As Odie said, just because you can doesn't mean that you must. The only time that I've ever "stalled" the lathe was when a coring blade got stuck. Actually, the motor didn't stall ... it kept going while the belt squealed.

 

[Bernie Hrytzak]

it kept going while the belt squealed.

Yes, thats one way of refreshing the belt surface.

 

[William Rogers]

Thanks for the response. I decided my next lathe will be a 3hp. My old lathe (PM 90) was a 1hp. For a 12" swing it was OK. I raised that lathe to 18" swing and could tell it was under powdered with larger blanks. My current lathe has 18" swing and 2hp. For the most part has performed well, but I don't core. A 3hp on a 18" swing lathe would be overkill IMO. However on a 24" lathe it would be a better fit. I want to avoid that "I should have" thought. Odie, I don't take heavy cuts, however I want to feel better.

 

[Bill Boehme]

Yes, thats one way of refreshing the belt surface.

But, it was a brand new belt.

 

[robo hippy]

When roughing, especially for production work, I just want bulk out of the way. This is a different cut than finish cuts, which are more 'dainty'. With the scrapers I use, there is no wood compression and the cutting edge does not come out of the wood, just back and forth till desired shape is achieved. It isn't pretty, but it is efficient. For the recreational turner, then turning using pretty much a finish cut with each pass is excellent practice.

I haven't met a lathe I couldn't stall yet. For my roughing cuts, I cut as fast as the lathe, wood, and tool will go. Pretty much keeping the cuts on the edge of stalling the lathe.

robo hippy

 

[odie]

Odie, I don't take heavy cuts, however I want to feel better.

If you follow what anyone else has to say, when your heart says something else.....you will be eternally unhappy with that decision!

I follow my heart, and end up doing and believing many things that others overwhelmingly disagree with......but, I've always figured the results I get are worth my straying from the "herd think". (A lot of people are bothered by my use of the word "herd"......nevertheless, I believe the concept is real, and it influences many to stay within the corral.....whether they are aware of it's influence, or not!)

-----odie-----

 

[hockenbery]

lot of people are bothered by my use of the word "herd"......nevertheless, I believe the concept is real, and it influences many to stay within the corral.....whether they are aware of it's influence, or not!)

“Herd” doesn’t bother me. I just don’t know what experiences you base your herd concepts on,
How often have you walked among the herd?
How many of the Herd have you met? How many instant galleries have you seen? how many demonstrations have you seen.

Some people don’t see the trees for the forest
Other don’t see the forest for the trees.

When I walk through 1500 pieces in an AAW instant gallery I am overwhelmed by the individualism of the creators.

I am quite confident you would hard pressed to define any herd think that could produce what you could see in the Raliegh instant gallery.

 

[odie]

When I walk through 1500 pieces in an AAW instant gallery I am overwhelmed by the individualism of the creators.

Oh, but I agree wholeheartedly, Al.......I really do, however, the creativity you are seeing is overwhelmingly the product of embellishment. I am very much so an appreciator of great embellishment. I see outstanding creativity, just as you do. What I see in the instant galleries, is great stuff......absolutely......but very simple shapes in cross grain bowl turning with great amounts of sanding. Just take a quick look at the AAW gallery here for a quick fact-check synopsis. I do see a lot of great spindle turning with terrific tool control, but the dynamics of spindle turning vs bowl turning are like comparing apples and oranges.

-----odie-----

 

[hockenbery]

but very simple shapes in cross grain bowl turning with great amounts of sanding.

You have to go see an instant gallery. Some cross grain surfaces are not even sanded.

The NE bowls can’t take any sanding and maintain their shape and wall thickness
Can’t sand a box joint.

A great curve cannot take much sanding.
Flats are easy to sand true with sandpaper on a board. Segmented turners do this frequently.

Can you sand a bowl a lot Sure. many beginners use 80 grit. Some production turners just sand because it is quicker.

The tool finish you see in most demos is pretty darn good.

At the Florida symposium a few years ago James McClure and I did an entertainment demo of a 11” bowl in 20 minutes. I turned the outside with a turned bead below the rim.
James hollowed the bowl and I turned off the bottom. We finished in a bit over 21 minutes.
Nick Cook was asking why we took so long.

They couple who bought the bowl at the auction gave me annual reports on it for several years.
They did not sand it just put oil on it an used it just about every day.
They were happy with it.

I would have sanded it with 220 and 320 but it was easy cutting maple and the tool surface was good. It was helped by being fairly small bowl. Tool finish on small bowls is usually real good.

 

[robo hippy]

"I agree that taking the light cuts is essential for a smooth finished surface.
Your roughing method may compress the wood, mine does not.

I use a non bevel riding roughing cut - there is little if any compression - nothing presses on the wood.
What does happen is there is tear out some of it rather deep. 1/8” or so."

Trying to figure out this 'insert quotes thing..... Anyway, I had to ponder this a bit. I am getting ready for a basic bowl turning demo in Washington next week. I will be turning on a long bed lathe (Sweet 16) which will be a challenge, and since it is 'basic' I have to use gouge skills that I don't normally do. One essential skill involves trying to learn "The bevel should rub the wood, but the wood should not know it." Easier said than done. We have a tendency, when doing roughing cuts with gouges, to push really hard on the bevel, which does compress and bruise the wood. This also adds to making the bowl out of round when turning the inside. You can put more 'push' into the wing and nose, and less on the bevel, which makes for a deeper cut with less damage to the wood.

Not sure how you can do a 'non bevel rubbing roughing cut' unless you are scraping. For sure, scraping does not compress the wood fiber. Shear scraping can remove wood, but I would never consider it a roughing cut... My heavy duty scraping cuts do pull some fiber, but how much depends on the wood, and there is less tear out when I am doing light scraping 'shaping' cuts. These are just for refining the shape, then one pass with a gouge, taking off maybe a 1/8 inch wide shaving, which means about 1/16 inch of depth of cut since the gouge nose is at about a 45 degree angle to the wood....

robo hippy

 

[hockenbery]

Not sure how you can do a 'non bevel rubbing roughing cut' unless you are scraping. For sure, scraping does not compress the wood fib

in demos and basic classes I usually only show the bevel riding cut.

Basically the roughing cut looks like the bevel riding cut except the bevel is off the wood just a little.
Cutting foot to rim the wing cuts through the wood very efficiently taking up to a wings width of wood.
This results in tearout where the bevel is because the nose of the gouge is pulling the fibers.
In most demo the blanks are in the 10-12” range so you can’t take many roughing passes.

Take a look at 7:33-8:02 the bevel is only riding as I get near the rim at the end.
Through much of the cut you see the space between the heel of the bevel and wood is much larger than it would be for a bevel riding cut. And the surface is much rougher.

View: https://www.youtube.com/watch?v=Lo0bGSafZq4

 

[odie]

As usual, some of my offbeat beliefs are difficult for some to accept, and I have learned to come to expect that. Sooooooo, how would one really know if he's actually disrupted wood fibers beneath the surface of the cut?.....enough to make a difference in the final finished surface? This condition can't be seen or felt, but it's there, just the same. The only indication that it is there, is several steps down the process when the final sanded surface takes the finish. If the sheen can be distinguished from areas where the fibers have, and haven't been disrupted, then the difference is in the aesthetic interpretation your eye can, and will detect. This experiment is totally dependent on the ability to exactly reproduce identical circumstances, and results in two separate examples.

-----odie-----

 

[hockenbery]

As usual, some of my offbeat beliefs are difficult for some to accept, and I have learned to come to expect that. Sooooooo, how would one really know if he's actually disrupted wood fibers beneath the surface of the cut?.....enough to make a difference in the final finished surface? This condition can't be seen or felt, but it's there, just the same. The only indication that it is there, is several steps down the process when the final sanded surface takes the finish. If the sheen can be distinguished from areas where the fibers have, and haven't been disrupted, then the difference is in the aesthetic interpretation your eye can, and will detect. This experiment is totally dependent on the ability to exactly reproduce identical circumstances, and results in two separate examples.

-----odie-----

I think you answered you own question. You do see it

When you compress the fibers with too much bevel pressure or have torn grain It looks different.
It looks more different when wet or when finish is applied.

This is covered in most basic woodturning classes.
It is basic woodturning to avoid compressing the grain and avoid tearout.

Slicing cuts with minimal bevel pressure -> virtually no torn grain no compressed fibers

With some woods there may be tiny torn grain on the backside of the endgrain and where there is figured grain going in different directions.
Shear scraping will almost always eliminate this minor torn grain.

 

[Bill Boehme]

This thread has run its course and drifted far enough. I'm putting a padlock on it.