Lathe mass?

[William C Rogers]

Well compared to Leo's and Olaf's lathes I have a 700 mini PM 90 (still setting up after move). To move I put it on a couple oh HF small moving dollys. It was top heavy doing that. I haven't noticed any stability problem, but also have not cannot turn the mass you guys can. Still learning.

Note: Olaf, thanks for reminding me to put a floor sweep near the lathe.

[Olaf Vogel]

But, in the lighter weight category, I will stick with my theory that simply adding more weight high on the lathe "can" decrease stability. Obviously, there are other factors, including the splay of the legs, which I believe is very important.

At the risk of stirring up the hornets, there are two things that concern me with the Grizzly 0766, based solely on the only pic available. The leg stance appears to be narrow, and the height of the bed (thickness from top/bottom) doesn't seem to be increased for the extra weight of the headstock and extended length of the bed. Add to that, the increased weight above the typical center of gravity, and I think the stability could be compromised. In addition, I think there may be some weakness in the bed that could cause sway affecting the alignment of centers.

John

Sorry for the thread hijack - these are all very good points.
For a 22" swing, it does look a bit light, but offers a lot of features for the price.

With manufacturing mostly overseas and shipping weight being an economic issue, there is the temptation to make them lighter.
Something that didn't apply in 1880 when mine was poured.....
(and still running on the original babbitt bearings...)

[carl mesaros]

But, in the lighter weight category, I will stick with my theory that simply adding more weight high on the lathe "can" decrease stability. Obviously, there are other factors, including the splay of the legs, which I believe is very important.

Very good point John and the specs below prove that the higher end lathes use a wider footprint along with more mass.

Grizz 766 23""
Grizz 733 19"
Oneway 2036 32"
Robust 29-30"
Powermatic 3520B 24"
Laguna Revo 2036 26"
Jet 1642 20"

[Dennis Nagle]

Mine weighs 4008 lbs but once in a while an out of balance peice will make it shack and "almost" move. It is an Oliver 20D.

[Thom Sturgill]

But, in the lighter weight category, I will stick with my theory that simply adding more weight high on the lathe "can" decrease stability. Obviously, there are other factors, including the splay of the legs, which I believe is very important.

Very good point John and the specs below prove that the higher end lathes use a wider footprint along with more mass.

Grizz 766 23""
Grizz 733 19"
Oneway 2036 32"
Robust 29-30"
Powermatic 3520B 24"
Laguna Revo 2036 26"
Jet 1642 20"

I would agree totally. Lyle Jameison has an interesting video on You tube about this -https://www.youtube.com/watch?v=AWYEPfqRet8

[Dale Miner]

Mine weighs 4008 lbs but once in a while an out of balance peice will make it shack and "almost" move. It is an Oliver 20D.

Color me envious.

[Leo Van Der Loo]

Olaf, yes the gussets are required, as the single centre web isn’t able to stop the twisting, so at the lathe mounting areas I have welded the gussets in and there is no twisting as is.

I used the pieces of thick walled high pressure pipes to have nothing to stumble over, 6 bolts in the concrete hold it down, originally I had just four but found that the working of the lathe would loosen the bolts in the concrete, so added two at the heavy end, I never had to re-torque the bolts again.

I have moved and brought the lathe along, that was quite a chore, disassembled the lathe and though still heavy pieces I could handle them, the base was near impossible.
using steel pipes as roller I was able to get it closer to my trailer, them with a hydraulic jack I was able to lift one end high enough to back the trailer under that end, then with a come along pulled it into the trailer, sliding it out was much easier, (Back-up and a hard stop got it to move right out, didn’t hurt itself )

I have a couple of pictures of people that used higher placed weights to reduce oscillation/vibration, I also talked to a turner years ago that used weight on a rod to help steady his home-build lathe, (John Williams I think was his name) I had pictures of his setup, but somewhere along the line with getting new computers I have lost them, but there was a writeup about it, and the anti-vibration setups in the pictures below sure look like a takeoff of his idea.

According to John he did have to fiddle with the height of the weights every time to get good results, anyway he bought a new big Oneway lathe and never looked back.

Here are the pictures I have, but I can’t guarantee that they do work as was claimed

Anti vibration setup.jpg antivibration.jpg

This doesn’t look very safe, and I doubt that there is much need for it, if only turning relative small pieces like shown, but it was proffered
Powermatic 3520 vibration problem solving.jpg

[Leo Van Der Loo]

Olaf, you and Leo are operating on lathes that are in an entirely different category than the typical Jet, Grizzly, etc., and handsomely so, I might add!!

But, in the lighter weight category, I will stick with my theory that simply adding more weight high on the lathe "can" decrease stability. Obviously, there are other factors, including the splay of the legs, which I believe is very important.

At the risk of stirring up the hornets, there are two things that concern me with the Grizzly 0766, based solely on the only pic available. The leg stance appears to be narrow, and the height of the bed (thickness from top/bottom) doesn't seem to be increased for the extra weight of the headstock and extended length of the bed. Add to that, the increased weight above the typical center of gravity, and I think the stability could be compromised. In addition, I think there may be some weakness in the bed that could cause sway affecting the alignment of centers.

For those that are purchasing, I hope I am wrong, as the lathe does seem to otherwise offer value. Again, none of us really knows at this point, if those conditions are true. When we get some hands on reviews, then more will be known. In the meantime, I am happy with my Jet!!

And, again, congrats to both you and Leo for some REALLY OUTSTANDING equipment and some extraordinary engineering and design work.

Yes John it isn’t all straight forward, however weight at center height will do more than that same amount strapped low to the legs, as you will have something like a lever,.... where the power is applied to the top and it can move/lift a lot more weight at the bottom with relative little power/weight shifting, a lot more is required to move that same amount of weight at the spindle height, splay the legs and the low weight will have more affect, as the lever affect diminishes, but adding a tripping hazard, it isn’t always a win-win.

Sorry for the hi-jack, but well worth it I think

[Roger Chandler]

At the risk of stirring up the hornets, there are two things that concern me with the Grizzly 0766, based solely on the only pic available. The leg stance appears to be narrow, and the height of the bed (thickness from top/bottom) doesn't seem to be increased for the extra weight of the headstock and extended length of the bed. Add to that, the increased weight above the typical center of gravity, and I think the stability could be compromised. In addition, I think there may be some weakness in the bed that could cause sway affecting the alignment of centers.

For those that are purchasing, I hope I am wrong, as the lathe does seem to otherwise offer value. Again, none of us really knows at this point, if those conditions are true. When we get some hands on reviews, then more will be known. In the meantime, I am happy with my Jet!!

Just as a point about the bed thickness on the G0766 that JK mentioned ..... the spec sheet lists the bed at being 10 inches in width........my 18/47 G0698 is 7" in width on the top and 8.5" on the bottom.........not sure if their measurement is at the top of the bed or bottom of its casting, but if the spec sheet is correct, then they have added considerable mass to the bed, over the 18/47 units and the stance is wider as well.

[Dale Bonertz]

Carl,
The only experience I have had with the new Laguna is that our woodcraft store got one of the first units to test drive. It has been used at our club meetings and it seems to be quite and runs smoothly. The demonstrators were impressed by it. Now this doesn't speak of their ongoing customer service issues in which I hope they have cured. It also doe not speak of the lathes longevity since any new machine may run and operate smooth at first and after a bit of wear and tear things change. BTW it was the 2036.

[Olaf Vogel]

Yes John it isn’t all straight forward, however weight at center height will do more than that same amount strapped low to the legs, as you will have something like a lever,....

Heres a practical example, if somewhat rough in execution:
http://www3.sympatico.ca/3jdw8/antivibration.htm

A lot of old metal lathes employ the same idea. The motor is mounted above:
http://vintagemachinery.org/photoind....aspx?id=11728

If you are worried about a 500lb lathe with a 50lb top heavy mass tipping over, you can always attach it to the wall (loosely), but the point about vibration damping remains.

btw rigidly attaching the headstock to wall for the same purpose does not work.
Don't ask how I know....😳
olaf

[carl mesaros]

Carl,
The only experience I have had with the new Laguna is that our woodcraft store got one of the first units to test drive. It has been used at our club meetings and it seems to be quite and runs smoothly. The demonstrators were impressed by it. Now this doesn't speak of their ongoing customer service issues in which I hope they have cured. It also doe not speak of the lathes longevity since any new machine may run and operate smooth at first and after a bit of wear and tear things change. BTW it was the 2036.

Thanks for the information Dale. There just hasn't been much written or discussed on this lathe. The numbers sound good but as you mentioned hard to say on the longevity side. The electronics (Delta), and bearings (one step above Powermatic) seem fine. The only concern would be the motor, which I understand to be a DC brushless. Is that good or bad?
The lathe (2436) has the size and weight I've been looking for. I'd love a Oneway or Robust but hard to Justify almost double the price.
Thanks again for the information.

[Roger Chandler]

Thanks for the information Dale. There just hasn't been much written or discussed on this lathe. The numbers sound good but as you mentioned hard to say on the longevity side. The electronics (Delta), and bearings (one step above Powermatic) seem fine. The only concern would be the motor, which I understand to be a DC brushless. Is that good or bad?
The lathe (2436) has the size and weight I've been looking for. I'd love a Oneway or Robust but hard to Justify almost double the price.
Thanks again for the information.

Carl........the Laguna line used to be the same as the Grizzly.......at least in the 18/47 lathe. My [well it has been sold now, but] Grizzly G0698 has a D/C brushless motor [2 hp] and it has been going strong for over 5 years with pretty steady usage. I did some research on D/C brushless motors, and they are smaller than A/.C and are generally more efficient than a carbon brush motor on most A/C for the same hp rating. They can be used with a controller inside the motor to read torque requirements so they are suited to applications where low rpm and high torque are required, such as wood turning. They also run much cooler than a brushed motor.

I would think you would be in good shape with the Revo 2436. There is a NZ turner who has gotten one [basically same lathe with another label on it] and he speaks highly of it over on WOW........don't remember his name off the top of my head. The Revo 2436 has a place to connect an outboard attachment at 90 degrees to the ways, if I recall, so you might like that feature as well.

Do a google search for brushless D/C motors and read up on them........they are used in lots of industrial settings where reliability is required, so if you educate yourself, you might alleviate your concerns.

[carl mesaros]

[QUOTE=Roger Chandler;2394015]Carl........the Laguna line used to be the same as the Grizzly.......at least in the 18/47 lathe. My [well it has been sold now, but] Grizzly G0698 has a D/C brushless motor [2 hp] and it has been going strong for over 5 years with pretty steady usage. I did some research on D/C brushless motors, and they are smaller than A/.C and are generally more efficient than a carbon brush motor on most A/C for the same hp rating. They can be used with a controller inside the motor to read torque requirements so they are suited to applications where low rpm and high torque are required, such as wood turning. They also run much cooler than a brushed motor.

Wow Roger thanks for all the information. One of the "selling points from Laguna" talks about increased torque at low rpm because of the DC brushless motor.
I have followed your comments about your Grizzly 698 for quite sometime but didn't realize it also ha a DC brushless motor.
I am really looking forward to your review of the new GO766. Hopefully it arrives soon.
Thanks again Roger for the info.

[Eric Coyle]

years ago buddy dave tuttle showed me his lathe stand built with baltic biirch hollow end legs which he filled with sand for wieght/mass. When he moved, and you pay by the pound, he just dumped out the sand, filled the hollow legs with his lathe tools (instant packing boxes!!) and moved on. Very clever I thought.

Eric in Calgary