I'm apprehensive about putting some 17"-19" dia. 4" to 8" thick wet NIP
blanks on my VS N3K with the headstock rotated and no tail support. I've
stressed mine before, but what is the experience & advice from you
engineers and those who have far exceeded the lathe's design limits?

My lathe stand, faceplates, toolrest etc. will be OK and I'll start up
from zero, but If things go wrong what likely happens to machines that
are far overstressed? A cracked head casting, ruined bearings or what?

I know, I know....give the blanks to a Stubby owner or buy one Arch, but
in the meantime....


Turn to Safety, Arch
Fortiter



http://community.webtv.net/almcc/MacsMusings

Hi Arch

Cut the blanks in 2" slabs, proceed to cut in to rings, then stack, glue
etc., you know the drill !!
Then again you could just go at it very carefully, and if your VS N3K
does give up the ghost, well than maybe you will have to UPGRADE GHiHi.
You can't take it with you even if you like !!!

Have fun and take good care
Leo Van Der Loo


Arch wrote:
I'm apprehensive about putting some 17"-19" dia. 4" to 8" thick wet NIP
blanks on my VS N3K with the headstock rotated and no tail support. I've
stressed mine before, but what is the experience & advice from you
engineers and those who have far exceeded the lathe's design limits?

My lathe stand, faceplates, toolrest etc. will be OK and I'll start up
from zero, but If things go wrong what likely happens to machines that
are far overstressed? A cracked head casting, ruined bearings or what?

I know, I know....give the blanks to a Stubby owner or buy one Arch, but
in the meantime....


Turn to Safety, Arch
Fortiter



http://community.webtv.net/almcc/MacsMusings

Hi Arch,

Here's text from an old article of mine. Not quite on the mark for you,
but perhaps something in it will prove useful.


Turning Big on the Nova 3k

A few people have contacted me having trouble finding my earlier
comments about turning larger pieces on the Nova 3k, so I thought I'd
update and repost this as a separate thread.

Here's how I manage to use the Nova for large pieces.

1. Balance the log as well as possible both before and after mounting
it. My Delta 14 inch bandsaw (plus riser) simply won't handle big logs
well or at all, so I usually use a chain saw. Though some might not
approve, I've often taken a 16 inch electric chainsaw or a Tiger Saw
(Sawsall) to the log, even after having it mounted (or nearly so) on the
lathe. A fairly well balanced log is essential (well, at least highly
desirable) when using a smaller lathe like the Nova 3k. Don't hesitate
to take a big hand chisel and knock off a few corners. It will be a lot
easier to do this with a hammer and chisel, then have those corners
banging against your gouge later on.

2. I have my Nova on a custom built stand that is a combination of cast
iron and hard maple. The stand with its sand filling weighs in at over
600 pounds (without the lathe). It has a base of 22 inches by 50 inches.
The whole lathe is bolted down to a 3 inch maple top that is 24x60
inches. Since I later added an extension bed, I have that separately
supported at its end with a 2" pipe and flanges.

3. I use the Nova outrigger. I suspect this makes a real difference
since it allows the headstock bed to be bolted down on both sides of the
headstock. I think this greatly adds to the rigidity of headstock. For
those who don't wish to use the outrigger, I suggest obtaining the
thickest available 4 inch angle iron and doing the same.

4. I use a 1.5 hp Leeson DC motor which allows me to turn at slow speeds
with plenty of torque. The extra weight of the motor may help
counterbalance the larger logs as well. That said, I don't hesitate to
move the belt down to the lower pulleys. I often leave mine set for a
maximum speed in the 600 rpm range.

5. For 11-18 inch logs, I always rough out using a Oneway Cast Iron
faceplate (either 4 inch or six inch depending on the size of the log
and the form desired) using lots of Robertson head sheet metal screws
(Craft Supplies is a convenient source for these).

6. I always bring up the tailstock when, and for as long as possible.
Since, IMO, the tailstock is the weakest link on this lathe, it try to
use the least quill extension possible. I usually use the optional Nova
interchangeable point live center as it provides extra extension and has
a fairly good bearing. A Oneway live center probably would be even
better.

7. Even though I use a faceplate, I put a drive center in the headstock
spindle to help rigidify the spindle. The drive center has been ground
down to fit flush with the faceplate.

8. For large pieces, I really crank down on the headstock locking screw.
If you ever have reason to have the headstock off, it's probably a good
idea to go over the headstock and bed faces with a file to make sure
that they are level and without any large ridges or flash that would
interfere with solid contact between the two faces.

9. The outrigger, while not essential, can sometimes come in handy to
work the headstock side of larger diameter (particularly if they are
longer) pieces, as the standard banjo is relatively short. The
outrigger is, of coarse, essential if you want to rough out or work on
pieces larger than 16 inches. I've found the standard toolrest to hold
up just fine, even after some awful smacks from a 3/4" Glaser Gouge.

This arrangement makes the Nova work for me with pretty big pieces. I
don't argue that some have experienced vibrations with wood as small in
diameter as 10 inches, but would suggest that following the above
recommendations is likely to overcome their problems.

That said, the Nova definitely has it's limits. I've turned a really
large log (around 22-23) inches, and despite all my other measures, this
was simply too much for the Nova. I made it work, but I was stupid to
have done it (all the more so, as this was the second time I'd done
this). The Nova is not a high end lathe, and even following the above
recommendations IMO is not suitable for regular use on pieces much over
15 inches (Of course, up to 30 inch in diameter thin table tops are
quite feasible with the outrigger.) Frankly, I don't really enjoy
working with things much over that size, and I'm not sure I would enjoy
much larger pieces even if I owned a bigger lathe (of course I'd be
happy to test this out if someone wants to donate a Poolewood 2000 or
Stubby). That's not to say that larger lathes don't have other
advantages as well. But for many of us, the Nova has the right range of
features at the right price. Even if money were not a deciding factor,
size and other priorities may rule out a large lathe. So for those
who already have or are considering a Nova 3k, just know that the above
has worked well to allow me to turn what I consider to be some fairly
large pieces, and to do so in a way that has been enjoyable. As always,
YMMV.

Lyn


Arch wrote:

I'm apprehensive about putting some 17"-19" dia. 4" to 8" thick wet NIP
blanks on my VS N3K with the headstock rotated and no tail support. I've
stressed mine before, but what is the experience & advice from you
engineers and those who have far exceeded the lathe's design limits?

My lathe stand, faceplates, toolrest etc. will be OK and I'll start up
from zero, but If things go wrong what likely happens to machines that
are far overstressed? A cracked head casting, ruined bearings or what?

I know, I know....give the blanks to a Stubby owner or buy one Arch, but
in the meantime....


Turn to Safety, Arch
Fortiter



http://community.webtv.net/almcc/MacsMusings

Leo & Lyn, good advice for us middle sized folks. I may take it.
Thanks.


Turn to Safety, Arch
Fortiter



http://community.webtv.net/almcc/MacsMusings

Arch

Lyn's advice on this is good. The Nova should be able to handle a 20 to 25"
piece of wood with no problem so long as the wood is balanced. The larger
the piece, the faster the speed, and the greater the unbalanced force the
greater the vibration. My guess it the bearings will give out first but if
you hit the right harmonic frequency you could work fracture the shaft. I
think that before you get to that point evey Lyn's 600 lb stand will start
walking across the floor.

I have cut pieces up to 18" with my DRV and have had no problem so long as i
do the prep work on the wood and take it slow.

Henry

"Arch" wrote in message
...
I'm apprehensive about putting some 17"-19" dia. 4" to 8" thick wet NIP
blanks on my VS N3K with the headstock rotated and no tail support. I've
stressed mine before, but what is the experience & advice from you
engineers and those who have far exceeded the lathe's design limits?

My lathe stand, faceplates, toolrest etc. will be OK and I'll start up
from zero, but If things go wrong what likely happens to machines that
are far overstressed? A cracked head casting, ruined bearings or what?

I know, I know....give the blanks to a Stubby owner or buy one Arch, but
in the meantime....


Turn to Safety, Arch
Fortiter



http://community.webtv.net/almcc/MacsMusings